Breakthrough in Predicting Invasive Breast Cancer
WEDNESDAY April 28, 2010 -- A new way to predict whether women with the most common form of breast cancer are at risk of developing more invasive tumors later in life will help those women be more selective about their treatment, U.S. researchers report.
They analyzed the medical records of 1,162 women, aged 40 and older, who were diagnosed with ductal carcinoma in situ (DCIS) and underwent lumpectomy, which is surgical removal of the tumor and some of the surrounding normal tissue.
The researchers found that two factors -- method of diagnosis and expression of several biomarkers -- were predictors of the risk of developing invasive breast cancer within eight years of being diagnosed with DCIS.
The risk was higher among women who had a breast lump diagnosed as DCIS than among those whose DCIS was diagnosed by mammography. Women with high levels of the biomarkers p16, cyclooxygenase-2, and Ki67 in DCIS tissue were also more likely to develop invasive breast cancer.
Women with the lowest risk had only a 2 percent chance of developing invasive breast cancer at five years after diagnosis and a 4 percent chance at eight years.
As a result of the research, doctors can better predict whether women treated with a lumpectomy only are at a very low or a high risk of developing invasive cancer later.
The findings mean that women with DCIS "will have much more information, so they can better know their risk of developing invasive cancer. It will lead to a more personalized approach to treatment. As many as 44 percent of patients with DCIS may not require any further treatment, and can rely instead on surveillance," study author Dr. Karla Kerlikowske, a professor of medicine, and epidemiology and biostatistics at the University of California, San Francisco Helen Diller Comprehensive Cancer Center, said in a news release.
Only about 1 percent to 2 percent of women with DCIS die of breast cancer within 10 years of diagnosis, but many choose aggressive treatment because they don't fully understand their risk of developing invasive breast cancer, the researchers said.
The study appears online April 28 in the Journal of the National Cancer Institute.
Breastcancer.org has more about DCIS.
Posted: April 2010