Abstract P1-15-05: Oncologists' perception of anti-estrogen therapy benefit

Abstract

Abstract Background Recent publication of Suppression of Ovarian Function (SOFT) and Tamoxifen and Exemestane (TEXT) trials provides additional options for premenopausal women with hormone receptor (HR)-positive breast cancer in improving estrogen blockade - tamoxifen (T) plus ovarian function suppression (OFS) and aromatase inhibitors (AI) plus OFS. Analysis of these trials conclude that, for a premenopausal woman with HR-positive breast cancer with high risk features for recurrence have an absolute benefit for five-year breast cancer free interval (BCFI) would be 5% with the use of T + OFS and 10 - 15% with AI + OFS compared to the usof T-alone. However, therapeutic option decision-making is dependent on the oncologists' perception of the benefit and risk for adjuvant anti-estrogen therapy. We aimed to evaluate an oncologist's perception of the absolute benefit for anti-estrogen therapy options in HR–positive breast cancer and identify predictors for variations in perceptions of benefit. Methods We designed a survey using a clinical vignette of a young, premenopausal woman with stage IIIA HR-positive breast cancer with high risk of recurrence. After obtaining Institutional Review Board (IRB) approval from the University of Kentucky, we sent online and paper survey forms to a convenience sample of 510 oncologists in the United States. Using a scale between 0 and 100, the oncologists were asked to estimate the five-year BCFI (first occurrence of invasive locoregional, distant or contralateral breast cancer) for a woman with similar characteristics if treated with the following: 1) lumpectomy (L) + Radiation (RT); 2) L + RT + chemotherapy (C); 3) L + RT + C + T x five years; 4) L + RT + C + T + OFS; and 5) L + RT + C + AI + OFS. Baseline demographics such as gender, practice setting (academic vs community), years in practice and proportion of breast cancer patients in practice were also collected. Results The highest estimated mean five-year BCFI for the study patient was 76.5% with the addition of AI + OFS to L + RT + C. The estimated absolute benefit for anti-estrogen therapy options: T + OFS vs T-alone was 3.4% (95% CI: 2.7 – 4.0) and for AI + OFS vs T-alone was 5.9% (95% CI: 5.1 – 6.7). Oncologists' Perception of Absolute Benefit Therapy in Premenopausal Women with Breast CancerAnti-Estrogen Therapy5-year BCFI (mean)Standard DeviationL+ RT43.6+/- 18.6L + RT + C59.5+/- 15.5L + RT + C + T x 5 year70.6+/- 13.4L + RT + C + T + OFS74.1+/- 12.9L + RT + C + AI + OFS76.5+/- 12.7 There was no difference in perception of benefit with these anti-estrogen therapy options by gender, practice setting, years in practice or proportion of breast cancer patients seen in practice. Discussion Regardless of their gender, practice setting, clinical experience or volume of breast cancer patients, oncologists significantly underestimate the absolute benefit for various estrogen blockade therapies when compared to the estimated benefit of data from randomized, controlled SOFT and TEXT clinical trial data. We highlight an area for improvement in quality of care that offers an immediate impact on positive outcomes for large numbers of premenopausal women with breast cancer. Citation Format: Patel RA, Maxwell S, Yan D, Dressler E, Mathew A. Oncologists' perception of anti-estrogen therapy benefit [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 P1-15-05.