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Active, not recruitingNCT03480776Updated Sep 16, 2026

ASA in Prevention of Ovarian Cancer (STICs and STONEs)

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

Phase
Phase 2
Study type
Interventional
Enrollment
117
Allocation
Randomized
Ages
18 Years and older
Sex
Female
01

Study summary

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.

Read the detailed description

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).

02

Conditions studied

  • Ovarian Cancer Prevention
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
Yes

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

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.
04

Study design

Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Triple (Participant, Care provider, Investigator)
Enrollment
117 participants (actual)

Study arms

  • Active comparator
    Acetylsalicylic Acid (ASA)

    Drug: Acetylsalicylic acid

  • Sham comparator
    Placebo

    Other: Placebo

Interventions

  • DrugAcetylsalicylic acid

    81 mg PO daily or 325 mg PO daily

    Also known as: ASA

  • OtherPlacebo

    One tablet PO daily

05

What researchers measure

Primary outcomes

  1. Proportion of pre- & malignant lesions found during prophylactic risk reduction surgery using a stratified Cochran-Mantel-Haenszel test

    Time frame: 5 years

Secondary outcomes

  1. Acceptance of the ASA intervention from the self-report Credibility/Expectancy Questionnaire

    Time frame: 5 years

  2. Compliance of taking ASA by serum monitoring

    Time frame: 5 years

Other outcomes

  1. Compliance of taking ASA by evaluation of treatment completion rates

    Time frame: 5 years

  2. Compliance of taking ASA by reasons for early discontinuation of protocol intervention.

    Time frame: 5 years

06

Study locations

17 sites
  • Royal Prince Alfred Hospital
    Camperdown, New South Wales 2050, Australia
  • Prince of Wales Hospital
    Randwick, New South Wales 2031, Australia
  • Westmead Hospital
    Westmead, New South Wales 2145, Australia
  • Peter McCallum Cancer Institute
    Melbourne, Victoria 3002, Australia
  • King Edward Memorial Hospital
    Subiaco, Western Australia 6008, Australia
  • St John of God Subiaco
    Subiaco, Western Australia 6008, Australia
  • Tom Baker Cancer Centre
    Calgary, Alberta T2N 4N2, Canada
  • Clinical Research Unit at Vancouver Coastal
    Vancouver, British Columbia V5Z 1M9, Canada
  • CancerCare Manitoba
    Winnipeg, Manitoba R3E 0V9, Canada
  • Dr. H. Bliss Murphy Cancer Centre
    St. John's, Newfoundland and Labrador A1B 3V6, Canada
  • Kingston Health Sciences Centre
    Kingston, Ontario K7L 2V7, Canada
  • North York General Hospital
    Toronto, Ontario M2K 1E1, Canada
  • Women's College Hospital
    Toronto, Ontario M5S 1B2, Canada
  • CIUSSS de l'Est-de-I'lle-de-Montreal
    Montreal, Quebec H1T 2M4, Canada
  • CHUM-Centre Hospitalier de l'Universite de Montreal
    Montreal, Quebec H2X 3E4, Canada
  • Hotel-Dieu de Quebec
    Québec, Quebec G1R 2J6, Canada
  • CIUSSS de l'Estrie - Centre hospitalier
    Sherbrooke, Quebec J1H 5N4, Canada
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT03480776
Lead sponsor
Canadian Cancer Trials Group
Collaborators
Apotex Inc.
Responsible party
Sponsor
First posted
Mar 29, 2018
Start date
Jul 24, 2018
Primary completion
Dec 31, 2026 (estimated)
Completion
Jun 30, 2027 (estimated)
Last update
Sep 16, 2026

Study contacts

Amit Oza
study chair · Univ. Health Network-OCI/Princess Margaret Hospital, Toronto, ON Canada
Stephanie Lheureux
study chair · Univ. Health Network-OCI/Princess Margaret Hospital, Toronto, ON Canada

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

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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