A new study is challenging the conventional approach to treating low-risk ductal carcinoma in situ (DCIS), the earliest stage of breast cancer. The findings suggest that active monitoring, involving regular mammograms and potential hormone therapy, may be a viable alternative to immediate surgery and radiation for select patients.
The study, presented at the San Antonio Breast Cancer Symposium, involved nearly 1,000 women diagnosed with low-risk DCIS. Researchers, led by Dr. Shelley Hwang at Duke Cancer Institute, compared outcomes between women who underwent standard treatment (surgery and radiation) and those who opted for active monitoring. The initial analysis, with a two-year follow-up, revealed that 5.9% of women in the treatment group developed cancer, compared to 4.2% in the active monitoring group. This suggests active monitoring is a viable option for certain low-risk DCIS cases.
COMET Trial Details
The Comparing an Operation to Monitoring with or without Endocrine Therapy (COMET) trial included women with low-risk DCIS, representing about half of all DCIS cases in the U.S. Patients with higher-risk DCIS, such as estrogen-negative DCIS or those presenting with a palpable lump, were excluded. Participants in both groups had the option to take hormone therapy.
Interestingly, a significant number of women initially assigned to surgery chose not to undergo the procedure (44%), while some in the active monitoring group opted for surgery (14%). Despite these crossovers, statistical analyses, both as-assigned and as-treated, indicated that active monitoring did not lead to a higher incidence of cancer development.
Expert Perspectives
Dr. Hwang emphasizes that these results are preliminary and require longer-term follow-up (at least five years) to confirm the safety and efficacy of active monitoring. She also plans to investigate the role of endocrine therapy in active monitoring, comparing outcomes between women who used hormone therapy and those who did not.
Dr. Henry Kuerer, professor and executive director of breast programs at MD Anderson Cancer Network, notes that the findings could empower patients to make more informed decisions about their treatment. He plans to discuss the study results with patients diagnosed with DCIS, presenting active monitoring as a potential option alongside standard treatment guidelines.
Implications for Clinical Practice
While the study offers encouraging evidence for active monitoring in low-risk DCIS, experts caution against widespread adoption without further research. Dr. Larry Norton, medical director of the Evelyn H. Lauder Breast Center at Memorial Sloan Kettering Cancer Center, points out that the 5% invasive cancer rate after two years in the treatment group remains a concern. He advocates for continued research to improve DCIS management and reduce the risk of cancer development.
Future Directions
As screening methods become more sensitive, detecting smaller and earlier forms of cancer like DCIS, active monitoring may become increasingly relevant. Researchers are also exploring the possibility of avoiding invasive surgery in other breast cancer scenarios, such as cases with lymph node metastases.
The findings suggest a potential shift towards more personalized treatment approaches in breast cancer, where less may be more for certain patients. However, further research and long-term follow-up are crucial to validate these findings and refine treatment strategies for DCIS.
