Explaining the Effects of Systemic Therapy on Survival in Advanced Cancer

Abstract

Explaining the effects of systemic therapy on survival to patients with advanced cancer is a central yet challenging aspect of cancer care, particularly with contemporary treatments such as immunotherapy. This thesis examined how these effects are communicated and understood in clinical practice, and evaluated tools available to support these conversations.

A scoping review identified tools designed to help oncologists convey survival times in advanced cancer, including decision aids, question prompt lists, prognostic calculators, visual framing tools, and clinician-focused communication frameworks. Although useful, most were developed for chemotherapy-based treatments, were not well integrated into routine practice, and were poorly suited to explaining the effects of contemporary therapies on survival.

A systematic review summarised survival distributions from pivotal first-line immunotherapy trials in advanced NSCLC and evaluated whether simple multiples of the median overall survival could estimate worst-case, typical, and best-case scenarios. These multiples reliably estimated scenarios for chemotherapy-containing regimens but required adjustment for single-agent immunotherapy, as they overestimated worst-case and typical outcomes. Best-case scenarios could not be reliably estimated in some groups due to limited long-term follow-up.

Two complementary surveys of oncologists and patients revealed discordance in perceptions of treatment benefit. Many oncologists believed cure was possible for selected patients with metastatic cancer but were reluctant to communicate this explicitly, while a substantial proportion of patients expected cure from palliative systemic therapy.

Overall, the findings demonstrate that as systemic therapies improve survival in advanced cancer, approaches to explaining their effects must evolve. Updated communication strategies are needed to better explain uncertainty and variability in outcomes and to support shared decision-making.