Risk factors for neuroendocrine neoplasms: protocol for a case-control study based on a record linkage of registry and claims data.

BACKGROUND

Recent studies showed an increase in neuroendocrine neoplasms, especially for the digestive tract. Several risk factors have been suggested to explain this increase, including a family history of cancer, tobacco smoking, alcohol consumption and metabolic disorders such as diabetes and obesity. Another risk factor may be depressive disorders, which could increase the risk of neuroendocrine neoplasms either directly or mediated through associated risk behaviours and/or antidepressant medication. Here, we outline the design of our study to identify the risk factors for neuroendocrine neoplasms in Germany.

METHODS AND ANALYSIS

A case-control study of the resident population of Bavaria, the second most populous federal state in Germany, based on a record linkage of data from the Bavarian Cancer Registry and data from the Bavarian Association of Statutory Health Insurance Accredited Physicians. Cases have a diagnosis of a malignant neuroendocrine neoplasm, either of the bronchopulmonary system or the gastroenteropancreatic system, in the period from 2021 to 2023. Controls are sampled from the non-cases and matched on sex, birth year (in 5-year intervals) and time of diagnosis (by calendar quarter). Risk factor prevalence of cases and controls is assessed on the basis of assured outpatient diagnoses, that is, diagnoses documented in at least 2 out of 4 consecutive quarters in the 16 quarters preceding the diagnosis of a neuroendocrine neoplasm. The analysis uses conditional logistic regression to estimate ORs and 95% CIs.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ethics Committee of the Bavarian State Chamber of Physicians (reference number: 24008). Approval by the supervisory authority has been obtained from the Bavarian State Ministry of Health, Care, and Prevention (reference number: G35h-A1080-2023/20-2) and also the Bavarian Data Protection Commissioner stated to have no concerns after presentation of the study protocol (reference number: DSB/7-692/1-275). The results of the case-control study will be presented at national as well as international conferences and be published in the form of scientific articles in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT06282016.