Abstract

Velaiutham S, Nuraishah MT, Yip CH
Department of Surgery, University of Malaya Medical Centre, Kuala Lumpur

CA 15-3 is the most well known and widely used tumour marker in Malaysia. This test is easily done and available at most primary care units and hospitals in Malaysia. Current data are insufficient to recommend its use as a screening and diagnostic tool, however this test is still being indiscriminately prescribed. Our objective is to correct positivity rates of CA 15-3 with breast cancer patients in different stages of tumour. From this analysis we hope to postulate and confirm that CA 15-3 is indeed an ineffective screening tool among Malaysian women.

A retrospective review was carried out in all breast cancer patients presenting to University of Malaya Medical Centre from January 1999 to October 2003. Analysis was limited to 322 women ( median age 48 years, range 26-83 years ) who had CA 15-3 levels taken pre-operatively or two weeks post-operatively. 72 patients ( 22.4% ) had Stage 1 disease, 139 ( 43.2% ) Stage 2 disease, with 60 ( 18.6% ) and 51 ( 15.8% ) women with Stage 3 and Stage 4 disease respectively.

No patients with Stage 0 and Stage 1 disease had elevated CA 15-3 levels ( 0%, n=0 ). Elevated CA 15-3 levels were detected in merely 8% of patients with Stage 2 disease while it was seen in 36.7% of patients with Stage 3 disease and 68.6% of patients with Stage 4 disease. Only 21% ( n=68 ) of the 322 patients with breast cancer had elevated CA 15-3 levels with 16.2% ( n=11 ) with Stage 2 disease, 32.3% (n = 22) with Stage 3 disease and 51.5% ( n = 35 ) with Stage 4 disease. While comparing CA 15-3 with tumour size, 0% ( n=0 ) have DCIS lesions, 1.4% ( n=1 ) with pT1 tumour, 16.2% (n=11) pT2, 7.4% ( n=5 ) pT3 and 75% ( n= 51 ) pT4.

Results show a significant relationship between CA 15-3 levels with clinical stage and tumour size, with levels higher in patients with locally more advanced tumour and of higher stage. The low incidence of CA 15-3 elevation in early-stage cancer indicates that it cannot be used in screening or diagnosis.