Clinical relevance of pancreatobiliary and intestinal subtypes of ampullary and duodenal adenocarcinoma: Pattern of recurrence, chemotherapy, and survival after pancreatoduodenectomy.

BACKGROUND: The clinical relevance of the classification of ampullary adenocarcinoma (AC) into pancreatobiliary (PB) or intestinal (Int) subtypes has not been resolved.

METHODS: Clinicopathological factors, survival, and localization and treatment of recurrence were investigated for patients with AC and duodenal adenocarcinoma (DC) treated by pancreatoduodenectomy from 2000 to 2015.

RESULTS: A total of 109 AC (45 PB, 64 Int) and 71 DC (all Int) were identified. Median overall survival (OS) for ACPB vs DC vs ACInt was 43.6 vs 51 vs 75 months, respectively. ACPB had significantly shorter OS than ACInt (p = 0.036). However, for AC stage (HR = 2.39; 95 %CI 1.23-4.64, p = 0.010) was the only factor associated with mortality risk in multivariate analysis. Localization of recurrence (n = 88) was predominantly distant (ACPB 81.5%; ACInt 92%; DC 91.7%, p = 0.371). Post-recurrence survival (PRS) for ACPB, ACInt and DC did not differ (6.9 vs 9.2 vs 7.5 months, p = 0.755). Best supportive care or palliative chemotherapy were offered for recurrent disease to 44.5%/48.1% for ACPB, 40%/56% for ACInt, and 41.7%/52.8% for DC (p = 0.947). The choice of chemotherapy regimen varied considerably. Five patients underwent surgical resection or ablation with curative intent. All deaths among ACPB were caused by recurrent disease, whereas 29.4% of ACInt and 23.1% of DC deaths was non-cancer related or caused by other specific cancer.

CONCLUSION: ACPB, ACInt and DC have similar recurrence patterns and PRS. The difference in survival between ACPB and ACInt was not statistically significant when stratified by stage. The optimal chemotherapy in patients with recurrent AC remains undefined.