A high value of
mucin-like carcinoma associated antigen (MCA), CA-15.3 or H23, in a woman known to have a diagnosis of
breast cancer, may reflect presence of disease. A low level in a
breast cancer patient may be accepted for remission, but a false negative result cannot be excluded. On the other hand, a low level of serum
tumor marker in the general population actually lacks any significance. However, what is the meaning of an elevated level of marker, known to have a relatively high sensitivity and specificity, in an otherwise healthy woman? Does it mean an occult
breast cancer or a false positive? Sera samples were obtained from 155 consecutive, otherwise healthy women, who were referred for mammography, and assayed for
tumor markers. MCA was elevated in 15-24% of patients with normal mammogram, depending on their ages. Lack of elevation of a second marker in most of the cases supported the assumption that the elevation of the MCA was insignificant. Elevation of H23 occurred more frequently in younger women than in the elders, but was not associated with elevation of a second marker. In the cases with abnormal mammogram due to histologically proven benign disorders, serum
tumor markers were generally within the normal ranges. Our results pointed to the lack of diagnostic significance of an elevated level of serum
tumor marker, as far as the mammogram was normal or benign, there was no history of
cancer nor any other systemic disease (including
malignancy), and a second
tumor marker was within the normal range. The women with presently false positive marker level may, however, be followed, because of the possible risk for future development of
breast cancer.