We reviewed 1051 consecutive patients with nonmetastatic exocrine pancreatic cancer who underwent resection at our institution between March 1987 and January 2011. Among them, 458 had adequate follow-up and evaluation for study inclusion. All patients received adjuvant chemotherapy (n=80 [17.5%]) or chemoradiation therapy (n=378 [82.5%]). Chemotherapy and chemoradiation therapy most frequently consisted of 6 cycles of gemcitabine and 50.4 Gy in 28 fractions with concurrent 5-fluorouracil, respectively. Locoregional control (LRC) and OS were estimated with the Kaplan-Meier method. Univariate and multivariate analyses were performed with Cox proportional hazards regression models incorporating propensity score.
Median patient age was 64.5 years (range: 29-88 years). Median follow-up for living patients was 84 months (range: 6-300 months). Extent of resection was R0 (83.8%) or R1 (16.2%). Overall crude incidence of LRF was 17% (n=79). The 5-year LRC for patients with and without radiation therapy was 80% and 68%, respectively (P=.003; hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.28-0.76). Multivariate analysis, incorporating propensity score, indicated radiation therapy (P<.0001; HR: 0.23; 95% CI: 0.12-0.42) and positive lymph node ratio of ≥0.2 (P=.02; HR: 1.78; 95% CI: 1.10-2.9) were associated with LRC. In addition, LRF was associated with worse OS (P<.0001; HR: 5.0; 95% CI: 3.9-6.3).
In our analysis of 458 patients with resected pancreatic cancer, positive lymph node ratio of ≥0.2 and no adjuvant chemoradiation therapy were associated with increased LRF risk. LRF was associated with poor OS. Radiation therapy should be considered as adjuvant locoregional treatment following pancreatic cancer resection.