Aspirin is a widely available over-the-counter medication that shows substantial effects at promoting survival and reducing risk of many types of cancer, plus reducing inflammation and managing pain due to inflammation.

How can aspirin help me? What the research says

We summarize the clinical evidence for each medical benefit here. We begin with our assessment of the strength of evidence within each category, followed by a brief summary of individual studies or reviews of several studies. In assessing the strength of evidence, we consider the study design, number of participants, and the size of the treatment effect (how much outcomes changed with treatment).

Learn more about how we research and rate therapies.

Selected preclinical evidence is in Are you a health professional?

Treating cancer

Is aspirin linked to improved survival? Is it linked to less cancer growth or metastasis? Does it enhance the anticancer action of other treatments or therapies? We present the evidence.

Cancer as a whole

Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) of lower mortalitydeath, or the death rate in a population; cancer studies often report all-cause mortality (death from any cause) and cancer-specific mortality (death due to the cancer under investigation) among people with adenocarcinoma using aspirin regularly, particularly among those without metastasis

Strong evidence of substantially fewer metastases with cancer as a whole among people using aspirin

Bladder cancer

Strong evidence of moderately better survival among people with bladder cancer using aspirin

Breast cancer

Insufficient (conflicting) findingspreclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example) (this is the CancerChoices definition; other researchers and studies may define this differently) indicate that any benefit in breast cancer may depend on the dose or the type of cancer, and in fact substantially higher all-cause mortality is seen among people with postmenopausal hormone receptor-positive breast cancer using low-dose aspirin

Colorectal Cancer

Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently) of better colorectal cancer survival among people using aspirin after diagnosis

Strong evidence of substantially less risk of metastasis among people with colorectal cancer using aspirin, especially after diagnosis and among people who smoke

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of slower polyp progression in people with hereditary nonpolyposis colorectal cancer using aspirin

Preliminary evidence of substantially better survival among people with type 2 diabetes and colorectal cancer being treated with metformin and using aspirin

Good evidence of better survival with aspirin use among people with mutated PIK3CA colorectal tumors using aspirin after diagnosis

Preliminary evidence of better overall survival among people with wild-type BRAF tumors, but not mutated BRAF tumors, using aspirin after diagnosis

Preliminary evidence of better survival among people with low CD274 using aspirin regularly

Insufficient (conflicting) evidence of better tumor response to chemoradiation treatment among people with rectal cancer using aspirin

Gastrointestinal cancer

No evidenceoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. of improved survival among people with esophageal or gastrointestinal cancer using low-dose aspirin after diagnosis in a combined analysis of 2 studies

Modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently) of better survival among people with hepatobiliary tract cancer using aspirin regularly after diagnosis

Head and neck cancer

Preliminary evidence of better survival and smaller tumor volume among people with head and neck cancer with PIK3CA mutations or amplification using NSAIDs—predominantly aspirin—after diagnosis

Ovarian cancer

Preliminary evidence of better survival among people using aspirin after diagnosis but not before diagnosis

Prostate Cancer

Modest (somewhat conflicting) evidence of better survival among people using aspirin after diagnosis

Modest evidence (due to inclusion of non-aspirin nonsteroidal anti-inflammatory drugs, NSAIDs) of lower metastasis among people using aspirin, with a stronger effect with use after diagnosis

Optimizing your body terrain

Does aspirin promote an environment within your body that is less supportive of cancer development, growth, or spread? We present the evidence.

Inflammation

Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) of anti-inflammatory action from aspirin

Managing side effects and promoting wellness

Is aspirin linked to fewer or less severe side effects or symptoms? Is it linked to less toxicity from cancer treatment? Does it support your quality of life or promote general well-being? We present the evidence.

See evidence not specific to people with cancer in Are you a health professional?

Pain

Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) of less chronic cancer pain among people using codeine plus aspirin

Symptoms not specific to cancer

Cardiovascular side effects: preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of fewer vascular disease events, not specific to people with cancer, among people using aspirin

Reducing cancer risk

Is aspirin linked to lower risks of developing cancer or of recurrence? We present the evidence.

Cancer as a whole

Insufficient (conflicting) evidencepreclinical evidence only OR clinical studies with such poor or unclear methodology that no conclusion can be drawn OR conflicting findings across clinical studies with no preponderance of evidence in one direction; conflicting evidence occurs when studies find conflicting effects (positive effect vs no effect or negative effect) with the same treatment and the same general study population (same cancer type, for example) (this is the CancerChoices definition; other researchers and studies may define this differently) of lower cancer-related mortality among people without cancer at baseline using aspirin regularly

Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) of lower risk of distant metastasis among people without cancer at baseline using aspirin regularly, with greater benefit among people who smoke

Bladder cancer

No evidence of an effectoverall, one or more studies did not demonstrate that a treatment or intervention led to an expected outcome; this does not always mean that there is no effect in clinical practice, but that the studies may have been underpowered (too few participants) or poorly designed. Larger, well-designed studies provide more confidence in making assessments. of aspirin use on bladder cancer risk among older adults in a large study

Breast cancer

No evidence of an effect on recurrence among people with high-risk, HER2-negative breast cancer using aspirin in a very large study

Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently) of lower risk of some subtypes of breast cancer—hormone receptor positive tumors, in situ breast tumors—or among postmenopausal women, but not of breast cancer as a whole among people regularly using aspirin

Colorectal cancer

Good evidence of substantially lower risk of recurrence among people using aspirin regularly

Strong evidence of lower risk of colorectal cancer among people using aspirin regularly

Strong evidence of lower risk of cancer or of polyp progression among people with higher risk due to hereditary, family, or personal history using aspirin regularly

Good evidence of lower risk of recurrence of adenomas or polyps among people using aspirin

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of reduced risk only when aspirin use was started before age 65

Gastrointestinal cancer

Strong evidence of lower risk of several types of gastrointestinal cancer, including esophageal, stomach, gallbladder, and liver/bile duct hepatobiliary tract cancers, among people using aspirin

Modest evidence of lower secondary primary cancer, especially esophageal cancer and stomach cancer, among people with head and neck cancer using aspirin

No evidence of an effect on risk of esophageal cancer or stomach cancer among individuals aged 65 years or older using aspirin in a large study

Gynecological cancers

No evidence of an effect on risk of uterine cancer among people aged 65 or older using aspirin in a large study

Head and neck cancer

No evidence of an effect on risk of head and neck cancer among people using aspirin in a large combined analysis of studies

Lung cancer

Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) of lower risk of lung cancer with aspirin use, except among people aged 65 years or older; also see cautions about aspirin use in older adults in Safety and precautions

Pancreatic cancer

Modest evidence of lower risk of pancreatic cancer with aspirin use, but not among older adults

Prostate Cancer

Good evidence of lower prostate cancer risk, especially of advanced or lethal cancer, among people using aspirin

Keep reading about aspirin

Authors

Nancy Hepp, MS

Lead Researcher and Program Manager
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher, program manager, and writer for CancerChoices. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS Lead Researcher and Program Manager

Laura Pole, RN, MSN, OCNS

Senior Clinical Consultant
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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, RN, MSN, OCNS Senior Clinical Consultant

Reviewer

Barry D. Elson, MD

Integrative physician and CancerChoices advisor
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Barry D. Elson, MD, has been practicing and teaching integrative medicine for over 40 years. He has been the medical director of Northampton Wellness Associates, adjunct faculty for Touro University College of Medicine, medical director at Commonweal, and professor of medicine at the Pacific College of Naturopathic Medicine. He recently retired from clinical practice and has been providing freelance medical consulting. He is an avid biker, cross country skier, and sailor. He currently resides in the rolling hills of western Massachusetts.

Barry D. Elson, MD Integrative physician and CancerChoices advisor

Maria Williams

Research and Communications Consultant
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Maria Williams is a research and communications consultant who brings over 15 years’ experience in research, consumer education, and science communication to CancerChoices. She has worked primarily in public health and environmental health.

Maria Williams Research and Communications Consultant

Last update: June 4, 2022

CancerChoices provides information about integrative in cancer care, a patient-centered approach combining the best of conventional care, self care and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocial therapy, and acupuncture therapies and self-care lifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

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