Selenium levels in neoplastic breast lesions

The aim of this prospective case controlled study was to evaluate the tissue levels of selenium in patients with cases of fibroadenoma, cancer of the breast and in the controls in order to relate them to the occurrence of breast diseases.

Consecutive consenting patients who had histologically confirmed breast cancer and fibroadenoma attending the General surgical outpatients departments of Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, were recruited for the study. One gram of core disease breast tissues was taken for Selenium level estimation.

There were 127 female subjects;. 95 (74.8%) cases of fibroadenoma and 32 (25.2%) of breast cancer. While breast cancer was common on the left, fibroadenoma was more common on the right breast (? = 8.994; p=0.011). The median tissue level of selenium in patients with fibroadenoma was 0.0272 mg/g with a range of 0.0124 to 0.0576 mg/g and that of the cancer patients was 0.0178 mg/g with a range 0.0072 to 0.0436 mg/g. These were statistically significantly different ( p=0.001). Factors affecting tissue selenium level include age (p<0.001), overall stage of breast cancer (p<0.001), maximum length of breast mass (p=0.023), previous delivery (p=0.004), age at last confinement (p=0.007), parity (p<0.001), oestrogen receptor (ER) status (p<0.001) and progesterone receptor (PR) status (p=0.021).

Tissue selenium was lower in breast cancer than in fibroadenoma; Tissue selenium inhibits carcinogenesis; low tissue level of selenium therefore may be a factor in the development of breast cancer.