The effect of postoperative gemcitabine on overall survival in patients with resected pancreatic cancer: A nationwide population-based Danish register study

<b>Background:</b> Adjuvant chemotherapy following curative resection is the standard treatment for pancreatic adenocarcinoma (PC). Randomized clinical trials using gemcitabine have shown a median overall survival (mOS) of 2 years and a 5-year survival rate of 15-20%. However, the effect of gemcitabine outside these trials is less clear. We examined the effect of postoperative gemcitabine on survival in an unselected cohort of patients receiving curative resection for PC in Denmark during a five-year period. <b>Material and methods:</b> From 1 May 2011 to 30 April 2016, 731 patients treated with curative resection were identified in the Danish Pancreatic Cancer Database (DPCD). Thirty patients died within 10 weeks postoperatively; 78 received other regimens or preoperative chemotherapy and were excluded. Of the remaining 623 patients, the chemotherapy (CT) group (<i>n</i> = 409, 66%) received gemcitabine within 10 weeks after resection, whereas the non-chemotherapy (NCT) group (<i>n</i> = 214, 34%) did not receive CT within 10 weeks. <b>Results:</b> CT patients were slightly younger than NCT patients but did not otherwise differ in baseline characteristics. The CT group showed a mOS of 24 months (95% CI; 21–27) and a 5-year survival rate of 22% (95% CI; 17–27); the NCT group had a mOS of 22 months (95% CI; 16–26, <i>p</i> = .27) and a 5-year survival rate of 26% (95% CI; 19–34, <i>p</i> = .66). Most patients (415/623) had lymph node metastases. Of these patients, those in the CT group (<i>n</i> = 280) had significantly longer mOS [20 months (95% CI; 18–24)] than those in the NCT group (<i>n</i> = 135) [14 months (95% CI; 11–17)]. <b>Conclusions:</b> In this national Danish cohort of PC patients undergoing resection between 2011 and 2016, the survival after postoperative gemcitabine was similar to that reported in previous clinical trials. However, the survival advantage of postoperative gemcitabine was limited to patients with lymph node metastases.