Circulating HDL and Non-HDL Associated Apolipoproteins and Breast Cancer Severity

Abstract

Plasma lipids are carried within lipoproteins with various apolipoprotein content. This study evaluates the interest of measuring the apolipoproteins of circulating lipoproteins in breast cancer. Patients with early-stage breast cancer (n = 140) were included. Tumors differed by the expression of estrogen and progesterone receptor (HR- and HR+ for negative and positive expression) and the proliferation marker Ki-67 (≤20% or ≥30%). Apolipoprotein concentrations were determined in plasma, HDL and non-HDL fractions, and results are given in mg/dL, median (25th-75th). Patients did not differ in their plasma and lipoprotein lipid concentrations. HDL apoC-I and non-HDL apoC-II were reduced (1.34 (1.02-1.80) vs. 1.61 (1.32-2.04), p = 0.04; 0.31 (0.18-0.65) vs. 0.63 (0.39-1.02), p = 0.01; respectively), in RH-/high Ki-67 patients in comparison to RH-/low Ki-67 patients, while plasma apoD and HDL apoD were higher (3.24 (2.99-4.16) vs. 3.07 (2.39-3.51), p = 0.04; 2.74 (2.36-3.35) vs. 2.45 (2.01-2.99), p = 0.04; respectively). When RH+/high Ki-67 patients were compared with RH+/low Ki-67 patients, HDL apoC-I and HDL apoC-III were higher (1.56 (1.20-1.95) vs. 1.35 (1.10-1.62), p = 0.02; 2.80 (2.42-3.64) vs. 2.38 (1.69-2.96), p = 0.02; respectively). The distribution of exchangeable apolipoproteins, such as apoC-I, apoC-II, apoC-III, apoD, between lipoproteins is linked to the severity of breast cancer.

Keywords: HDL; Ki-67; apolipoproteins; breast cancer; lipoproteins; non-HDL.