- Histopathologically confirmed metastatic well differentiated Neuroendocrine Tumour (NET) (Grade G1 or G2 according to the World Health Organisation 2010 classification): Gastro-entero-pancreatic (GEP) or Bronchopulmonary (BP) primary tumour, or tumour of unknown origin believed to be of GEP origin, if a primary tumour elsewhere was excluded by multiphasic computerised tomography (CT) or magnetic resonance imaging (MRI)