Influence of concurrent anastrozole on acute and late side effects of whole breast radiotherapy.

OBJECTIVES: To retrospectively compare radiation toxicity in patients treated with concurrent anastrozole and whole breast irradiation versus women treated sequentially with whole breast irradiation followed by hormonal suppression. METHODS: The records of 249 consecutive estrogen or progesterone receptor positive breast cancer patients treated with breast-conserving surgery and postoperative whole breast irradiation were reviewed. Of total, 57 patients (the concurrent anastrozole group) received concurrent anastrozole prior to and during radiotherapy. In 126 patients (the sequential group), adjuvant hormone suppression therapy (anastrozole, other aromatase inhibitors, or tamoxifen) was administered after the completion of breast irradiation. In 66, women either concurrent tamoxifen was given with radiation or the sequence of hormonal therapy was not known. These women were excluded from the analysis. RESULTS: The frequency of acute grade 2 radiation dermatitis (24.6% in the concurrent anastrozole group vs. 20.6% in the sequential group; P = 0.55), grade 3 radiation dermatitis (8.8% vs. 7.1%; P = 0.77) and treatment interruptions due to skin reactions (14.0% vs. 11.2%; P = 0.69) did not differ between groups. The rates of clinically detectable breast fibrosis were not different (24.2% vs. 24.7%; P = 0.97). With a median follow-up of 28 months and 30.8 months, respectively, 1 local failure occurred in the concurrent anastrozole group and 5 in the sequential group. CONCLUSIONS: Anastrozole, administered concurrently with whole breast irradiation, did not increase acute or late morbidity when compared with sequential administration of radiation and hormonal suppression therapy.

Reduction in radiation-induced morbidity by use of an intercurrent boost in the management of early-stage breast cancer.

PURPOSE: Electron or photon boost immediately following whole-breast irradiation performed after conservation surgery for early-stage breast cancer is the accepted standard of care. This regimen frequently results in Grade III dermatitis, causing discomfort or treatment interruption. Herein, we compare patients treated with whole-breast irradiation followed by boost compared with a cohort with a planned intercurrent radiation boost. METHODS AND MATERIALS: The records of 650 consecutive breast cancer patients treated at Allegheny General Hospital (AGH) between 2000 and 2008 were reviewed. Selected for this study were 327 patients with T1 or T2 tumors treated with external beam radiotherapy postlumpectomy. One hundred and sixty-nine patients were treated by whole-breast radiotherapy (WBRT) followed by boost at completion. One hundred fifty-eight were treated with a planned intercurrent boost (delivered following 3,600 cGy WBRT). The mean whole breast radiation dose in the conventionally treated group was 5,032 cGy (range, 4500-5400 cGy), and the mean whole breast dose was 5,097 cGy (range, 4860-5040 cGy) in the group treated with a planned intercurrent boost. RESULTS: The occurrence of Grade III dermatitis was significantly reduced in the WBRT/intercurrent boost group compared with the WBRT/boost group (0.6% vs. 8.9%), as was the incidence of treatment interruption (1.9% vs. 14.2%). With a median follow-up of 32 months and 27 months, respectively, no significant difference in local control was identified. CONCLUSIONS: Patients treated with intercurrent boost developed less Grade III dermatitis and unplanned treatment interruptions with similar local control.