SERUM MUCIN ANTIGENS CASA AND MSA IN TUMORS OF THE BREAST, OVARY, LUNG, PANCREAS, BLADDER, COLON, AND PROSTATE - A BLIND TRIAL WITH 420 PATIENTS

Background. The tumor markers CASA (cancer-associated serum antigen) a nd MSA (mammary serum antigen) have previously been shown to be useful in the clinical management of ovarian and breast carcinoma, respectiv ely, but have not been assessed in other types of cancer. These assays were compared with carcinoembryonic antigen (CEA) and prostate-specif ic antigen (PSA) in a blind trial using sera from the Mayo Clinic-Nati onal Cancer Institute (NCI) Diagnostic Serum Bank. Methods. CASA and M SA were assessed retrospectively in a blind trial using 465 serum samp les from the Mayo Clinic-NCI Diagnostic Serum Bank representing malign ant and benign disease of the breast, ovary, lung, pancreas, bladder, colon, and prostate and age-matched and gender-matched healthy control donors. CASA, MSA, and PSA levels were determined using commercially available kits, and CEA values and clinical details were later provide d by the Mayo Clinic. Results. CASA and MSA showed good reproducibilit y in 45 duplicate samples. (ASA values were significantly elevated in the serum of patients with malignant tumors of the breast (44%), ovary (58%), lung (56%), prostate (48%), and bladder (54%), but not in thos e with benign conditions of these organs or pancreatic or colon cancer . MSA levels were only elevated significantly in cancers of the breast (52%) and ovary (58%). CASA showed significantly better sensitivity t han either CEA (20%) or MSA (25%) in the detection of lung cancer, whe reas CEA showed significantly superior detection of colon cancers (78% ). CASA was not as sensitive as PSA in prostate cancer (48% versus 96% ), but gave superior specificity in nonmalignant conditions of the pro state (93% versus 70%), although this was not statistically significan t. Conclusions. The commercial CASA and MSA assays are reliable and re producible tests for these tumor markers. In addition to ovarian cance r, CASA is also elevated significantly in many patients with breast, l ung, prostate, and bladder cancer and has potential clinical use in pa tients with these tumors. The use of the MSA assay appears restricted to breast cancer.