The addition of chemotherapy and radiation to surgery does not prolong life for these patients
Individuals younger than 50 years of age who are diagnosed with rectal cancer do not experience an overall survival benefit from currently recommended treatments, according to the study, ‘Rectal cancer patients under 50 years of age lack a survival benefit from NCCN guideline-directed treatment for stage II and III disease’, published in Cancer - a peer-reviewed journal of the American Cancer Society.
Specifically, the study found that the addition of chemotherapy and radiation to surgery does not prolong life for these patients, suggesting that the early onset disease may differ from later onset disease in terms of biology and response to therapy.
The overall incidence of rectal cancer is decreasing in patients older than 50 years of age, likely due to improved screening adherence; however, there is a disproportionate increase in rectal cancer incidence in patients under the age of 50 years. In addition, the mortality rate from rectal cancer among younger patients has increased in the past several decades.
Current national guidelines - which recommend a combination of chemotherapy, radiation, and surgery for stages II and III rectal cancer - are predominantly based on data from patients older than 50 years of age. To examine how younger patients fare, a team led by Dr Atif Iqbal of the University of Florida College of Medicine, in Gainesville, examined 2004-2014 information from the National Cancer Database. A total of 52,519 patients were analysed.
The researchers report that younger patients were more likely to be female and minorities, to be diagnosed at a higher stage, and to have travelled further to be treated at academic/integrated centres. Short‐ and long‐term outcomes were significantly better for patients younger than 50 years, with age‐specific survival rates calculated. Younger patients were more likely to receive radiation treatment outside NCCN guidelines for stage I disease. In younger patients, the administration of neoadjuvant chemoradiation for stage II and III disease was not associated with an overall survival benefit.
"Our findings support the notion that rectal cancer in young patients may be biologically different from older patients, with differing response to treatment, as has been previously shown in colon cancer," said Dr Iqbal. "These findings may help stimulate future research trial proposals focused on the younger patient population."
The study also reveals age-specific survival data for younger patients. "These data provide practicing physicians the ability to offer a prognosis personalised to the younger population, which can greatly improve discussions with younger patients."
In an accompanying editorial, Dr Matthew Kalady of the Cleveland Clinic noted that the findings highlight the need to continually evaluate approaches to colorectal cancer prevention, screening, and treatment: "This manuscript should open the eyes of physicians treating rectal cancer patients and of those making treatment guideline recommendations and screening policies.”
He also noted that the study did not address other clinically important endpoints for rectal cancer patients such as local recurrence and disease-free survival. He added that studies are needed to evaluate how factors such as diet, physical activity and obesity, underlying genetics, and gut microbes may interact with rectal cancer biology.