Lumpectomy plus tamoxifen or anastrozole with or without whole breast irradiation in women with favorable early breast cancer.
OBJECTIVE
In women with favorable early breast cancer treated by lumpectomy plus tamoxifen or anastrazole, it remains unclear whether whole breast radiotherapy is beneficial.


METHODS
Between January 1996 and June 2004, the Austrian Breast and Colorectal Cancer Study Group (ABCSG) randomly assigned 869 women to receive breast radiotherapy +/- boost (n = 414) or not (n = 417) after breast-conserving surgery (ABCSG Study 8A). Favorable early breast cancer was specified as tumor size <3 cm, Grading 1 or 2, negative lymph nodes, positive estrogen and/or progesterone receptor status, and manageable by breast-conserving surgery. Breast radiotherapy was performed after lumpectomy with 2 tangential opposed breast fields with mean 50 Gy, plus boost in 71% of patients with mean 10 Gy, in a median of 6 weeks. The primary endpoint was local relapse-free survival; further endpoints were contralateral breast cancer, distant metastases, and disease-free and overall survival. The median follow-up was 53.8 months.


RESULTS
The mean age was 66 years. Overall, there were 21 local relapses, with 2 relapses in the radiotherapy group (5-y rate 0.4%) vs. 19 in the no-radiotherapy group (5.1%), respectively (p = 0.0001, hazard ratio 10.2). Overall relapses occurred in 30 patients, with 7 events in the radiotherapy group (5-y rate 2.1%) vs. 23 events in the no-radiotherapy group (6.1%) (p = 0.002, hazard ratio 3.5). No significant differences were found for distant metastases and overall survival.


CONCLUSIONS
Breast radiotherapy +/- boost in women with favorable early breast cancer after lumpectomy combined with tamoxifen/anastrazole leads to a significant reduction in local and overall relapse.
Pötter
Richard
R
Department of Surgery, Medical University of Vienna, Vienna, Austria. Richard.Poetter@meduniwien.ac.at
Gnant
Michael
M
Kwasny
Werner
W
Tausch
Christoph
C
Handl-Zeller
Leonore
L
Pakisch
Brigitte
B
Taucher
Susanne
S
Hammer
Josef
J
Luschin-Ebengreuth
Gero
G
Schmid
Marianne
M
Sedlmayer
Felix
F
Stierer
Michael
M
Reiner
Georg
G
Kapp
Karin
K
Hofbauer
Friedrich
F
Rottenfusser
Andrea
A
Pöstlberger
Sabine
S
Haider
Karin
K
Draxler
Wolfgang
W
Jakesz
Raimund
R
D000368:Aged; D000369:Aged, 80 and over; D000077384:Anastrozole; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009570:Nitriles / Q000627:therapeutic use*; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D015996:Survival Rate; D013629:Tamoxifen / Q000627:therapeutic use*; D014230:Triazoles / Q000627:therapeutic use*
D018931:Antineoplastic Agents, Hormonal; D009570:Nitriles; D014230:Triazoles; D013629:Tamoxifen; D000077384:Anastrozole