Rising Rectal Cancer Deaths Among Adults in Their 30s and 40s Outpace Colon Cancer Growth at Alarming Rate

Deaths from rectal cancer are increasing at a rate two to three times faster than deaths from colon cancer among adults in their thirties and forties, according to new research to be presented at the Digestive Disease Week conference in May 2026.

The findings, based on an analysis of U.S. Death records from 1999 to 2023 using a machine learning model, show that while colon cancer deaths in adults aged 35 to 44 are rising slowly by about half a percent each year, rectal cancer mortality in the same age group is increasing by nearly 2 percent annually.

While the numbers appear modest at first glance, the concern isn’t just how many additional deaths We find today, but that the curve is moving in the wrong direction and accelerating in young, otherwise low-risk individuals.

Mythili Menon Pathiyil, MBBS, gastroenterology fellow at SUNY Upstate Medical University in Syracuse, New York

Colorectal cancers, which include both colon and rectal cancer, were once rare in younger adults but now account for one in five new cases in people under 55. Although both cancers affect the large intestine, rectal cancer develops closer to the outside of the body, which can make symptoms more noticeable earlier in some cases.

With colon cancer, you are less likely to notice bright red blood on the stool or the toilet paper because the blood from colon cancer has time to mix in with the stool before the stool reaches the anus. Colon cancers are more likely to cause black stools.

Cindy Kin, MD, associate professor of surgery at Stanford Health Care in Palo Alto, California

When a cancer tumor stretches the rectum, you’re more likely to feel it and have difficulty passing stool or to experience anal or pelvic pain.

Rachel Gordon, MD, physician double board-certified in colorectal and general surgery at Episcopal Health Services in Queens, New York

Common symptoms of colorectal cancer include persistent changes in bowel habits, rectal bleeding or blood in the stool, unexplained weight loss, persistent abdominal pain or cramps, and fatigue. However, early-stage disease often produces no symptoms, underscoring the importance of screening.

Treatment approaches differ based on cancer location. Rectal cancer that has reached the muscle layer of the bowel wall or nearby lymph nodes is typically treated with radiation and chemotherapy first, followed by surgery if needed. In contrast, most colon cancers are treated with surgery first, followed by chemotherapy if the cancer has spread to lymph nodes. For metastatic disease in either cancer type, chemotherapy is generally the initial treatment.

The American Cancer Society recommends regular screening for average-risk individuals starting at age 45. Those with increased risk — such as a family history of colorectal cancer, personal history of polyps or prior cancer, inflammatory bowel disease, or certain genetic syndromes — should consult their healthcare provider about earlier screening.

Experts note that while the exact causes of the rising rectal cancer rates in younger adults remain under investigation, potential contributing factors include chronic dietary exposures leading to inflammation or microbiome changes, as well as lifestyle factors such as physical inactivity, obesity, tobacco, and alcohol use.

Because younger adults are not routinely screened, symptoms are sometimes mistaken for benign conditions like hemorrhoids or stress, which can delay diagnosis until the cancer reaches a more advanced stage. As Dr. Pathiyil emphasized, rectal bleeding and changes in bowel habits in people under 45 should not be automatically attributed to non-cancerous causes without thorough evaluation.

Greater use of flexible sigmoidoscopy, a less invasive procedure that examines the lower colon and rectum, may help increase detection of rectal cancers. However, colonoscopy remains the gold standard for screening as it examines the entire colon and rectum.

The prognosis for both rectal and colon cancer is generally favorable when detected early, but survival rates decline significantly if the disease has spread. Researchers stress that while the current annual increases in mortality may seem small, the accelerating trend among young adults warrants urgent attention and further study.