Roughly 65 million women go through mammograms every year, which has helped reduce breast cancer mortality rates somewhat. However, experts worry about overdiagnosis and overtreatment for women with noninvasive ductal carcinoma in situ (DCIS). This diagnosis indicates a lesion in the milk ducts that does not have the potential to spread and cause symptoms unless it progresses to a more invasive form. Doctors have been arguing about the best way to treat this condition.
Comparing Monitoring to Surgery:
A new study compared active monitoring to guideline-based surgical treatment with or without radiation (JAMA, Dec. 12, 2024). In this study of nearly 1,000 women, almost 6% of those in the surgical treatment group developed invasive cancer in that breast over the next two years. Among those in the active surveillance group, the rate was 4%, demonstrating that active monitoring is as safe as surgery for women with low-risk ductal carcinoma in situ.
An editorial comment in the same JAMA journal questions the safety of this recommendation, however. The authors remain unconvinced that women with DCIS should skip surgery.
An Earlier Look at the Treatment for DCIS
Data published nearly a decade ago in JAMA Oncology raised questions about the best treatment for DCIS (JAMA Oncology, online, Aug. 20, 2015). About 60,000 women in the US are diagnosed with this each year on the basis of mammography.
Is DCIS Stage 0 or No Cancer at All?
DCIS is sometimes referred to as Stage 0 breast cancer, but there is debate about whether these abnormal cells lining a milk duct in the breast should be considered cancer at all.
The research used 20 years of follow-up data on more than 100,000 women diagnosed with DCIS between 1988 and 2011. Many of these women had been treated with lumpectomies. Others got mastectomies or radiation.
No Difference in Survival Based on Treatment:
The method of treatment did not make any difference in the likelihood that a woman diagnosed with DCIS would later die of breast cancer. Just over 3 percent of the women had died of breast cancer after 20 years, regardless of treatment.
Some Women Were at Much Higher Risk:
Women under 35 at the age of diagnosis with DCIS were 17 times more likely than women without such a diagnosis to die of breast cancer within 10 years. African American women were also more than twice as likely to die of breast cancer after a diagnosis of DCIS than women in the general population.
In 2015, we wrote:
“Studies are needed to determine if treatment can lower breast cancer mortality rates in women diagnosed with DCIS.”
Unfortunately, that statement is still true in 2024.
Citations
- Hwang ES et al, "Active monitoring with or without endocrine therapy for low-risk ductal carcinoma in situ: The COMET Randomized Clinical Trial." JAMA, Dec. 12, 2024. DOI: 10.1001/jama.2024.26698