Several studies done in the United States and around the world suggest that regular screening has found more early-stage breast cancers, but also may have overdiagnosed a large number of women. Still, the studies also show that screening saves lives.
Overdiagnosis means either:
- a screening mammogram finds a suspicious area that would have been eventually diagnosed as cancer by other means, without any effect on the outcome of the cancer
- a screening mammogram finds a suspicious area that never would have affected a woman’s health if it hadn’t been found or treated
Overdiagnosis also is a concern in prostate, thyroid, and other cancers.
To help lower the number of people who are overdiagnosed and then treated for cancer, a group of top scientists called together by the National Cancer Institute (NCI) has proposed a major update to the way cancers are classified.
The proposal is an opinion piece, not a research study, and was published online on July 29, 2013 by The Journal of the American Medical Association. Read “Overdiagnosis and Overtreatment in Cancer: An Opportunity for Improvement.”
In the proposal, the scientists point out that when cancer screening programs were started 30 years ago, doctors’ understanding of cancer was much more simplistic than it is now. The goal of screening programs was to find cancer as early as possible, when it’s most treatable.
Still, besides finding cancer, screening programs also find slow-growing, low-risk lesions that may not need the same treatment as cancer.
The scientists also point out that doctors now recognize that cancer is a number of different diseases and each cancer is unique. Their goal in proposing the new cancer classifications is to personalize screening and focus screening policies on conditions that are the most aggressive and life-threatening.
The proposal calls for changing the names of some conditions, such as DCIS (ductal carcinoma in situ), so the word “carcinoma” isn’t in the name. This would make the condition less scary and may reassure some women who opt to not have aggressive treatment for DCIS.
DCIS is the most common type of non-invasive breast cancer and is currently considered stage 0 cancer. DCIS isn’t life-threatening, but can increase the risk of developing invasive breast cancer later on in life.
The proposal also calls for a new classification for tumors that are unlikely to cause harm. These tumors would be called “indolent” instead of classified as cancer. The classification would be changed to “indolent lesions of epithelial origin,” shortened to IDLE. So DCIS might become “ductal IDLE.”
The researchers also think that registries of lesions that have a low-risk of becoming malignant should be created so doctors and patients have information on their history and prognosis.
It’s worth noting that the day after this proposal was released, a small study came out suggesting that certain women diagnosed with either atypical lobular hyperplasia or LCIS (lobular carcinoma in situ) may be able to avoid surgery. Instead, the areas would be closely watched by doctors.
The study was published online on July 30, 2013 by the journal Radiology. Read the abstract of “Atypical Lobular Hyperplasia and Lobular Carcinoma in Situ at Core Breast Biopsy: Use of Careful Radiologic-Pathologic Correlation to Recommend Excision or Observation.”
LCIS is similar to DCIS, except the abnormal cells are growing in the lobules, the milk-producing glands at the end of breast ducts. Like DCIS, LCIS isn’t life-threatening, but can increase the risk of developing invasive breast cancer later in life.
Atypical lobular hyperplasia means that cells are growing faster than normal in the lobules and look abnormal.
In the study, the researchers looked at 50 cases of atypical lobular hyperplasia or LCIS that were diagnosed in 49 women who were 40 to 73 years old. All the women had the suspicious areas biopsied. Some of the women had the suspicious area surgically removed and some decided to carefully watch the area and have regular imaging tests.
The researchers compared the pathology reports from the biopsy or surgery to the readings of the regular imaging tests on the suspicious areas to see if the pathologic and radiologic information matched.
Of the 50 cases, 43 of them had matching pathologic and radiologic results and were classified as benign (not cancer). None of these benign cases were upgraded to cancer at the time of surgery to remove the suspicious area or during the follow-up of careful monitoring. This suggests that the women who had surgery to remove the suspicious areas could have done just as well with careful monitoring.
Of the seven cases where the pathologic and radiologic results didn’t match, two were upgraded to DCIS during surgery and none were upgraded during the follow-up of careful monitoring.
So the researchers concluded that if the pathologic and radiologic information from atypical lobular hyperplasia or LCIS matches, women don’t need to have surgery and instead could safely monitor the area with imaging tests. This study seems to support the NCI experts’ proposal of taking a more conservative approach to treating many types of cancer. Still, the study is very small and is retrospective, meaning it’s looking back at information collected for other reasons than this study.
At Breastcancer.org, we recognize that overdiagnosis does happen. Not all cancers or precancerous conditions grow and metastasize. Some suspicious areas that are found by mammogram would likely not cause any problems if never detected.
But right now, tests aren’t available that say for certain which suspicious areas will turn out to be fast-growing cancers and which will never grow and cause a problem. Because we can’t be sure, it makes sense to treat suspicious areas as aggressively as women and their doctors feel is necessary.
“Which cases of DCIS will turn into an aggressive cancer and which ones won’t?” commented Dr. Larry Norton, medical director of the Evelyn H. Lauder Breast Center at Memorial Sloan-Kettering Cancer Center and member of the Breastcancer.org Professional Advisory Board. “I wish we knew that. We don’t have very accurate ways of looking at tissue and looking at tumors under the microscope and knowing with great certainty that it is a slow-growing cancer.”
The change in the name of certain conditions may come to pass, though it will likely take several years. There is already debate about whether LCIS should be considered cancer. For DCIS, taking “carcinoma” out of the name wouldn’t change treatment recommendations, but may ease some women’s stress and worry about their diagnosis. Women diagnosed with larger, high-grade DCIS (or whatever the new name might be) would still receive more aggressive treatment than women diagnosed with small, low-grade DCIS.
Still, some doctors and women are worried that if “carcinoma” is removed from the name of DCIS and other precancerous conditions, insurance companies may not pay for more aggressive treatment.
Everyone does agree that doctors need to talk to their patients clearly and in detail about the condition that’s been found and if it’s likely to grow and spread or not.
If you’ve been diagnosed with DCIS, LCIS, or another precancerous condition that raises your risk of developing invasive breast cancer later in life, make sure you talk to your doctor about all the characteristics of your condition. You and your doctor will consider a number of factors when deciding on how to treat or monitor the condition, including:
- the characteristics of the precancerous condition
- your age
- any other health problems you have
- your medical history
- the results of any genetic testing you may have had
- your preferences
Together, you and your doctor will come up with a treatment plan that makes the most sense for you and your unique situation.
Stay tuned to Breastcancer.org Research News for more information on the NCI proposal to reclassify cancer.