Aspirin may help prevent colon cancer

“The data on aspirin and cancer is constantly changing,” says Maen Abdelrahim, an oncologist at Houston Methodist Hospital in the US who specializes in the treatment of colorectal cancer. However, there are still many unanswered questions about how aspirin can prevent and slow the progression of these cancers, and what group of patients would benefit from daily aspirin.

People who take aspirin chronically have a lower risk of developing colorectal cancer, “but you have to weigh that against the risks,” which include the possibility of bleeding in the gastrointestinal tract, says Jeff Meyerhardt, an oncologist and co-director of the Cancer Center. . colon and rectum at the Dana-Farber Cancer Institute in Boston (USA).

There are several studies that suggest a link between aspirin and the prevention and slowing of colorectal cancer. However, the mechanism by which aspirin achieves this is still unknown. This makes it difficult to predict which patients will benefit most.

In a 2020 meta-analysis analyzing the results of 45 observational studies, researchers found that regular aspirin use was associated with a lower incidence of colorectal cancer.

The low dose, 75 to 100 milligrams, was associated with a 10 percent reduction in the risk of colorectal cancer; the usual dose of 325 milligrams resulted in a 35 percent reduction.

“Numerous studies of colorectal cancer have shown that a stronger immune response appears to improve outcomes,” says Meyerhardt; “We’re studying how aspirin might interact with this.”

During the study, researchers obtained tissue samples from 238 patients who had undergone surgery for colorectal cancer. Of these patients, 12% took daily low-dose aspirin to prevent cardiovascular disease. Compared with patients who did not take aspirin, the researchers observed lower rates of lymph node metastasis and more immune cells infiltrating tumors.

This higher level of infiltration is thought to be associated with slower cancer progression (including a lower rate of spread to lymph nodes), allowing immune cells to infiltrate the tumor mass and fight cancer cells more effectively.

The researchers also found higher levels of immune markers responsible for triggering the immune system’s response. “It strengthens the immune system and helps the immune system inside the tumor,” Abdelrahim says.

In recent years, the role of the immune system in protecting against the development of cancer has been recognized.

Patients with a suppressed immune system are at higher risk of developing cancer compared to patients with a fully functional immune system. These results suggest that aspirin may enhance immune system control in the detection of colorectal cancer.

“Your immune system is doing all these things in the background that you’re not even aware of,” Keane says; “It’s not just the behavior of the tumor and how aggressive it is, but how your body resists the tumor.”