177Lu-DOTATATE in older patients with metastatic neuroendocrine tumours: safety, efficacy and health-related quality of life

Purpose The safety and efficacy of 177 Lu-DOTATATE in older patients with advanced neuroendocrine tumours (NET) are not well understood. Methods Patients ≥70 years of age and treated with 177 Lu-DOTATATE were included. Toxicity, health-related quality of life (HRQoL), objective response, progression-free survival (PFS) and overall survival (OS) were assessed. The relationship between baseline characteristics and PFS and OS was analysed using the Kaplan-Meier method. Univariate analyses were performed using the Cox proportional hazards model. Results In total, 71 patients were included (76.1% midgut primary). The median age at diagnosis and age at 177 Lu-DOTATATE treatment were 70 and 74 years, respectively. The majority (78.9%) of patients completed 4 cycles of 177 Lu-DOTATATE. Clinically significant myelosuppression was rare (2.8%). There was no deterioration in HRQoL and ‘disease-specific worries’ significantly improved ( P = 0.029). Radiological response assessment was available in 66 patients. Partial response, stable disease and progression of disease were found in 10 (15.2%), 52 (78.8%) and 4 patients (6.1%), respectively. Median PFS and OS were 36.0 and 47.0 months, respectively. Increased baseline alkaline phosphatase was associated with poorer PFS ( P = 0.002) and OS ( P = 0.006). Conclusion Patients ≥70 years of age with advanced NET treated with 177 Lu-DOTATATE have efficacy and toxicity profiles similar to the wider NET population, without deterioration of HRQoL.