Researchers link shortened chromosomes to cancer

Canadian Cancer Society
Media Release

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Canadian Cancer Society researchers have discovered that certain changes in DNA may help predict which patients are at higher risk for developing cancers related to an inherited genetic condition called Li-Fraumeni syndrome. The results of the study are published in the February 15 issue of Cancer Research.

Li-Fraumeni syndrome (LFS) affects children and young adults and significantly increases their risk of developing cancer, most commonly brain, bone, breast and soft tissue tumours. In this study, the researchers found that shortened telomeres - the end-caps on chromosomes that help preserve genetic integrity - are linked to the earlier onset of tumours. Specifically, the researchers found that telomere length was much shorter in LFS children with cancer than in their LFS siblings without cancer. Telomere length was also shorter in these cancer patients than in patients without LFS.

"This discovery, while at a basic stage, is crucial to enhancing our understanding of the causes of cancer in some families," says Dr. Barbara Whylie, CEO of the Canadian Cancer Society. "We hope this knowledge can be used to improve diagnosis and treatment of those at increased risk of the disease."

"One of the challenges of caring for patients with Li-Fraumeni syndrome is the unpredictable and varying ages at which cancer may develop," says lead researcher Dr. David Malkin, a Canadian Cancer Society researcher and co-director of the Cancer Genetics Program at The Hospital for Sick Children. "This discovery could potentially provide a reliable way to assess the risk and the appropriate screening tests for carriers of LFS."

The research team analyzed blood samples of individuals from nine LFS families with specific genetic mutations that may be associated with earlier onset of cancer. In addition to finding significantly shorter telomere length in LFS carriers with cancers than in LFS carriers without cancers, the researchers also observed that telomere length in children with cancer was even shorter than in parents with cancer.

"That this genetic condition appears to occur earlier in age from parent to child underscores the need for careful monitoring across generations," says Malkin.

The researchers note that the possible link between telomere maintenance and the development and progression of cancer must be further studied, particularly in respect to other conditions that appear to predispose people to cancer.

The Canadian Cancer Society is a national community-based organization of volunteers whose mission is to eradicate cancer and to enhance the quality of life of people living with cancer. It is the largest charitable funder of cancer research in Canada. This year, the Society is funding more than $47 million in leading-edge research projects across the country. When you want to know more about cancer, visit our website at www.cancer.ca or call our toll-free, bilingual Cancer Information Service at 1 888 939-3333.

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