Episode 367: 378. What is the Best Way To Treat Ductal Carcinoma In Situ

https://jamanetwork.com/journals/jama/article-abstract/2828218

DCIS is a non-invasive form of breast cancer, meaning the abnormal cells are contained within the milk ducts. For years, the standard treatment has been surgery, often followed by radiation and/or hormone therapy - the same treatments used for invasive breast cancer. But is this aggressive approach always necessary for low-risk DCIS?(Transition Music - Short and subtle - 2 seconds)

Host: That's the question the COMET trial, or Comparing an Operation to Monitoring, With or Without Endocrine Therapy for Low-Risk DCIS, set out to answer. This large, randomized trial enrolled nearly 1000 women with newly diagnosed, low-risk DCIS across 100 centers in the US between 2017 and 2023. Participants were randomly assigned to either guideline-concordant care, meaning surgery with or without radiation, or active monitoring, involving regular check-ups with imaging and physical exams, reserving surgery only if the DCIS progressed to invasive cancer. The study focused on women who had hormone receptor-positive, grade 1 or 2 DCIS without evidence of invasive cancer.(Transition Music - Short and subtle - 2 seconds)

Host: The Major Finding: After a median follow-up of about 3 years, the study found that active monitoring was not inferior to surgery in terms of the rate of invasive cancer developing in the same breast. Specifically, the 2-year cumulative rate of ipsilateral invasive cancer was 4.2% in the active monitoring group and 5.9% in the guideline-concordant care group. This difference was statistically non-significant, meeting the pre-defined criteria for non-inferiority.(Transition Music - Short and subtle - 2 seconds)

Host: This means that, at least in the short term, women with low-risk DCIS who chose active monitoring did not have a higher risk of developing invasive cancer compared to those who underwent surgery.(Transition Music - Short and subtle - 2 seconds

)Host: So, how should this change practice? For carefully selected women with low-risk DCIS, active monitoring could be a reasonable and safe alternative to immediate surgery. This approach could avoid the risks and side effects associated with surgery, radiation, and hormone therapy, such as pain, altered body image, and other long-term complications.(Transition Music - Short and subtle - 2 seconds)

Host: Important Considerations: This study focused on low-risk DCIS. Active monitoring requires strict adherence to follow-up appointments and imaging. Further research is needed to determine the long-term outcomes of active monitoring and to identify which patients are most suitable for this approach. Patients considering active monitoring should have a thorough discussion with their healthcare provider to weigh the risks and benefits and make an informed decision.(Transition Music - Short and subtle - 2 seconds)