Published online Oct 28, 2017. doi: 10.3748/wjg.v23.i40.7283
Peer-review started: June 30, 2017
First decision: July 27, 2017
Revised: August 31, 2017
Accepted: September 13, 2017
Article in press: September 13, 2017
Published online: October 28, 2017
To discover unknown factors associated with carcinoid syndrome (CS) with the goal of earlier diagnosis of CS.
In this retrospective case-control study using United States administrative claims, patients (≥ 18 years) newly-diagnosed with gastrointestinal neuroendocrine tumors (GI NETs) without CS (controls) were exactly matched to patients with CS (cases) based on NET diagnosis date at a 3-to-1 ratio. Study index date was first CS diagnosis (controls: same distance from NET diagnosis as cases). The most observed conditions, excluding CS-associated symptoms/diagnoses, during the year before index date were assessed. Forward-stepwise logistic regression models were used to derive predictors, and were validated within another claims database.
In the development database, 1004 patients with GI NETs were identified; 251 (25%) had CS and 753 (75%) were controls. In the validation database, 724 patients with GI NETs were identified; 181 (25%) had CS and 543 (75%) were controls. A total of 33 common diagnoses (excluding conditions already known to be associated with CS) in the development database were entered in forward step-wise logistic regression models. In the final, validated logistic regression model, three factors prior to CS diagnosis were found consistently associated with higher risks for CS, including liver disorder [odds ratio (95%CI): 3.38 (2.07-5.51)], enlargement of lymph nodes [2.13 (1.10-4.11)], and abdominal mass [3.79 (1.87-7.69)].
GI NET patients with CS were 2-4 times as likely to have preexisting diagnoses (i.e., liver disorder, enlarged lymph nodes, abdominal mass) than non-CS patients.
Core tip: By assessing patients with gastrointestinal neuroendocrine tumors from two independent United States claim databases, this study found that patients with carcinoid syndrome (CS) were 2-4 times as likely to have a preexisting diagnosis of a liver disorder, enlargement of lymph nodes, or abdominal mass than patients without CS.