Abstract P6-08-18: Prognostic multigene testing in breast cancer: Patterns, disparities, and opportunities for advancing standardized patient care

Abstract

Abstract Background: The decision to give adjuvant chemotherapy to patients with hormone receptor positive early stage breast cancer is controversial given the overall good prognosis with local therapy (surgery and radiation) plus hormonal therapy alone. In 2004, the 21-gene RT-PCR assay recurrence score (Oncotype) was developed to stratify early stage patients into categories of high, low, and intermediate recurrence rates considering treatment with local and hormonal therapy alone. This was incorporated into the NCCN guidelines in 2008. We sought to compare NCCN guidelines to actual practice patterns. Methods: By retrospective review, data were examined from eight state registries participating in the National Program of Cancer Registries' Comparative Effectiveness Research program: Alaska, Colorado, Florida, Idaho, Louisiana, North Carolina, New Hampshire, and Rhode Island. These were then compared to NCCN guidelines for prognostic multigene testing. Results: Of the 28,372 cases examined, 18.6% were classified as carcinoma in situ, 39.6% were stage I, 24.3% were stage II, 9.1% were stage III, 4.9% were stage IV, and 3.6% were unknown stage. The overwhelming majority of cases, 75.5%, were estrogen receptor (ER) or progesterone receptor (PR) positive, while 15.7% were ER and PR negative, and 8.8% were hormone receptor unknown. Approximately 40% of cases were human epidermal growth factor receptor 2 (HER2) positive, and the remaining 60% were HER2 negative or unknown. Approximately 72% of patients were node negative or had unknown nodal involvement, while the remaining 28% had at least micro-metastatic nodal disease. Invasive ductal carcinoma was the most common histology accounting for 71.4% of cases examined. Median age was 62. Data analysis for the use of prognostic multigene testing in relation to NCCN guidelines, race, age, and the above clinical factors is on-going and will be presented at SABCS 2017. Conclusion: The purpose of this study is to examine the factors associated with the use of prognostic multigene testing according to the NCCN guidelines, including personal and clinical factors. By identifying practice patterns we can then address disparities and opportunities for advancing standardized quality patient care. Citation Format: Bernhardt EB, Caffrey AG, Celaya MO, Celaya V, Chamberlin MD, Rees JR. Prognostic multigene testing in breast cancer: Patterns, disparities, and opportunities for advancing standardized patient care [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-08-18.