Germline mutations of homologous recombination genes and clinical outcomes in pancreatic cancer: a multicenter study in Taiwan

BACKGROUND

Cancer susceptibility germline mutations are associated with pancreatic ductal adenocarcinoma (PDAC). However, the hereditary status of PDAC and its impact on survival is largely unknown in the Asian population.

METHODS

Exome sequencing was performed on 527 blood samples from PDAC individuals and analyzed for mutations in 80 oncogenic genes. Pathogenic and likely pathogenic (P/LP) germline variants were diagnosed according to the ACMG variant classification categories. The association between germline homologous recombination gene mutations (gHRmut, including BAP1, BRCA1, BRCA2, PALB2, ATM, BLM, BRIP1, CHEK2, NBN, MUTYH, FANCA and FANCC) and the treatment outcomes was explored in patients with stage III/IV diseases treated with first-line (1L) platinum-based versus platinum-free chemotherapy.

RESULTS

Overall, 104 of 527 (19.7%) patients carried germline P/LP variants. The most common mutated genes were BRCA2 (3.60%), followed by ATR (2.66%) and ATM (1.9%). After a median follow-up duration of 38.3-months (95% confidence interval, 95% CI 35.0-43.7), the median overall survival (OS) was not significantly different among patients with gHRmut, non-HR germline mutations, or no mutation (P = 0.43). Among the 320 patients with stage III/IV disease who received 1L combination chemotherapy, 32 (10%) had gHRmut. Of them, patients receiving 1L platinum-based chemotherapy exhibited a significantly longer median OS compared to those with platinum-free chemotherapy, 26.1 months (95% CI 12.7-33.7) versus 9.6 months (95% CI 5.9-17.6), P = 0.001. However, the median OS of patients without gHRmut was 14.5 months (95% CI 13.2-16.9) and 12.6 months (95% CI 10.8-14.7) for patients receiving 1L platinum-based and platinum-free chemotherapy, respectively (P = 0.22). These results were consistent after adjusting for potential confounding factors including age, tumor stage, performance status, and baseline CA 19.9 in the multivariate Cox regression analysis.

CONCLUSIONS

Our study showed that nearly 20% of Taiwanese PDAC patients carried germline P/LP variants. The longer survival observed in gHRmut patients treated with 1L platinum-based chemotherapy highlights the importance of germline testing for all patients with advanced PDAC at diagnosis.

The experience of neoadjuvant chemotherapy versus upfront surgery in resectable pancreatic cancer: a cross sectional study

BACKGROUND

Upfront resection (UR) followed by adjuvant chemotherapy remains the standard treatment for resectable pancreatic cancer. There is increasing evidence suggesting favourable outcomes toward neoadjuvant chemotherapy (NAC) followed by surgery.

METHODS

All clinical staging with resectable pancreatic cancer patients treated at a tertiary medical centre from 2013 to 2020 were identified. The baseline characteristics, treatment course, surgery outcome and survival results of UR or NAC were compared.

RESULTS

Finally, in 159 resectable patients, 46 patients (29%) underwent NAC and 113 patients (71%) received UR. In NAC, 11 patients (24%) did not receive resection, 4 (36.4%) for comorbidity, 2 (18.2%) for patient refusal and 2 (18.2%) for disease progression. In UR, 13 patients (12%) were unresectable intraoperatively; 6 (46.2%) for locally advanced and 5 (38.5%) for distant metastasis. Overall, 97% of patients in NAC and 58% of patients in UR completed adjuvant chemotherapy. As of data cut-off, 24 patients (69%) in NAC and 42 patients (29%) in UR were still tumour free. The median recurrence-free survival in NAC, UR with adjuvant chemotherapy and without adjuvant chemotherapy were 31.3 months (95% CI, 14.4-not estimable), 10.6 months (95% CI, 9.0-14.3) and 8.5 months (95% CI, 5.8-11.8), P =0.036; and the median overall survival in each group were not reached (95% CI, 29.7-not estimable), 25.9 months (95% CI, 21.1-40.5) and 21.7 months (12.0-32.8), P =0.0053. Based on initial clinical staging, the median overall survival of NAC was not significantly different from UR with a tumour less than or equal to 2 cm, P =0.29. NAC patients had a higher R0 resection rate (83% versus 53%), lower recurrence rate (31% versus 71%) and harvested median number lymph node (23 versus 15).

CONCLUSION

This study demonstrates that NAC is superior to UR in resectable pancreatic cancer with better survival.

Real-World Data Validation of NAPOLI-1 Nomogram for the Prediction of Overall Survival in Metastatic Pancreatic Cancer

BACKGROUND

The nomogram derived from the pivotal phase III NAPOLI-1 study demonstrated a significant ability to predict median overall survival (OS) in gemcitabine-refractory metastatic pancreatic ductal adenocarcinoma (PDAC) treated with liposomal irinotecan plus fluorouracil and leucovorin (nal-IRI+5-FU/LV). However, the NAPOLI-1 nomogram has not been validated in a real-world setting and therefore the applicability of the NAPOLI-1 nomogram in daily practice remains unknown. This study aims to evaluate the NAPOLI-1 nomogram in a multicenter real-world cohort.

METHODS

The NAPOLI-1 nomogram was applied to a previously established cohort of metastatic PDAC patients treated with nal-IRI+5-FU/LV in nine participating centers in Taiwan. Patients were divided into three risk groups according to the NAPOLI-1 nomogram. The survival impact of relative dose intensity at 6 weeks (RDI at 6 weeks) in different risk groups was also investigated.

RESULTS

Of the 473 included patients, the median OSs of patients classified as low (n = 156), medium (n = 186), and high (n = 131) risk were 10.9, 6.3, and 4.3 months, respectively (p < 0.0001). The survival impact of RDI at 6 weeks remained significant after stratification by risk groups, adjustment with Cox regression, inverse probability weighting, or propensity score matching.

CONCLUSIONS

Our results support the usefulness of the NAPOLI-1 nomogram for risk stratification in gemcitabine-refractory metastatic PDAC treated with nal-IRI+5-FU/LV in daily practice. We further showed that the RDI at 6 weeks is an independent prognostic factor beyond the NAPOLI-1 nomogram.

A phase II randomised trial of induction chemotherapy followed by concurrent chemoradiotherapy in locally advanced pancreatic cancer: the Taiwan Cooperative Oncology Group T2212 study

BACKGROUND

The objective of this study was to evaluate the efficacy and safety of induction chemotherapy (ICT), GOFL (gemcitabine, oxaliplatin plus fluorouracil (5-FU)/leucovorin) versus modified FOLFIRINOX (irinotecan, oxaliplatin plus 5-FU/leucovorin), followed by concurrent chemoradiotherapy (CCRT) in locally advanced pancreatic adenocarcinoma (LAPC).

METHODS

Chemo-naive patients with measurable LAPC were eligible and randomly assigned to receive biweekly ICT with either mFOLFIRINOX or GOFL for 3 months. Patients without systemic progression would have 5-FU- or gemcitabine-based CCRT (5040 cGy/28 fractions) and were then subjected to surgery or continuation of chemotherapy until treatment failure. The primary endpoint was 9-month progression-free survival (PFS) rate.

RESULTS

Between July 2013 and January 2019, 55 patients were enrolled. After ICT, 21 (77.8%) of 27 patients who received mFOLFIRINOX and 17 (60.7%) of 28 patients who received GOFL completed CCRT. Of them, one and five had per-protocol R0/R1 resection. On intent-to-treat analysis, the 9-month PFS rate, median PFS and overall survival in mFOLFIRINOX and GOFL arms were 30.5% versus 35.9%, 6.6 (95% confidence interval: 5.9-12.5) versus 7.6 months (3.9-12.3) and 19.6 (13.4-22.9) versus 17.9 months (13.4-23.9), respectively. Grade 3-4 neutropenia and diarrhoea during induction mFOLFIRINOX and GOFL were 37.0% versus 21.4% and 14.8% versus 3.6%, respectively.

CONCLUSION

Induction GOFL and mFOLFIRINOX followed by CCRT provided similar clinical outcomes in LAPC patients.

CLINICALTRIAL

GOV IDENTIFIER

NCT01867892.

Novel systemic treatment approaches for metastatic pancreatic cancer

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) has a 5-year overall survival rate of 10 %, emphasizing the need for more effective therapies, especially in metastatic disease. The immunosuppressive tumor microenvironment, poor vascularization, and dense tumor stroma typical for PDAC are hurdles that need to be overcome by novel drugs. Investigations are moving towards more targeted treatments including immunotherapy and cell-based approaches.

AREAS COVERED

This article reviews emerging drugs in clinical development for metastatic PDAC, focusing on cellular therapies and novel treatments targeting metabolism, tumor stroma, oncogenic pathways and immunosuppression. With immunotherapy and CAR T cell therapy on the rise in hematological malignancies, the transfer to solid tumors remains intriguing. Multiple exciting clinical trials investigating innovative therapeutic strategies for PDAC are currently ongoing and reviewed herein. ClinicalTrials.gov, conference abstracts and PubMed were searched in August 2021 and assessed for information on ongoing and published clinical studies.

EXPERT OPINION

With many challenges to overcome, the optimal therapy for patients with metastatic PDAC is likely to consist of a combination of different agents. We are slowly moving from entity-dependent approaches to ones more focused on molecular and pathological features. Increasingly personalized treatment plans tailored to each patient may be the future of PDAC therapy.