A Phase 2 interventional study of Acetylsalicylic acid and Placebo in Ovarian Cancer Prevention, sponsored by Canadian Cancer Trials Group. Active, not recruiting at 17 sites in 2 countries. Open to female participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-16.
Sponsored by Canadian Cancer Trials Group · Phase 2, Interventional, and Prevention
While ASA is not a cancer medication, research suggests that taking ASA reduces the probability of getting many types of cancer because of its anti-inflammatory action. Inflammation in the ovaries during ovulation is thought to contribute to the development of ovarian cancer, and, because ASA is an anti-inflammatory medication, it may help to prevent it.
The standard or usual treatment for women with a high risk gene mutation, BRCA1 or BRCA2, is to have risk-reducing surgery to remove the fallopian tubes and ovaries (bilateral salpingo-oophorectomy or bilateral salpingectomy inclusive of fimbria) after they have decided not to have more children naturally.
Acetylsalicylic Acid (ASA) is a safe, well tolerated drug taken by mouth. ASA has been available for over 100 years and has been used mainly to relieve fever and pain, but also as an anti-inflammatory medication in order to reduce inflammation (swelling).
3,381 studies on the registry are indexed under Ovarian Neoplasms; 790 are open to participants now.
This study's enrollment of 117 is above the median of 54 across 2,548 interventional studies indexed under Ovarian Neoplasms.
Browse Ovarian Neoplasms studies →Canadian Cancer Trials Group is the lead sponsor of 93 studies on the registry; 29 are open to participants now.
Of its 8 completed or terminated interventional studies of FDA-regulated products, 7 (88%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Subjects with history of other , except:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Acetylsalicylic acid
Other: Placebo
81 mg PO daily or 325 mg PO daily
Also known as: ASA
One tablet PO daily
Proportion of pre- & malignant lesions found during prophylactic risk reduction surgery using a stratified Cochran-Mantel-Haenszel test
Time frame: 5 years
Acceptance of the ASA intervention from the self-report Credibility/Expectancy Questionnaire
Time frame: 5 years
Compliance of taking ASA by serum monitoring
Time frame: 5 years
Compliance of taking ASA by evaluation of treatment completion rates
Time frame: 5 years
Compliance of taking ASA by reasons for early discontinuation of protocol intervention.
Time frame: 5 years
Plan to share: No
No publications or documents are linked to this record.
This study is active, not recruiting, as verified in Jan 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Aspirin
Canadian Cancer Trials Group