DCIS: Mostly Good News
By: Diana Zuckerman, PhD December 2009
Thanks to widespread use of and technical improvements to screening mammography, there has been a dramatic increase in women diagnosed with ductal carcinoma in situ (DCIS), which account for 20-25% of new breast cancer cases diagnosed each year.1 According to the Agency for Healthcare Research and Quality (AHRQ), the number of cases of DCIS has increased by 750% over the last two decades.
This epidemic is good news and bad news. The epidemic is very good news because it means that cancer is being diagnosed very early, before it is life-threatening and before the most radical treatments that women most dread (mastectomy and chemotherapy) are necessary. It is bad news because many women, particularly lower-income women, are not fully informed or do not clearly understand the difference between DCIS and invasive cancer, and as a result of their fear of cancer, many undergo mastectomies that are not medically necessary. Standard treatment is mastectomy, lumpectomy with radiation, and sometimes hormonal treatment such as tamoxifen. In most cases, lumpectomy with radiation is as safe and effective as mastectomy or bilateral mastectomy.
A diagnosis of DCIS means that cancerous cells were found in the lining of the breast duct, and will not spread. However, DCIS can change to Stage 1 breast cancer, which can spread and can be fatal. DCIS is much less dangerous than other breast cancers, but patients are frightened by a diagnosis of cancer, often resulting in over-treatment. Equally worrisome, those who understand that DCIS is not dangerous in and of itself, may choose not to get any treatment, and that is risky because it may result in a later diagnosis of invasive breast cancer.
Although early detection is extremely important, especially for underserved, uninsured, and underinsured women, many women diagnosed with DCIS will undergo unnecessarily radical surgery and treatment. Over-treatment is expensive and can be harmful and debilitating to patients and their loved ones. And, when women diagnosed with DCIS undergo mastectomies just like women with later-stage breast cancer, it may discourage other women from having regular mammograms, since there seems to be no noticeable benefit to early diagnosis.
Whenever there is a growing body of new research that can be used to improve medical treatment, the National Institutes of Health (NIH) holds a Consensus Conference to bring together the best information and disseminate it to health professionals and patients. In September 2009, NIH held a State-of-the-Science Conference on “Diagnosis and Management of Ductal Carcinoma In Situ.” At the Conference, it was reported that at ages 50–64, approximately 88 of every 100,000 women will have DCIS. Risk of DCIS is low in women under age 40, but increases steadily from age 40 to 50, increases much more slowly after age 50, and stays high but plateaus after age 60.
The NIH concluded that breast-conserving surgery is as safe and effective as mastectomy, although mastectomy is more likely to be recommended if the DCIS is in more than one location in the breast. Combining radiation therapy with lumpectomy helps prevent recurrence and the development of invasive breast cancer, and Tamoxifen or other hormonal treatment is sometimes used in combination with one of these surgical treatments. According to the NIH, the long-term disease-free survival of women treated for DCIS is between 96% and 98%. Despite the high survival rate, the NIH concluded that the “current diagnosis and treatment of DCIS have considerable emotional and physical impact for women diagnosed” making it important “for the medical community to consider eliminating the inclusion of the term ‘carcinoma’ in this disease, as DCIS is by definition not invasive—a classic hallmark of cancer.”
While DCIS is not invasive, early diagnosis and early treatment are key to catching the condition before it changes to an invasive cancer. This approach can not change until the medical community is able to identify which cases of DCIS are likely to progress to invasive breast cancer if left untreated.
Breast cancer mortality and recurrence rates are higher for black women with DCIS than for white women—although for both populations the mortality risk is low. These differences persisted when controlling for differences in age, tumor characteristics, and treatment but not for differences in screening rates or mode of presentation.
In addition to racial differences, there are disparities in surgical treatment of DCIS, with low-income women more likely to undergo mastectomy instead of breast-conserving surgery with radiation, as compared to higher income women with the same diagnosis. One possible explanation for this is that mastectomy is less expensive than lumpectomy with radiation in the short-term. Treatment disparities often are unrelated to the woman’s actual condition or preferences, but rather to the information she receives and her understanding or confusion regarding that information.2 Physicians’ recommendations remain the most influential factor in a woman’s treatment choice.3 The rising numbers of DCIS cases, racial differences in DCIS prevalence and recurrence and mortality, and treatment disparities, combined with the fact that we still do not understand which cases of DCIS are most likely to progress to invasive breast cancer if left untreated, all point to the need for adequate testing, the most up-to-date and race-specific information for health care providers, and clear, reassuring explanations to patients about their treatment options.
Tackling the DCIS Epidemic
The Cancer Prevention and Treatment Fund of the National Research Center for Women & Families has worked on the forefront of patient education on this issue, and has also educated health professionals through a popular continuing medical education course. Several years prior to the NIH Consensus Conference, we received federal grants to convene two conferences at NIH for experts to discuss the most effective treatment options for early-stage breast cancer and DCIS, as well as how to improve patients’ understanding of their treatment options. The result of these meetings was a patient booklet for women with several different types of early-stage breast cancer, developed by our Center in partnership with the National Cancer Institute and NIH, and most recently, the NIH Consensus Conference on DCIS: https://cissecure.nci.nih.gov/ncipubs/detail.aspx?prodid=P994 With support from the Jacob and Hilda Blaustein Foundation, our Center is developing a patient booklet for women with DCIS.
1. Kerlikowske, K (2009). Epidemiology of Ductal Carcinoma in Situ [Abstract]. NIH State-of-the-Science Conference: Diagnosis and Management of Ductal Carcinoma in Situ (DCIS), September 22-24, 2009. Online version of conference abstracts available at http://consensus.nih.gov/2009/dcis.htm.
2. Ernster VL, Barclay J, Kerlikowske K, et al. Incidence of and Treatment for Ductal Carcinoma In Situ of the Breast. JAMA 1996 Mar 27; 275(12): 913-8
3. Abrams, Jeffrey S, Phillips, Pamela H., Friedman, Michael A. Meeting Highlights: a Reappraisal of Research Results for the Local Treatment of Early Stage Breast Cancer. Journal of National Cancer Institute, Vol.87.No.24, December 20, 1995