Role of radiotherapy in sarcoma of the breast - a retrospective review of the M.D. Anderson experience

Background: The role of adjuvant radiotherapy for sarcoma of the breast, ba sed on local extension of disease and patterns of failure, remains undefine d because of the rarity of the disease presentation. Methods: Fifty-nine cases of soft tissue sarcoma of the breast were retrosp ectively reviewed. Cystosarcoma phylloides was excluded from analysis. Surg ical intervention consisted of segmental resection (n = 16) or mastectomy ( n = 38); five patients underwent excisional biopsy. Adjuvant radiotherapy w as administered in four patients following segmental resection and in 13 pa tients after mastectomy, Doses totaled 50 Gy in the majority of patients, a nd conventional criteria and radiotherapy techniques for adjuvant breast ir radiation were used. Results: None of the dissected axillary nodes contained metastatic tumor on pathologic review. Patterns of failure were evaluated. Tumor size (P < 0.0 3) and surgical margins (P < 0.002) were predictive of local failure (LF). Due to limited patient numbers, no statistical significance was identified with any treatment modality. Following mastectomy alone, LF occurred in 13 patients (34%) versus the 13% rate of LF with mastectomy and radiotherapy ( P = NS), Distant metastases developed concurrently with the two local failu res in the group that underwent mastectomy and radiation, After segmental m astectomy, LF occurred in 3 cases (25%) concurrent with distant metastases; no LF were noted after segmental mastectomy and radiation (P = 0.27), For all treatment groups, local recurrences were characterized as multiple and involved the chest wall. Local failure occurred in 60% of patients with pos itive surgical margins who did not receive adjuvant irradiation. Irrespecti ve of surgical margins, over 75% of local recurrences developed among patie nts treated by surgery alone. Conclusions: The role of radiotherapy for breast sarcoma remains undefined due to the rarity of this disease presentation. This retrospective review f ailed to demonstrate a statistical benefit for the administration of adjuva nt irradiation in sarcoma of the breast, probably because of limited patien t numbers. Because large tumor size and positive surgical margins incur a h igher risk for LF, radiotherapy is probably indicated in these cases. Axill ary dissection obligates the radiotherapist to treat the axilla in order to include all tissues in the surgical bed, and should be avoided to reduce p otential treatment related morbidity. Established therapeutic principles an d techniques used for both soft tissue sarcoma and breast cancer should con tinue to be applied. (C) 1999 Elsevier Science Ireland Ltd. All rights rese rved.