Increased serum CA-15.3 levels in patients with megaloblastic anemia due to vitamin B12 deficiency

Objectives: To estimate the usefulness of serum tumor markers' monitoring, as predictors of gastric cancer in patients with pernicious anemia. Patients and Methods: We investigated serum levels of carcinoembryonic antigen (CEA), alpha-fetal protein, cancer antigen (CA)-19.9, CA-125 and CA-15.3 in 50 patients with pernicious anemia and in 24 healthy controls, matched for age and sex. In 38 patients, the evaluation was repeated 1 - 6 months after the correction of cobalamin deficiency. Results: All patients and controls had normal serum CEA and alpha-FP, and the levels of these markers as well as those of CA-125 and CA-19.9 did not differ between the two groups. All 50 patients, but only 2 controls exhibited increased serum CA-15.3, and the difference between the two groups was very significant (129.4 +/- 84.9 vs. 19.8 +/- 7.3 IU/ml, p < 0.001), while no difference between males and females was found. A thorough clinical examination of all patients, and mammographic study in 18 females did not reveal any finding suspicious of breast cancer. CA-15.3 levels were positively correlated with serum lactate dehydrogenase, and negatively with B-12 and hemoglobin, but they were substantially decreased after the correction of anemia, in all 38 patients tested, and in 33 of them they were restored to normal. After a median follow-up of 34 months, one patient developed a colon cancer, but none showed any sign suspicious of breast cancer. Conclusions: Serum CA-15.3 shows an aberrant increase in untreated patients with pernicious anemia, which is reversed after the correction of the anemia. The possible origin seems unrelated to mammary tissue, and may be released by the apoptosing bone marrow megaloblastic erythroblasts. Copyright (C) 2004 S. Karger AG, Basel.