title: Effects on survival of menstrual cycle phase of adjuvant surgical oophorectomy in premenopausal women with breast cancer.
abstract: Adjuvant surgical oophorectomy is an effective and remarkably cost effective treatment for premenopausal women with hormone receptor positive operable breast cancer. Previously published secondary analyses indicated a survival benefit for patients whose surgery was performed in the luteal phase of the menstrual cycle as opposed to the follicular. This study utilizes additional follow-up and more fully examines this hypothesis and the general implications of long-term follow-up on trial design. Beginning in 1993 we recruited women to a multicenter randomized clinical trial of adjuvant surgical oophorectomy and tamoxifen for 5 years. We recorded the reported day 1 of the patients' last menstrual cycle on the day of their adjuvant surgery. We conducted secondary analyses of the association of history-estimated luteal or follicular phase oophorectomy surgery with disease-free and overall survival. In multivariable Cox analyses, disease-free survival (DFS) exhibited a positive trend and overall survival (OS) showed a significant improvement in patients whose surgery was estimated to have occurred in the luteal phase of the menstrual cycle compared to the follicular (HR for DFS: 0.66, 95% CI: 0.37-1.16; HR for OS: 0.49, 95% CI: 0.27-0.88). From the hazard function plots, it appears that the luteal phase surgery effect on DFS diminishes after 6 years of follow-up. In conclusion, adjuvant surgical oophorectomy during the luteal phase of the menstrual cycle resulted in a reduced hazard of recurrence as compared to oophorectomy in the follicular phase during the first 5.5 years of follow-up. The practical and biological implications of these findings deserve rigorous evaluation in clinical trials.
authors.affiliation: Comprehensive Cancer Center, The Ohio State University, B402 Starling Loving Hall, 320W. 10th Ave, Columbus, OH 43210, USA. richard.love@osumc.edu
authors.forename: Richard R
authors.initials: RR
authors.lastname: Love
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Young
authors.forename: Erinn M
authors.initials: EM
authors.lastname: Hade
authors.forename: David
authors.initials: D
authors.lastname: Jarjoura
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000401:mortality / Q000601:surgery*; D005260:Female; D005498:Follicular Phase; D006801:Humans; D053208:Kaplan-Meier Estimate; D008183:Luteal Phase; D008207:Lymphatic Metastasis; D008875:Middle Aged; D015999:Multivariate Analysis; D010052:Ovariectomy; D017697:Premenopause; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000378:metabolism
chemical_list: D011960:Receptors, Estrogen