Rising Rectal Cancer Deaths Among Younger Adults

Deaths from rectal cancer are on the rise among younger adults, presenting a troubling pattern that has scientists puzzled over why millennials seem particularly affected.

According to Mythili Menon Pathiyil, who is leading a new study and is a gastroenterology fellow at SUNY Upstate Medical University in Syracuse, New York, the rate of rectal cancer is increasing at a rate two to three times that of colon cancer. If this trend continues, rectal cancer deaths may surpass colon cancer fatalities—currently the leading cause of cancer death for individuals under 50—by the year 2035.

The American Cancer Society projects that in 2026, there will be 158,850 new cases of colorectal cancer diagnosed, with approximately 55,230 deaths, a significant portion of which will occur in those under 65. While colon and rectal cancers arise in different sections of the digestive tract, they are similar overall.

This new research, which has yet to be peer-reviewed, is slated for presentation at a national gastroenterology meeting in May. However, it aligns with earlier findings from the American Cancer Society that indicate increasing rates of rectal cancer among younger adults are contributing to the rise in overall colorectal cancer cases in those under 65. Since the late 1990s, colorectal cancer rates have surged by about 3% per year in individuals under 50, prompting scientists to explore the causes behind this trend.

Dr. Ben Schlechter, a gastrointestinal oncologist at Dana-Farber Cancer Institute in Boston, expressed concern, stating, “This is a medical crisis. It shouldn’t be ignored.” He was not directly involved in the study.

The research utilized death records from the CDC spanning from 1999 to 2023, specifically focusing on individuals ages 20 to 44. Throughout this period, deaths from early-onset colorectal cancer climbed, with the most significant acceleration in rectal cancer fatalities.

Notably, Hispanic adults experienced the sharpest increase in rectal cancer deaths, leading all demographic groups in growing mortality rates.

The study did not pinpoint the reasons for the increase in tumors or whether they’re becoming more aggressive. Andreana Holowatyj, an assistant professor of hematology and oncology at Vanderbilt University Medical Center, mentioned, “It’s a pressing concern that we need to understand better to improve treatment.” She was not involved in the new research.

Standard approaches for treating rectal cancer often include surgery, alongside radiation and chemotherapy, which can impact a patient’s bladder, bowel, and sexual functioning.

Why Are Rectal Cancer Rates Rising Among Millennials?

There’s no clear answer yet. Researchers are striving to find potential links among younger adults diagnosed with rectal cancer in their 30s and 40s. It appears that most of the cancers driving the current surge are not hereditary. Dr. Schlechter suggested that some form of risk exposure might have emerged around the 1960s or 70s.

“It’s not like there’s a new gene in the population,” he noted. “This is something modern.”

There may be a disruption in the colon’s microbiome due to factors such as high sugar intake during childhood. However, many younger rectal cancer patients have “zero risk factors,” which raises additional concerns.

Rectal Cancer Symptoms to Beware Of

Symptoms related to colon cancer can be quite vague, including fatigue, abdominal discomfort, bloating, and unexplained weight loss. Rectal cancer symptoms often involve visible blood on toilet paper or in the toilet bowl, along with an urgent compulsion to use the bathroom even after a bowel movement.

Any noticeable changes in bowel habits should prompt a visit to a doctor. “If things are different, you should really talk to a doctor and specifically ask, ‘Could this be colon cancer? I hear it’s affecting young people,’” emphasized Dr. Schlechter.

The U.S. Preventive Services Task Force advises that colon cancer screening should start at 45, generally through a colonoscopy. However, younger individuals with a family history of the disease may need to begin screening earlier. This poses a challenge for younger adults without such a history who are experiencing symptoms, as there can be a significant delay—up to seven months—before a diagnosis is made.

“That can have a real impact on outcomes,” Pathiyil remarked. “Colorectal cancer is treatable when found early. Yet, around 75% of individuals under 50 are diagnosed at an advanced stage, which likely contributes to the rise in mortality.”