Influence of concurrent anastrozole on acute and late side effects of whole breast radiotherapy.
OBJECTIVE
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.
Valakh
Vladimir
V
Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, PA 15212, USA. vladimir@valakh.com
Trombetta
Mark G
MG
Werts
E D
ED
Labban
George
G
Khalid
Mian K
MK
Kaminsky
Anna
A
Parda
David
D
D000328:Adult; D000368:Aged; D000077384:Anastrozole; D018931:Antineoplastic Agents, Hormonal / Q000008:administration & dosage* / Q000009:adverse effects; D047072:Aromatase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D009570:Nitriles / Q000008:administration & dosage* / Q000009:adverse effects; D010414:Pennsylvania; D011832:Radiation Injuries / Q000209:etiology / Q000517:prevention & control*; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D012189:Retrospective Studies; D013997:Time Factors; D014230:Triazoles / Q000008:administration & dosage* / Q000009:adverse effects
D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D009570:Nitriles; D014230:Triazoles; D000077384:Anastrozole