Optimizing Chemotherapy of Pancreatic Acinar Cell Carcinoma: Our Experiences and Pooled Analysis of Literatures

Background: Pancreatic acinar cell carcinoma (PACC) is rare and its appropriate treatment remains unknown dued to limited and selection-biased data Methods: : The data on clinicopathologic characteristics, molecular alteration, treatment and survival of patients diagnosed as PACC in Sun Yat-sen university cancer center from 2005 to 2020 were collected. We explored the optimal treatment by co-analyzing our results and published literatures. Results: 22 PACC patients were enrolled. 8/17 non-metastatic patients received adjuvant chemotherapy. The patients receiving fluoropyrimidine-based regimen (n=3) had better mDFS than those with gemcitabine-based regimen (n=5) (unreached vs . 27 months). 8 metastatic patients received 1 st -line chemotherapy. 4/5 patients with FOLFIRINOX regimen achieved partial response (PR) and 3 patients with AG (albumin paclitaxel+gemcitabine) regimen got progressive disease (PD). 4 patients received 2 nd -line chemotherapy. 2 patients with FOLFIRINOX regimen achieved PR while 2 patients with AG regimen got PD. One patient who had responded to 1 st -line FOLFIRINOX regimen received Olaparib as maintenance treatment for 5 months with good tolerance. 31 published literatures and a total of 86 cases were included in the co-analysis. Objective response rate of 1 st -line fluoropyrimidine-based regimen (n=47) was higher than that of gemcitabine-based regimen (n=39) (59.6% vs. 15.3%, P <0.001). 8/11 patients treated with FOLFIRINOX regimen achieved PR. Conclusions: : The benefit of adjuvant chemotherapy remained unclear; however, fluoropyrimidine-based chemotherapy deserves attention. For metastatic patients, fluorouracil-based regimen such as FOLFIRINOX is preferred, and maintenance treatment of PARP inhibitors after effective platinum-containing treatment for BRAC mutation patients is worthy of exploration.