Expression of ERCC1 and class IIIβ tubulin for predicting effect of carboplatin/paclitaxel in patients with advanced inoperable non-small cell lung cancer

It was recently reported that expression of excision repair cross-complementation group 1 (ERCC1), a DNA repair protein, predicts sensitivity to platinum-based chemotherapy drugs. Microtubule inhibitors such as paclitaxel demonstrate anticancer effects by inhibiting spindle fibers during mitosis; and class III beta tubulin (III beta tubulin), a microtubule component, is thought to be resistant to microtubule inhibitors. The purpose of the present study was to examine the correlation between prognosis and expression of these proteins using biopsy tissues obtained from 40 patients with advanced inoperable non-small cell lung cancer who had been treated with carboplatin plus Taxol. On immunostaining 27 patients (68%) were positive for ERCC1 and 22 (55%) were positive for III beta tubulin. The prognosis of the ERCC1-negative group was significantly better than that for the ERCC1-positive group (P = 0.014). As for III beta tubulin, the prognosis for the negative group was also significantly better than that for the positive group (P = 0.025). Multivariate analysis showed that the expression of ERCC1 was an independent predictor of prognosis (hazard ratio: 3.485; 95% confidence interval: 1.123-10.818, P = 0.031). It was concluded that determination of the expression of these proteins is useful to predict the effects of platinum-based anticancer drugs.