F-box and WD repeat domain-containing 7 (FBXW7) mRNA and outcome in biliary tract cancer.

Abstract

e14521 Background: Thestandard treatment for biliary tract cancer is gemcitabine plus platinum, but median progression-free survival (PFS) is only 5-8 months (m) (Valle et al, NEJM 2010). Gene expression or somatic mutations may influence the clinical phenotype, which will affect decisions on individualized treatment. Methods: We retrospectively analyzed tissue blocks from 54 advanced or metastatic cholangiocarcinoma, gallbladder or ampulllary cancer patients (p) treated with single-agent gemcitabine or gemcitabine plus carboplatin or cisplatin. Using RT-PCR, we analyzed the mRNA expression levels of oncogenes, tumor suppressors and DNA repair genes (BRCA1, RRM1, AEG-1, RAP80, SPINK1 and FBXW7) and correlated results with PFS, overall survival (OS) and response. In addition, FBXW7 hotspot mutations were assessed. Results: p characteristics: 72% females; median age, 60 (40-87). Only FBXW7 expression correlated with PFS and OS. When FBXW7 levels were dichotomized at the median value, PFS was 4.2 m for p with low levels vs 12.6 m for p with high levels (p=0.02). When FBXW7 expression was divided by terciles, PFS was 4.9 m for p in the lowest tercile, 7.6 for p in the intermediate tercile, and 26.9 m for p in the highest tercile (p=0.08). OS was 6.2 m for p in the lowest tercile, 8 m for p in the intermediate tercile, and not reached for p in the highest tercile. No other significant correlation was observed between expression levels of the other genes examined and PFS or OS. Only AEG-1 expression correlated with response (p=0.05). No FBXW7 hotspot mutations were detected. Conclusions: Although we did not find the FBXW7 hotspot mutations previously described in biliary tract cancer, FBXW7 mRNA expression significantly influenced PFS and OS. A separate cohort of p is being analyzed to validate the prognostic role of FBXW7.