Abstract P5-18-09: Performance of Oncotype DX DCIS score across diverse ethnic populations

Abstract

Abstract There is a paucity of data on Oncotype DX DCIS Score and ethnic variation. It has been postulated that there are different molecular features /drivers among different ethnic populations. The Oncotype DX DCIS Score is a genomic test designed to analyze the expression of a group of 12 genes which can quantify 10-year local recurrence risk after surgery. The purpose of this study is to evaluate diverse ethnic patients with DCIS relative to traditional clinical pathologic factors and Oncotype DX DCIS Score We analyzed consecutive cases of DCIS from 2011-2017 who underwent Oncotype DX DCIS Score testing at a single institution. Eighty-four female patients were divided into 5 groups based on self-reported ethnicity: White (36%), African American (AA) (48%), Asian (8%), Hispanic (4%) and Other (4%). Clinical and traditional pathologic factors were collected including age, nuclear grade (NG), ER/PR status and Oncotype DX DCIS Score. The distribution of NG and Oncotype DX DCIS Score was analyzed across ethnic groups. The mean age at diagnosis was 63. Overall 99 % of cases were hormone positive. Comparison of White and AA patients revealed a correlation between ethnic group and DCIS Score, with a p value of 0.0087 (Table 1). Similarly, we looked at all five ethnic groups and Oncotype DX DCIS Score and found a p value of 0.022. We evaluated ethnicity with White and AA patients versus NG and obtained a p value of 0.084 (Table 2). In addition, we assessed all five ethnic groups and NG. We obtained a p value of 0.068. No AA patients with DCIS had a high DCIS Score. No patients with low NG DCIS had a high DCIS Score. Analysis of the three factors (NG, ethnicity and DCIS Score) concurrently showed that they are not independent. In summary, our study provides valuable data on Oncotype DX DCIS Score and NG across a diverse patient population. These data highlight the importance of incorporating both traditional clinical pathologic factors and DCIS Score molecular testing for making treatment decision across different ethnic patient populations. Table 1.Comparison of DCIS Score and Ethnic GroupEthnic GroupLow DCIS ScoreIntermediate DCIS ScoreHigh DCIS ScoreAA3730White2704p=0.0087 Table 2.Comparison of Nuclear Grade and Ethnic GroupEthnic GroupNuclear Grade 1Nuclear Grade 2Nuclear Grade 3AA17194White1399p=0.084 Citation Format: Mittar P, Casella S, Bombonati A, Emiloju O, Jablon L, Schultz D, Leighton JC, Solin LJ. Performance of Oncotype DX DCIS score across diverse ethnic populations [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-09.