What’s in a Name? Why It Matters if We Call DCIS “Cancer” or Not

By Rachel Walden

Women’s Health Activist readers are likely familiar with the National Institutes of Health (NIH) 2010 Consensus Statement on vaginal birth after cesarean (VBAC) released after a widely covered meeting on the topic. Another recent NIH consensus statement is attracting much less attention and controversy, but may be equally important to women: the 2009 statement on ductal carcinoma in situ (DCIS). 
 
This condition is diagnosed when abnormal cells are found in a woman’s breast ducts, usually through mammography. DCIS is generally considered the earliest form of breast cancer. U.S. DCIS incidence is reported to have increased more than seven-fold from the early 1970s to the late 1990s, at least partly due to increased mammography screening. By 2005, a half-million U.S. women were thought to be living with a DCIS.¹
 
While more women are getting a DCIS diagnosis, what to do next is a matter of considerable uncertainty. Treatment with either mastectomy or breast-conserving surgery (either with or without radiation) is often recommended to prevent DCIS from progressing to invasive breast cancer, but it’s not readily apparent who will experience cancer without such treatment, and who would be fine with watchful waiting. It’s unclear how often DCIS develops into invasive disease even if left untreated. This makes it very hard for women to effectively weigh the risks of treatment versus watchful waiting.
 
In September 2009, NIH convened a state-of-the-science conference on DCIS to try to resolve some of these issues. The consensus statement is accompanied by an evidence report from the Agency for Healthcare Research and Quality (AHRQ) synthesizing the published evidence.²  A video from the consensus meeting and information about the meeting sponsors and participants are also available on-line (although some may find the information to be very technical). The evidence report and conference attempted to answer a few key questions, including how outcomes vary by the women’s characteristics (like age or race) and the tumor’s characteristics (like size and location), and the effects of treatment. (All of these materials are available on-line for free. )³

Regarding therapy, the consensus statement reports: “Mastectomy and local excision with radiotherapy are both effective local therapeutic approaches in patients who have DCIS. A randomized controlled trial comparing mastectomy with local excision and radiation has not been done, but current data demonstrate that long-term survival is similar with either approach...In randomized clinical trials, tamoxifen has been shown to reduce the risk of invasive cancer in the ipsilateral and contralateral breasts, but no survival benefit has been shown. There is currently no defined role for raloxifene in patients who have DCIS. There is no role for chemotherapy in patients who have pure DCIS.”¹
 
So, less and more invasive approaches may have similar results. The question of whether to treat could not be resolved. The consensus statement highlighted the need for further research to better define who might most benefit from treatment: “It is important to stress that DCIS has a high probability of long-term disease-free survival and that all current therapies have short- and long-term side effects. Therefore, future therapeutic research efforts should focus on the identification of patients who are at high risk for developing recurrence.” ¹ The statement recommends research to help guide decisions about best therapy approaches and identify which women might be at high risk of recurrence of DCIS or invasive cancer.
 
When thinking about how to respond to any diagnosis, it’s difficult to accept the idea of watchful waiting when the diagnosis includes the word “carcinoma.” The consensus document noted that a DCIS diagnosis has a negative connotation for patients and physicians. The report concluded that: “Because of the noninvasive nature of DCIS, coupled with its favorable prognosis, strong consideration should be given to remove the anxiety-producing term ‘carcinoma’ from the description of DCIS.” ¹ 
 
A 2010 commentary in the Journal of the American Medical Association also argued that “minimal risk lesions should not be called cancer,” and that there was no real evidence that treatment substantially reduced invasive breast cancer incidence. Changing DCIS’ name would help focus on “how to reduce or eliminate therapeutic interventions while achieving a good outcome.”⁴  Psychosocial harm stemming from anxiety over a diagnosis, such as DCIS, is a legitimate concern when considering medical decision-making and treatment, especially if fear leads to treatment that may ultimately be neither necessary nor beneficial. 
 
The consensus statement outlined the need for future research to inform and improve decision-making with a DCIS diagnosis; develop and evaluate decision aids; and understand DCIS’ impact on women’s quality of life. Ideally, we will learn more so women can better understand their own risks and the benefits and harms of various treatment options after diagnosis. Only then will women be empowered to place a DCIS diagnosis in the appropriate context and decide how best to proceed.

While there is much that we don't know about DCIS, and the consensus statement emphasizes those unknowns by including a long list of research questions -- there's one certainty that women can count on.  Unlike invasive cancer, DCIS by itself doesn't kill women, and when treated, 10-year survival rates are nearly 100%.  Future research is likely to help determine which treatment approaches – from watchful waiting to more extreme therapy - most benefit which groups of women.
 
Rachel R Walden, MLIS is a medical librarian and blogger for Women’s Health News and Our Bodies Our Blog.

References:
 
1.  Allegra CJ, Aberle DR, Ganschow P, et al., “National Institutes of Health State-of-the-Science Conference Statement: Diagnosis and Management of Ductal Carcinoma In Situ -- September 22–24, 2009.” J Natl Cancer Inst. 2010; 102(3):161–169. Available on-line at: http://consensus.nih.gov/2009/dcisstatement.htm. 

2.  Virnig BA, Shamliyan T, Tuttle TM, et al., Diagnosis and Management of Ductal Carcinoma in Situ (DCIS). Evidence Report/Technology Assessment No. 185 (Prepared by the Minnesota Evidence-based Practice Center under Contract No. 290-02-10064-I). AHRQ Publication No.09-E018, Rockville, MD: Agency for Healthcare Research and Quality, September 2009. Available on-line at: http://www.ahrq.gov/clinic/tp/dcistp.htm

3.  NIH Consensus Development Program NIH Ductal Carcinoma in Situ Conference website. September 2009: http://consensus.nih.gov/2009/dcis.htm

4.  Esserman L, Shieh Y, Thompson I, “Rethinking Screening for Breast Cancer and Prostate Cancer”, JAMA 2009; 302(15):1685-1692.