Bilateral Breast Cancer

ABSTRACT

Bilateral breast cancer is not a common clinical problem, and its occurance is not suprising in this paired organ. Bilateral breast cancer is categorized as synchronous or metachronous. We propose to evaluate clinical and biological characteristics in bilateral breast cancer. Previous cancer in one breast is the strongest known risk factor for cancer to develop in the second breast, and a young age at dignosis of a breast cancer and lobular type of tumor are additional risk factors related to bilaterality. Seventeen cases of bilateral breast cancer have been admitted to the department of General surgery, Samsung Cheil general Hospital from 1980 till 1995. We report the analysis of these cases with the references. The incidence of bilateral breast cancer among all case of total breast cancer was 2.1%(17/827). Synchronous breast cancer was 3 cases(0.4%) and metachronous breast cancer was 14cases (1.7%). The median age was 41 years. The mean age at diagnosis of the primary tumor in the metachronous group was 40 years. Among metachronous cases, the mean interval between the treatment of the primary cancer and the detection of secondary cancer was 37months. The clinical stage was 0-I in 12%, II in 50%, III in 32%, and IV in 6% of tumors. The majority of patients (88%) were clinically node positive. Out of a total of 34 tumors, the clinical tumor size Tis-T1 in 8 tumors, T2 in 21 tumors, and T3 in 5 tumors. Histopathologic type of the pimary tumor was the same with the second in 70%(12/17). The location of secondary breast cancer was in the upper outer quadrant in 9 cases, and in the upper medial quadrant of breast in 2 cases. The premenopausal primary cancer was in 50% of the patients, and postmenopausal primary cancer was in 50% of patients for whom this information was available. Median survival period was 57 months, and 5 year survival rate was 80%. Bilateral breast cancers have similar biological features to unilateral breast cancer more freqently than would be predicted by chance alone. The similarity in clinical aspects of unilateral and bilateral breast cancers should be considered in clinical management of patients with breast cancer. Further investigation is required to know these similaritics and differences between unilateral and bilateral breast cancer.