Abstract P5-09-02: Impact of therapeutic complexity on practice patterns for metastatic breast cancer (MBC) in the United States: Results of a 2-phase national study
Authors: Quill TA , Jahanzeb M , Obholz KL , Brady E , Howson A , Rasulina M , Willis C , Hurvitz S 
Published: May 2016

Abstract
Background: The rapidly changing clinical management of MBC has challenged the ability of clinicians to understand and integrate new data, which relates directly to the quality of clinical care and is a key determinant of patient outcomes. This study was designed to determine the potential impact of the increased clinical complexity of decision making in MBC on optimal patient care by quantifying professional practice gaps and barriers among oncology specialists at academic medical centers and community clinic settings in the United States.
Methods: From October 2014 to February 2015, 216 actively practicing US oncology specialists with a caseload of ≥1 patient/year with MBC were recruited to participate in a 2-phase national needs assessment study. In the first, qualitative phase, 35 participants consented to a 45-minute telephone interview focused on the personal, contextual, and behavioral factors that influence their clinical reasoning process in diagnosis and treatment of MBC. Findings from this initial phase informed the second phase of the study. This quantitative phase included an online survey comprising specific multiple choice questions, semantic differential rating scales, and case vignettes. Respondents' (N = 181) answers to these questions were compared with optimal answers, as identified by treatment guidelines and MBC experts.
Results: Eight core practice gaps were identified through combined analysis of data from the in-depth interviews and online surveys. Of note, only 15% of respondents agreed with the experts' choice of letrozole + palbociclib as initial treatment for a postmenopausal patient with HR+ MBC with bone and visceral lesions after a prolonged response to adjuvant endocrine therapy. Survey respondents indicated that they use chemotherapy substantially more frequently than experts when treating patients with HR+ MBC. Only 36% of respondents' current practice matched expert recommendations regarding management of toxicity associated with exemestane + everolimus and 32% opted for management strategies with a risk of worsening treatment-related toxicity. Just over 30% of respondents agreed with the expert choice of ado-trastuzumab emtansine as second-line therapy for HER2+ MBC after progression on trastuzumab/paclitaxel. In addition, a minority of respondents knew the mechanisms of action of newly approved (palbociclib [45%]) and investigational agents, including dovitinib (19%), neratinib (30%), pembrolizumab (49%), and pictilisib (28%).
Conclusions: A significant percentage of US oncology specialists are not applying optimal care in patients with MBC. Most notably, this study indicated that participants overuse chemotherapy in patients with HR+ MBC, suboptimally manage treatment-related toxicities, and are challenged to select optimal therapy for HER2+ MBC patients who progress on previous therapy. Finally, a lack of familiarity with mechanisms of action of approved and promising investigational agents in MBC may lead to delays in the appropriate integration of new agents or indications into clinical practice. A full review of the study results and recommendations will be presented.
Citation Format: Quill TA, Jahanzeb M, Obholz KL, Brady E, Howson A, Rasulina M, Willis C, Hurvitz S. Impact of therapeutic complexity on practice patterns for metastatic breast cancer (MBC) in the United States: Results of a 2-phase national study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-09-02.