colorectal cancerMany young people are missing out on vital screening for colorectal cancer because they’re not over 50 years of age, meaning they often present at advanced stages of the disease.

In a recent analysis of US data, 1 in 7 colorectal patients was younger than 50 years old, the recommended age to begin screening. Younger patients were more likely to be diagnosed with advanced stage disease.

However, despite the late diagnosis, these patients often receive more aggressive therapy and lived longer without a cancer recurrence, suggesting some compensation for their later diagnosis. 

Although traditionally regarded as a disease of the elderly, the number of cases seen cases in younger individuals is increasing. To assess the treatment patterns and outcomes of these patients, a team led by Samantha Hendren, MD, MPH, of the University of Michigan, conducted a population-based retrospective study of the nationally representative Surveillance, Epidemiology, and End Results registry, looking specifically at information on patients diagnosed with colorectal cancer in the United States from 1998 to 2011.

In total, 258,024 patient records were analysed, of which 37,847 (nearly 15%) of patients were younger than 50 years old, the age at which screening begins in the US. 

Young colorectal patients were more likely to be diagnosed with regional or distant disease, which are both more dangerous than localised disease. Among colorectal cancer patients with distant metastasis, those who were younger were more likely to receive surgical therapy for their primary tumour (72% versus 63% of older patients). Also, radiation therapy was used more often in younger than in older rectal cancer patients (53% versus 48%). 

Overall, colorectal cancer patients who were younger than 50 years old lived slightly longer without a cancer recurrence, even though they tended to have more advanced disease when they were diagnosed. The 5-year cancer-specific survival for younger patients was 95.1% versus 91.9% for patients 50 and older for localised disease, 76% versus 70.3% for regional disease, and 21.3% versus 14.1% for distant disease, respectively.

“This study is really a wake-up call to the medical community that a relatively large number of colorectal cancers are occurring in people under 50,” said Dr Hendren. “In a practical sense, this means that we should look out for warning signs of colorectal cancer such as anaemia, a dramatic change in the size or frequency of bowel movements, and dark blood or blood mixed with the stool in bowel movements.” 

“Also, people with a positive family history for colorectal cancer (in first-degree relatives such as parents or siblings) and some others who are at higher risk should begin screening earlier than 50. This is already recommended, but we don’t think this is happening consistently, and this is something we need to optimise.” 

In the UK, test kits for faecal occult blood (FOB) screening are sent to patients in England, Northern Ireland and Wales every two years from age 60-74 and from 50-74 in Scotland. 

Pilots of the more sensitive faecal immunochemical test (FIT) may lead to it replacing the guaiac FOB (gFOB) test.

Flexible sigmoidoscopy screening involves an invitation for a one-off sigmoidoscopy at the age of 55.

Pilots began in 2013 and it is currently being introduced in England. Pilots offering it to 60-year-olds have started in Scotland. An added benefit of this screening, as well as diagnosing cancer earlier, is the prevention of cancer by identification and removal of adenomas.

Overall 5-year survival rate is around 50% in the UK, but when detected at the earliest stage (Dukes A) this rises to about 93%. Currently fewer than 9% of cases in the UK are diagnosed at this stage. A similar percentage is diagnosed with late stage disease (Dukes D) with 5-year survival of less than 7%.

The results of the study were published early online in CANCER, a peer-reviewed journal of the American Cancer Society.