Hypocholesterolemia in cancer patients may be caused by elevated LDL receptor activities in malignant cells.

Several epidemiological studies indicate an inverse relation between plasma cholesterol and the occurrence of cancer. Since we in previous studies have found that certain malignant cell types have an elevated LDL receptor activity, the aim of the present study was to further explore the possibility that an elevated LDL consumption by tumor cells causes hypocholesterolemia. The plasma cholesterol concentrations in patients with acute leukemia were inversely correlated with the rate of receptor-mediated degradation of 125I-LDL by the leukemic cells. During chemotherapy, the total plasma and the LDL cholesterol levels increased concomitantly with the reduction in the leukemic cell count in a patient whose leukemic cells exhibited a high rate at receptor-mediated degradation of 125I-LDL. In certain patients with inoperable urinary bladder carcinoma, the plasma cholesterol concentration fell as the disease progressed. Studies in breast cancer patients indicate that the number of LDL receptors in the tumor tissue may have prognostic significance. The results are in agreement with the hypothesis that an elevated LDL receptor activity in malignant cells may lead to hypocholesterolemia.