Phytosterols and Cholesterol in Malignant and Benign Breast Tumors¹

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 β-sitosterol in malignant and benign tumors (µg/g wet weight) did not significantly differ (p > 0.1):

In the malignant tumors, tissue cholesterol correlated with campesterol (r = 0.97) and β-sitosterol (r = 0.97) (p < 0.01), but not with stigmasterol (r = −0.06). In benign tumors, tissue cholesterol correlated with campesterol (r = 0.43), stigmasterol (r = 0.64), and β-sitosterol (r = 0.94), with p < 0.01 for the latter two. Phytosterols were present in four samples of normal breast tissue with mean (±S.E.) campesterol, stigmasterol, and β-sitosterol (2 ± 0.8, 15 ± 9, 7 ± 5 µg/g wet weight) slightly but not significantly lower than in benign and malignant breast tumors, p > 0.1. The comparability of tissue phytosterols in benign and malignant breast tumors and in normal breast tissue appears to render unlikely any putative etiological relationship between phytosterols and breast carcinoma.