Understanding and optimising decision-making about chemotherapy for older adults with cancer

Abstract

This thesis presents a collection of work aiming to better understand and optimise decision-making about treatment with chemotherapy for older adults with cancer. Australian oncologists were surveyed about how they make chemotherapy recommendations for their older patients. Most important when making a recommendation was patient performance status. Other considerations varied with treatment intent. Oncologists were less likely to recommend chemotherapy as patient age and toxicity increased. The Cancer and Aging Research Group’s (CARG) Toxicity Score was tested in older adults commencing chemotherapy. Neither the CARG Score nor oncologists’ estimates predicted severe chemotherapy-related toxicity in this population. Oncologists found both the GA and CARG Score useful, but did not use them to modify chemotherapy recommendations. The nature and accuracy of oncologists’ estimates of survival time was assessed for older adults with advanced cancer. Oncologists’ estimates of survival time were imprecise, but were well calibrated, and simple multiples of these estimates accurately described best-case, typical, and worst-case scenarios for survival. Older adults with advanced cancer were surveyed about their preferred roles in decision-making, their priorities and information needs. Preferred decision-making roles were active in 39%, collaborative in 27%, and passive in 35%. The most important considerations when deciding about chemotherapy were “doing everything possible”, “my doctor’s recommendation”, “quality of life”, and “living longer”. Decision-making about chemotherapy for older adults with cancer is complex. Individualised consideration of anticipated benefits and harms is needed. Shared understanding of patient priorities, goals of care, and provision of tailored information about likely outcomes are required. Further evidence is needed to support the use of additional assessments or prediction tools in guiding decision-making about treatment with chemotherapy.