Breast-conserving surgery and tumour bed positivity in patients with breast cancer.

Between March 1988 and April 1992, in 264 patients undergoing breast-conserving surgery for stage I and II cancer, the tumour bed was analysed for residual disease. After a conventional breast-conserving operation the entire wall of the cavity from which the lumpectomy specimen had been taken was excised. This was involved with disease in 38 per cent of patients. Additional random biopsies of the secondary cavity were performed in 130 patients and were involved with disease in 13 per cent. Residual disease was detected in the tumour bed of 37 per cent of patients with screen-detected tumours.