Abstract 6457: Blood magnesium level is associated with liver cancer risk in a prospective cohort of liver cirrhosis patients
Authors: Zhang Xinyuan , Zhao Longgang , Hou Tao , Lai Michelle , Dai Qi , Zhang Xuehong 
Published: June 2023

Abstract
Background: Previous studies showed that higher magnesium intake was linked to a lower risk of liver cancer. However, the relationship between blood magnesium level and the risk of liver cancer has not been fully established, especially among cirrhosis patients where magnesium deficiency commonly occurred. To address this knowledge gap, we have established a prospective cohort of patients with liver cirrhosis based on real-world, electronic health record data.
Methods: In the Mass General Brigham Biobank, a biorepository of consented patients, we established a prospective cohort by identifying liver cirrhosis patients using the International Classification of Diseases 9th and 10th version codes (ICD-9: 571.2, 571.5, and 571.6; ICD-10: K70.3, K74.3-6). We excluded patients with liver cancer history or without blood magnesium assessment at the time of cirrhosis diagnosis (baseline). We identified subsequent incident liver cancer (ICD-9: 155; ICD-10: C22) and levels of liver function biomarkers assessed at each hospital visit, including alanine transaminase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP). We used Cox regression models to generate ratios (HRs) with 95% confidence intervals (CIs) for developing liver cancer according to quartiles (Qs) of baseline blood magnesium levels, adjusting for age, sex, race, smoking status, alcohol intake, physical activity, body mass index, diabetes, ALT, and hepatitis B/C infection. We used generalized estimating equation (GEE) models to estimate the associations between baseline blood magnesium levels and repeated measurements of liver function biomarkers after cirrhosis diagnosis.
Results: We included 1257 liver cirrhosis patients (median age at diagnosis 59.5 years; 36% female; 87% white) with magnesium levels measured at baseline. During a median follow-up period of 3.55 (range: 0.1-12) years from liver cirrhosis diagnosis, 106 developed liver cancer. In multivariable-adjusted Cox models, higher baseline blood magnesium (Q4: ≥2.10 mg/dL vs. Q1: &lt;1.80 mg/dL) was associated with a lower risk of liver cancer (HRQ4 vs. Q1 = 0.57; 95% CI: 0.33, 0.99; p-trend =0.03). Results remained similar in 1-year lagged analysis. In multivariable-adjusted GEE models, higher magnesium was associated with a slower change of ALT (coefficientQ4 vs. Q1 = -7.09; 95% CI: -12.6, -1.62) and AST (coefficientQ4 vs. Q1 = -8.06; 95% CI: -13.9, -2.25).
Conclusions: In a prospective cohort of high-risk population with liver cirrhosis, higher blood magnesium was associated with a lower risk of developing liver cancer and a slower change of biomarkers suggestive of liver function. Magnesium is implicated in liver carcinogenesis and progression, therefore monitoring and maintaining blood magnesium could be important to delay the progression from cirrhosis to cancer.
Citation Format: Xinyuan Zhang, Longgang Zhao, Tao Hou, Michelle Lai, Qi Dai, Xuehong Zhang. Blood magnesium level is associated with liver cancer risk in a prospective cohort of liver cirrhosis patients. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6457.