Reduced low-density-lipoprotein cholesterol causing low serum cholesterol levels in gastrointestinal cancer: a case control study.

Several epidemiological studies suggested an inverse relation between serum cholesterol level and cancer mortality. We analyzed the relation between gastrointestinal cancers and serum cholesterol levels. A total of 631 patients were recruited as cancer-bearing cases, comprising 181 esophageal cancers, 251 gastric cancers and 199 colorectal cancers. A case-control analysis was conducted on the serum TC, HDL-C, LDL-C and TG levels. TC and LDL-C were significantly lower in cancer-bearers by approximately 15 mg/dl. Furthermore, analyses by cancer site also showed significantly lower TC and LDL-C levels in cancer-bearers than in controls for all three sites. In this analysis, early stage cancer-bearers showed a significant decrease in TC levels by approximately 11 mg/dl compared with controls, and also a similar decrease in LDL-C levels. These results suggest that low TC levels are not related to cancer stage. Furthermore, findings of no significant differences in HDL-C and TG between cancer-bearing cases and controls in addition to a specific decrease in LDL-C in cancer-bearers suggest that hypocholesterolemia observed in these cases stems from low LDL-C. However, cancer-bearers and controls showed a similar distribution of TC and LDL-C levels. We should be aware that latent cancer bearers may be present among subjects with hypocholesterolemia.