A prospective study of plasma ascorbic acid concentrations and breast cancer (United States)

Objectives: To investigate the association between prediagnostic plasma asc orbic acid concentrations and subsequent breast cancer risk in a nested cas e-control study. Methods: Female volunteer residents of Washington County, MD, donated 14,62 5 non-fasting blood samples in 1989. Incident breast cancer cases (n = 115) and controls (n = 115) were matched by age, menopausal status at donation, and date and hour of blood donation. Results: Median ascorbic acid concentrations were similar between cases and controls (1.44 mg/dl vs. 1.39 mg/dl, p = 0.78). There was no evidence for a dose-response relationship between higher plasma ascorbic acid concentrat ions and breast cancer risk [highest vs. lowest fifths: ORadjusted = 0.90, p(trend) = 0.98). Conclusions: Findings from this prospective study do not suggest a protecti ve association between prediagnostic plasma ascorbic acid concentrations an d breast cancer risk in the subsequent 5years of follow-up.