title: Prognostic effect of menstrual cycle on timing of surgery in premenopausal breast cancer patients.
abstract: BACKGROUND
  It is controversial whether surgery during different menstrual phases (a kind of host milieu may influence biological characteristics of micrometastatic foci) affects clinical outcomes.
  
  
  METHODS
  Survival outcomes were compared between patients who underwent surgery during the follicular (cycle days 1 to 14) and luteal (days 15 to 31) phases. A range of cutoff days from day 10 to 22 was used to observe the risk trend.
  
  
  RESULTS
  The follicular phase was associated with a more favorable prognosis than the luteal phase in disease-free survival (DFS) [hazard ratio (HR) .318, 95% confidence interval (CI) .10 to .99, P = .049] and overall survival (OS) (HR .260, 95% CI .07 to .92, P = .036). Similar results were detected when the cutoff day was set at days 14, 18, and 19 in DFS and days 11, 13, and 14 in OS. A low HR flat fluctuation was observed from cutoff days 10 to 22, and the risk went up thereafter for both DFS and OS.
  
  
  CONCLUSIONS
  Surgery performed during the follicular phase provides a more favorable prognosis compared with the luteal phase.
authors.affiliation: Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Breast Surgery, Renji Hospital, Shanghai Jiaotong University, Shanghai, 200127, China.
authors.forename: Liheng
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Yin
authors.affiliation: Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China. Electronic address: followroad@163.com.
authors.forename: Wenjin
authors.initials: W
authors.lastname: Yin
authors.affiliation: Department of Breast Surgery, Renji Hospital, Shanghai Jiaotong University, Shanghai, 200127, China. Electronic address: lujjss@163.com.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Lu
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005498:Follicular Phase; D006801:Humans; D008183:Luteal Phase; D008408:Mastectomy; D015412:Mastectomy, Segmental; D008875:Middle Aged; D017697:Premenopause; D011379:Prognosis; D012189:Retrospective Studies
keywords: Breast cancer; Menstrual cycle; Prognosis; Surgery