Differences in Older and Younger Colorectal Cancer Patients

There are several differences between the colorectal cancer tumors of younger and older patients, according to findings presented at the 2015 European Cancer Congress in September.

Researchers from Memorial Sloan Kettering Center examined the tumors of two age defined patient groups to highlight the differences between the colorectal cancer tumors of older and younger patients.

The patients were divided into two groups by age: there were 126 patients in the under 50 years group and 368 in the remaining group. For their tumor sample analysis, the researchers used genomic sequencing techniques to identify gene mutations and other DNA changes that would signal changes in genes’ behavior. If patients demonstrated large numbers of mutations or the investigators found proteins-controlled DNA replication was misfiring, those patients were excluded from the study.

“In the early onset group we found that 154 genes were under methylated,” explained study presenter Andrea Cercek in a press release. “Both under and over methylation of genes are found in cancer. We also found that an increase in methylation went hand in hand with an increase in age among the younger patients, and that this intensification was beyond that which would occur naturally in normal tissue. Finding such a distinctive molecular make-up in this group encourages us to believe that we may, in the future, be able to tailor treatments to them and attempt to prevent or slow down these processes in order to improve outcomes for them.”

According to data collected between 1992 and 2011 by the Surveillance, Epidemiology, and End Result Registries, younger onset colorectal cancer has increased at a rate of 1.5% in men and 1.6% in women. Overall, younger patients tend to be diagnosed later — by the time their cancer is more developed and more difficult to treat. Typically, the researchers believe this is due to a lack of awareness of symptoms in both patients and doctors.

“Changes in bowel habits may be attributed to Crohn’s disease, food allergies, or simply stress, for example, and doctors send younger patients for early colorectal cancer screening much less frequently than they do older ones,” continued Cercek. “Raising awareness of the increasing frequency of younger onset colorectal cancer among clinicians is very important.”

In the future, the investigators hope their findings contribute to developing more effective therapies for younger onset colorectal cancer patients in addition to improving those patients’ overall survival and quality of life. Although there is no difference in the therapies used between older and younger colorectal cancer patients, younger patients tend to be treated more aggressively, the researchers added.