The use of herbal preparations to alleviate climacteric disorders and risk of postmenopausal breast cancer in a German case-control study.
BACKGROUND
The use of herbal preparations (HEP) to alleviate climacteric disorders is expected to increase as women seek alternatives to menopausal hormone therapy to avoid the associated breast cancer risk. Data are sparse on the long-term effects of HEP containing phytoestrogens and black cohosh on breast cancer risk.


METHODS
Within a German case-control study, associations between patterns of HEP use and incident breast cancer were investigated in 10,121 postmenopausal women (3,464 cases, 6,657 controls). Information on HEP use was collected in face-to-face interviews supported by a list of brand names. Multivariate logistic and polytomous regression analyses were done.


RESULTS
Ever use of HEP (9.9%) was inversely associated with invasive breast cancer [odds ratio (OR), 0.74; 95% confidence interval (CI), 0.63-0.87] in a dose-dependent manner (OR, 0.96 per year of use; P = 0.03). Classes of HEP did not differ significantly (P(heterogeneity) = 0.81). Risks for invasive ductal (OR, 0.72; 95% CI, 0.60-0.87) and combined lobular/mixed/tubular tumors (OR, 0.76; 95% CI, 0.58-1.01) were similarly reduced by any HEP use but not for in situ carcinomas (1.34; 95% CI, 0.86-2.09). There were no substantial differences in associations of HEP use by estrogen receptor status (ER(+) OR, 0.74; 95% CI, 0.62-0.89; ER- OR, 0.68, 95% CI, 0.50-0.93) and progesterone receptor status of the tumor.


CONCLUSIONS
Our findings support the hypothesis that HEP use protects from invasive breast cancer in postmenopausal women. Among conceivable modes of action, those independent of estrogen receptor-mediated pathways seem to be involved (i.e., cytotoxicity, apoptosis).
Obi
Nadia
N
Institute for Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, [corrected] Germany. Nadia.Obi@uk-sh.de
Chang-Claude
Jenny
J
Berger
Jürgen
J
Braendle
Wilhelm
W
Slanger
Tracy
T
Schmidt
Martina
M
Steindorf
Karen
K
Ahrens
Wolfgang
W
Flesch-Janys
Dieter
D
D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology*; D002278:Carcinoma in Situ / Q000453:epidemiology; D018270:Carcinoma, Ductal, Breast / Q000453:epidemiology; D016022:Case-Control Studies; D002979:Climacteric / Q000187:drug effects*; D005260:Female; D005858:Germany; D006801:Humans; D008875:Middle Aged; D008517:Phytotherapy; D028321:Plant Preparations / Q000627:therapeutic use*; D017698:Postmenopause / Q000187:drug effects*; D012307:Risk Factors; D011795:Surveys and Questionnaires
D028321:Plant Preparations