The incidence of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) has continued to increase over the last few decades, and researchers have developed a nomogram that may help predict survival in these patients. 

The researchers reported GEP-NETs incidence data and described the nomogram in JAMA Network Open. 

The study included data from 43,751 patients diagnosed with GEP-NETs from January 1, 1975, through December 31, 2015. 

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The age-adjusted incidence of GEP-NETs increased from 1.05 per 100,000 people in 1975 to 5.45 per 100,000 people in 2015, which translates to an annual percentage change (APC) of 4.98 (95% CI, 4.75-5.20; P <.001). 

The greatest increases in incidence occurred in GEP-NETs of the rectum and stomach, which “may be associated with the increased availability of routine monitoring, cross-sectional imaging, and endoscopy in clinical practice,” the researchers wrote. 

When it came to disease stage, the most significant increase in incidence was seen in localized GEP-NETs. This may be a result of increased detection of asymptomatic, early-stage disease, according to the researchers. 

They also noted a “sharp increase” in the incidence of G1 GEP-NETs, which may be due to “the increased awareness and widespread application of the nomenclature and classification of these diseases,” the researchers wrote.

Over the study period, the mean age at diagnosis increased by 9 years for localized cases (P =.002) but was unchanged for patients diagnosed with regional and distant disease. 

Predicting Survival

The researchers conducted a multivariable analysis and found several factors associated with overall survival (OS), including age, sex, marital status, tumor size, tumor grade, disease stage, and primary tumor site.

For example, patients diagnosed with distant disease had significantly worse OS compared with patients who had localized disease (hazard ratio [HR], 10.32; 95% CI, 8.56-12.43). Likewise, patients diagnosed with grade 4 disease had worse OS compared with those who had grade 1 disease at diagnosis (HR, 6.37; 95% CI, 5.39-7.53). 

Based on these findings, the researchers developed a nomogram for predicting OS and included the following factors: age, tumor size, tumor grade, disease stage, and primary tumor site. 

The nomogram proved more accurate than TNM staging for predicting 3-year and 5-year OS. The area under the receiver operating characteristic curve (AUC) for 3-year OS was 0.908 for the nomogram and 0.795 for TNM classification. The AUCs for 5-year OS were 0.893 and 0.791, respectively.

“[T]his simple and effective tool could more accurately evaluate various parameters of GEP-NETs, thereby facilitating clinical decision-making and communication with patients and their families,” the researchers wrote.


Xu Z, Wang L, Dai S, et al. Epidemiologic trends of and factors associated with overall survival for patients with gastroenteropancreatic neuroendocrine tumors in the United States. JAMA Netw Open. Published online September 23, 2021. doi:10.1001/jamanetworkopen.2021.24750