People with a family history of pancreatic cancer now have a way to accurately predict their chance of carrying a gene for hereditary pancreatic cancer and their lifetime risk of developing the disease. Developed by Johns Hopkins Kimmel Cancer Center researchers, the novel computer software tool is designed to help genetic counselors and physicians decide who would most benefit from early screening.

An estimated 10 percent of aggressive and highly fatal cases of the disease are caused by inherited genes. Even if there is a 100 percent chance that an individual carries a pancreatic cancer gene, their risk for developing the disease is only 20 to 25 percent over their lifetime, says Alison Klein, Ph.D., assistant professor and director of the National Familial Pancreas Tumor Registry at Johns Hopkins. So, while its a rare disease, the need for screening in these persons is important.

The risk calculator, based on similar tools for breast and colon cancer, calculates a percentage score of probability that a person carries a pancreatic cancer gene. Called PancPRO, it also computes an individuals lifetime risk of developing the disease.

Eventhough scientists have still not identified specific genes that cause the disease, they can estimate high risk based on clusters of family members with a history of pancreatic cancer. We know how genes behave, and coupled with information about a family - who has the disease, their age, family size, and causes of death - our model can provide a good estimate of an individuals risk, says Klein.

Early risk assessment has long been sought for pancreatic cancer that runs in families, Klein says because of the difficulty doctors have diagnosing it before it has already spread. Survival rates are extremely low.

To test the models effectiveness for predicting cancer, Klein and her colleagues fed the software family history information given by more than 6,000 individuals in 961 families when they initially joined the Hopkins pancreatic cancer registry several years ago. Kleins team divided registrants into groups representing the number of pancreatic cancer patients in each family - from one to three or more members. They compared predictions from the PancPRO model with what actually occurred in these families from one to 11 years later. On average, the model calculated higher risk scores for individuals who developed pancreas cancer than for those who remained disease free.

Current practices for identifying pancreas cancer risk without the new model are slightly better than a coin toss at 61 percent, but PancPRO correctly assesses risk 75 percent of the time, taking into account all potential threshold values for defining risk. Overall, 26 individuals developed cancer, and PancPRO predicted slightly more at 31. Their published results appear in the April 10 issue of the Journal of Clinical Oncology.

Studies are under way to determine the effectiveness of screening, based on risk assessment, which includes an ultrasound procedure conducted through an endoscope inserted through the mouth, esophagus and stomach to detect premalignant changes. The test provides sound-wave pictures of the pancreas, which sits next to the stomach.


Posted by: Andria    Source

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