Chemotherapy increases caspase-cleaved cytokeratin 18 in the serum of breast cancer patients

BACKGROUND: Apoptosis is thought to be induced by chemotherapy in cancer patients. Therefore, the measurement of its amplitude may be a useful tool to predict the effectiveness of cancer treatment sooner than conventional methods do. PATIENTS AND METHODS: In the study presented, apoptosis was assessed with an ELISA-based assay in which caspase-cleaved cytokeratin 18 (M30-antigen), a novel specific biomarker of apoptosis, is measured. Thirty seven patients with malignant (nonmetastatic and metastatic) breast cancer, 35 patients with benign breast disease, and 34 healthy subjects were studied. Cancer patients received neoadjuvant chemotherapy consisting of either fluorouracil, epirubicin, and cyclophosphamide (FEC) or epirubicin plus docetaxel (ED). Apoptosis was detected before chemotherapy, 24 and 48 h after chemotherapy in the malignant group. RESULTS: It was found that the baseline apoptosis level in either malignant but nonmetastatic group or benign group was not statistically different from that in the control group (p>0.05). However, it was statistically significantly higher in the metastatic group than that in the control group (p<0.05). Following the drug application, M30-antigen levels significantly increased at 24 h (p<0.05). The baseline M30-antigen levels increased about 3-times in patients showing tumor regression. CONCLUSIONS: M30-antigen level is increased after chemotherapy and its measurement may help clinicians to predict the effectiveness of chemotherapy sooner in breast cancer cases although confirmative larger trials are needed.