The natural history and effect of adjuvant therapy on resected AJCC stage I-II lymph node-negative pancreatic cancer.

Abstract

264 Background: Previous investigation has suggested that early stage, lymph node negative pancreatic adenocarcinoma (PAC) has a relatively good prognosis and adjuvant therapy provides little benefit over surgery alone. The purpose of our trial was to evaluate patients with stage I-II PAC receiving surgical resection to determine their clinical characteristics, overall outcome, and the impact of adjuvant therapy on survival. Methods: Utilizing the population-based registry data from the Kentucky Cancer Registry (KCR) we identified patients with lymph node negative, AJCC I-II, PAC who underwent pancreatic resection during the years of 1995-2008. Patients were further stratified by receipt of surgery alone versus surgery with adjuvant chemotherapy or chemoradiation. Clinical and pathologic data included patient demographics, tumor characteristics, and lymph node status. Kaplan-Meier and Cox-regression survival analyses were performed. Results: During the study period, 203 patients meeting criteria were identified from the KCR. Median survival (MS) for the entire cohort was 21.7 months. The majority of patients were >70 years old, Caucasian, had well or moderately differentiated tumors and tumors <5cm. 46% (n=94) and 54% (n=109) of patients had stage I and II disease respectively. When stratified by surgery only (n=119, 59%) versus adjuvant therapy (n=84, 41%), only younger age predicted receipt of adjuvant therapy (p=0.002). Adjuvant therapy provided no benefit over surgery alone regardless of stage (stage I MS: 21.5 vs. 24.7 months, p=0.97 and stage II MS: 24.2 vs. 18.0, p=0.13, respectively). By multivariate analysis, only tumor size >5cm predicted worse survival (HR 2.32, CI 1.21-4.45, p=0.012). Age, stage, adjuvant therapy, differentiation, and lymph node retrieval had no impact on survival. Conclusions: Our data indicate that the survival for surgically resected early stage, lymph node negative pancreatic adenocarcinoma remains poor and is not improved by the addition of adjuvant chemotherapy. These findings should be considered when designing future adjuvant therapy trials for this deadly disease.