Aspirin
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.
Aspirin at a glance
Aspirin is widely available as an over-the-counter medication used to reduce inflammation and related pain. General use became widespread before its safety was fully assessed. Use of aspirin presents more risks than many people are aware of.
Good to strong evidence links regular aspirin use to better survival with several types of cancer and reduced risk of even more cancer types. However, as of 2022 the US Preventive Services Task Force no longer recommends that physicians offer or provide low-dose aspirin to prevent colorectal cancer for some patients.
Use for reducing risk of cancer is considered an off-label use of aspirin—using an FDA-approved drug for a purpose other than its approved use. However, the task force also weighs the risks of aspirin use in its recommendations and does not recommend use by everyone.
CancerChoices ratings for aspirin
We rate aspirin on seven attributes, with 0 the lowest rating and 5 the highest. We rate the strength of the evidence supporting the use of aspirin for a medical benefit, such as improving treatment outcomes or managing side effects.
The strongest evidence summaries are presented here; full details are in How can aspirin help you? What the research says ›
See how we evaluate and rate complementary therapies ›
Improving treatment outcomes
See MoreEvidence of benefit
- 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 mortality among people with adenocarcinoma using aspirin regularly, particularly among those without metastasis, and with greater benefit among people who smoke
- 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 progression-free survival but no evidence of an effect on overall survival among people with cancer as a whole treated with low-dose aspirin during treatment with immune checkpoint inhibitors
- Strong evidence of substantially fewer metastases with cancer as a whole among people using aspirin
- Good evidence of moderately better survival among people with bladder cancer using aspirin
- Good evidence of better colorectal cancer survival among people using aspirin after diagnosis, with 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) that benefit is seen mostly among people with normal prediagnosis body weight
- Good evidence of substantially less risk of metastasis among people with colorectal cancer using aspirin, especially after diagnosis and among people who smoke
- Good evidence of better survival with aspirin use among people with mutated PIK3CA colorectal tumors using aspirin after diagnosis
- Modest evidence of lower cancer-specific mortality and lower risk of metastasis among people with breast cancer treated with aspirin
No evidence of benefit
- 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. on overall survival among people with cancer treated with low-dose aspirin during treatment with immune checkpoint inhibitors
- No evidence of an effect on survival among people with esophageal or gastrointestinal cancer using low-dose aspirin after diagnosis in a combined analysis of 2 studies
- No evidence of an effect on survival among people with head and neck cancer treated with aspirin in a combined analysis of studies
- No evidence of an effect on response rate, event-free survival, or overall survival after chemoimmunotherapy among people with diffuse large B-cell lymphoma treated with aspirin in a mid-sized study
- No evidence of an effect on overall survival among people with ovarian cancer treated with aspirin
Optimizing your body terrain
See More- 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
- Aspirin use may lead to more immune activation against colorectal cancer tumors.
Managing side effects and promoting wellness
See More- 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, but see a related commentary about this use for cancer-related pain in How do experts use aspirin? ›
Reducing cancer risk
See MoreEvidence of benefit
- 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 slightly lower risk of cancer as a whole among people using aspirin
- 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
- Good evidence of lower risk of some subtypes of breast cancer—hormone receptor positive tumors or in situ breast tumors—or among postmenopausal women regularly using aspirin
- Good evidence of substantially lower risk of colorectal cancer 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 colorectal adenomas or advanced lesions among people using aspirin, but varying by the duration of aspirin use
- Good evidence of lower risk of recurrence of adenomas or polyps among people using aspirin
- Good evidence of lower risk of adenocarcinoma of the esophagus and gastric cardia or of squamous-cell esophageal cancer among people using aspirin regularly
- Good evidence of lower risk of liver, bile duct, or gallbladder cancer among people using aspirin
- Good evidence of lower risk of stomach cancer among people using aspirin
- Good evidence of slightly lower risk of endometrial cancer among people using aspirin
- Good evidence of lower risk of lung cancer with aspirin use, except among people aged 65 years or older
- Good evidence of lower risk of ovarian cancer among people using aspirin
- Good evidence of lower risk of pancreatic 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 ›
- Good evidence of lower risk of prostate cancer, especially of advanced or lethal cancer, among people using aspirin
No evidence of an effect
- 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. on risk of bladder cancer among people using aspirin in combined analysis of observational studies
- No evidence of an effect on risk of brain cancer among people using aspirin in a combined analysis of observational studies
- No evidence of an effect on risk of breast cancer among healthy women aged 45 years or older taking aspirin every other day in a very large study
- No evidence of an effect on risk of head and neck cancer among people using aspirin in several combined analyses of studies
- No evidence of an effect on risk of kidney cancer among people using aspirin in a combined analysis of studies
- No evidence of an effect on risk of leukemia among people using aspirin in a combined analysis of studies
- No evidence of an effect on risk of lymphoma among people using aspirin in a combined analysis of studies
Use by integrative oncology experts
See More- Not recommended by any clinical practice guidelines
- Used by several of the published programs and approaches we reference
Safety
See More- Moderate caution is needed, with some serious or fatal reactions
- Supervision by a medical professional is highly recommended
Affordability and access
See More- Widely available without restriction
- Generally inexpensive (less than $500 US/year)
Keep reading about aspirin
Authors
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 and writer for CancerChoices and also served as the first program manager. 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.
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.
Reviewers
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.
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.
Last update: June 10, 2024
Last full literature review: September 2021
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.
Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.