Adjuvant radiotherapy and chemotherapy for pancreatic carcinoma: The Mayo Clinic experience (1975-2005)

Purpose: To determine prognostic factors and impact of adjuvant chemotherapy (CT) and radiotherapy (RT) on overall survival (OS) after resection of pancreatic adenocarcinoma. Patients and Methods: We performed a retrospective review 472 consecutive patients who underwent complete resection with negative margins (R0) for invasive carcinoma (T1-3N0-1M0) of the pancreas between 1975 and 2005 at the Mayo Clinic in Rochester, MN. Exclusion criteria included metastatic or unresectable disease at surgery, positive surgical margins, and indolent tumor types (islet cell tumors and mucinous cystadenocarcinoma). Median RT dose was 50.4 Gy in 28 fractions; 98% of RT patients also received concurrent fluorouracil-based CT. Results: Six patients died within 30 days of surgery. For the 466 surviving patients, median follow-up was 32.4 months; median OS was 21.6 months. Median OS after adjuvant CT-RT was 25.2 versus 19.2 months after no adjuvant therapy (P = .001). Two-year OS was 50% versus 39%, and 5-year OS was 28% versus 17%. Adverse prognostic factors identified by univariate and multivariate analysis included positive lymph nodes (risk ratio [RR] = 1.3; P < .001), high histologic grade (RR = 1.2; P < .001), and no adjuvant therapy (RR = 1.3; P < .001). Tumor extension beyond the pancreas was an adverse prognostic factor by univariate analysis alone (P = .03). Patients receiving adjuvant therapy had more adverse prognostic factors than those not receiving adjuvant therapy (P = .001). Conclusion: This study represents one of the largest, single-institution, retrospective reviews of adjuvant therapy in patients after R0 resection of carcinoma of the pancreas. Overall survival was better in patients who received adjuvant CT-RT.