A common over-the-counter medication could help prevent the spread of colorectal cancer (CRC), the nation's third most common type of cancer and second most common cause of death from the disease.

A study recently published in the journal Cancer showed that CRC patients who took a daily dose of aspirin had better outcomes and lower rates of metastasis to the lymph nodes than CRC patients who didn't take aspirin regularly.

Houston Methodist surgical oncologist and colorectal cancer expert Dr. Maen Abdelrahim, who wasn't involved in the research, spoke with National Geographic about the findings, which he says provides evidence that aspirin helps boost the immune system's ability to hunt for and fight off cancer cells.

"It's boosting the immune system, and it's helping the immune system inside the tumor," said Dr. Abdelrahim, who has published related research on the anticancer properties of aspirin and other drugs.

The exact mechanisms of how aspirin may prevent and delay the progression of cancers remains unknown but Dr. Abdelrahim and other researchers believe it helps immune cells infiltrate the physical barriers constructed by the solid tumors.

Prior to obtaining his medical degree, Dr. Abdelrahim received a Ph.D. in pharmacology and toxicology and worked as a pharmacist, providing additional context on how cancer and non-cancer drugs may impact cancer patients.