According to Surveillance, Epidemiology, and End Results (SEER) data, the age-adjusted incidence of NETs rose from 1.9 to 5.25 cases per 100,000 people between 1973 and 2004.4 Diagnosed incidence of NETs is predicted to continue rising at a faster rate than other malignant neoplasms.7 This may be due to improved surveillance and diagnostic techniques.8
The SEER database is a comprehensive cancer statistics program operated by the National Cancer Institute. SEER is widely used to establish the epidemiologic landscape for various types of cancer throughout the world.
SEER data also demonstrate that the prevalence of NETs is similar to that of other types of gastrointestinal cancers.4
Most NETs occur sporadically. However, some may be associated with genetic syndromes, notably multiple endocrine neoplasia type 1 (MEN-1), as well as MEN-2a and MEN-2b.2,3
As with other solid tumors, 5-year survival rates for patients with NETs depend largely on the tumor histology and extent of disease. The table at right shows 5-year and median survival for both well-differentiated NETs and poorly differentiated neuroendocrine neoplasms, according to long-term SEER data (1973-2004).4
This reflects, in part, the long delay that can occur (up to 5 to 7 years for certain types of NETs)2 before patients are definitively diagnosed and optimally managed.
Extent of disease at diagnosis also varies according to location of the primary tumor, as shown at right.4