Referral and treatment patterns in pancreatic acinar cell carcinoma: A regional population-level analysis

Clinical Outcomes and Molecular Profiling of Pancreatic Acinar Cell Carcinoma: A Retrospective Study

PURPOSE

Pancreatic acinar cell carcinoma (PACC) is a rare and aggressive form of pancreatic cancer that originates in the acinar cells of the exocrine pancreas. In this study, we aimed to investigate the clinical and molecular characteristics of patients with PACC at our institution.

METHODS

This was a retrospective study of patients with PACC seen at Mayo Clinic between 2002 and 2023. Baseline patient characteristics, tumor pathology, treatment strategies used, and survival outcomes were analyzed. Kaplan-Meier curves were estimated using newsurv macros in SAS.

RESULTS

The study included a total of 65 patients with PACC. The median age at diagnosis was 66 years. Almost half of the patients (48%) presented with resectable/borderline-resectable disease (n = 28). Five-year overall survival (OS) for resectable/borderline-resectable, locally advanced/unresectable, and metastatic disease were 72.0%, 21.6%, and 20.9%, respectively. Somatic and germline next-generation sequencing identified numerous potentially actionable targets including homologous recombination (43% somatic, 33% germline), RAF alterations (29% somatic), and mismatch repair (14% somatic).

CONCLUSION

Our findings underscore the heterogeneity and aggressive nature of PACC. Despite the improved prognosis for patients with resectable/borderline-resectable disease, OS remains poor, particularly for those with locally advanced or metastatic disease. The identification of actionable molecular targets in a significant proportion of patients highlights the potential for personalized therapeutic approaches. Future research should focus on tailored treatment strategies to exploit these molecular vulnerabilities, which may offer new options for improving outcomes in this rare malignancy.

The role of chemotherapy in the management of pancreatic acinar cell carcinoma

INTRODUCTION

Pancreatic acinar cell carcinoma (pACC) is a rare malignancy with unique clinical and molecular features. The role of chemotherapy in pACC management is not well established.

METHODS

The National Cancer Database (NCDB) for pACC was used. Cox regression was used in resected pACC patients to identify significant overall survival (OS) predictors. Patients were then divided based on these risk factors into propensity-matched group of surgery versus surgery + chemotherapy and Kaplan-Meier analysis was performed with log-rank tests to compare OS.

RESULTS

The NCDB 2004-2020 included 1592 pACC patients, 1553 were selected. Median age was 66 and 1090 (70.2%) were males. 622 (40.1%) received chemotherapy only, 257 (16.5%) had surgery only, and 365 (23.5%) had both. 189 Patients who received surgery were only matched to peers who had surgery + chemotherapy. The median OS for surgery only was 57.8 ± 6.0 versus 54.2 ± 9.9 months for surgery + chemotherapy (p = 0.836). Cox regression identified nodal and margin status as independent predictors of OS. Therefore, subgroups of patients with node-negative, node-positive, margin-negative, and margin-positive resections were similarly matched 1:1 for the receipt of surgery only versus surgery + chemotherapy. Only patients with node-positive disease had a significant OS benefit with the addition of chemotherapy (44.2 ± 7.3 vs. 27.5 ± 10.5 months; p = 0.036).

CONCLUSION

Our analysis suggests that surgical resection remains the cornerstone of therapy for pACC. Node status and margin status are the primary prognosticators. The addition of chemotherapy provides an OS benefit only in node-positive disease.

Comprehensive review of pancreatic acinar cell carcinoma: epidemiology, diagnosis, molecular features and treatment

Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from pancreatic ductal adenocarcinoma. Pancreatic acinar cell carcinoma occurs more frequently in males and can occur in children. Serum lipase is elevated in 24-58% of patients with pancreatic acinar cell carcinoma. Pancreatic acinar cell carcinomas tend to be large at diagnosis (median tumour size: ~5 cm) and are frequently located in the pancreas head. Radiologically, pancreatic acinar cell carcinoma generally exhibits a solid appearance; however, necrosis, cystic changes and intratumoral haemorrhage can occur in larger lesions. Immunostaining is essential for the definitive diagnosis of pancreatic acinar cell carcinoma. Compared with pancreatic ductal adenocarcinoma, pancreatic acinar cell carcinoma has a more favourable prognosis. Although radical surgery is recommended for patients with pancreatic acinar cell carcinoma who do not have distant metastases, the recurrence rate is high. The effectiveness of adjuvant therapy for pancreatic acinar cell carcinoma is unclear. The response to FOLFIRINOX is generally favourable, and some patients achieve a complete response. Pancreatic acinar cell carcinoma has a different genomic profile compared with pancreatic ductal adenocarcinoma. Although genomic analyses have shown that pancreatic acinar cell carcinoma rarely has KRAS, TP53 and CDKN2A mutations, it has a higher prevalence of homologous recombination-related genes, including BRCA1/2 and ATM, than pancreatic ductal adenocarcinoma, suggesting high sensitivity to platinum-containing regimens and PARP inhibitors. Targeted therapies for genomic alternations are beneficial. Therefore, genetic testing is important for patients with pancreatic acinar cell carcinoma to choose the optimal therapeutic strategy.