Patient perceptions about potential side effects and benefits from chemotherapy agents.

Abstract

6595 Background: Little is known about how breast cancer patients (pts) perceive the relative side effects and benefits of different chemotherapy (CT) agents. The objective of this study was to better understand these preferences in pts receiving CT at a Canadian cancer center. Methods: Pts completed a Web survey. Grade I/II (mild to moderate) and III/IV (moderate to severe) descriptions of 9 common CT side effects were assigned preferences by: conjoint and standard gamble (SG). Conjoint involved making trade-offs among different risks of side effects, yielding preferences (utilities) for each side effect. SG involved choosing to stay in a selected side effect state or taking a gamble between full health (probability p) or being dead (1-p). For each side effect, p was varied until the patient was indifferent of the side effect. Pts were also asked to rate how much of detriment in quality of life they would endure for benefits in survival. Results: 102 women participated, mean age 54 + 11, stage 1 (21%), 2 (24%), 3 (38%) and 4 (18%). Among the grade I/II side effects, a 5% reduction in risk of sensory neuropathy, nausea, and motor neuropathy had the highest impact on preferences. Among grade III/IV side effects, motor neuropathy, nausea/vomiting, and mucositis made the most difference. SG preferences for side effects were lowest (i.e. least preferred) for grade III/IV nausea (0.624) followed by diarrhea (0.633), hand-foot syndrome (0.681), and highest for grade I/II sensory neuropathy (0.757), mucositis (0.756), and myalgia (0.750). Agree/disagree items revealed patients are willing to endure quality of life detriments for improvement in survival; this willingness increased as disease stage increased (p=0.01). Conclusions: Relatively small changes in the risks of some CT side effects may have substantial impacts on pt treatment preferences. Nevertheless, pts will endure significant toxicity for a potential gain in survival. The standard gamble utilities from this population may also be used to quality-adjust life expectancy in cost-effectiveness evaluations of breast cancer chemotherapies.