Clinical characteristics of breast cancer patients in Korea in 2000

HYPOTHESIS: Breast cancer in Korea continues to rise year by year, and its clinical features will become closer to those now observed in Western countries. DESIGN: Nationwide multicenter survey of the Korean Breast Cancer Society in 2000. PARTICIPANTS: A total of 5401 patients (median age, 46 years) with newly diagnosed breast cancer who underwent surgery at 38 university and 45 surgical training hospitals. MAIN OUTCOME MEASURES: All participating hospitals provided the essential data, including sex, age, the surgical method used, and the American Joint Committee on Cancer classification to determine the clinical characteristics of breast cancer and to compare the results with those of previous surveys conducted in 1996 and 1998 to obtain an epidemiological pattern of breast cancer in Korea. RESULTS: An estimated crude incidence was 23/100 000 patients. Premenopausal women younger than 50 years constituted 61.2%. Of the study population, 71.5%underwent mastectomy; 27.1%, breast-conserving surgery; and 1.4%, other surgical treatments. In all, 52.8% were diagnosed as having stage II disease (American Joint Committee on Cancer classification), and the proportion of early cancer (stages 0 and I) was 31.5%. Comparisons with 1996 and 1998 results indicated that the number of patients with breast cancer is increasing. Mastectomies occurred less frequently and breast-conserving surgery more frequently (P<.001), and we noted an increase in the proportion of early cancer (P<.001). The number of patients with risk factors such as early menarche (P =.003), late menopause (P =.01), a high-fat diet (P =.048), and familial history of breast cancer (P =.046) was also found to have significantly increased. CONCLUSIONS: Although our epidemiological survey was limited in terms of its duration, our findings suggest that the incidence of breast cancer in Korea will continue to rise and that the clinical features will become closer to those now observed in Western countries.