Survival Benefit of Surgery Lower for Low-Grade vs Higher-Grade Ductal Carcinoma in Situ
In a population-based cohort study reported in JAMA Surgery, Sagara et al found that the breast cancer–specific survival benefit associated with surgery for low-grade ductal carcinoma in situ is lower than that associated with surgery for intermediate- or high-grade ductal carcinoma in situ.
Study Details
The retrospective study included 57,222 cases of ductal carcinoma in situ with known nuclear grade and surgery status diagnosed between 1988 and 2011 from the SEER (Surveillance, Epidemiology, and End Results) database. Propensity score weighting was used to balance patient characteristics between analyzed groups.
Among all cases, 1,169 (2.0%) did not receive surgery and 56,053 (98.0%) were managed with surgery. For the nonsurgery and surgery groups, 20% and 16% had nuclear grade 1, 41% and 38.5% had nuclear grade 2, and 39.5% and 46% had nuclear grade 3. After a median follow-up of 72 months from diagnosis, 576 breast cancer–specific deaths had occurred (1.0%), with weighted 10-year breast cancer–specific survival being 93.4% in the nonsurgery group and 98.5% in the surgery group (P < .001).
Survival by Grade
After adjustment for other clinical factors, the degree of breast cancer–specific survival benefit among patients undergoing vs not undergoing surgery differed according to nuclear grade (P = .003). Among patients with low-grade ductal carcinoma in situ, weighted 10-year breast cancer–specific survival was 98.8% in the nonsurgery group and 98.6% in the surgery group (P = .95).
On multivariate analysis, the reduction in risk for breast cancer–specific mortality among patients with low-grade ductal carcinoma in situ undergoing vs not undergoing surgery was not significant (weighted hazard ratio [HR] = 0.85, P = .83), whereas benefit was significant among those with intermediate-grade (HR = 0.23, P < .001) and high-grade ductal carcinoma in situ (HR = 0.15, P < .001). Similarly, on multivariate analysis, the benefit of surgery for overall survival was not significant in the low-grade group (HR = 0.88, P = .60) but was significant in the intermediate- (HR = 0.73, P = .04) and high-grade groups (HR = 0.40, P < .001).
The investigators concluded: “The survival benefit of performing breast surgery for low-grade ductal carcinoma in situ was lower than that for intermediate- or high-grade ductal carcinoma in situ. A prospective clinical trial is warranted to investigate the feasibility of active surveillance for the management of low-grade ductal carcinoma in situ.”
Yasuaki Sagara, MD, of Dana-Farber/Brigham and Women’s Cancer Center, is the corresponding author of the JAMA Surgery article.
The authors reported no conflicts of interest.
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