INTRODUCTION– Breast cancer (BC) was the most common cancer in women (23% of all new cases in women). In India, Breast cancer is the second most common cancer after carcinoma cervix. CA15.3 is an established tumour marker for the breast cancer. It has the value in early diagnosis in recurrence of breast cancer. CA 15.3 is a better Tumour Marker than CEA and Tissue Polypeptide Antigen (TPA) as it has greater sensitivity than CEA and higher specificity than TPA.

MATERIALS AND METHOD– A prospective cross sectional study was done in 64 individuals from Pt.  JNM medical college and associated Bhim Rao Ambedkar Hospital  Raipur (C.G.) India. 32 females with histologically diagnosed breast cancer were taken as subjects and 32 healthy individuals with no diagnosed cancer or family history of cancer were taken as control in this study. The institutional ethics committee approved the study and all study participants gave informed written consent before participating in the study. After consent 3 ml blood samples were collected for serum CA 15–3 quantification in a plain tube. CA 15–3 serum level were quantified by two step sequential chemiluminescent immunometric assay with 0.2 U/ml as the lower limit of sensitivity.

RESULTS–The mean age in of the case was 45.9+8.7 years and in case of controls it was 44.9+9.11years. Mean value of the Tumour marker CA15.3 was 133.32+ 73.20 (Mean + SD) U/ml among the breast cancer cases and 16.2 + 8.26 (Mean + SD) U/ml. Serum CA15.3 was significantly higher in patients of the breast cancer than that of the healthy individuals and was statistically extremely significant as the P value was < 0.0001. Out of 32 cases in the study, the maximum number of cases was of Invasive Ductal carcinoma (28 out of 32=87.5%). Medullary carcinoma constitutes 6.25% of the total cases (2 out of 32).92.85% of the total invasive ductal carcinoma had serum CA15.3 level above reference value while 7.15% had below the reference value.

CONCLUSION– CA 15.3 is cost effective & reliable method in diagnosis & prognosis of Breast cancer.