Small intestinal neuroendocrine tumors are the most common gastrointestinal neuroendocrine tumor.
However, their natural history and outcome remain poorly defined, which hinders both the prediction of disease progression and appropriate therapeutic options.
Dr Irvin Modlin and colleagues from New Haven, USA examined patterns, incidence, prognosis, and outcomes of these tumors over a 30-year period.
Data were extracted from the neuroendocrine tumors SEER registry from 1973 to 2002.
Incidence rates, distribution, and 5-year survival rates were analyzed and adjusted.
Of the 18,641 neuroendocrine tumors, the team noted that 3,911 were small intestinal, of which 1,953 were ileal.
|There was an overall 2- to 4-fold increase in tumors|
|American Journal of Gastroenterology|
Since 1973, both small intestinal neuroendocrine tumors, and its ileal variant have increased annually by 4% and 2%, respectively.
The research team found that ileal tumors, as a percentage of small intestinal tumors, have increased from 52% to 64%.
The age-adjusted incidence of ileal, small intestinal, and digestive system neuroendocrine tumors has increased 225%, 460%, and 720% over 30 years.
Ileal tumors have specifically increased in prevalence in white and black men and women.
The researchers observed an overall increase of 4-fold in blacks and 2-fold in whites.
Although 83% of small intestinal neuroendocrine tumors were staged, 84% were histologically ungraded.
The team observed that the 5-year survival rates for small intestinal neuroendocrine tumors were 63% at all stages, and 74% in localized tumors.
The 5-year survival rates were 72% in regional, and 43% in distant small intestinal neuroendocrine tumors.
The research team found that these have not significantly altered since 1973.
Dr Modlin's team concludes, "Small intestinal neuroendocrine tumors have increased, particularly in men and in the black population, which may be due to in vivo changes, increased clinical and pathological awareness, or increased detection of tumors."
"Small intestinal neuroendocrine tumors are malignant, diagnosed late, and survival rates have remained unchanged over 30 years."