Ductal carcinoma in situ – known more by its abbreviation DCIS – has been a term mired in controversy for decades. Over the years, it’s been termed “stage 0” breast cancer, “precancer”, and skeptics have gone so far as to say it is perhaps not much of anything. Before the advent of mammography, the proportion of women with DCIS was as low as 3%, but now 20% of women diagnosed with breast cancer have DCIS. That’s why this morning’s news, about the evolution of DCIS, should give women and their doctors pause about how they have approached a DCIS diagnosis.
In short, Steven A. Narod, MD, and colleagues, analyzing retrospective data on nearly 109,000 women from the Surveillance, Epidemiology and End Results (SEER) database, found the following after a diagnosis of DCIS:
- Overall, 20 years later, the breast cancer mortality rate was 3%, whereas, ten years after, it was 1.1%;
- Black women were an exception, with a 7% mortality rate;
- Women diagnosed before age 35 also had a higher rate of 7.8%;
- Using radiation or mastectomy did not prevent deaths;
- Preventing an invasive cancer on the same breast as the DCIS did not prevent death from cancer
The researchers analyzed data from a large database of women diagnosed with DCIS between 1988 and 2011 using data from cancer registries across the United States, The paper is published online today in the peer-reviewed JAMA Oncology.
Addressing the big picture, Dr. Susan Love, Dr. Susan Love Research Foundation, told PatientPOV: “This is yet another argument that we shouldn’t be overtreating. this is more support for doing less.” However, she added: This clearly does not apply to every woman. This is just an observational study, not a randomized study. You also have to study what accounts for the higher death rates in young and black women. Further research should explore what accounts for this difference, including looks at the anatomy, biology, and screening practices.”
An inadvertent casualty of the fight against overdiagnosis is that patients who do not fit that profile are overlooked. Just as overdiagnosis can spell waste and harm, the health care community must no longer sweep under the rug bad health outcomes for subgroups. It’s not just a footnote. Failure to delve deeper inadvertently fosters continuing health disparities and inequality.