Cancer Clinical Research Unit

Inclusion Criteria: - Participants that are greater than or equal to 18 years of age - For U.S. sites, patients can read and understand English or Spanish; for Canadian site, participants can read and understand English or French - Histology confirmed, or clinical suspicion of, invasive epithelial ovarian, fallopian tube, or peritoneal carcinoma. Must be grade 2 or 3 or high (where high is defined as grade 2/3). All histologies including serous, endometrioid, clear cell sarcoma, or carcinosarcoma histology is acceptable. Mixed histology also acceptable. - Treatment naïve for this cancer diagnosis - Planned for neoadjuvant chemotherapy (platinum-based doublet with taxane +/- anti-VEGF antibody) for at least 3 but no more than 5 cycles followed by an interval debulking surgery. [Note: this study evaluates response while on neoadjuvant treatment. The final collection of specimen and questionnaire is at the time of surgery and immediate post-operative state. Therefore, there are no eligibility criteria related to treatment in the adjuvant setting (e.g., intraperitoneal treatment) and adjuvant therapy should proceed as the physician deems appropriate.] - Measurable disease as defined by RECIST 1.1, CT scan (with or without contrast) within 12 weeks of study enrollment. - Eastern Cooperative Oncology Group (ECOG) performance status of 0,1, or 2 - Able to provide tissue biopsy (core or excisional) sufficient for diagnosis and biomarker analysis, may use outside archival tissue if available. - If currently using anti-coagulation medication, no contraindication for temporary stoppage of use during the study based on physician judgement - Willing and able to swallow pills without difficulty - Un-transfused platelet count > 100,000 cells/μL - Willing and able to participate in all required evaluations and procedures in this study protocol (e.g. undergoing treatment, scheduled visits and examinations, serum testing, questionnaires, pill log/diary) - Absolute neutrophil count > 1.5 x 109 cells/L - Hemoglobin > 9.0 g/dL, may use transfusions and the value can be post-transfusion - Estimated creatinine clearance of > 30 mL/min, calculated using the formula Cockcroft-Gault [(140-age) x Mass (kg)/(72 x creatinine mg/dL)] x 0.85 for female - No severe hepatic impairment defined as AST or ALT elevation < 2.5 x institutional ULN, unless liver metastasis is present < 5 x ULN Exclusion Criteria: - Definite contraindication for either aspirin use or stopping current aspirin use based on physician's clinical judgment - History of vascular event in the last 12 months (e.g., myocardial infarction or unstable angina, stroke, coronary artery angioplasty or stenting, coronary artery bypass graft, relevant [serious or significant] arrhythmias, significant vascular disease, congestive heart failure or vascular interventions). - History of hypertensive crisis and/ or uncontrolled HTN, systolic blood pressure > 150 mmHg; diastolic blood pressure > 90mmHg. Participants must have blood pressure < 150/90 mmHg taken in a clinic setting by a medical professional within 2 weeks prior to starting study. - Current or history of ulcers which prohibits aspirin consumption, severe hepatic failure, or acute or chronic renal disease where aspirin use is contraindicated - History of gastrointestinal or genitourinary bleeding or other bleeding diathesis or coagulopathy within 6 months prior to enrollment of study - Uncontrolled erosive esophagitis requiring 2 or more treatments - Other cancer diagnosis in the last 3 years other than non-melanoma skin cancer - Autoimmune disorder requiring systemic therapy - Chronic steroid use defined as 3 weeks in the past year or any length of time in the past 30 days. - Other aspirin or NSAID hypersensitivities or contraindications (e.g. allergy) - History of bariatric surgery - Currently pregnant at the Screening visit or planning on becoming pregnant during the study period - Participant is unable to swallow orally administered medication and patients with gastrointestinal disorders likely to interfere with study medication. - Metabolism CYP2C9, known G6PD deficient patients