Oncologist preferences in advanced soft tissue sarcoma: A discrete choice experiment.

Abstract

147 Background: Soft-tissue sarcomas (STS), a rare heterogeneous group of cancers originating in the muscle, fat, blood vessels or other fibrous/connective tissues, account for 1% of all cancers diagnosed annually in the US. The National Comprehensive Cancer Center guidelines include a wide range of regimens that lack supporting randomized trial evidence, and there are few treatment pathways to guide treatment decision making. A discrete choice experiment (DCE) was conducted to quantify the relative value of overall survival (OS), progression-free survival (PFS), tumor response rate (RR), risk of hospitalization due to side effects, and convenience of therapy (days per month to administer treatment) among oncologists. Methods: An online DCE survey was administered to oncologists recruited from an online panel, who were licensed to practice in the US at the time of the survey and prescribed chemotherapy to patients with STS. Oncologists were asked to choose between pairs of hypothetical treatments characterized by a common set of attributes: OS (14, 20 or 26 months), PFS (3, 5 or 7 months), RR (12, 18, or 26%), risk of hospitalization due to side effects (12, 30 or 46%), and days/month to administer treatment (1, 2 or 4 days). A hierarchical Bayes model was used to analyze preferences, the relative importance of treatment attributes (from 0-100%), and trade-offs between attributes. Results: 160 eligible oncologists completed the survey: 74% male; 41% private practice; and 64% affiliated with an academic teaching hospital. OS had the highest relative importance (44.6%, standard deviation, SD, 16.0%), followed by the risk of hospitalization (18.4%, SD 8.3%). PFS, RR, and days to administer treatment had lower relative importance (16.5%, 10.6%, and 9.9%, respectively). For a 1-month increase in OS, oncologists were willing to trade off 8.9 percentage points increase in hospitalization risk, a 2.1 month reduction in PFS, 13.1 percentage points decrease in RR, and an additional 4.6 days/month to administer treatment. Conclusions: Oncologists in the US value maximizing the life of patients with STS while avoiding hospitalizations. Patient preference interviews are ongoing with patients with STS, which will be presented at the meeting.