Health
New screening tool boosts breast cancer detection
■ The role genes play in disease development can be thwarted if women are correctly identified and given heightened scrutiny and targeted treatment.
By Susan J. Landers — Posted Nov. 6, 2006
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Washington -- A new, simple-to-use screening tool that identifies women at risk for hereditary breast cancer was found in a recent trial to be extremely sensitive, according to a study in the Oct. 15 journal Cancer.
The pedigree assessment tool, or PAT, was designed to be used by primary care physicians to help them identify women with family cancer histories that suggest a hereditary breast cancer syndrome.
An estimated one in 200 to 300 women carry genes for this susceptibility, said Kent F. Hoskins, MD, an oncologist and director of the cancer risk assessment program at the OSF Saint Anthony Center for Cancer Care in Rockford, Ill. He developed the PAT with center colleagues.
The most widely recognized breast cancer genes are BRCA1 and BRCA2, but there likely are others yet to be found. The lifetime risk for women who inherit these mutated genes is 50% to 80% for developing breast cancer and 10% to 40% for developing ovarian cancer, he noted.
Once identified, these high-risk women can be referred for additional help from genetic counselors who could recommend rigorous screening or preventive medications.
To have the greatest impact on this population, Dr. Hoskins and colleagues set out to develop a tool for breast cancer risk assessment that could be used broadly, much as screening mammography is employed, and in the primary care setting rather than by specialists.
Several tools already were on the market but tended to be complex and time consuming, Dr. Hoskins said. The widely used modified Gail model, although quick and easy, was not designed to look for many indicators of hereditary susceptibly, he said. The Gail model identifies five risk factors: age, age at menarche, age at first live birth, number of prior breast biopsies and number of first-degree relatives with breast cancer.
The PAT draws on such risk factors as instances of breast or ovarian cancer in second- or third-degree maternal and paternal relatives, cases of male breast cancer in the family and Jewish heritage. A varying number of points is assigned to each cancer instance, and women who score 8 or higher are considered at high risk and are to be referred to genetic counselors for additional evaluation.
The researchers pitted the PAT against the modified Gail model in a trial of nearly 4,000 women who had come in for a mammogram. They found that the new tool performed better in correctly assigning women to the high BRCA probability group with a sensitivity score of 100% and a specificity of 93%. The Gail model calculations were no better than 27% and 73% respectively.
The PAT study "demonstrated that a simple point-scoring system performs very well in identifying women in a screening mammography population who would benefit from referral to a cancer risk clinic for genetic counseling and consideration of DNA testing of appropriate family members," the authors concluded.