Rectal cancer deaths are on the rise among adults under 50, a demographic historically less affected by the disease. This concerning trend, particularly impacting millennials, has led experts to warn that rectal cancer could become the leading cause of cancer death in individuals under 50 by 2035 if current trajectories continue.
Colorectal cancer, a classification encompassing both colon and rectal cancers, is now the leading cause of cancer-related mortality in adults younger than 50. While medically similar due to the rectum being the final section of the large intestine, rectal cancers are experiencing a more rapid increase in fatalities compared to colon cancers within this age group.
"The rate of rectal cancer is rising more quickly than the rate of colon cancer. We don’t know why," said Dr. Jatin Roper, a gastroenterologist with Duke Health. "It is now recognized that rates of colon and rectal cancer are rising dramatically in younger people."
Key Warning Signs
The most frequently reported symptoms of rectal cancer include rectal bleeding and abdominal pain. Rectal bleeding, which can manifest as blood in the stool or maroon-colored stools, is particularly common in younger individuals diagnosed with the disease. This symptom can sometimes be mistaken for hemorrhoids or, in women, menstruation.
Other indicators may include changes in bowel habits, persistent constipation, thinner stools, unexplained fatigue, and weight loss. Anemia can also be a sign. Dr. Michael Foote, a gastrointestinal medical oncologist at Memorial Sloan Kettering Cancer Center, noted that because rectal cancers occur at the end of the digestive tract, symptoms like thinner stools or blood in stool are more likely.
"I think the key message is that any change in your gastrointestinal tract should not be ignored," Roper advised. "The most concerning signs that should prompt an investigation include any sign of blood in the stool."
However, some individuals may experience no symptoms, underscoring the importance of regular screenings. Research indicates that colorectal cancer rates have increased by 63% in adults under 50 since 1988, with the rate rising from 8 to 13 cases per 100,000 individuals.
Potential Contributing Factors
While the exact causes for this rise remain unclear, experts are investigating several potential factors. Changes in diet and lifestyle over the past several decades are considered significant contributors. A "Western diet," characterized by high animal fat, high carbohydrates, processed meats, refined grains, and processed sugars, is frequently cited.
"The rise in colorectal cancer in younger people started sometime between probably 1950 and 1990... and [rates have] been increasing at a greater rate since," Foote stated, adding that the increase is unlikely due to increased screening alone.
Other theories include alterations in the gut microbiome, potentially influenced by changing dietary habits and exercise patterns. While obesity and diabetes are known risk factors for colorectal cancer, many younger individuals diagnosed with the disease do not fit these profiles.
Reducing Risk and Importance of Screening
To mitigate the risk of rectal cancer, experts recommend regular screenings. For individuals at average risk, screening for colon and rectal cancer should begin at age 45. Stool-based tests, such as fecal immunochemical tests (FIT) and Cologuard, are viable alternatives for those who cannot undergo colonoscopies.
Individuals with a first-degree family history of colon or rectal cancer may qualify for earlier screening.
Beyond screenings, lifestyle modifications can play a role. Adopting a diet rich in fiber and low in animal fats, similar to a Mediterranean diet, is encouraged. Limiting sugar-sweetened beverages and alcohol consumption is also advised.
"If you do have obesity or diabetes, think about trying medications or trying a lifestyle change to reduce your risk there as well," Foote said. "And then talk to your doctor, get established with a primary care doctor early."
Experts emphasize the importance of not ignoring potential symptoms and seeking medical attention promptly. If a doctor dismisses concerns, patients are encouraged to seek a second opinion.
The increase in diagnoses among younger populations has prompted a shift in how the medical community views these symptoms, recognizing that they warrant thorough investigation.