Phytosterols and cholesterol in malignant and benign breast tumors.

Tissue phytosterol and cholesterol levels in 10 benign and 8 malignant breast tumors were quantitated to reexamine the hypothesis that malignant tumors had distinctive phytosterol content. Phytosterols were present in 9 of 10 benign and 7 of 8 malignant breast tumors. Mean (+/- S.E.) cholesterol, campesterol, stigmasterol, and beta-sitosterol in malignant and benign tumors (microgram/g wet weight) did not significantly differ (p greater than 0.1): (formula: see text) In the malignant tumors, tissue cholesterol correlated with campesterol (r = 0.97) and beta-sitosterol (r = 0.97) (p less than 0.01), but not stigmasterol (r = -0.06). In benign tumors, tissue cholesterol correlated with campesterol (r = 0.43), stigmasterol (r = 0.64), and beta-sitosterol (r = 0.94), with p less than 0.01 for the latter two. Phytosterols were present in four samples of normal breast tissue with mean (+/- S.E.) campesterol, stigmasterol, and beta-sitosterol (2 +/- 0.8, 15 +/- 9, 7 +/- 5 microgram/g wet weight) slightly but not significantly lower than in benign and malignant breast tumors, p greater than 0.1. The comparability of tissue phytosterols in benign and malignant breast tumors and in normal breast tissue appears to render unlikely and putative etiological relationship between phytosterols and breast carcinoma.