BMJ

Ductal carcinoma in situ: Cancer outcomes vary in women without upfront surgery

July 16, 2025

The variability in outcomes between women with low risk and high risk ductal carcinoma in situ (DCIS) emphasizes the need for accurate risk stratification tools in women with a diagnosis of DCIS. For patients at an elevated risk of invasive progression, offering them timely surgery and adjuvant therapy is important. At the other end of the risk spectrum, select patients may benefit from de-escalation of treatment.

Objective: To determine the the risk of subsequent ipsilateral invasive breast cancer in women who don't receive upfront surgery on diagnosis of DCIS.

Design: Observational cohort study using data abstracted directly from patients’ medical records and from a national cancer registry in patients with primary DCIS diagnosed between 2008 and 2015.

Setting: Commission on Cancer accredited facilities (n=1,330) in the U.S.

Participants: 1,780 women with diagnosis of primary DCIS on needle biopsy who were alive and free of invasive breast cancer at 6 months after diagnosis.

Interventions: No surgery within 6 months of diagnosis.

Main outcome measures: Primary outcome: ipsilateral invasive breast cancer; secondary outcome: death due to breast cancer. Subgroup analysis by risk status, based on eligibility criteria of ongoing active monitoring trials: low risk if aged ≥40 years at diagnosis of an imaging detected, nuclear grade I/II, and hormone receptor-positive DCIS; high risk otherwise.

Results: Median age at diagnosis was 63 years, and median follow-up was 53.3 months. Among all 1,780 women, the number of ipsilateral invasive breast cancer events was 115 (6.5%) and the number of deaths from breast cancer was 29 (1.6%). The 8 year cumulative incidence of ipsilateral invasive breast cancer was 10.7% (95% confidence interval [CI] 8.4% - 12.8%). Incidence of invasive cancer differed by both disease and patient-related factors, with 8 year cumulative incidences of ipsilateral invasive breast cancer ranging from 8.5% (95% CI, 4.7% - 12.1%) among women at low risk (n=650) to 13.9% (10.5% - 17.2%) among those at high risk (n=833). The 8 year disease specific survival probability was 96.4% (95% CI, 95.0% - 97.9%) overall and 98.1% (96.7% - 99.6%) among women at low risk.

Conclusions: In a cohort of patients who didn't receive initial surgery for DCIS, the 8 year cumulative incidence of invasive cancer in the same breast varied between 8% and 14%. Effective risk stratification tools and shared decision making are essential for this patient population.

Source:

Ryser MD, et al. (2025, July 8). Cancer outcomes in women without upfront surgery for ductal carcinoma in situ: observational cohort study. https://pubmed.ncbi.nlm.nih.gov/40628457/