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, based on local extension of disease and patterns of failure, remains undefined because of the rarity of the disease presentation. Methods: Fifty-nine cases of soft tissue sarcoma of the breast were retrospectively reviewed. Cystosarcoma phylloides was excluded from analysis. Surgical intervention consisted of segmental resection (n = 16) or mastectomy (n = 38); five patients underwent excisional biopsy. Adjuvant radiotherapy was administered in four patients following segmental resection and in 13 patients after mastectomy, Doses totaled 50 Gy in the majority of patients, and conventional criteria and radiotherapy techniques for adjuvant breast irradiation were used. Results: None of the dissected axillary nodes contained metastatic tumor on pathologic review. Patterns of failure were evaluated. Tumor size (P < 0.03) 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 failures in the group that underwent mastectomy and radiation, After segmental mastectomy, 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 positive surgical margins who did not receive adjuvant irradiation. Irrespective of surgical margins, over 75% of local recurrences developed among patients 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 failed to demonstrate a statistical benefit for the administration of adjuvant irradiation in sarcoma of the breast, probably because of limited patient numbers. Because large tumor size and positive surgical margins incur a higher risk for LF, radiotherapy is probably indicated in these cases. Axillary dissection obligates the radiotherapist to treat the axilla in order to include all tissues in the surgical bed, and should be avoided to reduce potential treatment related morbidity. Established therapeutic principles and techniques used for both soft tissue sarcoma and breast cancer should continue to be applied. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.