ASSOZIATIONEN ZWISCHEN PFLANZLICHEN PRÄPARATEN ZUR LINDERUNG KLIMAKTERISCHER BESCHWERDEN UND DEM POSTMENOPAUSALEN BRUSTKREBSRISIKO :Datenanalyse einer populationsbezogenen Fall-Kontroll-Studie

The use of herbal preparations (HEP) to alleviate menopausal disorders tends to increase, since women seek for alternatives to menopausal hormone therapy (HT). Whether phytoestrogens and other polyphenolic substances in HEP exert a beneficial, any effect or increase the risk for breast cancer is of ongoing debate, and data on HEP use is sparse. Within a large German case-control-study, associations between patterns of use of HEP and incident breast cancer were investigated in 10121 postmenopausal women (3464 cases, 6657 controls). Information on HEP use was collected in face-to-face interviews supported by a list of brand names. Logistic and polytomous regression analysis were performed, adjusted for HT and lifestyle factors. Ever use of any HEP (9.9%) was inversely associated with invasive breast cancer (OR 0.74, 95%CI 0.62-0.87) as well as current and past use (OR 0.70, 95%CI 0.53-0.91; OR 0.75, 95%CI 0.61-0.91, respectively). Increasing duration (years) of HEP was related to risk for invasive tumours in a dose-dependant manner (0.94, 95%CI 0.93-0.98, p = 0.03). Considering histology, risk reduction of use of HEP was similar for invasive ductal (OR 0.72, 95%CI 0.60-0.87) and for combined lobular/mixed/tubular (OR 0.76, 95%CI 0.58-1.01) but not for in situ tumours (1.34, 95%CI 0.86-2.09). Regarding ER/PR status, use of HEP appeared to be slightly stronger associated with negative compared to positive status (ER/PR both neg. OR 0.66, 95%CI 0.47-0.93; ER or/and PR pos. OR 0.74, 95%CI 0.62-0.89). These results support the hypothesis, that HEP may be protective against invasive breast cancer. Among several conceivable modes of action, those independent from estrogen receptor mediated pathways seem to be involved (i.e. anti-oxidation and apoptosis).