ABSTRACT
Ductal carcinoma in situ (DCIS) represents about 20% of all breast malignancies but with a very low breast cancer−specific mortality rate due to either occult invasive disease or invasive recurrence. Treatment is with local surgery in the form of mastectomy alone or breast-conserving surgery (BCS) with, or without, radiotherapy (RT). However, risk-stratified treatment is important to prevent overtreatment of low-risk disease and undertreatment of high-risk disease. Local recurrence rates were high before RT in BCS. Therefore, the National Surgical Adjuvant Breast and Bowel Project (NSABP) group recommended RT after BCS following the NSABP B-17 trial which had shown high rates of recurrence after BCS which were reduced by RT, but disease characteristics were not stratified. 1 Following this, the Silverstein group in Van Nuys, California, used real-world data relating to DCIS to develop a predictive index for local recurrence, helping to shape surgical and radiotherapeutic management with stratification according to DCIS size, grade and margin width (and, in a later publication, patient age). The proposed Van Nuys Prognostic Index (VNPI) was widely used for decades in clinical practice but has now fallen out of favour as newer margin thresholds and algorithms have been adopted. Emerging technology on DCIS molecular profiling, combined with clinical parameters, may well see further changes in practice. Similarly, ongoing trials (LORIS, Low-Risk DCIS [LORD] and Comparison of Operative versus Monitoring and Endocrine Therapy [COMET]) may see the future emergence of nonsurgical management for very low-risk cases.
