title: Isopropanolic black cohosh extract and recurrence-free survival after breast cancer.
abstract: OBJECTIVE
  To investigate the influence of an isopropanolic Cimicifuga racemosa extract (iCR) on recurrence-free survival after breast cancer, including estrogen-dependent tumors.
  
  
  METHODS
  This pharmacoepidemiologic observational retrospective cohort study examined breast cancer patients treated at general, gynecological and internal facilities linked to a medical database in Germany. The main endpoint was disease-free survival following a diagnosis of breast cancer. The impact of treatment with iCR following diagnosis was analyzed by Cox-proportional hazards models, controlling for age and other confounders.
  
  
  RESULTS
  Of 18,861 patients, a total of 1,102 had received an iCR therapy. The mean overall observation time was 3.6 years. Results showed that iCR was not associated with an increase in the risk of recurrence but associated with prolonged disease-free survival. After 2 years following initial diagnosis, 14% of the control group had developed a recurrence, while the iCR group reached this proportion after 6.5 years. The primary Cox regression model controlling for age, tamoxifen use and other confounders demonstrated a protractive effect of iCR on the rate of recurrence (hazard ratio 0.83, 95% confidence interval 0.69 0.99). This effect remained consistent throughout all variations of the statistical model, including subgroup analyses. TNM status was unknown but did not bias the iCR treatment decision as investigated separately. Hence, it was assumed to be equally distributed between treatment groups. Correlation analyses showed good internal and external validity of the database.
  
  
  CONCLUSIONS
  An increase in the risk of breast cancer recurrence for women having had iCR treatment, compared to women not treated with iCR is unlikely.
authors.affiliation: Schaper & Brümmer GmbH & Co. KG, Salzgitter.
authors.forename: H H
authors.initials: HH
authors.lastname: Henneicke-von Zepelin
authors.forename: H
authors.initials: H
authors.lastname: Meden
authors.forename: K
authors.initials: K
authors.lastname: Kostev
authors.forename: D
authors.initials: D
authors.lastname: Schröder-Bernhardi
authors.forename: U
authors.initials: U
authors.lastname: Stammwitz
authors.forename: H
authors.initials: H
authors.lastname: Becher
mesh_terms: D019840:2-Propanol / Q000737:chemistry; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology; D031885:Cimicifuga / Q000737:chemistry*; D015331:Cohort Studies; D018572:Disease-Free Survival; D004965:Estrogen Antagonists / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008875:Middle Aged; D010936:Plant Extracts / Q000627:therapeutic use; D012997:Solvents / Q000737:chemistry; D013629:Tamoxifen / Q000627:therapeutic use
chemical_list: D018931:Antineoplastic Agents, Hormonal; D004965:Estrogen Antagonists; D010936:Plant Extracts; D012997:Solvents; D013629:Tamoxifen; D019840:2-Propanol