M30/M65 ratio predicts the outcome of paclitaxel chemotherapy for NSCLC

Paclitaxel is an effective treatment for some of the non-small-cell lung cancer (NSCLC) patients. However, prediction of the outcome of paclitaxel treatment at the early stage of the chemotherapy is difficult. M30 and M65 are circulating fragments of cytokeratin 18 released during apoptosis or necrosis, respectively, and have been used as markers to evaluate chemotherapy in some cancers. Here, we aimed to examine M30 and M65 values for predicting the therapeutic outcome of paclitaxel treatment of NSCLC. The serum levels of M30 and M65 before and after paclitaxel treatment in advance-stage NSCLC patients were analyzed, and compared to those in healthy controls. The importance of the M30 and M65 levels to the outcome of chemotherapy was analyzed. We found that the serum M30 and M65 levels were higher in patients with NSCLC (n = 44) than in control healthy subjects (n = 56) (p < 0.001). Two days after paclitaxel treatment, the serum levels of both M30 and M65 significantly increased in NSCLC patients (p < 0.001). Neither marker alone significantly correlated with overall patient survival, but the ratio of M30 vs M65 appeared to be an important prognostic factor for the overall survival of the patients (p < 0.01). Our results suggest that the serum M30/M65 ratio may be a prognostic factor for the outcome of paclitaxel treatment in NSCLC.