Has a better prognosis than pancreatic exocrine adenocarcinomas and account for less than 2% of pancreatic cancers in the U.S.
Annual incidence of pancreatic neuroendocrine tumors 0.32 cases per hundred thousand.
Neuroendocrine tumor of the pancreas accounts for 1% of pancreatic tumors and 10% by prevalence (Yao JC).
Incidence has increased over time.
The true incidence may be higher than reported because many lesions are small initially and not reported to SEER (Lam KY).
Of neuroectodermal origin.
Most patients have advanced disease at the time of diagnosis, and the liver if the major sites of metastases.
Incidence has increased over time.
While most are sporadic they may be seen with multiple endocrine neoplasia type I, von Hippel-Lindau disease, neurofibromatosis and tuberous sclerosis.
The average time from onset of symptoms to diagnosis of the tumor is 2.7 years.
Sporadic in 90% of patients, solitary in 90%, benign in 90%, less than 5 cm in 90% and 95% intrapancreatic.
Likely to be diagnosed at advanced stage, with 14% of cases localized, 22% regional and 64% distant at the time of diagnosis (Yao JC).
Median age 52 years.
More indolent, than other pancreatic cancers.
Abdominal pain presenting symptom in 75% of patients.
About 45% located in the head of the pancreas while approximately 55% in the body or tail.
Overall median survival duration and 5-year survival rate from the time of diagnosis are 3.2 years and 43%, respectively.
5 year overall survival of approximately 50% or metastases are present at diagnosis.
Tumor grade, as defined by KI-67 proliferation influences overall survival with low-grade tumors manifesting a better outcome than intermediate or high-grade tumors.
Median survival 27 months among patients with advanced disease (SEER).
For patients with advanced disease estimated five-year survival is 23% in patients with distant metastases (Yao JC et al).
Patients with metastases at the time of diagnosis have a median survival of 2.2 years compared with 7.1 years for patients with localized, nonmetastatic disease.
More vascular than pancreatic cancer and enhances with the arterial phase of the CT scan of the abdomen.
Sometimes the pancreatic neuroendocrine tumors are divided on the basis of the functioning or nonfunctional status based on whether the lesion causes hormonal symptoms.
The functional status of the tumor may change over time.
In patients with liver metastases the combined pancreatic and hepatic resections can be performed safely with acceptable morbidity and mortality with an overall 5-year survival of 71%.
Survival of unresected lesion with liver metastases ranges from 1.7 to 3.1 years.
Patients with low-grade,, low volume, non-hormone secreting tumors may be asymptomatic and should be observed to monitor disease pace.
Therapy is indicated at disease progression or development of symptomatology.
Debulkation of tumor provides relief from endocrine symptoms and prolongation of survival in patients with unresectable metastatic disease with a 79% 5-year survival.
Combination of streptozotocin and doxirubicin associated with a response rate of 69%, 20 month time to progression and a median survival of 2.2 years in one study, but other studies report much lower response rates.
An endocrine carcinoma that may be functional and produce gastrin, insulin, glucagon, somatostatin, vasoactive intestinal polypeptide, growth-hormone releasing factor, and adrenocorticotropic hormone.
The use of somatostatin analog therapy can prolong time to tumor progression in patients with advanced midgut neuroendocrine tumors (Arnold R).
Functional pancreatic neuroendocrine tumors can be managed with somatostatin analogs such as octreotide or lanreotide.