Effect of acetylsalicylic acid on radiation and cosmetic results after conservative surgery for early breast cancer: a randomized trial.
OBJECTIVE
Acetylsalicylic acid (ASA) can reduce the incidence of stroke and myocardial infarction by inhibiting platelet-fibrin thrombi in small blood vessels. To determine if ASA could reduce late effects of radiation therapy mediated by damage to small blood vessels, a prospective, placebo-controlled, double-blind trial was conducted in women with early breast cancer, receiving radiotherapy to the conserved breast.


METHODS
Cosmetic outcome and late radiotherapy effects were recorded prospectively for 186 women with T1 or T2, pathologically node-negative breast cancer treated with breast conservation and randomized to receive ASA (325 mg daily) or placebo for 1 year from the start of radiation therapy. Radiation was a tangent pair to the breast alone delivering a modal dose of 44 Gy in 16 daily fractions in 22-25 days.


RESULTS
Median follow-up is 6.5 years. The use of ASA has not had any effect on the acute (erythema, edema or discomfort) or late (induration, telangiectasia) effects of radiotherapy (all P > 0.10), the patients' or physicians' assessment of the cosmetic outcome (all P > 0.25) or rates of breast recurrence (P > 0.25).


CONCLUSIONS
ASA cannot be recommended to improve the outcome of radiotherapy complementing breast conserving surgery.
Olivotto
I A
IA
Division of Radiation Oncology, British Columbia Cancer Agency, Vancouver, Canada.
Kim-Sing
C
C
Bajdik
C D
CD
Trevisan
C H
CH
Ludgate
C M
CM
Weir
L M
LM
Jackson
S M
SM
Basco
V E
VE
D001241:Aspirin / Q000008:administration & dosage / Q000627:therapeutic use*; D001940:Breast / Q000528:radiation effects*; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D017060:Patient Satisfaction; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies; D011832:Radiation Injuries / Q000517:prevention & control*; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D011882:Radiotherapy, High-Energy; D013997:Time Factors
D010975:Platelet Aggregation Inhibitors; D001241:Aspirin