High-density Lipoprotein Cholesterol and the Development of Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue.

To date, no studies have examined the effect of high-density lipoprotein cholesterol (HDL-C) on the development of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). We investigated, for the first time, the relationship between HDL-C and the risk of MALT lymphoma. In this nationwide population-based cohort study, 4.25 million cancer-free individuals that underwent a National General Health Examination and cancer screening in 2010 were enrolled and followed until the end of 2017. Subjects were classified into 5 groups based on HDL-C levels (< 30, 30-39, 40-49, 50-59, or ≥ 60 mg/dL). MALT lymphoma was diagnosed in 1,119 of the 4.25 million study subjects during the follow-up period. Subjects with the lowest HDL-C level (< 30 mg/dL) had a higher risk of MALT lymphoma (adjusted hazard ratio [aHR] 1.79, 95% CI 1.08-2.96) than those with a HDL-C level of 40 to 49 mg/dL, whereas those with the highest HDL-C level (≥ 60 mg/dL) had a lower risk of MALT lymphoma (aHR 0.84, 95% CI 0.71-0.99). Sensitivity analyses, excluding individuals who were diagnosed with MALT lymphoma within 2-year of follow-up, also revealed similar association. In subgroup analysis, the hazardous effect of low HDL-C on MALT lymphoma development was significant in females (aHR 2.31, 95% CI 1.13-4.72) but not in males. An unfavorable effect of low HDL-C on MALT lymphoma was significant in never smokers (aHR 2.20, 95% CI 1.19-4.05) but not in smokers. In conclusion, a low HDL-C level was found to be associated with an increased risk of MALT lymphoma particularly in females or never smokers.