ABSTRACT
Aim/Introduction: 177Lutetium-[DOTA,Tyr3]octreotate (177Lu-DOTATATE) is a type of peptide receptor radionuclide therapy that garnered FDA approval in January 2018 for the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumour patients.The objective of this study is to analyse if there is any tumour characteristic that is associated with the response to treatment with 177Lu-DOTATATE at 12 months. Material(s) and Method(s): Patients with metastatic neuroendocrine tumour who received the first dose of 177Lu-DOTATATE between June/2017 and February/2021 at UCMHMNA were included. Clinical, analytical, histological, imaging test and survival data available in the clinical history until October/2021 were collected. Response at 12 months was assessed by morphologic and metabolic criteria (partial response vs stability vs progression). Result(s): 28 patients met the inclusion criteria: 67% male and age range 41-83 years. According to the origin of the tumour, 23 were digestive, 3 pulmonary and 2 of unknown origin. According to the degree of differentiation, 11 were G1, 13 G2, 3 G3 and 1 unspecified. 82.2% of the patients had received the 4 doses of 177Lu-DOTATATE. Among those who did not complete the regimen, 4 were due to tumour progression and 1 due to an adverse effect (grade 3-4 thrombocytopaenia). At 12 months, 4 patients achieved a partial response, 12 had a stable disease and 8 disease progression. 8 patients died: 1 due to COVID-19, 1 due to cardiac disease and 6 (21% of the sample) due to disease progression (being in 4 of them in less than 1 year). In the statistical analysis, the degree of tumour differentiation (G1-G2 vs G3) obtained a statistically significant difference (p<0.0002) in terms of response to 177Lu-DOTATATE treatment at 12 months. In contrast, Ki67, origin of the tumour, type of metastasis, PFS, and OS were not associated with the response achieved at one year. Conclusion(s): The degree of tumour differentiation is the only characteristic that has a statistical association with 177Lu-DOTATATE one-year treatment, with a higher percentage of tumour progression in the group G3.