Number of Young Patients With Newly Diagnosed Colorectal Cancer Anticipated to Double
In the next 15 years, more than 1 in 10 colon cancers and nearly 1 in 4 rectal cancers will be diagnosed in patients younger than the traditional screening age, according to researchers at The University of Texas MD Anderson Cancer Center. This growing public health problem is underscored by data trends among 20- to 34-year-olds in the United States, among whom the incidence of colorectal cancer is expected to increase by 90% and 124.2%, respectively, by 2030.
Reported by Bailey et al in JAMA Surgery, the findings build on prior studies of colorectal cancer and provide quantitative estimates of exponentially increasing risk for colorectal cancer among patients who fall under 50, the age at which colorectal screening becomes recommended for the general public. The authors pointed to lifestyle and behavioral factors such as obesity, lack of physical activity and a Western diet as major risk factors for colorectal cancer, though the exact causes of the predicted increases are not known.
“This is an important moment in cancer prevention,” said principal investigator George J. Chang, MD, MS, Associate Professor in the Departments of Surgical Oncology and Health Services Research. “We’re observing the potential real impact of colorectal cancer among young people if no changes are made in public education and prevention efforts. This is the moment to reverse this alarming trend.”
Study Details
The retrospective cohort study analyzed Surveillance, Epidemiology, and End Results (SEER) data on more than 393,000 patients with histologically confirmed colorectal cancer between 1975 and 2010, examining age at diagnosis in 15-year intervals starting at age 20.
Researchers observed that the annual incidence rate for colorectal diagnosed in patients under age 34 is increasing across all stages of disease: localized, regional, and distant. The trends indicate that by 2020 and 2030, the incidence rate of colon cancer will increase by 37.8% and 90%, respectively, for patients aged 20 to 34. By 2030, this represents a 131.1% incidence rate change of colon cancer in younger patients compared to patients older than 50 years of age. Similarly, by 2020 and 2030, the incidence rates for rectosigmoid and rectal cancers are expected to increase by 49.7% and 124.2%, respectively, for the same age group—a 165% incidence rate change compared to patients older than 50 years for these cancers by 2030. Among patients aged 35 to 49, incidence rates are anticipated to increase 27.7% for colon cancer and 46% for rectal cancer in the same timeframe.
An opposite trend was observed in older patients largely thanks to screening and prevention efforts. There has been a steady decline in the incidence rate of colorectal cancer in patients 50 and older, with the most notable declines in regional and distant disease. Based on the predictive model, the researchers anticipate this trend will continue, with incidence declining by 21.2% and 37.8% in 2020 and 2030 for colon, respectively, and 19.0% and 34.3% in 2020 and 2030 for rectum, respectively. The largest decrease is expected for patients older than 75 years.
Study Implications
Lack of screening and risk factors such as obesity and physical inactivity are known contributors to colorectal cancer. The authors encouraged reduced consumption of processed and fast food and more vegetables and fruits to reduce risk. While the researchers noted that the findings do not suggest revisiting screening guidelines at this time, Christina E. Bailey, MD, MSCI, surgical oncology fellow and the study’s first author, added that physicians should be on the lookout for colorectal cancer symptoms that might otherwise be dismissed in younger people and only identified as cancer after the disease has progressed.
“While our study observations are limited to colorectal cancer, similar concerns are being raised about breast cancer, as we see incidence increasing among younger women,” said Dr. Chang. “Identifying these patterns is a crucial first step toward initiating important shifts in cancer prevention.”
Dr. Change is the corresponding author for the JAMA Surgery article.
The study was supported by grants from the National Institutes of Health/National Cancer Institute. The study authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
