Factors influencing receipt of adjuvant chemotherapy after surgery for pancreatic cancer: a two-center retrospective cohort study

Objective: The addition of adjuvant chemotherapy after surgical resection has improved survival rates for patients with pancreatic ductal adenocarcinoma (PDAC). However, outside clinical trials, many operated patients still do not receive adjuvant chemotherapy due to clinical and tumor-related factors. The aim of this study was to investigate factors that may influence the receipt of adjuvant chemotherapy and the effect on long-term survival. Materials and methods: Patients undergoing macroscopically curative resection for PDAC at the University Hospitals in Lund and Linköping, Sweden, between 1 January 2007 and 31 December 2015, were retrospectively reviewed. Clinical and pathological data were compared between adjuvant and non-adjuvant chemotherapy groups and factors affecting chemotherapy receipt were analyzed by multiple logistic regression. Multivariable Cox regression analysis was performed to select predictive variables for survival. Results: A total of 233 patients were analyzed. Adjuvant chemotherapy was administered to 167 patients (71.7%). The likelihood of receiving adjuvant chemotherapy decreased with age, OR 0.91, 95% CI 0.86–0.95, p < .001. Moreover, patients with severe postoperative complications (Clavien–Dindo grade ≥ III) were less likely to receive adjuvant chemotherapy, OR 0.31, 95% CI 0.14–0.71, p = .005. The presence of lymph node metastases on histopathological reporting was associated with increased likelihood of initiating adjuvant chemotherapy, OR 2.19, 95% CI 1.09–4.40, p = .028. Adjuvant chemotherapy was an independent factor for prolonged survival on multivariable Cox regression analysis, HR 0.45 (95% CI 0.31–0.65), p < .001. Conclusions: Age, postoperative complications and the presence of lymph node metastases affect the likelihood of receiving adjuvant chemotherapy after PDAC surgery.