As colorectal cancer cases rise in younger people, regularly taking aspirin could help lower the risk in those with unhealthier lifestyles, new research suggests.

Two cancer-related studies were published in medical journals JAMA Oncology and Lancet Public Health this week. While one shows a disturbing trend for the younger population, the other raises hope for the prevention of one of the most common cancers.

The JAMA study published Thursday found that taking two or more standard tablets (325 milligrams) of aspirin per week was associated with a lower risk of colorectal cancer in individuals with less healthy lifestyles.

More than 100,000 people — both men and women — were included in this U.S. research, which looked at people’s alcohol intake, physical activity, diet and smoking habits.

Over a 10-year period, analyzed from October 2021 to May 2023, the absolute risk reduction of colorectal cancer “associated with aspirin use was greatest among those with the unhealthiest lifestyle scores and progressively decreased with healthier lifestyle scores,” the study said.

“The findings of the study suggest that lifestyle risk factors may be useful to identify individuals who may have a more favourable risk-benefit profile for cancer prevention with aspirin.”

This latest study adds to previous research signalling the benefits of aspirin use for colorectal cancer outcomes.

One particular study from 2021 suggested that long-term, regular use of aspirin (for more than two years and taking 15 or more pills a month) before a colorectal cancer diagnosis was linked with a lower mortality risk.

Colorectal cancer starts in the colon or rectum – which are part of the large intestine – and can spread to other parts of the body.

It is the fourth most common form of cancer in Canada and the second deadliest, according to data published by the World Health Organization (WHO) earlier this year.

Cases of colorectal cancer have particularly been increasing among the country’s younger population.

It is one of 17 cancers that appears to be more prevalent among millennials and gen X than older generations, according to a Lancet study published this week, looking at U.S. data from January 2000 to December 2019.

The study found that the cancer risk was roughly two to three times higher for those born in 1990 compared with those born in 1955 for the small intestine, kidney and renal pelvis, and pancreas in both men and women, and for the liver and intrahepatic bile duct in women.

Nine types of cancers, including colorectal, estrogen receptor-positive breast, uterine corpus, non-cardia gastric, gallbladder and other biliary, ovarian, testicular and anal in men, were also found to be rising in the younger generation after declining in older cohorts.

“These findings add to growing evidence of increased cancer risk in younger generations, highlighting the need to identify and tackle underlying risk factors,” the authors wrote.

Colorectal cancer death rates increased in millennials and gen X (collectively, those aged roughly 25 to 49 years), the Lancet study showed.

Experts say unhealthy diet, physical inactivity, smoking and alcohol consumption increase the risks for this type of cancer, but family history is also a contributing factor.

The Canadian Cancer Society estimates that 25,200 people will be diagnosed with colorectal cancer this year and 9,400 will die from it.

Colorectal cancer is commonly treated with surgery and chemotherapy.

In advanced cases, targeted therapy involving drugs to “target specific molecules on cancer cells or inside them” may also be sometimes used, according to the CCS.