Implications of the new histological classification (WHO 2010) for pancreatic neuroendocrine neoplasms.

Pancreatic neuroendocrine tumors (PanNETs) are rare
neoplasms with a more favorable prognosis than pancreatic
adenocarcinoma. However, up to 60% of patients with
PanNETs present with advanced disease or will recur after
surgical resection, requiring multimodal therapy to improve
clinical outcomes. In 2011, two phase 3, randomized, placebo-controlled trials provided optimism regarding the treatment of malignant PanNETs. The tyrosine kinase inhibitor sunitinib and
the mTOR inhibitor everolimus were effective in improving
progression-free survival in advanced PanNETs. These
two trials involved patients with well-differentiated or
intermediate/low-grade PanNETs as defined by previous
histological classifications including the World Health
Organization (WHO) 2000 system. Patients with poorly
differentiated endocrine carcinomas (PDECs) were excluded
from these trials, as PDECs are highly malignant tumors
commonly treated with cisplatin and etoposide.