RESUMO
Tumor markers are biochemical substances elaborated by tumor cells either due to the cause or effect of malignant processes. Here we investigated serum levels of cancer antigen (CA15.3) and carcino embryonic antigen (CEA) in 153 pre and post operated southern Indian breast cancer patients (stage-I- 45, stage-II-55, stage-III- 53 samples) and 37 normal controls.Patients with malignant lesions had high frequencies of abnormal CA15.3 in stage-II (46.3%) and stage-III ( 42.6%) and of CEA in stage-III (64.3%). The mean serum levels of CA 15.3 in all stages dropped significantly after 9 days of mastectomy, but this was not the case with CEA even after 27 days. At 27 days after mastectomy, values for CA 15.3 had again significantly increased. Tumor size, node metastases (>or= 4) and stage of disease (>or= III), but not patient's age, were associated with higher preoperative levels. Evaluation of CA15.3 and CEA values showed sensitivities and specificities of 35.3% and 18.3% and 95.6% and 62.7%, respectively. Based on these findings we conclude that correlation with CA 15.3 was superior to CEA in terms of stage of disease, so that this is the more powerful marker for detecting lesions and determining response to treatment.