The prevalence of colorectal cancer is increasing in US patients who are younger than 50 years and who are thus younger than the age for which routine colorectal cancer screening is recommended. Because they are not being screened, they are presenting with more advanced disease than patients aged 50 years or older, a nationally representative study indicates.
"In our study, we found that about 1 in 7 colorectal cancers are diagnosed in patients younger than the screening age of 50, and to put this in context, less than 1 in 20 invasive breast cancers are diagnosed before the screening age of 40," senior author Samantha Hendren, MD, MPH, University of Michigan, in Ann Arbor, told Medscape Medical News in written correspondence.
"This certainly raises the question of whether screening for colorectal cancer should begin at an earlier age," she said, "but regardless of any changes that may be made to colorectal cancer screening, we think this research has the potential to improve practice today by raising awareness among patients and medical providers about the increasing number of patients under 50 who are developing colorectal cancer."
The study was published online January 25 in Cancer.
The researchers, with lead author Zaid Abdelsattar, MD, University of Michigan, Ann Arbor, used the Surveillance, Epidemiology and End Results database to identify all patients aged 20 to 79 years who were diagnosed with colon or rectal cancer between January 1998 and December 2011.
Patients were categorized as those aged 50 years and older and those younger than 50 years.
Of 258,024 patients who were diagnosed with colon or rectal cancer during the study interval, 37,847, or 14.7%, of the cohort were too young, at a mean age of 42.5 years, to have been recommended for usual-risk screening.
After adjusting for sex, race, marital status, tumor location, and year of diagnosis, younger patients were 37% more likely to present with regional vs localized disease compared with older patients (P < .001).
They were also 58% more likely to present with distant disease than localized disease compared with older patients (P < .001).
Younger patients with distant disease were also more likely, at 70.8%, to have undergone surgery on their primary tumor compared with older cancer patients, at 66.6% (P < .001). Younger patients with rectal cancer were also significantly more likely to receive radiotherapy for all stages of the disease compared with older rectal cancer patients (P < .001).
Table 1. Adjusted Rates for Cancer-Directed Therapy by Stage of Disease
|Disease Stage||Age <50: Surgery||Age ≥50: Surgery||Age <50: Radiation||Age ≥50: Radiation|
5-Year Survival Rates
"The overall crude 5-year survival rate for young patients and all stages of disease combined was 67.7% versus 66.8% for patients ≥50 years (P = .008)," Dr Abdelsattar and colleagues write.
Despite the greater likelihood of younger patients presenting with more advanced-stage disease, survival was significantly better in younger patients across all stage groups compared with older patients.
Table 2. Adjusted 5-Year Cancer-Specific Survival for Patients Aged <50 Years vs ≥50 Years
|Age <50||Age ≥50|
Asked by Medscape Medical News why the proportion of colorectal cancer cases occurring in younger patients might be increasing, Dr Hendren said this was likely the result of the very successful screening program for colorectal cancer detection in patients aged 50 years or older.
"Screening tests can detect precancerous polyps which can be removed, preventing cancer from developing," she elaborated.
"In fact, colorectal cancer is one of the only cancer types which is decreasing in frequency overall due to screening tests," she added.
"As a result of this decrease, the relative proportion of cases in people too young for screening has increased."
Dr Hendren also noted that young patients often report that they have had symptoms for a long while but that they or their healthcare provider did not think their symptoms were serious, likely because colorectal cancer has traditionally been thought of as a disease of the elderly.
"This study is really a wake-up call to the medical community that a relatively large number of colorectal cancers are occurring in young people," she cautioned.
"In a practical sense, this means that we should be looking out for warning signs of colorectal cancer such as anemia, a dramatic change in the size or frequency of bowel movements, and bleeding with the bowel movements," she added.
Although not all bleeding is associated with cancer, dark blood or blood mixed with the stool is a warning sign, Dr Hendren confirmed.
Dr Hendren also suggested that any patient with a parent or sibling who has been diagnosed with colorectal cancer should begin colonoscopy screening at age 40 years or even earlier if the relative had cancer before age 50 years.
Dr Abdelsattar and coauthor Sandra Wong, MD, are supported by the Agency for Healthcare Research and Quality. Dr Hendren has disclosed no relevant financial relationships.
Cancer. Published online January 25, 2016. Abstract
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Cite this: 1 in 7 Colorectal Cancers Found in Younger Patients (<50) - Medscape - Feb 02, 2016.