# Germline BRCA1 ‐Mutated Synchronous and Metachronous Pancreatic Acinar Cell Carcinoma With Long‐Term Survival

## TL;DR

A rare case of pancreatic cancer linked to a BRCA1 mutation is reported, highlighting the need for genetic testing in similar cases.

## Contribution

First reported case of germline BRCA1-mutated synchronous and metachronous pancreatic acinar cell carcinoma.

## Key findings

- A patient with BRCA1-mutated pancreatic cancer had synchronous and metachronous tumors.
- Genetic testing led to cascade testing in family members, identifying the same BRCA1 mutation.
- Treatment with olaparib failed after 4 months, but overall survival was prolonged.

## Abstract

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic neoplasm. Recently, molecular analysis revealed that PACC shows a high frequency of the BRCA1/2 mutation and is likely to be considered a cancer associated with hereditary breast and ovarian cancer (HBOC). Hereditary cancers, including HBOC, are characterized by multifocal and/or metachronous tumors. However, no case reports exist of germline BRCA1‐mutated synchronous and metachronous PACC.

A 58‐year‐old man was diagnosed with synchronous and metachronous PACC at the age of 56 and underwent two surgeries. Ten months after the second surgery, the patient developed multiple liver metastases. Gemcitabine plus nab‐paclitaxel therapy was administered as first‐line chemotherapy. After seven cycles, computed tomography examination revealed progressive disease (PD). Therefore, modified FOLFIRINOX (mFFX) was administered as second‐ line chemotherapy. After 19 cycles of mFFX, comprehensive cancer genomic profiling (CGP) identified a BRCA1 pathogenic variant that was confirmed to be germline origin. Accordingly, we treated the patient with olaparib; however, he was diagnosed with PD after 4 months. He subsequently died 5 years and 9 months after the initial surgery, and 3 years and 10 months after chemotherapy. Based on the genetic data of the patients, his family members received genetic counseling followed by cascade testing. Consequently, the same gBRCA1 pathogenic variant was detected in the son and his surveillance for HBOC‐related cancers was initiated.

We diagnosed a 58‐year‐old man with a synchronous and metachronous PACC with germline BRCA1 pathogenic variant. Considering that PACC is likely to have BRCA1/2 mutations responsible for HBOC, we need to be aware of the possible presence of multifocal and/or metachronous tumors in patients with PACC. Additionally, patients with PACC should undergo genetic examinations, which would be beneficial in determining treatment strategies and health care for blood relatives.