Fas/FasL expression in tumor biopsies: a prognostic response factor to fluoropyrimidines?

Various studies suggested that cytotoxicity induced by 5-fluorouracil (5-FU) is an apoptotic mechanism possibly mediated by the Fas/FasL system. In this preliminary work, we studied retrospectively the role the Fas/FasL expression as a predictive response factor with fluoropyrimidine-based chemotherapies. We developed a real-time PCR method for measuring Fas and FasL expression in various biopsies from patients treated with a FUFOL-like protocol. No correlation was found between Fas or FasL expression and overall survival or partial response. However, the PCR assay was simple and convenient to use for quantitation of Fas/FasL in tumor biopsies.