유방암 수술 후 호르몬 수용체와 나이에 따른 재발 위험률에 대한 연구

Abstract

Purpose: Breast cancer can recur many years after treatment. Most studies have focused on survival rate and survival curves. We estimated hazard rates for recurrence to evaluate the risk of recurrence at a given time and how to recurrence changes over time according to hormone receptor status and patient age. Methods: We retrospectively reviewed the medical records of 6,308 patients with stage 1 to 3 breast cancer who received breast cancer operation from 1995 to 2010. Hazard rates were estimated by using Proc Lifetest. Patients were grouped according to estrogen receptor (ER) status; ER(+) (n=4,589), ER(-) (n=1,719) and age; less than 39 years (n=1,192), 40 to 59 years (n=4,250), more than 60 years (n=866). Results: Median follow-up period was 60 months. Estimated 5-year and 10-year recurrence rate were 11.2% and 19.5% in overall cohort. Estimated 5-year and 10-year recurrence rate were 10.6% and 18.4% in ER(+) patients, and 16.6% and 18.4% in ER(-) patients. Hazard of recurrence (HR) was highest in 2 to 3 years after surgery in overall cohort. ER(-) patients showed steep pattern of HR, while ER(+) patient showed steady pattern of HR. Five years after surgery, HR was higher in ER(+) patients than ER(-) patients. Younger patients showed higher HR than older patients regardless of ER status and stage. Conclusion: Our study proved that ER(-) patients showed high recurrence rate in early postoperative stage, however, in late postoperative stage, ER(-) patient showed lower recurrence rate than ER(+) patient. Young patients should be carefully observed because of high and long standing HR especially in ER(+) patients.