The Resurrection of Aspirin as an Anticancer and Pregnancy Drug

Aspirin has been getting mixed reviews lately. There’s good news and bad news. Once upon a time doctors recommended low-dose aspirin for middle-aged and older patients to prevent heart attacks and strokes. That was even for otherwise healthy people. Some doctors even suggested that some high-risk patients take aspirin as an anticancer agent. Then the “wonder drug that works wonders”  began to fall into disfavor. Most cardiologists now discourage routine aspirin use unless a patient is at very high risk for a heart attack. There are some signals that the pendulum may be starting to swing back, but perhaps not all the way.

Cardiologists Turn Away from Aspirin:

The American Heart Association (AHA) and the American College of Cardiology (ACC) says that low-dose aspirin should only be used by people at high risk of strokes or heart attacks. Others, they said, would be more likely to be harmed.

The 2019 ACC/AHA guidelines state:

“Low-dose aspirin for primary prevention [of cardiovascular disease] now reserved for select high-risk patients.”

Cardiologists believe that any anti-clotting benefits of aspirin that could prevent heart attacks or “ischemic” strokes are offset by an increased risk of bleeding.

Aspirin as an Anticancer Drug:

Now for the good aspirin news. Researchers from Roswell Park Comprehensive Cancer Center report that patients with head and neck cancer have a better chance of survival if they take low-dose aspirin while undergoing treatment. An additional 8 percent of patients taking the 81 mg daily dose were still alive five years after treatment compared to those not taking aspirin.

A different study at Roswell Park compared aspirin vs no-aspirin among 164 patients being treated for early stage non-small-cell lung cancer. The patients got precision radiation therapy. Two years after treatment, 57 percent of those taking low-dose aspirin were still alive, compared to 48 percent of those who did not take the drug.

Both studies were presented at the American Society for Therapeutic Radiation Oncology (ASTRO) Annual Meeting in Chicago, Sept. 15 and 16, 2019.

Breast Cancer:

A study published in the January issue of the Journal of Biomolecular Structure and Dynamics suggested that aspirin may be helpful against some breast cancer cases.

The authors wrote:

“Substantial epidemiologic evidence suggests that aspirin use reduces the risk of different cancers including BC [breast cancer], while its role as an adjuvant or a possible antineoplastic agent in cancer treatment is being investigated. In this study, we attempted to explore possibilities of ERα [estrogen receptor alpha] inhibition by Aspirin which may act through competitive binding to the ligand binding domain (LBD) of ERα.”

A study published in Women Health (Feb. 7, 2024) concluded:

“In conclusion, aspirin use after diagnosis might be associated with reduced recurrence and disease-specific mortality in women with breast cancer.”

Head and Neck Cancer:

Head and neck cancer (HNC) can be challenging.

A study published in Head & Neck (Jan. 16, 2024) concluded:

“This study suggests that aspirin intake may reduce the risk of HNC, driven mainly by decreases in risk for laryngeal [larynx] and oropharyngeal [tongue, palate, tonsils, side or back of throat] cancer.”

Aspirin and Genes:

We were especially impressed by a study in the journal Cancers, January, 2024, that analyzed plausible mechanisms whereby aspirin may “exert its effect on improving survival.” The authors reveal that their “…search identified 41 genes that are related to aspirin and cancer survival…” Without getting too deep into the weeds, those include tumor suppressor genes, cytokine regulators and DNA repair pathways.

Questions Raised About Aspirin for Breast Cancer:

Observational studies are the basis for much of aspirin’s perceived anti-cancer benefit. In general, people taking aspirin appeared to be about 20% less likely to die from their cancers.

Not all studies showed benefit, however. And a new randomized controlled trial published in JAMA was stopped early because there was no benefit from aspirin for people with breast cancer. In this trial, 3004 women and 16 men diagnosed with breast cancer were assigned to either placebo or 300 mg of aspirin daily (JAMA, April 29, 2024). The study was stopped after 34 months because there no benefits from aspirin.

The authors concluded:

“Among participants with high-risk nonmetastatic breast cancer, daily aspirin therapy did not improve risk of breast cancer recurrence or survival in early follow-up. Despite its promise and wide availability, aspirin should not be recommended as an adjuvant breast cancer treatment.”

Other Research Suggesting Aspirin as an Anticancer Agent:

History offers a somewhat different perspective. For more than three decades scientists have been studying the anticancer activity of aspirin. We have written extensively about this at the following links:

Will Aspirin Keep Barrett’s from Turning into Cancer?

Can You Prevent Breast Cancer with Aspirin?

Aspirin Vs. Cancer: What Are We Waiting For?

Should You Take Aspirin for Cancer Prevention or Not?

Aspirin Boosts Cancer Immunotherapy Treatment

Keep in mind, however, that randomized controlled trials provide higher quality evidnece than observational or epidemiological studies.

Aspirin During High-Risk Pregnancies

In 2014 the US Preventive Services Task Force recommended that obstetricians consider recommending low-dose aspirin to patients at risk of pre-eclampsia. This complication of pregnancy can be extremely serious for both mother and baby.

Women taking low-dose aspirin (60 to 150 mg/day) are 24 percent less likely to develop pre-eclampsia. It has been known that low-dose aspirin could be helpful for this condition for almost three decades.

Fast Forward a Decade:

Women are often warned to avoid medications during pregnancy for fear that a drug might harm the fetus. Of course there are exceptions when the medicine might benefit the mother.

Doctors often prescribe low-dose aspirin to women who are at high risk for preeclampsia and preterm birth. Preeclampsia, also known as hypertension of pregnancy can put both the mother and baby in jeopardy.

The ASPIRIN study (Obstetrics & Gynecology, Jan. 23, 2024) involved almost 12,000 women in six different countries. They were randomized to receive either low-dose aspirin or placebo starting as early as six weeks into their pregnancies. Women who took aspirin were less likely to deliver pre-term or experience hypertension, so the drug was effective.

In a follow-up study, researchers assessed neurodevelopment in more than 600 three-year-olds. The investigators did not discover any evidence that aspirin was harmful. The lead author stated:

“We were able to look at development using a number of different instruments and different domains and saw no differences in children who were exposed to aspirin early in pregnancy and those who were not.”

Words of Caution:

No pregnant should take any medication, Rx or OTC, without clearing it with an OB/GYN! Aspirin can interact with other medications in a dangerous way. And some women are susceptible to bleeding. Please use caution!

The same concerns apply to anyone contemplating aspirin to prevent cardiovascular problems or cancer. Aspirin can be very dangerous for some people, especially those who might be vulnerable to bleeding or ulcers. Anyone contemplating taking aspirin should be under medical supervision!

What is your experience with aspirin. Do you think it is a menace or a miracle? Share your experience in the comment section below.