A Novel Biosignature Identifies Patients With DCIS With High Risk of Local Recurrence After Breast Conserving Surgery and Radiation Therapy

• Purpose: There is an unmet need to identify women diagnosed with ductal carcinoma in situ (DCIS) with a low risk of in-breast recurrence (IBR) after breast conserving surgery (BCS), which could omit radiation therapy (RT), and also to identify those with elevated IBR risk remaining after BCS plus RT. We evaluated a novel biosignature for a residual risk subtype (RRt) to help identify patients with elevated IBR risk after BCS plus RT. Methods and Materials: Women with DCIS treated with BCS with or without RT at centers in the US, Australia, and Sweden (n = 926) were evaluated. Patients were classified into 3 biosignature risk groups using the decision score (DS) and the RRt category: (1) Low Risk (DS ≤2.8 without RRt), (2) Elevated Risk (DS >2.8 without RRt), and (3) Residual Risk (DS >2.8 with RRt). Total and invasive IBR rates were assessed by risk group and treatment. Results: In patients at low risk, there was no significant difference in IBR rates with or without RT (total, P = .8; invasive IBR, P = .7), and there were low overall 10-year rates (total, 5.1%; invasive, 2.7%). In patients with elevated risk, IBR rates were decreased with RT (total: hazard ratio [HR], 0.25; P < .001; invasive: HR, 0.28; P = .005); 10-year rates were 20.6% versus 4.9% (total) and 10.9% versus 3.1% (invasive). In patients with residual risk, although IBR rates decreased with RT after BCS (total: HR, 0.21; P < .001; invasive: HR, 0.29; P = .028), IBR rates remained significantly higher after RT compared with patients with elevated risk (HR, 2.5; 95% CI, 1.2-5.4; P = .018), with 10-year rates of 42.1% versus 14.7% (total) and 18.3% versus 6.5% (invasive). Conclusions: The novel biosignature identified patients with 3 distinct risk profiles: Low Risk patients with a low recurrence risk with or without adjuvant RT, Elevated Risk patients with excellent outcomes after BCS plus RT, and Residual Risk patients with an elevated recurrence risk remaining after BCS plus RT, warranting potential intensified or alternative treatment approaches. © 2022 The Authors

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Risk assessment

Surgery

Biosignatures

Breast-conserving surgery

Ductal carcinoma in situ

Hazard ratio

Local recurrence

Methods and materials

Recurrence rates

Residual risk

Risk decision

Risk groups

Radiotherapy

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)