Effect of Neuroendocrine Tumor Classification Updates on Survival Rates in Pancreatic Cancer
Survival rates for pancreatic cancer should be stratified by disease subgroup to better reflect prognostic differences across the subgroups in this category.
The incidence of age-adjusted pancreatic neuroendocrine tumors (NETs) rose annually by 6.7% from 1995 to 2007 and by 13.4% from 2008 to 2014 (P < .05) among patients across the Surveillance, Epidemiology, and End Result (SEER) registries following revisions in 2000 and 2010 to the way NETs are characterized.
Because pancreatic NETs generally have a much better prognosis than other cancers of the pancreas, their inclusion in the same category as the other pancreatic cancers — namely, in the same group as pancreatic adenocarcinomas — may mean that calculation of the survival rate for pancreatic cancer of any type could be skewed.
The 5-year survival rate for pancreatic cancer from 2008 to 2014 was 9.1%, but declined by 43% to 5.4% when NET cases began being excluded from the official count for pancreatic cancers. By lumping NET cases in with all types of cancer of the pancreas, the 5-year rate of survival rate shot up regardless of the presence of other potentially confounding patient-specific parameters such as age, sex, stage, and year of pancreatic cancer diagnosis.
The researchers acknowledged that while survival rates for pancreatic cancer are improving, “changes in NET classification and reporting artifactually increases SEER-reported survival. Given the divergent biology of NET and non-NET pancreas cancer, separate reporting of survival seems warranted.”1
- Mandelson M, Massman JD, Picozzi VJ, Mason V. Impact of neuroendocrine tumor classification on pancreas cancer survival rates in the United States, 1995-2014. Presented at: AACR Pancreatic Cancer: Advances in Science and Clinical Care conference; Boston, Massachusetts: September 21-24, 2018. Abstract A071.