Herpes zoster is not associated with subsequent gastrointestinal cancer: data from over 200,000 outpatients in Germany

Gastrointestinal (GI) cancers are an increasing global health challenge. Viral diseases play an important role in the development of GI cancers. For example, Epstein-Barr virus, which belongs to the human herpesvirus family, is a well-recognized risk factor for the development of gastric cancer. The purpose of this study was to investigate a possible association between varicella-zoster virus reactivation and subsequent diagnosis of GI cancer. In this retrospective cohort study, a total of 103,123 patients with a first diagnosis of herpes zoster (HZ) between 2005 and 2021 were propensity score matched to a cohort of 103,123 patients without HZ. Patient data was extracted from the Disease Analyzer database (IQVIA). The incidence of GI cancer was compared as a function of HZ. Cox regression analysis was used to examine the association between HZ and GI cancer. Over a follow-up period of up to 10 years, the incidence of GI cancer did not differ between the two cohorts (HZ cohort 2.26 cases per 1000 patient-years vs. non-HZ cohort 2.37 cases per 1000 patient-years, p = 0.548). In regression analysis, HZ was not associated with an increased risk of developing GI cancer (HR: 0.97; 95