Impact of Adjuvant Therapy on Overall Survival in Early Stage Ampullary Cancer: A Single Center Retrospective Review

Presenter: Yasmin Essaji MD | Virginia Mason Medical Center Background: Ampullary cancers are rare tumors accounting for approximately 6-7% of all periampullary cancers. True ampullary cancers generally present at earlier stages owing to the rapid development of obstructive jaundice. Due to earlier presentation and tumor biology, ampullary cancers continually demonstrate the longest median overall survival amongst periampullary tumors. Several retrospective studies and propensity-matched cohort studies have shown significant benefit of adjuvant therapy for node positive disease or advanced stage disease. The aim of our study was to investigate any benefit of adjuvant therapy in early stage ampullary cancer. Methods: A retrospective review was performed including patients who underwent pancreatoduodenectomy (both pylorus preserving and classic) for ampullary adenocarcinoma between 2006 – 2020. Categorical data are presented as counts with proportions and continuous data as means or median as appropriate. Univariable and multivariable Cox proportional hazard analysis was performed with survival presented using Kaplan-Meier method and log rank test. Analysis was performed using SPSS software (version 27, Chicago, IL, IMB Corp). Results: Overall, 114 patients were identified who underwent resection for ampullary carcinoma. Three patients were excluded as they were lost to follow-up and, therefore, receipt of adjuvant therapy was not confirmed. A total of 78 patients received adjuvant therapy (chemotherapy or chemotherapy with consolidative chemoradiation) while 33 patients were treated with resection alone. There was no significant difference in median overall survival for early stage (stage ≤ 2b) ampullary cancers in patients who did receive adjuvant therapy or did not receive adjuvant therapy (60.4 months vs 57.1 months respectively). There was no significant difference in tumor characteristics between patients who did or did not receive adjuvant therapy including tumor differentiation, histopathologic subtype, or resection margin status. Patients with lymph node metastasis and stage ≥ 2b were more likely to receive adjuvant therapy reflecting their higher stage of disease. Patients with ampullary cancer of the pancreatobiliary subtype had significantly higher rates of lymph node metastasis than intestinal subtype (p=0.046). As well, patients with ampullary cancer of the pancreatobiliary subtype had higher rates of disease recurrence than intestinal subtype (34.8% vs 20.0%, p=0.010). Conclusion: Among patients with early stage ampullary cancer (stage ≤ 2b), there was no significant difference in overall survival between those who did or did not receive adjuvant therapy. Patients with ampullary cancer with pancreatobiliary subtype had significantly higher incidence of lymph node metastasis and higher incidence of disease recurrence in comparison to intestinal subtype. Tumor characteristics such as lymph node metastases and pancreatobiliary subtype portend a worse prognosis and adjuvant therapy should be considered in those patients. Adjuvant therapy for early stage ampullary cancer requires further investigation in the way of a randomized trial.