Treatment selection for patients with ductal carcinoma in situ (DCIS) of the breast using the University of Southern California/Van Nuys (USC/VNPI) prognostic index

Abstract

The University of Southern California/Van Nuys Prognostic Index (USC/VNPI) is an algorithm that quantifies five measurable prognostic factors known to be important in predicting local recurrence in conservatively treated patients with ductal carcinoma in situ (DCIS) (tumor size, margin width, nuclear grade, age, and comedonecrosis). With five times as many patients since originally developed, sufficient numbers now exist for analysis by individual scores rather than groups of scores. To achieve a local recurrence rate of less than 20% at 12 years, these data support excision alone for all patients scoring 4, 5, or 6 and patients who score 7 but have margin widths ≥3 mm. Excision plus RT achieves the less than 20% local recurrence threshold at 12 years for patients who score 7 and have margins <3 mm, patients who score 8 and have margins ≥3 mm, and for patients who score 9 and have margins ≥5 mm. Mastectomy is required for patients who score 8 and have margins <3 mm, who score 9 and have margins <5 mm and for all patients who score 10, 11, or 12 to keep the local recurrence rate less than 20% at 12 years. DCIS is a highly favorable disease. There is no difference in mortality rate regardless of which treatment is chosen. The USC/VNPI is a numeric tool that can be used to aid the treatment decision-making process.

Keywords: DCIS; ductal carcinoma in situ; noninvasive breast cancer.