A United Kingdom prospective, multicentre, observational cohort study investigating tolerance of anti-cancer systemic therapy in the elderly: The TOASTIE study.

Abstract

1521 Background: Older adults have a higher risk of developing chemotherapy (CTx) related toxicity. The Cancer Aging Research Group (CARG) score was developed and validated in the USA to predict risk of severe CTx induced toxicity in older adults; subsequent validation studies have had varying results. The TOASTIE study sought to evaluate the CARG score prospectively in a United Kingdom (UK) population. Methods: This multicentre, prospective, observational study recruited patients aged ≥65 years commencing first-line neo-adjuvant, adjuvant or palliative CTx for any solid organ malignancy. Those receiving non-CTx agents were excluded. Baseline demographics and established frailty measures were recorded, including Eastern Cooperative Oncology Group performance status (ECOG PS), Rockwood Clinical Frailty Scale (CFS), Geriatric-8 (G8) score and Charlson Co-morbidity Index (CCI). CARG score was calculated after initial Oncology consultation. Follow-up data including CTCAEv5 toxicity and hospital admissions were collected retrospectively. Results: 19 centres recruited 330 patients between Nov 2019 - Dec 2022. Median age was 73 years (range 65-92) and 51.9% were male. 54.9% had a primary tumour of gastrointestinal origin, 48.7% received CTx with palliative intent and 70.8% received doublet therapy. At baseline, 85% patients had an ECOG PS 0 or 1, with median CFS 3 (range 0-8), G8 score 12 (range 6-16) and CCI 6 (range 2-12). Follow-up data was available for 314 (92.6%) patients; the median CTx cycles received was 4 (range 1-16) with 124 (39%) patients dose reduced at cycle one. Treatment delays occurred in 83 (26.4%) patients and 123 (39.2%) stopped treatment early, with 60 (48.8%) cases due to treatment-related toxicity. 69(22.3%) patients experienced a CTCAE grade ≥3 toxicity and 84 (27%) requiring hospital admission. CARG score was available for 313 patients; 107 (34.2%) low risk, 167 (53.4%) medium risk and 39 (12.5%) high risk. Increasing CARG risk groups had increased toxicity rates (low 19.6%, medium 22.2%, high 28.2%) however this was non-significant with no evidence of robust predictive performance (Table). The performance of CFS and ECOG PS was superior to CARG. Conclusions: In this UK older patient population, baseline frailty was prevalent. CARG score was unable to robustly discriminate or predict risk of high-grade toxicity. ECOG showed superior, albeit limited, ability to predict and discriminate toxicity risk. This study highlights the need for development of further tools predictive of toxicity in this population. [Table: see text]