title: Effectiveness of adjuvant tamoxifen therapy among older women with early stage breast cancer.
abstract: To investigate the effectiveness of adjuvant tamoxifen in older women with early-stage breast cancer. Between 1997 and 1999, women > or = 65 years old at diagnosis with stage I-IIIa breast cancer were recruited from four geographic regions of the United States and followed prospectively for 5 years after diagnosis. Data sources included tumor registries, medical records review, and telephone interviews. The primary end points were breast cancer-specific and overall survival ascertained by matching identifying data with the National Death Index and Social Security Administration master death file. Tamoxifen prescription was operationalized as tamoxifen prescribed by 6 months after diagnosis. Survival analysis was undertaken using Kaplan-Meier curves and Cox proportional hazards modeling. We studied 689 women whose average age was 74.2 years at diagnosis (SD = 6.3, range 65-96 years). The median follow-up was 67 months (range 3.5-88 months). Of the 689 patients, 519 (76%) were prescribed tamoxifen. The 5-year breast cancer-specific survival was 93% (95% CI = 90-95) and 89% (95% CI = 83-94) for the ever tamoxifen and never tamoxifen groups, respectively. The ratio of adjusted breast cancer mortality hazards was 0.61 (95% CI = 0.31-1.12) for the ever tamoxifen group versus the never tamoxifen group. Similarly, the 5-year overall survival was 81% (95% CI = 76-85) and 70% (95% CI = 61-78) for the ever tamoxifen and never tamoxifen groups, respectively, with an adjusted hazard ratio of 0.53 (95% CI = 0.37-0.77). Adjuvant tamoxifen is associated with improvement in 5-year breast cancer-specific and overall survival in older women with early-stage breast cancer.
authors.affiliation: Division of Hematology and Oncology, Department of Medicine, Case Western Reserve University Cleveland, Ohio, USA. cynthia.owusu@case.edu
authors.forename: Cynthia
authors.initials: C
authors.lastname: Owusu
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Lash
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Silliman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D002423:Cause of Death; D017024:Chemotherapy, Adjuvant; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013629:Tamoxifen / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen