Epidemiology and survival of neuroendocrine tumors in Ontario: A 15-year population-based study.

Abstract

184 Background: A recent study of the SEER database in the United States showed a 5-fold increase in neuroendocrine tumours (NETs) over the last 30 years. An increasing incidence has also been reported in Norway, Sweden, England, Holland, Italy and Japan, but interestingly not in Denmark and Switzerland. The objective of our study is to describe the incidence, anatomical distribution and survival of NETs in Ontario. Methods: A population based study was initiated using the Ontario Cancer Registry, cross-linked with the Registered Persons Database and the Canadian Institute of Health Information Discharge Abstract Database. All cases of NETs were identified in Ontario (> 13 million persons) from 1994 to 2009. Baseline demographic, clinical and outcomes data were abstracted to allow for an analysis of annual incidence rates, and overall survival. Results: A total of N = 5619 cases were identified. The incidence rate increased from 2.46/ 100,000 (95% CI, 2.13-2.83) in 1994 to 5.86/ 100,000 (95% CI, 5.40 – 6.35) in 2009. The median age was 62 with 50.5% female cases. When divided by site, bronchopulmonary NETs where the most common (22%), then jejunum/ileum (17%) and rectal (16%) NETs, while pancreatic NETs (pNETs) and gastric NETs were 10% and 5% respectively. The absolute increase in the study period was most pronounced for pNETs (6-fold), rectal (5-fold) and gastric (5-fold) NETs. Metastatic disease was documented in 45% of the cases; 20% at diagnosis and 25% during follow-up. The 5-and 10-year overall survival (OS) was 61% and 46% respectively, for the entire population. Site specific 5-year OS were: rectal (87.0%), small bowel (73.4%), gastric (67.4%), colon (64.3%) and pancreas (48.8%). 5-year OS was compared for patients with and without metastatic disease after diagnosis (69.0% vs 40.1%, p<0.0001). Conclusions: There appears to be a significant increase of reported cases of NETs in Ontario, Canada, particularly pNETs, rectum NETs and gastric NETs. This supports much of the population-based reports worldwide. Survival appears to vary significantly according to anatomical site and extent of disease. Further research is required to understand the impact of this cancer previously perceived to be rare but clearly increasing.