Monitoring Risk & Health Behaviors
Predicting Local Invasive Recurrence After Conservative Treatment
Melvin Silverstein, MD; The USC/Norris Comprehensive Cancer Center
At 12 years follow-up, DCIS local recurrence rates are 32 percent for excision alone, 16 percent for excision plus radiotherapy (based on prospective randomized trials), and 1 percent for mastectomy. Most local recurrence occurs at or near the primary lesion and the most important cause of local recurrence appears to be inadequate excision.
The University of Southern California (USC)/Van Nuys Prospective Database contains data from single-piece excisions with oncoplastic resection; mini-excisions of the biopsy cavity wall are not included. Through 2006, the database included 1,289 samples with complete data. One study using this database found that using multivariate analysis, factors significantly associated with any recurrence in cases who were treated with breast conservation therapy included nuclear grade, size, margin width, necrosis, age, and treatment; Cox multivariate analysis indicated a 63 percent reduction in recurrence following radiotherapy (similar to the reduction found in the prospective randomized trials). In the excision-only group with invasive recurrence, the significant factors by multivariate analysis included tumor size and margin width.
When invasive recurrence in excision-only cases are broken down further, it is observed that margins less than 1mm, age less than 50 years, and a nuclear grade of 3 are factors predicting recurrence. In cases with all three factors present, the absolute recurrence rate is 45 percent; in cases with none of these present, the rate drops to 4 percent. The USC/Van Nuys Prognostic Index (USC/VNPI) uses these factors plus tumor size in a scoring system. Cases with USC/VNPI scores of 4, 5, or 6 have a high rate of recurrence-free survival; scores of 7, 8, or 9 indicate an intermediate rate of recurrence-free survival, whereas scores of 10, 11, or 12 indicate a low rate of recurrence-free survival. In the latter, mastectomy is generally recommended.
Last Modified: 18 Oct 2013