Background: Gastroesophageal reflux disease (GERD) is a common problem that affects patients. The constant irritation of the esophageal mucosa, in addition to the potential aspiration, has been suggested as a predisposing factor for lung cancer (LC). This study aims to investigate the association between GERD and LC. Methods: An electronic search was conducted on EMBASE, CENTRAL, and PubMed databases from inception through November 2025. Studies evaluating the association between GERD and lung cancer in adult populations were included. Reviews, non-English articles, pediatric studies, and non-human studies were excluded. Twelve studies involving 2,900,965 patients met the inclusion criteria. Three types of common and random effect meta-analyses were utilized, namely meta-analysis of proportion, log(HR) and log(OR) models. Included studies were examined for risk of bias using the Newcastle–Ottawa scale. Results: Twelve articles describing 2,900,965 patients were found to be fit for inclusion. Male and female sexes were equally represented. On average, patients were 57.67 ± 10.02 years of age. Pooled proportion of co-occurring LC and GERD in patients was estimated at 64% [95% C.I.: 15–95%; p = 0.02], with significant heterogeneity (I² = 96.8%, p < 0.01). Among studies calculating for hazard ratio (HR), an estimated pooled log(HR) of 1.01 [95% C.I.: 0.36–2.8; p = 0.98] with significant data heterogeneity (I² = 88%, p < 0.01) was found. In comparison, five studies included estimates of odds ratio (OR), which resulted in a pooled log(OR) of 1.32 [95% C.I.: 1.2–1.46; p < 0.01], with less heterogeneity (I² = 59.1%) which was marginally significant (p = 0.04). Conclusions: Our findings may suggest a possible association between LC and GERD; however, estimates were discordant across effect measures and heterogeneity was substantial, so this association should be interpreted with caution.

Background/Objectives Atrial fibrillation/flutter (AF) and liver cirrhosis both present a large disease burden internationally, with millions of adults afflicted. There is evidence of a link between these two diseases; however, the prevalence and impact of liver cirrhosis in patients with and without AF have not been extensively detailed. With the utilization of a large national database, we examined the relationship between liver cirrhosis and AF and the effects on hospital outcomes. Methods We conducted a nationwide review from 2016 to 2020 utilizing the Nationwide Inpatient Sample (NIS) database. Patients ≥ 18 years old with newly diagnosed atrial fibrillation or atrial flutter were identified. They were then further stratified into patients with and without liver cirrhosis. Characteristics and comorbidities were identified, evaluating in-hospital mortality as the primary outcome. Results A total of 3,866,486 patients with a primary diagnosis of AF were included. Patients with liver cirrhosis were younger in age (mean age 68.32 vs 74.36 years old), the majority were White (74.1%), followed by Black (10.2%), and Hispanic (10.5%). They had more comorbidities, such as diabetes (45.1% vs 37.3%, p<0.001), hypertension (78.5% vs 83.6%, p<0.01), and chronic kidney disease (22.1% vs 19.5%, p<0.001) when compared to patients without liver cirrhosis. Patients with liver cirrhosis had a higher risk of in-hospital mortality (OR=1.84, p<0.001), hypovolemic shock (OR=2.17, p<0.001), gastrointestinal bleed (OR=2.42, p<0.001), requiring blood transfusions (OR=1.84, p<0.001), and requiring ICU-level of care with intubation (OR=1.214, p<0.001), central line (OR=1.33, p<0.001), arterial line (OR=1.32, p<0.001) and vasopressors (OR=1.61, p<0.001). Moreover, patients with liver cirrhosis had a lower risk of having an acute cerebrovascular accident (OR=0.431), transient ischemic attack (OR=0.475), or pulmonary embolism (OR=0.68) while hospitalized (p<0.001). Conclusion Our results have demonstrated a remarkable relationship between AF and liver cirrhosis, with significantly increased morbidity and mortality reported in individuals with both conditions compared to AF without liver cirrhosis.