In Korea, the incidence of breast cancer is relatively lower than in western country, but it is in increasing slope. However the mammographic patterns of Korean breast cancer patients are not well known.

The authors collected the clinical and radiologic data from new breast cancer patients between January 1992 and December 1997, and analysed the mammographic pattern.

Of the 418 patients, the age-specific incidences were 153 (37.0%) for 40 to 49 years of age, 99 (23.9%) for 30 to 39 years, 81 (19,6%) for 50 to 59 years, 55 (13.3%) for 60 to 69 years, 14 (3.3%) for over 70 years, and 12 (2.9%) for 20 to 29 years. According to the TNM staging system, there were 2 (0.6%) with stage 0, 102 (24.9%) with stage I, 147 (35.9%) with stage IIA, 72 (17.6%) with stage IIB, 85 (20.8%) with stage IIIA, 1 (0.2%) with stage IV. The non-palpable lesions were 7.5% on physical examination. According to Wolfe's classification, there were 78 (19.0%) for N1, 78 (19.0%) for PI, 133 (32.4%) for P2, and 122 (29.7%) for DY pattern. On mammography, lumps were found in 312 cases (75.8%). Among mammographic lumps, 51.9% was not clearly defined margin. The mammographic calcifications were found in 48.3% of all patients. In the distribution of calcification, 20.6% was diffuse type and 79.4% was localized type. The size of calcifications was variable in 92.9% and the shape of calcifications was amorphous pattern in 85.6%. We could not suspect cancer in 14.7% of patients on mammography, and 10.1% of patients on ultrasound examination.

We believe that these baseline mammographic data of Korean breast cancer patients may contribute to the accurate diagnosis of breast cancer, but more data will be needed.