Anti-PD1 immunotherapy is standard of care in metastatic melanoma and non-small cell lung cancer (NSCLC). However, there is limited data to guide its use in elderly patients.1-5 CGA has been shown to correlate with outcomes in elderly patients receiving chemotherapy-based treatment.6,7 It is unclear if CGA can also be used meaningfully in those receiving immunotherapy.
This retrospective study aims to evaluate the utility of CGA in predicting immune related adverse events (irAEs), hospitalisation and survival outcomes in elderly patients with advanced melanoma or NSCLC receiving anti-PD1 immunotherapy.
Patients aged over 65 years with metastatic melanoma or NSCLC at Eastern Health between March 2015 and 2020 were identified. Demographics, disease characteristics, treatment, irAEs and survival outcomes were recorded. Patients were retrospectively categorised as CGA-fit, CGA-unfit, or CGA-frail, based on the CGA method developed by Tucci et al.7
50 patients were identified (35 melanoma; 15 NSCLC). Median age was 75 years (65-92 years). 19 patients were CGA-fit, 5 CGA-unfit and 26 CGA-frail. CGA-fit, CGA-unfit and CGA-frail patients received anti-PD1 immunotherapy for a median of 5.0, 9.0 and 6.0 months respectively.
47% of CGA-fit, 20% of CGA-unfit and 50% of CGA-frail patients experienced an irAE. 32% of CGA-fit, 20% of CGA-unfit and 19% of CGA-frail patients stopped immunotherapy due to an irAE. 58% of CGA-fit, 80% of CGA-unfit and 62% of CGA- frail patients were hospitalised during treatment.
The median progression free survival of CGA-fit, CGA-unfit and CGA frail patients was 7.2, 1.7 and 18.5 months respectively; the median overall survival was 13.8, 3.0 and 19.4 months respectively.
This study suggests baseline CGA may not associate with rates of irAEs, hospitalisation and survival outcomes. ‘Frail’ patients did not experience more toxicities and may derive similar benefits in outcomes as ‘fit’ patients. Limitations include its retrospectivity and limited patient numbers.