Benefit of postoperative adjuvant therapy for pancreatic cancer: A population-based analysis

BACKGROUND: Despite the recent completion of several trials of adjuvant therapy after resection for pancreatic adenocarcinoma, the absolute impact on survival and the identification of appropriate patients for treatment has remained controversial. In the current study, the authors sought to identify the impact of adjuvant therapy and factors associated with any improvement in survival after resection of pancreatic cancer. METHODS: Through the California Cancer Registry, all California residents diagnosed with pancreatic cancer between 1994 and 2002 were identified. Factors potentially impacting survival were analyzed, including patient demographics, tumor characteristics, and treatment provided. Univariate and multivariate survival analyses were performed by Kaplan-Meier and Cox regression methods. RESULTS: A total of 26,518 patients were identified; 3196 (12.1%) underwent resection as their primary treatment. The median overall survival was 16 months for patients who underwent resection. Prognostic factors associated with better survival included negative lymph node status, well-differentiated tumors, younger age, female sex, and the receipt of any adjuvant therapy. On multivariate analysis, adjuvant therapy demonstrated a statistically significant, although modest, impact on survival, with a hazards ratio of 0.79 (95% confidence interval, 0.72-0.87; P < .001). The benefit of adjuvant therapy was only apparent in those patients with lymph node-positive or poorly differentiated tumors. CONCLUSIONS: Adjuvant therapy provided for a modest improvement in overall survival after surgical resection of pancreatic cancer. The absolute effect was most pronounced in those patients with poor prognostic indicators. To identify effective systemic therapy for this deadly cancer, future clinical trials of adjuvant therapy should focus on these groups of patients.