Abstract P2-11-19: The influence of extended endocrine therapy decision making in multidisciplinary team
Authors: Chen Weilin , Wu Jiayi , Lin Chaijin , Andriani Lisa , Liu Deyue , Ding Shuning , Zhu Li 
Published: March 2020

Abstract
Background: Extending the duration of the endocrine therapy to 10 years has now proved to reduce the risk of late recurrence for ER+ breast cancer. However, controversies remain about the target population who may benefit from the extended endocrine therapy in clinical decision-making. MDT is a combination of multi-disciplinary diagnosis and treatment, its advantages are more recognized by clinician. In our study, we aim to analyze the clinicopathological factors which may influence the decision-making regarding the extended endocrine therapy for patients with ER+ breast cancer by the multidisciplinary team (MDT).
Method: The retrospective analysis was performed in patients with ER-positive breast cancer who have undergone MDT discussion in Shanghai Ruijin Hospital from October 2017 to January 2019. Here the extended endocrine therapy decision alteration was defined as a disagreement in extending the endocrine treatment or not, or inconsistence in regimens between the attending doctor and the multidisciplinary team. Descriptive statistics were used to summarize quantitative data. Associations between variables were evaluated using x2-tests. Logistic regression analysis was used for single factor analysis and multivariate analysis. Analyses were conducted using IBM SPSS Statistics 20.0 (IBM Corporation, Somers, NY, USA). A p-value &lt;0.05 was considered significant.
Results: A total of 130 patients participated in the multidisciplinary discussion, 79 patients (60.7%) were suggested to receive extended endocrine therapy, and 51 patients (39.3%) were suggested to stop the extended endocrine therapy. Univariate analysis suggests that age [ OR = 0.197, 95%CI( 0.071-0.551 ), P = 0.002 ],pT [ OR = 4.35, 95%CI(1.654-11.440), P = 0.003 ],pN [ OR = 36.667, 95%CI(10.389-129.410),P&lt;0.001 ], molecular subtype [ OR = 4.218, 95%CI(2.019-9.079), P&lt;0.001 ], HER-2 [ OR = 3.526, 95%CI(1.396-8.908), P=0.008 ], ki67 status [ OR = 2.462, 95%CI(1.167-5.193), P=0.018 ], receipt of chemotherapy [ OR = 11.143, 95%CI(4.837-25.668), P&lt;0.001], receipt of target therapy [ OR = 3.533, 95%CI(1.127-11.079), P&lt;0.001] were correlated with extended endocrine therapy. multivariate analysis suggests that age [OR=0.203, 95%CI(0.039-1.044), P=0.046 ], pN [ OR = 21.340, 95%CI(5.223-87.199), P&lt;0.001 ] and receipt of chemotherapy[OR=3.936, 95%CI(1.420-10.910), P=0.008] were independent predictors for extended endocrine therapy. Differences between the initial recommendation from the attending physicians and the final decision made by MDT panel were found in 5 (3. 85%) patients. Among them, 4(80%) patients changed to stop the endocrine therapy, of which 3 patients’ lymph node was negative and 1 patient developed complication.
Conclusion: Patients younger than 65, those with node positive disease, or those who have been treated with adjuvant chemotherapy are prone to receive extended endocrine therapy in the MDT setting.
Table1. Characteristics of patients of 130 ER-positive patientsStop endocrine therapyextended endocrine therapyORPAge,years&lt;6536(33.0)73(67.0)0.1970.001≥6515(71.4)6(28.6)pTpT148(66.7)24(33.3)4.35&lt;0.001pT2+3(5.2)55(94.8)pNpN057(70.4)24(29.6)36.667&lt;0.001PN1+2(2.4)57(96.6)molecular subtypeLuminal A31(59.6)21(40.4)4.218&lt;0.001Luminal B20(25.6)58(674.4)HER-2 statusHer-2 negative40(46.0)47(54.0)3.5260.006HER-2 positive7(19.4)29(80.6)Ki67 status&lt;1536(48.0)39(52.0)2.4620.017≥1515(27.3)40(72.7)PR statusPR negate6(31.6)13(68.4)/0.071PR positive45(40.5)66(59.5)receipt of chemotherapyNo36(72.0)14(28.0)3.936&lt;0.001Yes15(18.8)65(81.2)target therapyNo47(43.9)60(56.1)3.5330.013Yes4(18.2)18(81.8)
Citation Format: Weilin Chen, Jiayi Wu, Chaijin Lin, Lisa Andriani, Deyue Liu, Shuning Ding, Li Zhu. The influence of extended endocrine therapy decision making in multidisciplinary team [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-11-19.