This Cancer Rising Sharply Among WI Young People

WISCONSIN — A new study showing deaths from rectal cancer are rising sharply among younger adults in their 30s and 40s — a troubling trend that researchers in a recent study say is not fully understood — is an important reminder for Wisconsinites to include screening in their regular checkups.

The study, published March 2 in the American Cancer Society journal, found colorectal cancers — once more common in older adults — are increasingly diagnosed in younger people and are often more advanced at detection.

Colorectal cancer includes both colon and rectal cancer.

In Wisconsin, 34.7 in 100,000 people were diagnosed from 2018 to 2022, according to the researchers’ analysis of federal health data. Death rates from 2019 to 2023 were 12.9 in 100,000 people.

Screening guidelines now recommend testing begin at age 45 for average-risk adults, though many younger patients fall below that threshold.

In Wisconsin, about 5 percent of adults ages 45 to 54 are up-to-date on colorectal cancer screening, according to the data.

Researchers said rectal cancer deaths could surpass colon cancer deaths by 2035 if current trends continue. Colorectal cancer is already the leading cause of cancer death among Americans under 50, with mortality in that group rising about 1 percent per year even as death rates decline among older adults, particularly those 65 and older.

Rectal tumors now account for about one-third of all colorectal cancer diagnoses, up from roughly one-quarter in earlier decades, indicating a growing share of the overall burden.

Overall incidence has declined slightly, driven by a roughly 2.5 percent annual drop among adults 65 and older, but it is rising in younger groups—about 3 percent per year among those ages 20 to 49 and 0.4 percent annually among those 50 to 64. As a result, nearly half of new cases now occur in people under 65, up from about a quarter in the mid-1990s.

Researchers estimate 158,850 new colorectal cancer cases and 55,230 deaths nationwide in 2026, with about 45 percent of diagnoses and nearly one-third of deaths expected in people younger than 65.

The reasons for the rise in younger adults remain unclear. Researchers point to possible links to diet, obesity, environmental exposures and other lifestyle factors, as well as changes in the gut microbiome.

As these generations age, the burden of rectal cancer “will continue to swell like a tsunami moving through time, underscoring an urgent need for etiologic research to discover the cause of rising incidence,” the researchers said.

While rectal cancer is still relatively uncommon in younger adults, symptoms are often overlooked, leading to delayed diagnoses. Symptoms can include changes in bowel habits, blood in the stool, unexplained weight loss, abdominal pain and persistent fatigue.