May 7, 2010

Scientists have found a way to predict the risk of developing future tumors in some women with noninvasive breast cancer cells. This new discovery could mean fewer mastectomies for women with ductal carcinoma in situ (DCIS), the most common form of noninvasive breast cancer.

 “Women 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,” said Karla Kerlikowske, MD and professor of medicine and epidemiology and biostatistics at the UCSF Helen Diller Family Comprehensive Cancer center and the lead author of the study.

Up to 44 percent of patients with ductal carcinoma in situ, which is a noninvasive condition where abnormal cells are in the lining of a breast duct but have not spread outside the duct to other tissues in the breast, may not need any other treatment. They may just need to be monitored.

Lisa Layne of Seattle, WA was diagnosed with DCIS and her doctor told her she was not a candidate for radiation and should seriously consider a double mastectomy. Layne opted to wait and get a second opinion. She’s now a UCSF patient opting for surveillance.

“Women feel as if they’ve been given the death sentence when diagnosed with DCIS even though it’s 90 percent curable. It’s so different than full invasive breast cancer,” she said.

Researchers at the University of San Francisco and the San Francisco Veterans Affairs Medical Center (SFVAMC) published the study online in the Journal of the National Cancer Institute. They looked at the medical histories of 1,162 women who were 40 years and older with the diagnosis of DCIS who had had a lumpectomy.

They found two factors that predict the risk of an invasive cancer developing in the following eight years. DCIS detected through a breast lump has a higher chance of future invasive cancer than DCIS detected through mammography. Also the presence of a combination of certain biomarkers on the DCIS tissue is also a predictor. 

About 50 percent of women with a palpable DCIS lump and who have expression of protein levels of p16, cyclooxygenase-2 and Ki67 will develop invasive cancer in the future, the study states.

But in women with DCIS only about 11 out of 100 women treated by lumpectomy develop invasive cancer within eight years of diagnosis. However many women who get a DCIS diagnosis opt for aggressive treatment when it may not be necessary. About 35 percent choose a lumpectomy, 25 percent get a complete mastectomy, 3 to 5 percent choose active surveillance and the rest opt for lumpectomy plus radiation or hormone treatment or both.

“This is an exciting and powerful beginning to be able to predict which pre-cancers will lie dormant and which will lead to invasive cancers,” said Thea D. Tlysty, PhD, one of the principal investigators on the study. She is a professor of pathology and UCSF leader of the Cell cycling and Signaling Program at the UCSF Helen Diller Family Comprehensive Cancer Center.