Prognostic factors for recurrence and cosmesis in 393 patients after radiation therapy for early mammary carcinoma.

Abstract

Between 1978 and 1985, 393 of 2,765 (14%) patients with operable cancer of the breast (clinical stage T0-3N0-2M0) were irradiated after excisional biopsy and staging axillary dissection. Of 77 patients with microscopic axillary metastases, 68 received systemic adjuvant therapy. Treatment failed locally in 26 cases, and there were seven patients with distant metastasis. The three major factors for increased local treatment failure were (a) age below 40 years (P = .003), (b) negative estrogen receptor assay result (P = .03), and (c) failure to deliver a radiation boost dose when tumor was present at the margin of the specimen (P = .002). The size of the tumor, the nodal status, the progesterone receptor assay result, and the presence of ductal carcinoma in situ mixed with infiltrating carcinoma did not show a significant influence on local recurrence. In 274 of 393 (70%) patients, cosmesis was evaluated. The four major factors affecting cosmesis favorably were (a) utilization of a wedge (P less than .0001); (b) treatment of two fields a day (P less than .0001); (c) failure to use a separate treatment port to the regional lymph nodes, so as to avoid field junctions (P = .0003); and (d) small size of specimen (less than 50 cm2) (P = .0171). A second or third cancer was found in 39 of the 393 (10%) patients; contralateral breast cancer was the most common form (n = 23), followed by genitourinary cancer (n = 5). The most frequent complication was arm edema (6%).

Improving local control with breast‐conserving therapy

“…The most common indication for using a boost during that period was the presence of close, positive, or unknown margins, as has been reported by other studies. 45,46 The use of a boost had no effect on IBTR-free survival rates in multivariate analyses. However, our study is limited because of its retrospective nature and its small sample size compared with the sample size of a prospective trial reported by Romestaing et al 48 Because Romestaing's randomized trial showed a benefit in improving local control, our contemporary approach changed to use a boost routinely in every patient undergoing breast conservation after 1997.…”

“…Some studies, including NSABP B-06, have reported excellent results without the boost for patients with negative margins after BCS. 1,[45][46][47] However, a prospective randomized trial 48 of patients with negative margins showed that the addition of a boost dose to whole-breast irradiation resulted in a 20% reduction in the local recurrence rate at 5 years (4.5% for the no-boost group vs 3.6% for the boost group, P ϭ 0.044). In the study reported here, use of a radiation boost significantly declined for patients treated from 1994 to 1996.…”

Positive margins of breast biopsy: Is reexcision always necessary?

“…Ideally, breastconserving surgery requires excision of all gross tumor and subsequent radiation therapy to ensure sufficient local control [1,2]. However, the extent of surgical resection beyond gross excision, and specifically the importance of microscopically negative margins, remains unclear [3][4][5]. It is generally accepted that the presence of microscopically positive margins requires reexcision [4].…”

Techniques of tumour bed boost irradiation in breast conserving therapy: Current evidence and suggested guidelines

“…To overcome the adverse effects of positive margins on overall outcome of the patients many radiation oncologists have escalated the boost dose to increase total dose to tumour bed [14,56,58,60]. Although in all these studies, patients with positive margins underwent re-excision or revision surgery, the boost doses to tumour bed were escalated to 20 Gy.…”

“…Total radiation dose to affected breast and tumour bed is proportionately related to relapse free survival [40,41,56,61]. Other factors which significantly influence disease free survival are administration of chemotherapy and hormonal therapy.…”