Optimal Timing of Adjuvant Therapy in Patients with Poorly Differentiated Pancreatic Adenocarcinoma.

[BACKGROUND] Multimodal therapy, combining chemotherapy and surgical resection, is the standard of care for patients with resectable pancreatic ductal adenocarcinoma (PDAC). Patients with poorly differentiated PDAC have suboptimal overall survival (OS), partly owing to the limited understanding of optimal timing for return to intended oncologic therapy (RIOT) after upfront surgery. We aim to evaluate patients with poorly differentiated PDAC who undergo upfront surgical resection and assess how the timing of receipt of adjuvant chemotherapy is associated with OS.

[PATIENTS AND METHODS] Using the National Cancer Database, we identified patients with poorly differentiated nonmetastatic PDAC who received upfront surgical resection followed by adjuvant chemotherapy (2007-2016). Adjusted Cox proportional hazard models evaluated OS on the basis of RIOT timing. Logistic regression was used to identify factors associated with RIOT.

[RESULTS] Of 2737 included patients, 66.1% (n = 1810) did RIOT within 9 weeks and 33.9% (n = 927) after 9 weeks. The median age of the study cohort was 62 years; 52% (n = 1583) were male and 87.1% (n = 2657) were white. Adjusted multivariable analysis noted that patients who did RIOT within 9 weeks were associated with improved OS compared with patients who did RIOT after 9 weeks (adjusted hazard ratio [aHR] 0.90, 95% confidence interval [CI] 0.82-0.99, p = 0.03). Treatment at academic facilities was associated with lower odds of RIOT within 9 weeks compared with treatment at non-academic facilities (adjusted odds ratio [aOR] 0.83, 95% CI 0.70-0.98, p = 0.03).

[CONCLUSIONS] Patients with poorly differentiated pancreatic ductal adenocarcinoma may benefit from adjuvant therapy within 9 weeks after surgical resection. Opportunities may exist in academic facilities to facilitate adjuvant therapy within 9 weeks of surgical resection.