Annals of Oncology Advance Access published online on May 30, 2008
Annals of Oncology, doi:10.1093/annonc/mdn351
Pancreatic neuroendocrine tumors (PNETs): incidence, prognosis and recent trend toward improved survival

1 Division of Medical Oncology
2 Health Sciences Research, Mayo Clinic College of Medicine, Rochester, MN, USA
* Correspondence to: Dr T. R. Halfdanarson, University of Iowa Hospitals and Clinics, Division of Hematology, Oncology and Blood & Marrow Transplantation, 200 Hawkins Drive, Iowa City, IA 52242, USA. Tel: 319-356-2075; Fax: 319-353-8383. E-mail: thorvardur-halfdanarson{at}uiowa.edu
Background: Pancreatic neuroendocrine tumors (PNETs) are uncommon neoplasms that can present with symptoms of hormone overproduction. We evaluated the incidence, prognosis, and temporal trends of PNETs.
Patients and methods: We analyzed all cases of PNETs registered in the Surveillance, Epidemiology, and End Results database from 1973 to 2000. Age-adjusted incidence and survival rates were calculated and survival trends over time were evaluated.
Results: We identified 1483 cases of PNETs. The crude annual incidence per 1 000 000 was 1.8 in females and 2.6 in males and increased with advancing age. The incidence increased over the study period. Most patients (90.8%) had nonfunctional tumors. Advanced stage, higher grade, and age were the strongest predictors of worse survival. Patients with functional tumors had better outcomes than patients with nonfunctional tumors in both univariate and multivariate analysis (P = 0.004). Survival time increased over the period from 1973 to 2000. No differences were seen in the distribution of stage or age at diagnosis among time periods.
Conclusion: PNETs are uncommon neoplasms but the incidence may be increasing. Age, grade, stage, and functional status predict survival in patients with PNETs. Survival has improved over time, but this is not explained by earlier diagnosis or stage migration.
epidemiology, incidence, islet cell tumors, pancreatic neuroendocrine tumors
Current affiliation: University of Iowa Hospitals and Clinics and Iowa City VA Medical Center, Iowa City, IA. Received for publication January 15, 2008. Revision received April 17, 2008. Accepted for publication April 18, 2008.