Breast 'Pap Smear' Predicts Likely Cancer
New Test May Prevent Onset of Cancer by Identifying Early Cell Changes
How It Works
The test involves harvesting cells at eight specific sites in the breast and then having each cell individually evaluated by a specially trained pathologist to determine which ones are abnormally shaped, indicating they are "atypical" and likely to be precancerous.
"This would not replace mammograms, but [would] be another tool to monitor high-risk women," says Victoria Seewaldt, MD, director of Duke's Comprehensive Cancer Center, who is involved in the trials. "The advantage it offers is that unlike mammogram or MRI, which detect cancer that has already developed, this test allows us to survey individual cells from breast tissue and examine them under a microscope for early changes that often precede breast cancer, just as a Pap smear predicts cervical cancer."
Not only would this allow for early treatment with "pre-cancer" drugs to stop cancer before it fully develops, but it would allow scientists to better track which of these treatments are most effective at eradicating these abnormal cells. Agents being explored with this test as part of the new trials include Cox-2 inhibitors such as Celebrex, beta-carotene, flaxseed oil, and the breast cancer drug tamoxifen.
"We could administer chemo-preventative therapy to high-risk women and then sample their breast tissue cells six or 12 months later to see what is working and what isn't," Seewaldt tells WebMD. "It could be huge, because currently when we do clinical trials, we look at the end point -- whether there is cancer or no cancer -- and we sometimes have to guess on how we got there."
The test is not designed to screen all women, like mammogram or MRI, but rather only those with a strong family history of breast cancer, mutations in BRCA1 and BRCA2 genes, a history of abnormal breast biopsies, or with dense breast tissue that make mammograms hard to read. It would also be used to track women who have already been treated for breast cancer to further track their remission, says Seewaldt.
"Many women, especially those with super dense breast tissue, can do all the right things such as get regular mammograms and cancer still seems to come out of nowhere," she tells WebMD. "But since cancer takes 10 to 20 years to develop, this would allow high-risk women to get an early jump on treatment before breast cancer actually fully develops."