
==== Front
Sci Rep
Sci Rep
Scientific Reports
2045-2322
Nature Publishing Group UK London

73020
10.1038/s41598-024-73020-8
Article
Mcl-1 expression is a predictive marker of response to gemcitabine plus nab-paclitaxel for metastatic pancreatic cancer
Urabe Makiko 1
Ikezawa Kenji ikezawa-ke@oici.jp

1
Seiki Yusuke 1
Watsuji Ko 1
Kawamoto Yasuharu 1
Hirao Takeru 1
Kai Yugo 1
Takada Ryoji 1
Yamai Takuo 1
Mukai Kaori 1
Nakabori Tasuku 1
Uehara Hiroyuki 1
Nagata Shigenori 2
Ohkawa Kazuyoshi 1
1 https://ror.org/010srfv22 grid.489169.b Department of Hepatobiliary and Pancreatic Oncology, Osaka International Cancer Institute, 3-1-69 Otemae, Chuo-ku, Osaka, 541-8567 Japan
2 https://ror.org/010srfv22 grid.489169.b Department of Diagnostic Pathology and Cytology, Osaka International Cancer Institute, Osaka, Japan
20 9 2024
20 9 2024
2024
14 2195323 1 2024
12 9 2024
© The Author(s) 2024
2024
https://creativecommons.org/licenses/by/4.0/ Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Antiapoptotic protein, including Mcl-1, expression is frequently observed in pancreatic cancer. Gemcitabine plus nabpaclitaxel (GnP) is the standard chemotherapy for metastatic pancreatic cancer (MPC); however, predictive markers for its efficacy remain unestablished. This study evaluated the association between GnP’s therapeutic effects and Mcl-1 expression in tissue samples obtained using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic tumor or percutaneous ultrasound-guided biopsy for metastatic liver tumor. We retrospectively reviewed 38 patients with histologically diagnosed MPC who received GnP as the first-line chemotherapy at our institute between December 2014 and July 2018. Post-immunohistochemistry analysis for Mcl-1 expression detection, patients were divided to into two groups based on the cell proportion showing Mcl-1 immunoreactivity: positive (> 20%; 23 [60.5%] patients) and negative (≤ 20%; 15 [39.5%] patients) groups. Clinical characteristics did not differ between the two groups. The Mcl-1 positive group showed a significantly higher disease control rate (95.7% vs. 73.3%; P = 0.046), longer progressionfree survival (PFS) (7.2 months vs. 4.9 months; P = 0.018) and longer overall survival (OS) (14.9 months vs. 9.2 months; P = 0.008) than the Mcl-1 negative group. Multivariate analysis showed that Mcl-1 expression was an independent predictive marker for PFS and OS. Mcl-1 expression could be a predictive marker for favorable response to GnP.

Keywords

Anti-apoptotic protein
Chemotherapy
Endoscopic ultrasound-guided fine-needle aspiration
Liver tumor biopsy
Predictive marker
Subject terms

Cancer
Gastroenterology
Molecular medicine
Oncology
issue-copyright-statement© Springer Nature Limited 2024
==== Body
pmcIntroduction

Metastatic pancreatic cancer (MPC) accounts for approximately half of all cases of pancreatic cancer (PC) and has a 5-year survival rate of 3%1. Systemic chemotherapy, such as gemcitabine plus nab-paclitaxel (GnP) or modified FOLFIRINOX, is recommended as the first-line chemotherapeutic regimen for advanced PC2–4. GnP can be administered as systemic chemotherapy for patients with MPC in the > 75 years age group, which is the age group of a substantial proportion of patients with MPC4–7. Although GnP is an important treatment option for advanced PC, the available data regarding predictive markers for its therapeutic efficacy are limited8,9.

The apoptosis machinery, which causes programmed cell death, is regulated by the balance between pro-apoptotic and anti-apoptotic members of the Bcl-2 family10,11. Mcl-1 is an anti-apoptotic protein that binds to and inhibits the apoptosis-inducing proteins Bak and Bax, thereby exerting anti-apoptotic effects12,13. Avoidance of apoptosis is one of the hallmarks of cancer and contributes to both tumor progression and resistance to treatment14. Overexpression of Mcl-1 is frequently observed in human carcinomas15,16. Several important oncogenic pathways and transcriptional or post-transcriptional mechanisms induce increased expression of Mcl-117–19. Expression of anti-apoptotic proteins, such as Bcl-xL and Mcl-1, is elevated in PC [20]. PC with a high Bcl-xL expression is reported to have a poorer prognosis than that with a low Bcl-xL expression [21,22]. However, the association between Mcl-1 expression and the therapeutic efficacy of chemotherapy for PC has not been reported.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic tumor or percutaneous ultrasound-guided biopsy for metastatic liver tumor are pathological diagnostic modalities that are widely used to facilitate the differential diagnosis of pancreatic solid tumors20,21. The aim of this study was to examine the association between the therapeutic effects of GnP and the expression of Mcl-1 in tissue samples obtained using EUS-FNA or percutaneous ultrasound-guided liver tumor biopsy.

Methods

Study design and ethical considerations

This retrospective single-center study was approved by the Institutional Regimen Committee and Institutional Review Board of Osaka International Cancer Institute (19009-4) and conducted in accordance with the principles of the Declaration of Helsinki. The requirement for informed consent was waived by the Institutional Review Board of Osaka International Cancer Institute due to the retrospective nature of the study.

Patients and clinical data

Among the 505 patients with advanced PC who underwent GnP at the Osaka International Cancer Institute between December 2014 and July 2018, we reviewed the clinical data of 96 patients with MPC who were pathologically diagnosed with pancreatic ductal adenocarcinoma and underwent GnP as the first-line chemotherapy based on the results of the analysis of tissue samples obtained using EUS-FNA or percutaneous ultrasound-guided biopsy for metastatic liver tumor. The major inclusion criteria were as follows: (1) patients received at least two cycles of GnP as the first-line chemotherapy for MPC; (2) sufficient histological tissue samples diagnosed as adenocarcinoma were available; (3) there was no possibility of submitting tissue samples for genetic testing due to the death of patients or disease progression. Data on clinical variables, including age, sex, Eastern Cooperative Oncology Group performance status (PS), body mass index, pancreatic tumor location, metastatic sites, serum carcinoembryonic antigen (CEA), carbohydrate antigen 19 − 9 (CA19-9), albumin levels, neutrophil-to-lymphocyte ratio (NLR), biliary drainage, and chemotherapy were obtained from the patients’ medical records. The treatment protocol for GnP involved the administration of gemcitabine 1000 mg/m2 on days 1, 8, and 15 and nabpaclitaxel 125 mg/m2 on days 1, 8, and 15. This regimen was repeated every 4 weeks. The dosages and dosing schedules were adjusted at each physician’s discretion depending on the patient’s condition. Response to chemotherapy was assessed using computed tomography and categorized as complete response, partial response, stable disease, or progression, according to the guidelines in the Response Evaluation Criteria in Solid Tumors version 1.1. Progression-free survival (PFS) was defined as the time from the start of chemotherapy to the date of tumor progression. Overall survival (OS) was defined as the date from the start of chemotherapy to the date of death.

Acquisition of tissue samples

The specimens analyzed in this study were obtained using EUS-FNA or percutaneous ultrasound-guided liver tumor biopsy, which was performed for pathological diagnosis of PC before the initiation of chemotherapy. All EUS procedures were performed by endoscopists at our hospital using a linear-array echoendoscope (GF-UCT260; Olympus Medical Systems, Tokyo, Japan). EUS-FNA was performed with 19, 22, or 25-gauge franseen needles. The needle types, gauges and passes used were determined by the endoscopists. The aspirated biopsy materials were placed in a Petri dish with saline and into a formalin-filled container for histological analysis. Percutaneous ultrasound-guided liver tumor biopsy was performed using a 21-gauge aspiration needle (Sonopsy-C1; Hakko) or an 18-gauge core needle (MONOPTY). Thereafter, the formalin-fixed specimens were embedded in paraffin. Two experienced pathologists examined the hematoxylin and eosin-stained specimens and classified them as pancreatic ductal adenocarcinoma based on their findings.

Immunohistochemical analysis of the specimens

The formalin-fixed paraffin-embedded blocks of PC were cut into 3–5 μm slices, and the sections were subjected to immunohistochemical analyses to evaluate the immunoreactivity of the samples to Mcl-1. A monoclonal rabbit anti-Mcl-1 antibody (1:500, #39224; Cell Signaling Technology, Danvers, MA) was used for immunohistochemical staining. Antibody binding was visualized using the autoimmunostaining system VENTANA BenchMark ULTRA (Roche Diagnostics, Wetzlar, Switzerland) according to the manufacturer’s instructions.

The investigator, who was blinded to the clinical data, assessed the percentage of stained cells. Specimens with more than 20% stained cancer cells in the cytoplasm, excluding non-cancer cells such as fibroblasts or immune cells, were categorized as Mcl-1 positive, according to previously published protocols (Fig. 1)22–24.

Fig. 1 Representative immunohistochemical staining of Mcl-1 in specimens obtained using percutaneous ultrasound-guided liver tumor biopsy. Micrographs of pancreatic ductal carcinoma obtained using percutaneous ultrasound-guided liver tumor biopsy. (A) and (B): Well-differentiated adenocarcinoma (A: hematoxylin and eosin staining [HE], × 200) with more than 20% of the tumor cells in the cytoplasm showing immunoreactivity for Mcl-1 (B: immunohistochemical staining [IHC], × 200), which was considered positive. (C) and (D): Poorly differentiated adenocarcinoma (C; HE, × 200) with no cells showing immunoreactivity for Mcl-1 (D; IHC, × 200), which was considered a negative result.

Statistical analysis

The χ2 test and Fisher’s exact test were used to compare categorical data, whereas the Wilcoxon rank sum text was used for the comparison of continuous and categorical variables. PFS and OS were estimated using Kaplan-Meier analysis, and the curves were compared using the log-rank test. Univariate and multivariate analyses were performed using the Cox regression method to evaluate the prognostic factors for PFS and OS. Variables with a P value < 0.20 in the univariate analysis were selected for inclusion into the multivariate analysis. Statistical analyses were performed using the JMP Pro 16 software (SAS Institute Inc., Cary, NC, USA). Statistical significance was set at P ≤ 0.05.

Results

Patient characteristics and the outcomes of GnP therapy

A total of 38 patients with MPC were included in this study. All the patients were histologically diagnosed as having pancreatic ductal adenocarcinoma (EUS-FNA, 25 patients; percutaneous liver tumor biopsy, 13 patients). EUS-FNA was performed with 19-gauge needle in 1 patient, 22-gauge needle in 16 patients, and 25-gauge needle in 6 patients (detailed information of the needles was not available for 2 patients). There were no cases of cyst arising tumors such as invasive intraductal papillary mucinous neoplasm in imaging and histological diagnosis. The clinical characteristics of the patients are summarized in Table 1. The median age of the patients was 65 years (range, 38–80 years). Eighteen patients (47.4%) were male. Thirty (78.9%) and eight (21.1%) patients had an Eastern Cooperative Oncology Group PS of 0 or 1 and 2, respectively. The median body mass index of the patients was 21.1 kg/m2 (range, 16.2–28.4 kg/m2). The primary tumor locations were the pancreas head in 12 patients (31.6%) and the pancreas body/tail in 26 patients (68.4%). Thirty-one patients (81.6%) had liver metastases, 8 patients (21.1%) patients had lung metastasis, and 15 patients (39.5%) had peritoneal metastasis. The median CEA, CA19-9, and albumin levels were 11 ng/mL (range, 1–338 ng/mL), 5484 U/mL (range, 2–100000 U/mL), and 3.6 g/dL (range, 2.4–4.5 g/dL), respectively. Fourteen patients (36.8%) had an NLR of less than 3. Biliary drainage was performed for eight patients (21.1%).

Table 1 Characteristics of the patients.

	Total
(n = 38)	Mcl-1 positive (n = 23)	Mcl-1 negative (n = 15)	P value	
Age, median (range), (years)	65 (38–80)	65 (38–80)	64 (53–76)	0.917	
Sex, n (%)	
 Female	20 (53.6)	11 (47.8)	9 (60.0)	0.463	
 Male	18 (47.4)	12 (52.2)	6 (40.0)		
ECOG PS, n (%)	
 0	30 (78.9)	19 (82.6)	11 (73.3)	0.687*	
 1/2	8 (21.1)	4 (17.4)	4 (26.7)		
BMI, median (range), (kg/m2)	21.1 (16.2–28.4)	21.0 (16.2–28.2)	21.5 (17.5–28.4)	0.483	
Tumor site, n (%)	
 Pancreas body/tail	26 (68.4)	16 (69.6)	10 (66.7)	0.851	
 Pancreas head	12 (31.6)	7 (30.4)	5 (33.3)		
Metastatic sites, n (%)	
 Liver	31 (81.6)	18 (78.3)	13 (86.7)	0.681*	
 Lung	8 (21.1)	6 (26.1)	2 (13.3)	0.440*	
 Peritoneum	15 (39.5)	8 (34.8)	7 (46.7)	0.514	
 CEA, median (range), (ng/mL)	11 (1-338)	13 (1-239)	7 (1-338)	0.332	
 CA19-9, median (range), (U/mL)	5484 (2-100000)	4077 (2-100000)	5693 (2-100000)	0.621	
 Albumin, median (range), (g/dL)	3.6 (2.4–4.5)	3.6 (3.0-4.5)	3.6 (2.4–4.1)	0.245	
NLR, n (%)	
 < 3	14 (36.8)	11 (47.8)	3 (20.0)	0.082	
 ≧ 3	24 (63.2)	12 (52.2)	12 (80.0)		
Biliary drainage, n (%)	
 No	30 (78.9)	20 (87.0)	10 (66.7)	0.223*	
 Yes	8 (21.1)	3 (13.0)	5 (33.3)		
Statistical significance was set at p < 0.05.

Chi-square test, *Fisher’s exact test.

ECOG PS, Eastern Cooperative Oncology Group performance status; BMI, body mass index; CEA, carcinoembryonic antigen; CA19-9, carbohydrate antigen 19 − 9; NLR, neutrophil-to-lymphocyte ratio.

Regarding the outcomes of GnP therapy, the response and disease control rates were 55.3% and 86.8%, respectively (Table 2). The median PFS was 5.7 months (range, 2.0–21.5 months), and the median OS was 11.2 months (range, 3.0–27.1 months). All patients died due to disease progression. While seven patients selected best supportive care after the discontinuation of GnP, 31 patients underwent subsequent chemotherapy (oral fluoropyrimidine S-1, 21 patients; modified FOLFIRINOX, 7 patients; clinical trial, 3 patients).

Table 2 Treatment outcomes for patients with MPC who received GnP as first-line chemotherapy.

	Total
(n = 38)	Mcl-1 positive (n = 23)	Mcl-1 negative (n = 15)	P value	
Best response, n	
 CR	0	0	0		
 PR	21	15	6		
 SD	12	7	5		
 PD	5	1	4		
 NE	0	0	0		
 Overall response rate, (%)	55.3	65.2	40.0	0.127	
 Disease control rate, (%)	86.8	95.7	73.3	0.046*	
Statistical significance was set at p < 0.05.

Chi-square test, *Fisher’s exact test.

CR, complete response; PR, partial response; SD, stable disease; PD, progressive disease; NE, not evaluated.

Association between Mcl-1 expression and outcomes of GnP therapy

Of the 38 patients included in this study, 23 (60.5%) tested positive for Mcl-1 expression and 15 (39.5%) tested negative. Table 1 shows a comparison of patient characteristics between the Mcl-1 positive and negative groups. There were no significant differences in baseline characteristics between the two groups. The patients in the Mcl-1 positive group showed a significantly higher disease control rate than those in the Mcl-1 negative group (95.7% vs. 73.3%; P = 0.046, Table 2). In addition, the PFS and OS of the patients in the Mcl-1 positive group were significantly longer than those of the patients in the Mcl-1 negative group (PFS: 7.2 months [range, 2.0–21.5 months] vs. 4.9 months [range, 2.0–7.8 months], P = 0.018; OS: 14.9 months [range, 5.4–27.1 months] vs. 9.2 months [range, 3.0–13.3 months], P = 0.008; Fig. 2).

Fig. 2 Comparison of progression-free survival (PFS) and overall survival (OS).

Factors associated with PFS and OS

We analyzed the predictive factors associated with PFS in patients with MPC (Table 3). The univariate analysis showed that Mcl-1 expression was significantly associated with PFS (HR, 0.388; 95% CI, 0.182–0.822; P = 0.013). Multivariate analysis performed using three variables (male sex, NLR, and Mcl-1 expression) indicated that Mcl-1 expression was an independent predictor significantly associated with PFS (HR, 0.453; 95% CI, 0.210–0.975; P = 0.043).

Table 3 Univariate and multivariate analyses of factors associated with progression-free survival.

Factor	Univariate	Multivariate	
HR (95%CI)	P value	HR (95%CI)	P value	
Age	
 ≦  65 years	1	
 > 65 years	1.454 (0.722–2.926)	0.295			
Sex	
 Female	1	
 Male	0.584 (0.288–1.182)	0.135	0.648 (0.319–1.318)	0.231	
ECOG PS	
 0	1				
 1 or 2	0.724 (0.313–1.673)	0.450			
BMI	
 ≦ 20 kg/m2	1	
 > 20 kg/m2	1.282 (0.629–2.614)	0.494			
Tumor site	
 Pancreas body/tail	1	
 Pancreas head	0.791 (0.373–1.672)	0.539			
CEA	
 ≦ 5 ng/ml	1	
 > 5 ng/ml	1.133 (0.564–2.275)	0.727			
CA19-9	
 ≦59×ULN	1				
 >59× ULN	1.292 (0.656–2.543)	0.456			
Albumin	
 ≦3.5 g/dl	1	
 >3.5 g/dl	1.171 (0.573–2.390)	0.664			
NLR	
 ≦ 3	1	
 > 3	1.182 (0.913–3.606)	0.089	1.547 (0.766–3.120)	0.223	
Drainage	
 No	1	
 Yes	0.878 (0.358–2.116)	0.760			
Mcl-1	
 Negative	1	
 Positive	0.388 (0.182–0.822)	0.013	0.453 (0.210–0.975)	0.043	
Bold values indicate P < 0.05.

HR, hazard ratio; CI, confidence interval.

ECOG PS, Eastern Cooperative Oncology Group performance status; BMI, Body Mass Index; CEA, carcinoembryonic antigen; CA19-9, carbohydrate antigen 19 − 9; ULN, upper limit of normal; NLR, neutrophil-to-lymphocyte ratio.

We also evaluated the predictive factors associated with OS in patients with MPC (Table 4). The univariate analysis indicated that age (HR, 2.190; 95% CI, 1.028–4.667; P = 0.042) and Mcl-1 expression (HR, 0.276; 95% CI, 0.121–0.631; P = 0.002) were significantly associated with OS. Multivariate analysis performed using three variables (age, NLR, and Mcl-1 expression) revealed that Mcl-1 expression was an independent predictor significantly associated with OS (HR, 0.321; 95% CI, 0.136–0.759; P = 0.010).

Table 4 Univariate and multivariate analyses of factors associated with overall survival.

Factor	Univariate	Multivariate		
HR (95%CI)	P value	HR (95%CI)	P value	
Age	
 ≦  5 years	1	
 > 65 years	2.191 (1.028–4.667)	0.042	1.841 (0.837–4.047)	0.129	
Sex	
 Female	1	
 Male	0.829 (0.422–1.628)	0.585			
ECOG PS	
 0	1	
 1 or 2	0.705 (0.299–1.661)	0.424			
BMI					
 ≦ 20 kg/m2	1	
 > 20 kg/m2	1.189 (0.595–2.377)	0.625			
Tumor site	
 Pancreas body/tail	1	
 Pancreas head	0.868 (0.421–1.787)	0.701			
CEA					
 ≦ 5 ng/ml	1	
 > 5 ng/ml	0.974 (0.499-1.900)	0.938			
CA19-9	
 ≦ 59×ULN	1	
 > 59× ULN	1.005 (0.522–1.936)	0.988			
Albumin	
 ≦ 3.5 g/dl	1	
 > 3.5 g/dl	0.825 (0.418–1.623)	0.577			
NLR	
 ≦ 3	1				
 > 3	1.854 (0.946–3.635)	0.072	1.5330 (0.645–2.743)	0.440	
Drainage					
 No	1	
 Yes	1.220 (0.554–2.681)	0.621			
Mcl-1	
 Negative	1	
 Positive	0.276 (0.121–0.631)	0.002	0.321 (0.136–0.759)	0.010	
Bold values indicate P < 0.05.

HR, hazard ratio; CI, confidence interval.

ECOG PS, Eastern Cooperative Oncology Group performance status; BMI, Body Mass Index; CEA, carcinoembryonic antigen; CA19-9, carbohydrate antigen 19 − 9; ULN, upper limit of normal; NLR, neutrophil-to-lymphocyte ratio.

Discussion

Expression of Mcl-1, an anti-apoptotic protein, is elevated in PC. However, the clinical significance of Mcl-1 expression in PC and its association with therapeutic response are unclear25,26. In the present study, the PFS and OS of the patients in the Mcl-1 positive group were significantly better than those of patients in the Mcl-1 negative group. Furthermore, multivariate analysis showed that Mcl-1 expression was an independent predictive marker for favorable PFS and OS. While it has been reported that PC with elevated Mcl-1 expression has a poor prognosis, Mcl-1 inhibitors induce apoptosis more strongly in tumors with elevated Mcl-119,27. Gemcitabine has been reported to downregulate Mcl-1 expression and induce apoptosis in PC cells28,29. It is also reported that Mcl-1 is an important factor in determining the response to paclitaxel treatment, and the downregulation of Mcl-1 restores sensitivity to paclitaxel30,31. Together with these previous reports, favorable treatment responses of GnP in PC with elevated Mcl-1 expression may be possibly explained by downregulation caused by gemcitabine and subsequent restoration of sensitivity to paclitaxel.

GnP and fluorouracil-containing chemotherapeutic regimens (modified FOLFIRINOX and NALIRIFOX) are important treatment options for patients with MPC32,33. However, there are few clinical indicators of whether GnP or fluorouracil-containing regimens should be selected for chemotherapy. In the present study, patients with elevated Mcl-1 expression showed better treatment outcomes than those without elevated Mcl-1 expression. This finding suggests that Mcl-1 expression in tissue samples obtained by biopsy could be a predictive marker of the therapeutic effects of GnP. Studies conducted using comprehensive genomic profiling (CGP) tests have revealed that approximately 20% of patients with pancreatic ductal adenocarcinoma show mutations in homologous recombination genes, including BRCA1/2 and PALB234,35. Moreover, patients with homologous recombination gene-mutated PC show favorable PFS and OS with platinum-containing chemotherapeutic regimens35,36. Mutations in homologous recombination genes are promising predictive markers of response to chemotherapy and can guide the selection of appropriate regimens. However, given that it takes a long time to obtain the results of a CGP test, it is difficult to factor in the presence of these mutations in the selection of chemotherapeutic regimens before initiating chemotherapy37–39.

The results of the present study demonstrated that Mcl-1 expression in specimens obtained using EUS-FNA or percutaneous liver tumor biopsy could predict the efficacy of chemotherapy. EUS-FNA is the primary method used for the pathological diagnosis of pancreatic tumor40–42. With the recent improvements in puncture needles, histological samples have also been used for CGP tests43–45. Percutaneous liver tumor biopsy also plays an important role in pathological diagnosis and tissue acquisition for genetic testing46,47. As immunohistological examinations are simple and rapid, Mcl-1 expression in specimens can be analyzed prior to the initiation of chemotherapy. Thus, tissue samples obtained by EUS-FNA or percutaneous liver tumor biopsy may contribute not only to the diagnosis of PC but also to the selection of chemotherapeutic regimens as well.

This study has some limitations. First, this was a single-center retrospective study that examined cases meeting specific criteria, and it is unclear whether the findings can be generalized to patients with advanced PC who are undergoing GnP therapy in general. Second, we did not examine patients with MPC who received modified FOLFIRINOX as a first-line chemotherapeutic regimen, primarily because the number of patients who received the therapy was small. Further studies are needed to clarify the mechanism by which Mcl-1 influences the therapeutic effects of GnP.

In conclusion, this study demonstrated that Mcl-1 may be a predictive marker for the therapeutic effect of GnP in patients with MPC. This suggests that immunohistological examination of Mcl-1 expression before initiation of treatment could facilitate the selection of appropriate chemotherapeutic regimens.

Acknowledgements

We would like to thank Editage (www.editage.jp) for English language editing.

Author contributions

M.U. contributed to conceptualization, data curation, formal analysis, investigation, methodology, visualization and writing-original draft. K.I. contributed to conceptualization, data curation, formal analysis, investigation, methodology, project administration, visualization and writing-original draft. Y.S., K.W., Y. Kawamoto, T.H., Y. Kai, R.T., T.Y., K.M., T.N. and H.U. contributed to investigation and writing-review and editing. S.N. contributed to conceptualization, investigation, methodology, visualization, supervision and writing-review and editing. K.O. contributed to conceptualization, investigation, resources, supervision and writing-review and editing. All the authors have approved the final draft submission.

Data availability

Data supporting the findings of this study are available upon reasonable request from the corresponding author.

Competing interests

Ikezawa reports honoraria for lectures from Taiho Pharmaceutical, Yakult Honsha, Ono Pharmaceutical, MSD, Myriad Genetics, ASAHI KASEI PHARMA, Nihon Servier, AstraZeneca and Incyte Biosciences Japan, and research funding from ASKA Pharmaceutical. Takada reports honoraria for lectures from Taiho Pharmaceutical, Hisamitsu Pharmaceutical, Novartis, Myriad Genetics and TEIJIN PHARMA. Yamai reports honoraria for lectures from Taiho Pharmaceutical and Yakult Honsha. Ohkawa reports honoraria for lectures from Eisai, Chugai Pharmaceutical, Yakult Honsha, Incyte Biosciences Japan, Takeda, Gilead, AstraZeneca and Hisamitsu, and research grants from Towa Pharmaceutical and Sumitomo Chemical. The other authors have no conflict of interest.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
==== Refs
References

1. Siegel RL Miller KD Wagle NS Jemal A Cancer statistics, 2023 CA Cancer J. Clin. 2023 73 17 48 10.3322/caac.21763 36633525
Siegel, R. L., Miller, K. D., Wagle, N. S. & Jemal, A. Cancer statistics, 2023. CA Cancer J. Clin. 73, 17–48. 10.3322/caac.21763 (2023).36633525
2. Turner KM Wilson GC Patel SH Ahmad SA ASO practice guidelines series: Management of resectable, borderline resectable, and locally advanced pancreas cancer Ann. Surg. Oncol. 2024 31 1884 1897 10.1245/s10434-023-14585-y 37980709
Turner, K. M., Wilson, G. C., Patel, S. H. & Ahmad, S. A. ASO practice guidelines series: Management of resectable, borderline resectable, and locally advanced pancreas cancer. Ann. Surg. Oncol. 31, 1884–1897. 10.1245/s10434-023-14585-y (2024).37980709
3. Ozaka M A randomised phase II study of modified FOLFIRINOX versus gemcitabine plus nab-paclitaxel for locally advanced pancreatic cancer (JCOG1407) Eur. J. Cancer 2023 181 135 144 10.1016/j.ejca.2022.12.014 36652891
Ozaka, M. et al. A randomised phase II study of modified FOLFIRINOX versus gemcitabine plus nab-paclitaxel for locally advanced pancreatic cancer (JCOG1407). Eur. J. Cancer. 181, 135–144. 10.1016/j.ejca.2022.12.014 (2023).36652891
4. Okusaka T Clinical practice guidelines for pancreatic Cancer 2022 from the Japan Pancreas Society: A synopsis Int. J. Clin. Oncol. 2023 28 493 511 10.1007/s10147-023-02317-x 36920680
Okusaka, T. et al. Clinical practice guidelines for pancreatic Cancer 2022 from the Japan Pancreas Society: A synopsis. Int. J. Clin. Oncol. 28, 493–511. 10.1007/s10147-023-02317-x (2023).36920680
5. Kobayashi S Comparing the efficacy and safety of Gemcitabine plus Nab-Paclitaxel versus Gemcitabine alone in older adults with unresectable pancreatic Cancer Oncologist 2022 27 e774 e782 10.1093/oncolo/oyac157 35946841
Kobayashi, S. et al. Comparing the efficacy and safety of Gemcitabine plus Nab-Paclitaxel versus Gemcitabine alone in older adults with unresectable pancreatic Cancer. Oncologist. 27, e774–e782. 10.1093/oncolo/oyac157 (2022).35946841
6. Daiku K Chemotherapy effectiveness and age-group analysis of older adult patients with metastatic pancreatic cancer: A Japanese cancer registry cohort study J. Geriatr. Oncol. 2022 13 1208 1215 10.1016/j.jgo.2022.07.010 35931652
Daiku, K. et al. Chemotherapy effectiveness and age-group analysis of older adult patients with metastatic pancreatic cancer: A Japanese cancer registry cohort study. J. Geriatr. Oncol. 13, 1208–1215. 10.1016/j.jgo.2022.07.010 (2022).35931652
7. Kobayashi S Ueno M Ishii H Furuse J Management of elderly patients with unresectable pancreatic cancer Jpn J. Clin. Oncol. 2022 52 959 965 10.1093/jjco/hyac101 35789391
Kobayashi, S., Ueno, M., Ishii, H. & Furuse, J. Management of elderly patients with unresectable pancreatic cancer. Jpn J. Clin. Oncol. 52, 959–965. 10.1093/jjco/hyac101 (2022).35789391
8. Kato A Class III beta-tubulin expression is of value in selecting nab -Paclitaxel and Gemcitabine as First-Line Therapy in Unresectable Pancreatic Cancer Pancreas 2022 51 372 379 10.1097/MPA.0000000000002032 35695793
Kato, A. et al. Class III beta-tubulin expression is of value in selecting nab -Paclitaxel and Gemcitabine as First-Line Therapy in Unresectable Pancreatic Cancer. Pancreas. 51, 372–379. 10.1097/MPA.0000000000002032 (2022).35695793
9. Tozuka Y Prognostic significance of Sarcopenia as determined by bioelectrical impedance analysis in patients with advanced pancreatic cancer receiving gemcitabine plus nab-paclitaxel: A retrospective study Oncol. Lett. 2022 24 375 10.3892/ol.2022.13495 36238838
Tozuka, Y. et al. Prognostic significance of Sarcopenia as determined by bioelectrical impedance analysis in patients with advanced pancreatic cancer receiving gemcitabine plus nab-paclitaxel: A retrospective study. Oncol. Lett. 24, 375. 10.3892/ol.2022.13495 (2022).36238838
10. Singh R Letai A Sarosiek K Regulation of apoptosis in health and disease: The balancing act of BCL-2 family proteins Nat. Rev. Mol. Cell. Biol. 2019 20 175 193 10.1038/s41580-018-0089-8 30655609
Singh, R., Letai, A. & Sarosiek, K. Regulation of apoptosis in health and disease: The balancing act of BCL-2 family proteins. Nat. Rev. Mol. Cell. Biol. 20, 175–193. 10.1038/s41580-018-0089-8 (2019).30655609
11. Skwarska A Konopleva M BCL-xL targeting to Induce apoptosis and to Eliminate Chemotherapy-Induced senescent tumor cells: From Navitoclax to platelet-sparing BCL-xL PROTACs Cancer Res. 2023 83 3501 3503 10.1158/0008-5472.CAN-23-2804 37824434
Skwarska, A. & Konopleva, M. BCL-xL targeting to Induce apoptosis and to Eliminate Chemotherapy-Induced senescent tumor cells: from Navitoclax to platelet-sparing BCL-xL PROTACs. Cancer Res. 83, 3501–3503. 10.1158/0008-5472.CAN-23-2804 (2023).37824434
12. Adams JM Cory S The Bcl-2 apoptotic switch in cancer development and therapy Oncogene 2007 26 1324 1337 10.1038/sj.onc.1210220 17322918
Adams, J. M. & Cory, S. The Bcl-2 apoptotic switch in cancer development and therapy. Oncogene. 26, 1324–1337. 10.1038/sj.onc.1210220 (2007).17322918
13. Dewson G Kluck RM Mechanisms by which Bak and bax permeabilise mitochondria during apoptosis J. Cell. Sci. 2009 122 2801 2808 10.1242/jcs.038166 19795525
Dewson, G. & Kluck, R. M. Mechanisms by which Bak and bax permeabilise mitochondria during apoptosis. J. Cell. Sci. 122, 2801–2808. 10.1242/jcs.038166 (2009).19795525
14. Hanahan D Weinberg RA The hallmarks of cancer Cell 2000 100 57 70 10.1016/s0092-8674(00)81683-9 10647931
Hanahan, D. & Weinberg, R. A. The hallmarks of cancer. Cell. 100, 57–70. 10.1016/s0092-8674(00)81683-9 (2000).10647931
15. Wang H Guo M Wei H Chen Y Targeting MCL-1 in cancer: Current status and perspectives J. Hematol. Oncol. 2021 14 67 10.1186/s13045-021-01079-1 33883020
Wang, H., Guo, M., Wei, H. & Chen, Y. Targeting MCL-1 in cancer: current status and perspectives. J. Hematol. Oncol. 14, 67. 10.1186/s13045-021-01079-1 (2021).33883020
16. Tantawy SI Timofeeva N Sarkar A Gandhi V Targeting MCL-1 protein to treat cancer: Opportunities and challenges Front. Oncol. 2023 13 1226289 10.3389/fonc.2023.1226289 37601693
Tantawy, S. I., Timofeeva, N., Sarkar, A. & Gandhi, V. Targeting MCL-1 protein to treat cancer: Opportunities and challenges. Front. Oncol. 13, 1226289. 10.3389/fonc.2023.1226289 (2023).37601693
17. Beroukhim R The landscape of somatic copy-number alteration across human cancers Nature 2010 463 899 905 10.1038/nature08822 20164920
Beroukhim, R. et al. The landscape of somatic copy-number alteration across human cancers. Nature. 463, 899–905. 10.1038/nature08822 (2010).20164920
18. Akgul C Mcl-1 is a potential therapeutic target in multiple types of cancer Cell. Mol. Life Sci. 2009 66 1326 1336 10.1007/s00018-008-8637-6 19099185
Akgul, C. Mcl-1 is a potential therapeutic target in multiple types of cancer. Cell. Mol. Life Sci. 66, 1326–1336. 10.1007/s00018-008-8637-6 (2009).19099185
19. Kotschy A The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models Nature 2016 538 477 482 10.1038/nature19830 27760111
Kotschy, A. et al. The MCL1 inhibitor S63845 is tolerable and effective in diverse cancer models. Nature. 538, 477–482. 10.1038/nature19830 (2016).27760111
20. Ashida R Kitano M Endoscopic ultrasound-guided tissue acquisition for pancreatic ductal adenocarcinoma in the era of precision medicine Dig. Endosc 2022 34 1329 1339 10.1111/den.14344 35488448
Ashida, R. & Kitano, M. Endoscopic ultrasound-guided tissue acquisition for pancreatic ductal adenocarcinoma in the era of precision medicine. Dig. Endosc. 34, 1329–1339. 10.1111/den.14344 (2022).35488448
21. Fujimori N Minoda Y Ogawa Y What is the best modality for diagnosing pancreatic cancer? Dig. Endosc 2022 34 744 746 10.1111/den.14283 35318739
Fujimori, N., Minoda, Y. & Ogawa, Y. What is the best modality for diagnosing pancreatic cancer? Dig. Endosc. 34, 744–746. 10.1111/den.14283 (2022).35318739
22. Ikezawa K Increased Bcl-xL expression in pancreatic neoplasia promotes carcinogenesis by inhibiting senescence and apoptosis Cell. Mol. Gastroenterol. Hepatol. 2017 4 185 200e181 10.1016/j.jcmgh.2017.02.001 28948203
Ikezawa, K. et al. Increased Bcl-xL expression in pancreatic neoplasia promotes carcinogenesis by inhibiting senescence and apoptosis. Cell. Mol. Gastroenterol. Hepatol. 4, 185–200e181. 10.1016/j.jcmgh.2017.02.001 (2017).28948203
23. Ohuchida K Quantitative analysis of MUC1 and MUC5AC mRNA in pancreatic juice for preoperative diagnosis of pancreatic cancer Int. J. Cancer 2006 118 405 411 10.1002/ijc.21317 16052519
Ohuchida, K. et al. Quantitative analysis of MUC1 and MUC5AC mRNA in pancreatic juice for preoperative diagnosis of pancreatic cancer. Int. J. Cancer. 118, 405–411. 10.1002/ijc.21317 (2006).16052519
24. Tong Z Targeting CDK9 and MCL-1 by a new CDK9/p-TEFb inhibitor with and without 5-fluorouracil in esophageal adenocarcinoma Ther. Adv. Med. Oncol. 2019 11 1758835919864850 10.1177/1758835919864850 31384313
Tong, Z. et al. Targeting CDK9 and MCL-1 by a new CDK9/p-TEFb inhibitor with and without 5-fluorouracil in esophageal adenocarcinoma. Ther. Adv. Med. Oncol. 11, 1758835919864850. 10.1177/1758835919864850 (2019).31384313
25. Miyamoto, Y. et al. Immunohistochemical analysis of Bcl-2, Bax, Bcl-X, and Mcl-1 expression in pancreatic cancers. Oncology 56, 73–82 (1999). 10.1159/000011933
26. Friess H Moderate activation of the apoptosis inhibitor bcl-xL worsens the prognosis in pancreatic cancer Ann. Surg. 1998 228 780 787 10.1097/00000658-199812000-00009 9860477
Friess, H. et al. Moderate activation of the apoptosis inhibitor bcl-xL worsens the prognosis in pancreatic cancer. Ann. Surg. 228, 780–787. 10.1097/00000658-199812000-00009 (1998).9860477
27. Castillo L MCL-1 antagonism enhances the anti-invasive effects of dasatinib in pancreatic adenocarcinoma Oncogene 2020 39 1821 1829 10.1038/s41388-019-1091-0 31735913
Castillo, L. et al. MCL-1 antagonism enhances the anti-invasive effects of dasatinib in pancreatic adenocarcinoma. Oncogene. 39, 1821–1829. 10.1038/s41388-019-1091-0 (2020).31735913
28. Thummuri D Overcoming gemcitabine resistance in pancreatic cancer using the BCL-XL-specific degrader DT2216 Mol. Cancer Ther. 2022 21 184 192 10.1158/1535-7163.Mct-21-0474 34667112
Thummuri, D. et al. Overcoming Gemcitabine Resistance in Pancreatic Cancer using the BCL-XL-Specific Degrader DT2216. Mol. Cancer Ther. 21, 184–192. 10.1158/1535-7163.Mct-21-0474 (2022).34667112
29. Zhou Y Liu H Xue R Tang W Zhang S BH3 mimetic ABT-199 enhances the sensitivity of Gemcitabine in Pancreatic Cancer in vitro and in vivo Dig. Dis. Sci. 2018 63 3367 3375 10.1007/s10620-018-5253-7 30155839
Zhou, Y., Liu, H., Xue, R., Tang, W. & Zhang, S. BH3 mimetic ABT-199 enhances the sensitivity of Gemcitabine in Pancreatic Cancer in vitro and in vivo. Dig. Dis. Sci. 63, 3367–3375. 10.1007/s10620-018-5253-7 (2018).30155839
30. Jiménez-Guerrero R Obatoclax and paclitaxel synergistically induce apoptosis and overcome paclitaxel resistance in urothelial cancer cells Cancers (Basel) 2018 10 490 10.3390/cancers10120490 30563080
Jiménez-Guerrero, R. et al. Obatoclax and paclitaxel synergistically induce apoptosis and overcome paclitaxel resistance in urothelial cancer cells. Cancers (Basel). 10, 490. 10.3390/cancers10120490 (2018).30563080
31. Nie W Co-delivery of paclitaxel and shMCL-1 by folic acid-modified nonviral vector to overcome cancer chemotherapy resistance Small Methods 2021 5 e2001132 10.1002/smtd.202001132 34928100
Nie, W. et al. Co-delivery of Paclitaxel and shMCL-1 by folic acid-modified nonviral Vector to Overcome Cancer Chemotherapy Resistance. Small Methods. 5, e2001132. 10.1002/smtd.202001132 (2021).34928100
32. Wainberg ZA NALIRIFOX versus nab-paclitaxel and gemcitabine in treatment-naive patients with metastatic pancreatic ductal adenocarcinoma (NAPOLI 3): A randomised, open-label, phase 3 trial Lancet 2023 402 1272 1281 10.1016/S0140-6736(23)01366-1 37708904
Wainberg, Z. A. et al. NALIRIFOX versus nab-paclitaxel and gemcitabine in treatment-naive patients with metastatic pancreatic ductal adenocarcinoma (NAPOLI 3): A randomised, open-label, phase 3 trial. Lancet. 402, 1272–1281. 10.1016/S0140-6736(23)01366-1 (2023).37708904
33. Garajova I Peroni M Gelsomino F Leonardi F A simple overview of pancreatic cancer treatment for clinical oncologists Curr. Oncol. 2023 30 9587 9601 10.3390/curroncol30110694 37999114
Garajova, I., Peroni, M., Gelsomino, F. & Leonardi, F. A simple overview of pancreatic cancer treatment for clinical oncologists. Curr. Oncol. 30, 9587–9601. 10.3390/curroncol30110694 (2023).37999114
34. Yamai T Utility of Comprehensive genomic profiling tests for patients with incurable pancreatic cancer in clinical practice Cancers (Basel) 2023 15 970 10.3390/cancers15030970 36765927
Yamai, T. et al. Utility of Comprehensive genomic profiling tests for patients with incurable pancreatic cancer in clinical practice. Cancers (Basel). 15, 970. 10.3390/cancers15030970 (2023).36765927
35. Park W Genomic methods identify homologous recombination deficiency in pancreas adenocarcinoma and optimize treatment selection Clin. Cancer Res. 2020 26 3239 3247 10.1158/1078-0432.CCR-20-0418 32444418
Park, W. et al. Genomic methods identify homologous recombination deficiency in pancreas adenocarcinoma and optimize treatment selection. Clin. Cancer Res. 26, 3239–3247. 10.1158/1078-0432.CCR-20-0418 (2020).32444418
36. Hu ZI O’Reilly EM Therapeutic developments in pancreatic cancer Nat. Rev. Gastroenterol. Hepatol. 2024 21 7 24 10.1038/s41575-023-00840-w 37798442
Hu, Z. I. & O’Reilly, E. M. Therapeutic developments in pancreatic cancer. Nat. Rev. Gastroenterol. Hepatol. 21, 7–24. 10.1038/s41575-023-00840-w (2024).37798442
37. Kikuchi J Clinical significance of comprehensive genomic profiling tests covered by public insurance in patients with advanced solid cancers in Hokkaido, Japan Jpn J. Clin. Oncol. 2021 51 753 761 10.1093/jjco/hyaa277 33532831
Kikuchi, J. et al. Clinical significance of comprehensive genomic profiling tests covered by public insurance in patients with advanced solid cancers in Hokkaido, Japan. Jpn J. Clin. Oncol. 51, 753–761. 10.1093/jjco/hyaa277 (2021).33532831
38. Hagio K Assessment for the timing of comprehensive genomic profiling tests in patients with advanced solid cancers Cancer Sci. 2023 114 3385 3395 10.1111/cas.15837 37208840
Hagio, K. et al. Assessment for the timing of comprehensive genomic profiling tests in patients with advanced solid cancers. Cancer Sci. 114, 3385–3395. 10.1111/cas.15837 (2023).37208840
39. Kage H Human resources for administrative work to carry out a comprehensive genomic profiling test in Japan Cancer Sci. 2023 114 3041 3049 10.1111/cas.15833 37165760
Kage, H. et al. Human resources for administrative work to carry out a comprehensive genomic profiling test in Japan. Cancer Sci. 114, 3041–3049. 10.1111/cas.15833 (2023).37165760
40. Nakai Y Endoscopic ultrasonography-guided tissue acquisition for small solid pancreatic lesions: Does the size matter? DEN Open. 2022 2 e52 10.1002/deo2.52 35310760
Nakai, Y. et al. Endoscopic ultrasonography-guided tissue acquisition for small solid pancreatic lesions: Does the size matter? DEN Open. 2, e52. 10.1002/deo2.52 (2022).35310760
41. Itonaga, M. et al. Comparison of 22-gauge standard and Franseen needles in EUS-guided tissue acquisition for diagnosing solid pancreatic lesions: A multicenter randomized controlled trial. Gastrointest. Endosc. 96, 57–66 e52 (2022). 10.1016/j.gie.2022.02.005
42. Lisotti A Repeated endoscopic ultrasound-guided fine-needle biopsy of solid pancreatic lesions after previous nondiagnostic or inconclusive sampling Dig. Endosc 2024 36 615 624 10.1111/den.14686 37712906
Lisotti, A. et al. Repeated endoscopic ultrasound-guided fine-needle biopsy of solid pancreatic lesions after previous nondiagnostic or inconclusive sampling. Dig. Endosc. 36, 615–624. 10.1111/den.14686 (2024).37712906
43. Ishikawa K Optimization of endoscopic ultrasound-guided tissue sample acquisition for commercially available comprehensive genome profiling J. Gastroenterol. Hepatol. 2023 38 1794 1801 10.1111/jgh.16304 37495215
Ishikawa, K. et al. Optimization of endoscopic ultrasound-guided tissue sample acquisition for commercially available comprehensive genome profiling. J. Gastroenterol. Hepatol. 38, 1794–1801. 10.1111/jgh.16304 (2023).37495215
44. Ikeda G Fine-needle biopsy with 19G needle is effective in combination with endoscopic ultrasound-guided tissue acquisition for genomic profiling of unresectable pancreatic cancer Dig. Endosc 2023 35 124 133 10.1111/den.14423 35993898
Ikeda, G. et al. Fine-needle biopsy with 19G needle is effective in combination with endoscopic ultrasound-guided tissue acquisition for genomic profiling of unresectable pancreatic cancer. Dig. Endosc. 35, 124–133. 10.1111/den.14423 (2023).35993898
45. Hisada Y Proportion of unresectable pancreatic cancer specimens obtained by endoscopic ultrasound-guided tissue acquisition meeting the OncoGuide™ NCC oncopanel system analysis suitability criteria: A single-arm, phase II clinical trial J. Gastroenterol. 2022 57 990 998 10.1007/s00535-022-01926-z 36190682
Hisada, Y. et al. Proportion of unresectable pancreatic cancer specimens obtained by endoscopic ultrasound-guided tissue acquisition meeting the OncoGuide™ NCC oncopanel system analysis suitability criteria: A single-arm, phase II clinical trial. J. Gastroenterol. 57, 990–998. 10.1007/s00535-022-01926-z (2022).36190682
46. Okuno N Clinical utility of endoscopic ultrasound-guided tissue acquisition for comprehensive genomic profiling of pancreatic cancer Clin. Endosc 2023 56 221 228 10.5946/ce.2022.086 36879539
Okuno, N. et al. Clinical utility of endoscopic ultrasound-guided tissue acquisition for comprehensive genomic profiling of pancreatic cancer. Clin. Endosc. 56, 221–228. 10.5946/ce.2022.086 (2023).36879539
47. Larson BK Utility of endoscopic ultrasound-guided biopsy for next-generation sequencing of pancreatic exocrine malignancies Pancreas 2018 47 990 995 10.1097/MPA.0000000000001117 30028448
Larson, B. K. et al. Utility of endoscopic ultrasound-guided biopsy for next-generation sequencing of pancreatic exocrine malignancies. Pancreas. 47, 990–995. 10.1097/MPA.0000000000001117 (2018).30028448
