(August 2010) Is ductal carcinoma in situ (DCIS), early stage breast cancer that may not become invasive, a reason to have a single or double mastectomy? Or should it simply be monitored carefully? What does a DCIS diagnosis mean anyway?
Questions about DCIS, a noninvasive condition in which abnormal cells are found contained in the lining of a breast duct, have been surfacing for 30 years. They were raised last month after a New York Times article told of women who underwent treatment before learning that their pathologists had made mistakes, and they never had the early stage cancer at all. Meanwhile, the federal government is financing a study of breast pathology variation, concerned that 17 percent of cases identified by a common needle biopsy may be misdiagnosed.
“Confusion over DCIS is not a new issue,” says Fattaneh A. Tavassoli, MD, director of Yale Medical Group’s Pathology Women's Health Program, an internationally recognized expert who oversees a team of five pathologists dedicated to breast and gynecological cases. The group often provides second opinions and consults for referring physicians from all over the world.
Tavassoli says it’s important to note that breast imaging and pathology have improved vastly in the last several years. “We are able to detect very small lesions and take very small samples. For most of those samples, we can identify lesions with various patterns of proliferation, we can classify them and separate them from fibrocystic changes and attach levels of risk.”
The downside is that highly precise imaging can pick up tiny lesions the biologic significance of which has not been established, and it is difficult even for the most experienced pathologists to accurately predict the aggressive potential of these lesions.
“It’s also important to note that experts may and do differ in the criteria they use to diagnose DCIS, and may even differ in their interpretations of the same criteria,” Tavassoli says. She is working with other experts to develop a new classification system to make the terminology pathologists use more consistent—and even take the word cancer out of cases that will not necessarily become invasive.
“Especially for non-invasive lesions, instead of calling them ‘carcinoma in situ,’ we use the terms ‘ductal intraepithelial neoplasia (DIN)’ and ‘lobular intraepithelial neoplasia.’ We take the word carcinoma out of the designation,” Tavassoli says.
Diagnoses of DCIS, which is classified as “stage 0” or noninvasive cancer, rose sharply when mammography came into wider use in the 1980s. It is now diagnosed in 50,000 women a year in the U.S. If the abnormal cells aren’t removed, experts believe that it will develop into invasive cancer about 30 percent of the time, and for some women that could take decades.
Donald Lannin, MD, who has a $1.5 million grant from Susan G. Komen for the Cure to study DCIS, says it is a complex diagnosis that can range from hyperplasia to atypical hyperplasia to low- or high-grade DCIS, to invasive cancer.
“A few years ago, we thought that everything progressed along that spectrum,” says Lannin in a recent story in the New Haven Register. “It turns out that’s not the way all breast cancer develops. Sometimes it’s hard to know whether to call a particular lesion cancer or not. There are really good pathologists who could disagree on the nature and prognosis of a lesion and the chance of it developing to an invasive cancer,” he says.
Doctors don’t recommend mastectomy for DCIS unless the lesion is large or found in multiple areas, but many believe fear is driving the increase in mastectomies and even double mastectomies among diagnosed women.
Tavassoli finds this reaction unfortunate. “We’ve seen more double mastectomies over the past three or four years,” she says, “even though it was a major accomplishment to be able to recommend lumpectomies instead of mastectomies in many cases.” In fact, if a lesion is small, such as a 2 or even 3 millimeter low-grade DIN that is surgically removed with clear margins, it may not require any further therapy, she adds.
Women who are diagnosed with DCIS and want to make sure their diagnosis is accurate should gather as much information as possible about their case, and make sure their tumor is examined by a board-certified pathologist from an accredited laboratory. “It is always wise to inquire about the credentials of any physician,” says Tavassoli. If they still feel uncertain, they can seek a second opinion before making any quick treatment decisions.