Cell Insights May Predict Breast Cancer's Spread

Cell Insights May Predict Breast Cancer's Spread
FRIDAY, Nov. 16 (HealthDay News) -- U.S. researchers believethey're on the way to solving a major question about breast cancer: Whichwomen have a type of lesion in their breast duct that will progress toinvasive disease?
"It's an exciting step forward -- people have been trying to gettraction on this big clinical problem for about 40 years, and this is abig crack in the door," said lead researcher Thea Tlsty, a professor ofpathology at the University of California, San Francisco.
Ductal carcinoma in situ (DCIS), as this type of lesion is officiallyknown, is diagnosed in about 47,000 American women every year, accordingto the U.S. National Cancer Institute. To prevent its recurrence asinvasive breast cancer, DCIS generally is treated by lumpectomy alone(approximately 25 percent of cases) or lumpectomy with adjunctivetreatments such as radiation, chemotherapy, and/or hormones (approximately40 percent).
In about 25 percent of cases, complete mastectomies are performed. Lessthan an estimated 5 percent of women choose "watchful waiting" in lieu ofa surgical intervention, Tlsty said.
But doctors are still confronted with a guessing game when it comes topredicting those patients at highest risk for recurrence, Tlsty said."Only about 12 to 15 percent of women diagnosed with DCIS are going tohave a future invasive cancer, and all the others won't. Up until now, theproblem was that we couldn't distinguish the 12 to 15 percent from thosewho were not [at risk]," explained Tlsty.
Consequently, some women unknowingly are overtreated by having amastectomy, and others are undertreated if they chose a course of watchfulwaiting rather than surgical intervention, Tlsty added.
In their pilot study, published in the November issue of CancerCell, the UCSF team looked at how a collection of biomarkers,including molecules called p16 and ki67, interact to predict invasivetumors, she explained.
Because this initial study was done on tissue samples from 70 women, alarger retrospective study is under way at UCSF to validate the initialresults, Tlsty said.
Further research, including a large prospective trial, is also neededbefore the findings can be ready for clinical use, she added. If that workupholds the results of the pilot study, the biomarkers could be ready forclinical use within four to five years, Tlsty said.
Dr. Joseph Geradts, a professor of pathology at Duke University inDurham, N.C., said that finding biomarkers that predict the conversion ofDCIS into invasive cancer is "the holy grail of breast cancer research."He said there have been a number of previous studies that have beenpublished, but, so far, they've been "mostly a fruitless effort."
According to Geradts, the UCSF study "is valuable," because "theauthors propose two new biomarkers that in the past have not been lookedat." The UCSF team's findings "are intriguing preliminary data" that"merit confirmation and subsequent studies," he added.
Geradts said his own lab currently is researching whether changes inDNA may identify a tumor's capacity to metastasize or become invasive.Other researchers are looking at other DCIS biomarkers, he said.
"DCIS itself is a non-life threatening condition" with rare exceptions,noted Dr. Eric Winer, director of breast oncology at the Dana-FarberCancer Institute in Boston, and women are usually treated to help preventinvasive cancer. If the findings of the initial UCSF study are confirmed,then with "careful investigation, we may get to the point where we don'thave to treat all women with DCIS, and we may be able to tailor it so somewomen get less, and some women get more" depending upon their risk forinvasive breast cancer, Winer said.
"It's a very complex and interesting study" added Dr. Richard Bleicher,a surgical oncologist at Fox Chase Cancer Center in Philadelphia. "We needto be cautiously optimistic."
Bleicher added that while the findings have "significant potential,"women at this point shouldn't "pin all your hopes on it," because the p16assay is not something they can ask their doctors for at this point intime.