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Are We Overtreating Ductal Carcinoma in Situ (DCIS)?
Sadia Khan1,2, Melinda Epstein3, Michael D Lagios4
1Hoag Breast Care Program, Hoag Memorial Hospital Presbyterian, Newport Beach, USA. drkhanbreastsurgery@gmail.com.
Objective:
During 2015, the media was flooded with the issue of whether ductal carcinoma in situ (DCIS) was being overtreated and whether favorable cases could be simply watched (core biopsy only followed by surveillance). To answer this question, we looked at DCIS patients treated with excision alone with margin width <1 mm as inadequate and a surrogate for no treatment (surveillance group) and margin ≥1 mm as adequate surgical excision (excision group).
Methods:
A total of 720 patients with pure DCIS treated with excision alone were stratified into two groups based on margin width and further subdivided by nuclear grade. Kaplan-Meier analysis was used to determine local recurrence-free survival. Differences in outcome were analyzed using the log-rank test.
Results:
The 10-year local recurrence probabilities are statistically significant for low-grade versus high-grade and surveillance alone versus excision alone. The comparison of excision alone group with margins ≥1 mm for low-grade DCIS versus high-grade DCIS shows a 10-year local recurrence-free survival rate of 13 versus 35 % (p < 0.0001). The surveillance group had (margins <1 mm) had higher rates of recurrence in both the low-grade group (51 %) and high-grade group (70 %) (p < 0.001).
Conclusions:
This study indicates that there is not an acceptable level of local control in DCIS patients with tumor margins <1 mm that undergo active surveillance, regardless of tumor grade. Leaving even low-grade DCIS untreated would lead to local recurrence in more than half the patients in 10 years. Needle biopsy and surveillance for DCIS, regardless of grade, is just not adequate at this time.
Insights
Active surveillance for ductal carcinoma in situ (DCIS) is not adequate, even for low-grade cases. Surgical excision with adequate margins is crucial for preventing local recurrence in DCIS patients.
Area of Science:
- Oncology
- Surgical Pathology
- Breast Cancer Research
Background:
- Media discussions in 2015 questioned overtreatment of ductal carcinoma in situ (DCIS).
- The possibility of surveillance for favorable DCIS cases (core biopsy only) was debated.
- This study investigates the efficacy of surveillance versus surgical excision for DCIS.
Purpose of the Study:
- To evaluate local recurrence rates in DCIS patients treated with excision alone.
- To compare outcomes based on surgical margin width (<1 mm vs. ≥1 mm).
- To assess the impact of nuclear grade on recurrence after different treatment strategies.
Main Methods:
- Retrospective analysis of 720 pure DCIS patients treated with excision.
- Stratification into two groups: inadequate margins (<1 mm, surveillance surrogate) and adequate margins (≥1 mm, excision group).
- Kaplan-Meier analysis and log-rank test for local recurrence-free survival, subdivided by nuclear grade.
Main Results:
- Statistically significant differences in 10-year local recurrence rates were observed between low-grade and high-grade DCIS.
- Patients with adequate margins (≥1 mm) had 10-year local recurrence-free survival rates of 13% (low-grade) vs. 35% (high-grade).
- The surveillance group (margins <1 mm) showed significantly higher recurrence rates: 51% (low-grade) and 70% (high-grade).
Conclusions:
- Surgical margins <1 mm are insufficient for acceptable local control in DCIS patients undergoing active surveillance.
- Untreated DCIS, even low-grade, leads to local recurrence in over half of patients within 10 years.
- Current needle biopsy and surveillance protocols are inadequate for managing DCIS, irrespective of tumor grade.
