A new study has reported that breast cancer patients have higher levels of cadmium in their breast tissues and urine than women with benign breast tumors. The study included 57 breast cancer patients and 51 benign tumor patients among whom cadmium levels were determined in breast tissue, urine, and blood. Two samples of breast tissue from each patient — tumor tissue and healthy tissue — were analyzed.
Cadmium content in malignant tissue was found to differ significantly from that in benign tumor tissue. The average cadmium level in the tumor tissue of the breast cancer patients was 0.053 mug/g, whereas it was 0.037 mug/g in the benign tumor patients. Cancer patients with estrogen receptor positive (ER+) disease had significantly higher levels of cadmium in their breast tissue compared with patients with negative estrogen receptors (ER-). Cadmium levels were also found to be significantly higher in the urine of breast cancer patients than in women with benign tumors. The association between urinary levels of cadmium in breast cancer patients and lifetime number of cigarettes smoked was suggestive, but not statistically significant. The authors conclude that the finding of higher concentrations of cadmium in the breast tumors and urine of breast cancer patients support a possible relationship between cadmium exposure and breast cancer.