ASA in Prevention of Ovarian Cancer (STICs and STONEs)

Inclusion Criteria:

* Previously documented germline BRCA1/2 pathogenic mutation or likely pathogenic variant based on the ACMG 2015 guidelines
* Risk-reducing surgery (bilateral salpingo-oophorectomy or bilateral salpingectomy inclusive of fimbria) scheduled for within 6 months to 2 years after the date of randomization as standard of care, for women who have completed their families
* ECOG performance status 0 or 1
* Age ≥ 18 years old
* Subject is able (i.e. sufficiently literate) and willing to complete the Credibility/Expectancy questionnaire in English or French.
* Subject consent must be appropriately obtained in accordance with applicable local and regulatory requirements. Each subject must sign a consent form prior to enrollment in the trial to document their willingness to participate
* Subjects must be accessible for treatment and follow up. Subjects randomized on this trial must be treated and followed at the participating centre.
* In accordance with CCTG policy, protocol treatment is to begin within 2 working days after subject randomization
* Women of childbearing potential must have agreed to use a highly effective contraceptive method for the duration of the study treatment and for 30 days post last dose of study medication

Exclusion Criteria:

* Subjects with history of other malignancies, except:

  * adequately treated non-melanoma skin cancer;
  * curatively treated in-situ cancer of the cervix;
  * previously diagnosed (at any point) breast cancer, treated with curative intent; prior chemotherapy is allowed and the last dose must be ≥ 12 months prior to randomization; endocrine therapy for breast cancer is allowed at any time.
  * other solid tumours curatively treated with no evidence of disease for \> 5 years.
* Subjects who have been treated with any PARP-inhibitors (e.g. olaparib) at any time.
* Subjects with active bleeding or bleeding diathesis.
* Subjects with active peptic ulcer.
* Subjects with renal, hepatic or congestive heart failure.
* Subjects with concurrent use of anti-coagulants and/or anti-platelet agents.
* Subjects with prior bilateral salpingectomy.
* Subjects with history of chronic daily use of ASA or NSAIDs.
* Subjects with intolerance of ASA including subjects with a history of asthma induced by salicylates or substances with a similar action, notably non-steroidal-anti-inflammatory drugs.
* Ongoing or planned pregnancy.
* Subjects who are breastfeeding.