KRAS mutations and relation to prognosis in patients operated for localized pancreatic cancer and other periampullary cancers

Abstract

e15618 Background: Prognostic biomarkers in patients with pancreatic cancer might direct patients to optimal treatment. We studied the prognostic value of KRAS mutations in patients operated for pancreatic and other periampullary cancers. Methods: Retrospective study of 328 patients who were operated with a Whipples procedure at a single HBP-center during the period August 1976 to May 2008. For the present pilot study cancer tissue blocks were collected from 58 patients (31 men, 27 women, median age 64, range 33–81 years, ASA 1–3). All had localized pancreatic (n=26), ampullary (n=26) or duodenal cancer (n=6) and were operated during the period June 2001 to May 2008. 32 patients died (3 within the first month after operation and were excluded). Median follow-up time was 41 months (range 7–90). KRAS mutations in exon 1 and 2 were determined by LightScanner analysis (Idaho Technology). Results: KRAS mutations were found in 32 (55%) of the patients; 16 (62%) patients with pancreatic cancer, 13 (50%) with ampullary cancer and in 3 (50%) with duodenal cancer. KRAS status was neither associated with type of cancer (p=0.68), TNM stage (T stage p=0.64, N stage p=0.31). The median survival time for all patients was 22 months (KRAS mutation: 21, 95% CI: 10–40; Wildtype: not reached yet). Univariate Cox analysis showed that T stage (TNM) (1: HR=0.09, 95% CI: 0.02–0.48 p=0.004; 2: HR=0.18, 0.06- 0.51, p=0.0013; 3: HR=0.26, 0.09–0.71, p=0.0089) was a prognostic factor of OS. KRAS status (HR=0.70, 0.33–1.49, p=0.36) and N stage (TNM) (HR=0.53, 0.25–1.11, p=0.09) were not significant factors of OS, but there is a strong tendency for both factors. Conclusions: KRAS mutations are frequent in patients with localized pancreatic, ampullary and duodenal cancers. Preliminary analysis of 58 patients out of our cohort of 328 patients indicate that KRAS mutations may be a marker of overall survival and time to progression. No significant financial relationships to disclose.