Some creams may be risky in breast cancer patients

Skin moisturizers marketed as "youth enhancing" may contain estrogens, and daily use of products with such ingredients could pose a theoretical risk to women with breast cancer, particularly those with estrogen receptor-positive cancers who are taking aromatase inhibitors, according to research published online August 3 in the Journal of Clinical Oncology.

Adrienne C. Olson, of Breastlink in Rancho Palos Verdes, CA, and colleagues write in a correspondence piece that they suspected estrogenically active substances in the skin moisturizer of a patient with estrogen receptor-positive breast cancer. They sent samples of 16 moisturizers advertised as "rejuvenating" or "youth enhancing" to a lab for testing for estradiol, estriol, and estrone.

The researchers found that four of the samples contained more than 0.40% estriol, and one contained 0.17%. Another sample contained 0.05% estrone. By comparison, Estrace vaginal cream contains 0.01% estradiol.

Olson AC, Link JS, Waisman JR, et al. Breast cancer patients unknowingly dosing themselves with estrogen by using topical moisturizers. J Clin Oncol. Early Release, published online ahead of print August 3, 2009. doi:10.1200/JCO.2009.23.1225.