In comparison with poorly differentiated EPNEC, the subgroup of patients with well-differentiated tumours presented comparable frequencies of ERCC1, Bcl-2, and Lin28 IHC expression, similar RR (p = 0.94), but higher Ki-67 index (p = 0.048) and numerically longer OS (p = 0.23). Here, MKI67 is linked to neoplasm.