Avoidance of adjuvant radiotherapy in selected patients with invasive breast cancer.

Abstract

Current standard therapy for invasive breast carcinoma is mastectomy or breast conservation with adjuvant radiation. Data from randomized trials suggest no advantage for radiotherapy after lumpectomy in highly selected patients. Selective radiotherapy would make contemporary breast cancer therapy more rational with decreased morbidity and expense. A total of 163 patients were treated by breast conservation without adjuvant radiation between 1978 and June 2003. They declined radiation after discussion or had medical contraindications. The great majority were postmenopausal and had lower-grade T1 tumors with resection margins > or = 1 cm and no nodal metastases. The goal was to identify patients with favorable prognostic features for omission of postsurgical irradiation without impaired local recurrence or survival. Twenty patients (12%) had local recurrences; 17 (10%) were invasive, and 3 (2%) were ductal carcinoma-in-situ. An ideal patient subgroup >50 years of age with grade 1 or 2 cancers < or =1.5 cm in diameter and with surgical margins > or = 1 cm was empirically defined. Of 80 such patients, 5 (6%) had local recurrence; 3 (3.5%) were invasive, and 2 (2.5%) were ductal carcinoma-in-situ. A defined ideal subset of older breast cancer patients with smaller, lower-grade cancers and adequate excision margins can be treated with lumpectomy without irradiation and with minimal local recurrence.