title: Hazard rates of recurrence following diagnosis of primary breast cancer.
abstract: We calculated hazard rates for recurrence in patients with primary breast cancer (stage I, II; no adjuvant therapy). Previous publications have indicated a peak in hazard rates for recurrence (or death) at approximately 2-3 years after diagnosis of primary breast cancer. However, there have been conflicting reports concerning the presence of a second peak at 5-7 years after diagnosis. In this study, we estimated hazard functions by the Nelson-Aalen method and fit by cubic-linear and cubic-cubic-linear models to test for the presence of one or two peaks, respectively. We identified two peaks in hazard of recurrence, one at 2 years and another at 5 years. The 5-year peak, though statistically significant, represents very small differences in patient outcome. This additional peak may be an artifact of interval censoring due to a tendency to follow-up patients at specific bench-mark time points.
authors.affiliation: Department of Surgery, National Medical Center and the Uniformed Services University, 4301 Jones Bridge Rd, Bethesda, Maryland 20814, USA. ismail.jatoi@us.army.mil
authors.forename: Ismail
authors.initials: I
authors.lastname: Jatoi
authors.forename: Anna
authors.initials: A
authors.lastname: Tsimelzon
authors.forename: Heidi
authors.initials: H
authors.lastname: Weiss
authors.forename: Gary M
authors.initials: GM
authors.lastname: Clark
authors.forename: Susan G
authors.initials: SG
authors.lastname: Hilsenbeck
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D009367:Neoplasm Staging; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D013997:Time Factors