Bilateral primary breast cancers: a clinicopathological study of the second primary.

Out of 2238 patients with breast cancer 35 developed carcinoma of the contralateral breast. Thirty-three developed metachronous tumours while two developed synchronous tumours. The thirty-five patients were followed up for periods between 4-8 years. The majority of patients belonged to the fourth decade and the peak incidence of developing a metachronous tumour occurred three to five years after diagnosis of the first primary. T2 lesions were the most frequent initial primaries and N1 lesions were commoner than N2. IDC was the commonest histopathological subtype. The overall two-year survival rate was 57.1% (20/35).