Young people twice as likely to get colon cancer while rates fall for older generations – study

People born in the 1990s have double the risk of being diagnosed with colon cancer and four times the risk of getting rectal cancer that those born in the 1950s had at the same age, a new study shows.

The study released on Tuesday was conducted by the American Cancer Society, which found that, while colon and rectal cancers have been declining in older adults born between 1890 and 1950, there has been a sharp increase in both cancers among young people. 

The study found that, while colorectal cancer rates had been declining since 1974 due to advances and the prevalence of screening, colon cancer rates have been increasing for adults aged 20 to 39 by 1 to 2.4 percent every year since the mid-1980s.

“Since 1950, risk has been increasing in subsequent generations – it’s not specifically one generation – but risk is continuing to increase for every generation,” Rebecca Siegel, a researcher for the American Cancer Society, told NBC News.

“Every generation after 1950 has a little bit higher risk,” she said, noting “the largest increases are in people in their 20s.”

Colorectal cancer refers to cancers starting in the colon or rectum that often begins as a growth called a polyp, which forms on the inner wall.

The study finds that the increasing risk among young people is partly due to the fact that they are not usually screened for the disease until they are much older. The number of deaths caused by the cancer has decreased due to advancements in colonoscopies, and there are now over than a million survivors of colorectal cancer in the US as a result.

The study recommends that the screening age should be lowered to accommodate the trend, citing research conducted by the Cancer Intervention and Surveillance Modeling Network. CISNET recently reported that beginning screenings at age 45 is “more effective and provided a more favorable balance between life-years gained and screening burden than starting at age 50 years.”

While it is not known why there is an increase in colorectal cancer, the study says that it may be linked to obesity.

“It is not surprising that the timing of the obesity epidemic parallels the rise in CRC, because many behaviors thought to drive weight gain, such as unhealthy dietary patterns and sedentary lifestyles, independently increase CRC risk,” the study says.

The American Cancer Society lists obesity as one of the top risk factors for colorectal cancer, along with physical inactivity, heavy-meat diets, smoking, and heavy alcohol. They recommend exercising, eating more vegetables and fruits, and getting the recommended amounts of calcium and vitamin D as the best ways to lower the risk of colorectal cancer.

It is estimated that more than 95,000 new cases of colon cancer will be diagnosed in 2017, along with nearly 40,000 new cases of rectal cancer. The cancers are estimated to kill over 50,000 this year.