Purpose: The fragile histidine triad protein (FHIT) is a putative tumor suppressor in patients with lung cancer. In this study, we examined the prognostic value of FHIT expression for survival in patients with small cell lung cancer (SCLC).
Experimental design: As assessed by immunohistochemistry using formalin-fixed, paraffin-embedded tissue sections, tumors of 225 patients with SCLC were retrospectively evaluated for FHIT expression. The influence of FHIT staining intensities as well as the proportion of FHIT-positive cells within a tumor was taken into consideration for univariate and multivariate survival analysis.
Results: FHIT expression was observed in 61.8% of the SCLC tumors. Lack of FHIT was significantly associated with a shorter survival time for the patients with a median of 157 +/- 18 days compared with 210 +/- 18 days for those patients with FHIT-positive tumors (P = 0.0061). Furthermore, the proportion of FHIT-positive cells within the tumor was related to survival. Patients with tumors of <25% FHIT-positive cells had the worst survival of 155 +/- 21 days compared with 217 +/- 19 days for patients with a proportion of > or =25% of FHIT-expressing tumor cells (P = 0.0016). In contrast to the proportion of FHIT-positive cells within the tumor, no significant difference in survival was observed when different FHIT staining intensities (weak versus strong) were considered (median survival of 208 +/- 17 versus 234 +/- 34 days, P=0.665). Multivariate analysis using Cox regression including 11 variables confirmed the prognostic significance of FHIT expression next to performance status, tumor stage, and lactate dehydrogenase.
Conclusion: The presence of FHIT was correlated with a better prognosis for patients with SCLC.