Oncological safety of active surveillance for low-risk ductal carcinoma in situ - a systematic review and meta-analysis

Introduction: Current standard of care for patients diagnosed with "low-risk" ductal carcinoma in situ (DCIS) involves surgical resection. Ongoing phase III clinical trials are hoping to establish the oncological safety of active surveillance (AS) in managing "low-risk" DCIS.

Aims: To evaluate the oncological safety of AS versus surgery for "low-risk" DCIS.

Methods: A systematic review was performed in accordance with PRISMA guidelines. Survival outcomes were expressed as dichotomous variables and reported as odds ratios (OR) with 95% confidence intervals (95% CI) using the Mantel-Haenszel method.

Results: Four studies including 9626 patients were included, 3.9% of which were managed using AS (374/9626) and 96.1% with surgery (9252/9626). The mean age of included patients was 50.3 years (range: 30-99 years) and mean follow-up was 6.1 years. Invasive cancer detection after surgery and AS were similar (OR: 0.93, 95% CI: 0.41-2.11, P = 0.860, heterogeneity (I²) = 0%). At 5 years, BCSS (surgery 99.5% vs. AS 98.7%, P = 0.116) and OS (surgery 95.8% vs. AS 95.7%, P = 0.876) were similar for both groups. At 10 years, BCSS (surgery 98.7% vs. AS 98.6%, P = 0.789) and OS (surgery 87.9% vs. AS 90.9%, P = 0.183) were similar for both groups. Overall, 10-year OS outcomes were similar for both management strategies (OR: 0.32, 95% CI: 0.02-6.42, P = 0.460, I² = 69%).

Conclusion: This study outlines the provisional oncological safety of AS for cases of "low-risk" DCIS. While survival outcomes were comparable for both management strategies, ratification of these results in the ongoing phase III clinical trials is still required prior to changes to current management strategies.

Prospero registration: CRD42022313241.