Post-operative patterns of failure and outcomes reveal opportunities to optimize treatment of recurrent pancreatic cancer

Background/ObjectivesRecurrent pancreatic adenocarcinoma (PDAC) after curative resection is challenging to treat. We characterized recurrence patterns and outcomes, focusing on frequency of single-organ liver or lung metastases, and their distribution of oligometastases (1-5 lesions) versus polymetastases (> 5 lesions). MethodsPatients were evaluated after curative resection, and recurrence was classified as local, distant, or combined. Patients with metachronous disease and who received treatment and had single organ lung or liver disease were identified as MetachPDAC, followed by OligoMetach (1-5 lesions) and PolyMetach (> 5 lesions). Demographic features, disease free survival, and overall survival (OS) from surgery and time of recurrence were assessed using the Kaplan-Meier method. ResultsOf 572 patients who underwent surgery for pancreas cancer, 366 (64%) recurred: 90 (25%) local, 195 (53%) distant, and 81 (22%) combined. Median OS was shortest for patients who experienced combined failures (19.3 mo) versus those with local (34.8 mo) or distant failures (26.6 mo; p<0.0001). In patients with MetachPDAC recurrence with single-organ metastases (n=112), oligometastatic or OligoMetach (n=85, 76%) was more common as 35% of all distant metachronous recurrence and associated with longer OS (29.9 vs 24.3 mo; p=0.0089). Among OligoMetach, liver metastases (n=61, 72%) were more frequent, but lung only metastases (n=24, 28%) was associated with superior OS (63.8 vs 25.5 mo; p=0.0001). In the OligoMetach subgroup, patients receiving radiotherapy with chemotherapy (n=20, 24%) had longer OS than chemotherapy alone (68.4 vs 26.2 mo; p=0.0002). ConclusionsOligometastatic MetachPDAC is associated with longer survival than PolyMetach, represents 35% of metachronous failures, and radiotherapy may improve outcomes within the subset. These results highlight the value of recurrence pattern-based treatment strategies, though confirmation in larger prospective studies is needed.