Study points to a possible biomarker for colon cancer in people 50 and under

An abnormality of chromosomes long associated with diseases of aging has, for the first time, been linked to colon cancer in people 50 years old and younger, an age group usually considered young for this disease.

The finding may provide an early alert for younger patients with colon cancer and could prompt new research into colon cancer prevention and treatment strategies, say Mayo Clinic researchers.

The study results will be presented at 10 a.m., Saturday, Oct. 27, during the annual meeting of the American Society of Human Genetics in San Diego.

The Mayo Clinic team led by Lisa Boardman, M.D., a specialist in gastrointestinal malignancies, investigated the structures inside of cells known as telomeres, which are the caps on the ends of chromosomes that keep chromosomes from unraveling. Telomeres naturally shorten with aging and are associated with many diseases of aging, including cancer. Shortened telomeres have been found in colon cancer tumor cells, but this study links these telomeres to colon cancer.

Dr. Boardman and an interdisciplinary group of researchers examined the DNA in blood samples of 114 colon cancer patients 50 years old and younger and 98 people with no history of cancer. They found that the colon cancer patients had abnormal telomeres that were unusually short, particularly for a group of patients considered young for colon cancer: patients in the study were about 15 years younger than the average age of patients with colon cancer. In addition, colon cancer in this younger group affected men more often than women.

Colon cancer, also called colorectal cancer or bowel cancer, includes cancerous growths in the colon, rectum and appendix. It’s the second leading cause of cancer death in the United States, affecting nearly 145,000 people each year. The first cases tend to appear in people in their 40s, but most patients tend to be in their mid 60s by the time they are diagnosed.

Each year about 25,000 people 50 years old or younger are diagnosed with colon cancer, accounting for up to 17 percent of all cases which could potentially be affected by the outcomes of this study. Colon cancer is among the top 10 cancers to affect people between 20 to 49 years old, the authors report.

Unfortunately, young people diagnosed with colon cancer are more likely to be in the later stage of the disease. This group also is more likely to develop rectal cancer as compared to older patients. This information led researchers to suspect that colon cancer in younger people is biologically distinct from colon cancer in older patients.

To researchers, this association between cancer and prematurely short telomeres raises the possibility of one day using telomere length as a biomarker of cancer or an early warning system that can alert physicians to pre-symptomatic cancerous changes that are underway.

“Finding this association between colon cancer patients and increased telomere shortening is exciting because, if validated, it really opens up new possibilities for new treatment strategies. For example, we know that telomere length can be repaired, so we want to look at telomere maintenance genes which, when defective, might very well contribute to cancer,” she said.

Researchers intend to look at other associations that shorten telomere length. These include environmental factors, such as increased body mass index and smoking.

“We know that cancer is a disease of the environment and genes, both of which affect telomeres. If we can understand how this happens, it could lead us to develop therapies to reverse premature telomere shortening, stall it or protect the telomeres from destructive influences in the first place,” Dr. Boardman says.

Source: Mayo Clinic

Related stories:

Mayo Clinic estimates new, tiny, super-sensitive probe could cut colon polyp removal in half
Based on results of a landmark study, researchers at Mayo Clinic's Florida campus see a future in which virtual biopsies will eliminate the need to remove colon polyps that are not cancerous or will not morph into the disease.
CRC screening before Medicare age could save millions in federal health-care dollars
A screening program for colon cancer in patients starting ten years prior to Medicare eligibility, at age 55 instead of Medicare's 65, would save at least two dollars for every dollar spent, according to a new study presented at the American College of Gastroenterology's 73rd Annual Scientific Meeting in Orlando.
Study confirms colonoscopy associated with reduced colorectal cancer incidence
Patients who undergo a complete negative colonoscopy have a reduced incidence of colorectal cancer, confirms a study published in Clinical Gastroenterology and Hepatology. However, in the proximal colon, the incidence reduction of colorectal cancer following complete negative colonoscopy differs in magnitude and timing.
Breakthrough optical technology to assess colon cancer risk, accuracy
Researchers at NorthShore University HealthSystem (NorthShore) and Northwestern University have discovered that fiber optic technology can for the very first time effectively measure blood levels in the colonic lining (mucosa) in humans, thus having potential applications for analyzing risk of colon cancer.
Most adults under 50 unlikely need colorectal screening
Young adults without a family history of bowel disease are unlikely to develop adenomas, the colorectal polyps most likely to lead to cancer, according to new research directed by scientists at the Johns Hopkins Kimmel Cancer Center. The finding supports current cancer screening guidelines recommending adults in general undergo screening colonoscopies starting at age 50.
Surgical treatment provides new option for some colorectal cancer patients
Research out of Wake Forest University School of Medicine suggests that a surgical technique not traditionally used in advanced abdominal cancer may be a viable treatment option for some patients previously thought to be untreatable, offering the real possibility of extending survival for those patients.
Black Americans are at higher risk for colon polyps
Black Americans have a higher occurrence of colon polyps, according to a new study. This is a significant finding considering the incidence of colon cancer among black men has increased and remained unchanged among black women during the last 20 years.
Black patients at higher risk for colon polyps
Compared with white patients, black patients undergoing screening colonoscopy have a higher prevalence of colon polyps, according to a study in the September 24 issue of JAMA.

News discussion:

Medicine & Health news