Genetic Test Could Help Predict DCIS Recurrence
(HealthDay News) — For women who have ductal carcinoma in situ surgically removed, a genetic test may help predict the odds of a recurrence, according to research presented at the annual San Antonio Breast Cancer Symposium, held from December 9–13 in San Antonio.
The Oncotype test analyzes certain cancer-linked genes to see how "active" they are, then gives the patient's sample a score between 0–100. The test had already been "validated" using tumor samples from patients enrolled in a clinical trial, Eileen Rakovitch, MD, radiation oncologist at the Sunnybrook Health Sciences Center in Toronto and lead researcher on the new study, told HealthDay. The study team tested tumor samples from 1,569 women treated for ductal carcinoma in situ from 1994–2003 – 718 of whom received surgery only.
The researchers found that among those surgery-only patients, the higher the carcinoma score, the greater the risk of a recurrence over the next decade. For each 50-point increase in the score, the odds of a recurrence doubled. But the test does not just put women into lower- or higher-risk groups, Rakovitch noted. "An individual woman gets information about her personal risk of recurrence over the next 10 years," Rakovitch said. And that is "much more informative," she added, than relying on traditional factors, such as the tumor size and grade.
According to the American Cancer Society, ductal carcinoma in situ accounts for about 20% of breast cancer diagnoses – and nearly all women with it are cured. The hope, Rakovitch said, is that the Oncotype test will help some women avoid "overtreatment," while others can feel more confident that they need additional treatment after surgery.
The study was partly funded by Genomic Health, based in Redwood City, Calif., which markets the Oncotype test.