MKI67 and neuroendocrine carcinoma: As these two factors impacted independently on survival outcomes of patients with advanced EP-NEC, they were jointly applied to stratify this patient cohort into the following subgroups: (A) non-SC EP-NECs with a Ki-67 index of <55% (n = 21); (B) non-SC EP-NECs with a Ki-67 index of ≥55% (n = 60); (C) SC EP-NECs with a Ki-67 index of <55% (n = 5); (D) SC EP-NECs with a Ki-67 index of ≥55% (n = 55) (Figure 4).