ABC trial (A011502): A randomized phase III double-blinded placebo-controlled trial of aspirin as adjuvant therapy breast cancer.

Abstract

TPS600 Background: In-vitro and in-vivo evidence suggest that aspirin may have an anti-tumor effect. Multiple epidemiologic studies have reported improved breast cancer survival among regular aspirin users compared to non-users. Pooled data from randomized trials of aspirin for cardiovascular disease have also reported a decreased risk of metastatic cancer among aspirin users. However, the exact benefits and risks for breast cancer survivors need to be confirmed in a randomized controlled trial. Even if the clinical effect were modest, the global impact would be substantial since aspirin is inexpensive and widely available. Methods: The primary objective is to compare the effect of 300 mg daily aspirin versus placebo upon invasive disease-free survival (iDFS) in high risk HER2 negative breast cancer patients. Secondary objectives include effects on overall survival, cardiovascular disease, toxicity, and adherence. A biospecimen repository will be created for correlative analyses including tumor collection at baseline and blood and urine samples and questionnaires assessing lifestyle factors associated with inflammation (pain, sleep, stress, and depression) at baseline and 2 years. Study design: Subjects will be randomized (1:1) to aspirin 300 mg vs placebo daily for 5 years in a double-blinded fashion. Stratification factors include hormone receptor (HR) status (positive vs negative), body mass index ( < or ≥ 30 kg/m2), and stage (II vs III). Subjects will be followed every 6 six months while on study drug, then annually for 10 years. Accrual goal is 2936 patients to reach 381 iDFS events. We have 80% power to detect HR 0.75 assuming 5-year iDFS on placebo of 77%. Eligibility: Eligible subjects include patients aged 18-70 diagnosed with a primary invasive HER2 negative breast cancer. If HR positive, tumors need to be node positive and diagnosed within the past 10 years. If HR negative, tumor can be node positive or T2-4N0 within 18 months of diagnosis. Subjects who are currently anticoagulated or those with a prior history of GI bleeding, atrial fibrillation, or myocardial infarction are excluded. Subjects who regularly use aspirin (defined as ≥ 5 days per week) need to stop 30 days prior to enrollment. Updated accrual numbers will be given at the time of presentation. Clinical trial information: NCT02927249 .