Optimising outcomes for frail patients with oesophagogastric (OG) cancers: The impact of dose reduction and comprehensive geriatric assessment.

303 Background: Delivery of appropriate management of elderly patients with OG malignancies in the palliative setting remains challenging and unpredictable. Incidence of OG cancers increases markedly with age, and there are growing numbers of elderly, frail and medically complex patients referred to oncology services for treatment. An adaptive approach to their management is required, tailored to their complex medical needs. The GO2 study sought to optimise chemotherapy delivery in this cohort and demonstrated that upfront dose reductions do not reduce progression-free survival in OG cancers. We analysed the treatment and outcome of elderly patients undergoing first-line palliative chemotherapy at our centre, with or without comprehensive geriatric assessment (CGA). Methods: We retrospectively analysed the records of patients over the age of 75 treated at our centre between May 2011 and March 2023. Progression-free survival (PFS) was calculated from the date of treatment initiation to date of radiological progression, or 19 th March 2024 if patients had not progressed. Overall survival (OS) was calculated from treatment initiation to date of death per the electronic health record, or 19 th March 2024 if patients had not died. Grade 3 (G3) toxicities and dose reductions (DRs) were identified from medical records. Statistical analyses were performed using R v4.3.3. Results: 82 patients were included in the analysis. Overall median PFS was 6.5 months (1-107 months) and median OS was 10 months (1-107 months). Patients who qualified for chemotherapy with immunotherapy had improved PFS (median 16 months, range 2-27 months) and OS (median 16 months, range 10-27 months). G3 toxicities were increased in patients without upfront DR (44% vs. 30%). The most significant predictor for survival in multivariate analysis was performance status (PS), which was associated with worse PFS (hazard ratio 2.66, range 1.35–5.35, p = 0.004), and OS (hazard ratio 6.13, range 2.79–13.44, p < 0.001). Age was not associated with survival. Consistent with the GO2 trial, there was no association between upfront DR and PFS (p = 0.13) or OS (p = 0.72). 38% of patients underwent CGA as part of their workup for chemotherapy. These patients were more likely to have upfront DR (61% vs. 47%). In this cohort, G3 toxicity rates were comparable in patients with PS 0-1 who underwent CGA (39% vs. 35%). In patients with PS ≥ 2, G3 toxicity rates were higher in those who did not undergo CGA (67% vs. 30%). Conclusions: Upfront DR in elderly patients is safe and does not impact survival but does reduce the burden of toxicity. PS, rather than age, is a better predictor of survival and treatment outcome. CGA may help mitigate toxicity burden in patients with poor performance status.