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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #166619
Title: A PROSPECTIVE STUDY OF PLASMA TOTAL CYSTEINE AND RISK OF BREAST CANCER

Author
item ZHANG, SHUMIN - BRIGHAM & WOMEN'S HOSP
item WILLETT, WALTER - HARVARD MEDICAL SCHOOL
item SELHUB, JACOB - TUFTS-HNRCA
item MANSON, JOANN - BRIGHAM & WOMEN'S HOSP
item COLDITZ, GRAHAM - HARVARD MEDICAL SCHOOL
item HANKINSON, SUSAN - HARVARD MEDICAL SCHOOL

Submitted to: Cancer Epidemiology Biomarkers and Prevention
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2003
Publication Date: 11/1/2003
Citation: Zhang, S.M., Willett, W.C., Selhub, J., Manson, J.E., Colditz, G.A., Hankinson, S.E. 2003. A prospective study of plasma total cysteine and risk of breast cancer. Cancer Epidemiology Biomarkers and Prevention. 12:1188-1193.

Interpretive Summary: The amino acid cysteine is also part of glutathione, an important peptide that acts as an antioxidant. In the present study we measured folic acid, vitamins B12, vitamin B6, homocysteine and cysteine in blood from women who later had breast cancer. To determine if any of these measures can predict the occurrence of this cancer, we performed similar measurements in women who did not have cancer during the same period. The women who were inflicted with the breast cancer had lower cysteine levels than those women who did not have cancer. It appears that high blood concentrations of this amino acid protects against the development of a breast cancer.

Technical Abstract: Cysteine is the precursor of glutathione, a powerful intracellular antioxidant and an important detoxifying agent of carcinogens. However, data relating plasma total cysteine to breast cancer risk are sparse. We conducted a prospective nested case-control study among 32,826 women in the Nurses' Health Study who provided blood specimens during 1989-1990. Through 1996, a total of 712 incident breast cancer cases were identified and individually matched to 712 controls. We found that higher plasma total cysteine concentrations were significantly associated with a lower risk of breast cancer. For women in the highest quintile of plasma total cysteine, compared with those in the lowest quintile, the multivariate relative risk was 0.44 (95% confidence interval, 0.26-0.74). This association was dose dependent (P for trend = 0.002) and independent of plasma measures of folate, vitamin B6, vitamin B12, and total homocysteine. The inverse association between plasma total cysteine concentrations and risk of breast cancer was not significantly modified by other risk factors for breast cancer, except that a stronger association was observed among women who were leaner. The findings from this prospective study suggest that higher plasma concentrations of total cysteine predict a reduced risk of breast cancer. Cysteine or its precursors might have the potential to be chemopreventive against breast cancer.