The significance of serum CA 125 elevation in malignant and nonmalignant diseases

The aims of the study were to investigate whether an elevated CA 125 level signals malignancies other than ovarian cancer and to find the cause of death for 247 women with elevated values among the 5550 women screened in 1986-1988 in the Stockholm population.

The Swedish Regional Cancer Registry delivered malignancy diagnoses among the 5550 women screened. The Cause of Death Registry gave the cause of death among the women with elevated CA 125 values.

Patients with ovarian cancer were excluded. In 44 women with elevated CA 125 values other malignancies were reported to the Cancer Registry. They represent 18% of the entire group with elevated values. Among the 5297 women with normal CA 125 values 13% developed various malignancies. The difference between incidence of malignant disease in women with elevated values and women with normal values is significant, P = 0.02. Especially during the test-related period, from 1 year before to 1 year after the test, malignancies were detected in 6.9% of the population with elevated values and in only 1.6% with normal values (P = < 0.001). Breast cancer and lung cancer were overrepresented among women with elevated CA 125 values (P = 0.015 and < 0.001, respectively). Of the total 5500 women screened, 358 women died with different diagnoses. Elevated CA 125 values had been noted earlier in 25 women, and of these 20 died of malignant diseases, predominantly ovarian, breast, and lung cancer.

Asymptomatic postmenopausal women with elevated CA 125 levels in ovarian carcinoma screening trials should, if ovarian cancer is excluded, be investigated for possible breast or lung cancer. The findings also suggest that elevated CA 125 level is a risk factor for death from malignant disease.