The University of Southern California/Van Nuys prognostic index for ductal carcinoma in situ of the breast.

BACKGROUND: The original Van Nuys prognostic index (VNPI) was introduced in 1996 as an aid to the complex treatment decision-making process for patients with ductal carcinoma in situ (DCIS) of the breast. This update adds patient age to the previous predictors of local recurrence in breast preservation patients.
METHODS: A prospective database consisting of 706 conservatively patients with DCIS was examined using multivariate analysis. Four independent predictors of local recurrence (tumor size, margin width, pathologic classification, and age) were used to derive a new formula for the University of Southern California (USC)/VNPI.
RESULTS: In all, 706 patients with pure DCIS were treated with breast preservation. There was no statistical difference in the 12-year local recurrence-free survival in patients with USC/VNPI scores of 4, 5, or 6, regardless of whether or not radiation therapy was used (P = not significant). Patients with USC/VNPI scores of 7, 8, or 9 received a statistically significant average 12% to 15% local recurrence-free survival benefit when treated with radiation therapy (P = 0.03). Patients with scores of 10, 11, or 12, although showing the greatest absolute benefit from radiation therapy, experienced local recurrence rates of almost 50% at 5 years.
CONCLUSIONS: Ductal carcinoma in situ patients with USC/VNPI scores of 4, 5 or 6 can be considered for treatment with excision only. Patients with intermediate scores (7, 8, or 9) should be considered for treatment with radiation therapy or be reexcised if margin width is less than 10 mm and cosmetically feasible. Patients with USC/VNPI scores of 10, 11, or 12 exhibit extremely high local recurrence rates, regardless of irradiation, and should be considered for mastectomy, generally with immediate reconstruction or reexcision if technically possible.