Re-excision of margins before breast radiation-diagnostic or therapeutic?
OBJECTIVE
To identify factors in breast cancer patients that predict the pathologic results of re-excision for close or positive margins and to determine the effect on local control.


METHODS
We divided 1,044 patients with Stage I-II breast cancer with a close (< or =2 mm) or positive margin after initial excision into three groups. Group 1 included 199 patients without additional excision, Group 2 included 546 patients with re-excision found to be free of cancer, and Group 3 included 299 patients with re-excision and residual cancer. All patients were treated with radiotherapy with a median follow-up of 6.7 years.


RESULTS
The 10-year local control rate was 95% for Group 1 and 94% for Groups 2 and 3 (p = 0.788). Of the 846 patients, 65% had no residual disease on re-excision and 35% did have residual tumor. The factors significantly associated with positive re-excision findings were initial positive margins, positive nodes, Stage T2 tumor, and an extensive intraductal component. The 10-year local control rate was 95% for Group 2 vs. 91% for Group 3 (p = 0.038).


CONCLUSIONS
The low recurrence rates seen in this study suggest that selected patients with non-negative margins, particularly those with a low risk of having residual disease at re-excision, may be treated with radiotherapy.
Chism
Derek B
DB
Department of Radiation Oncology, North Shore Medical Center, Peabody, MA, USA.
Freedman
Gary M
GM
Li
Tianyu
T
Anderson
Penny R
PR
D000328:Adult; D000368:Aged; D001706:Biopsy; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D016009:Chi-Square Distribution; D003131:Combined Modality Therapy / Q000379:methods; D005260:Female; D006801:Humans; D016015:Logistic Models; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018365:Neoplasm, Residual; D012086:Reoperation