Elderly patients with gastrointestinal stromal tumour (GIST) receive less treatment irrespective of performance score or comorbidity - A retrospective multicentre study in a large cohort of GIST patients.

Abstract

<h4>Objective</h4>Although gastrointestinal stromal tumours (GIST) predominantly occur in older patients, data on treatment patterns in elderly GIST patients are scarce.<h4>Methods</h4>Patients registered in the Dutch GIST Registry (DGR) from January 2009 until December 2016 were included. Differences in treatment patterns between elderly (≥75 years) and younger patients were compared. Multivariate analyses were conducted using logistic regression.<h4>Results</h4>Data of 145 elderly and 665 non-elderly patients were registered (median age 78 and 60 years respectively). In elderly patients, performance score (WHO-PS) and age-adjusted Charlson comorbidity index (ACCI) were significantly higher (p < 0.05; p < 0.001), and albumin level significantly lower (p = 0.04). Hundred-and-nine (75.2%) elderly and 503 (75.6%) non-elderly patients had only localised disease. Surgery was performed in 57% of elderly versus 84% of non-elderly patients (p = 0.003, OR: 0.26, 95% CI: 0.11-0.63). No differences in surgery outcome or complications were found. Thirty-eight percent of elderly with an indication for adjuvant treatment did receive imatinib versus 68% of non-elderly (p = 0.04, OR: 0.47, 95% CI: 0.23-0.95). Thirty-six elderly and 162 non-elderly patients had metastatic disease. Palliative imatinib was equally given (mean dose 400 mg) and adverse events were mostly minor (p = 0.71). In elderly, drug-related toxicity was in 32.7% reason to discontinue imatinib versus 5.1% in non-elderly (p = 0.001, OR 13.5, 95% CI: 2.8-65.0). Median progression-free survival (PFS) was 24 months in elderly and 33 months in non-elderly (p = 0.10). Median overall survival (OS) was 34 months and 59 months respectively (p = 0.01).<h4>Conclusions</h4>Elderly GIST patients with localised disease receive less surgery and adjuvant treatment, irrespective of comorbidity and performance score. Drug-related toxicity results more often in treatment discontinuation. This possibly results in poor outcome.