The ratio of apolipoproteins B and A1 (apo B/A1) is an independent prognostic factor in patients with metastatic renal cell carcinoma, according to authors of a recent retrospective study.
The apo B/A1 ratio, evaluated prior to cytoreductive nephrectomy, was significantly linked with poor progression-free survival and overall survival, according to Fan Zhang, MD, of the Chinese PLA General Hospital in Beijing and coauthors.
Those findings suggest that patients with metastatic RCC should receive “consistent follow-up” that includes evaluation of that ratio, Dr. Zhang and colleagues said.
“As a novel prognostic factor, the preoperative apo B/A1 ratio can be utilized as a supplement to improve the current prognostic evaluation and treatment decision for patients with metastatic RCC,” they wrote in.
Apo B and A1, which are predominant components of low-density lipoprotein (LDL) and high-density lipoprotein (HDL), respectively, have “extensive connections” with cardiovascular disease, diabetes, and Alzheimer disease, the authors said.
The apo B/A1 ratio is a known risk index for cardiovascular disease, and in recent studies, it appeared to have some value in prognosis and prediction of gastric and colorectal cancer, among other neoplasms, they added.
In their retrospective study, Dr. Zhang and colleagues analyzed data on 287 metastatic RCC patients who underwent cytoreductive nephrectomy at the Chinese PLA General Hospital. The median age of the patients was 56 years, and the median apo B/A1 ratio was 0.859.
Significantly poorer progression-free survival was seen in the group of patients with a preoperative apo B/A1 ratio over the cutoff of 0.977 (P less than .0001) compared with those under the cutoff, the investigators reported. Likewise, overall survival was poorer for patients with an apo B/A1 ratio over a cutoff of 0.847 (P = .0005).
The apo B/A1 ratio was higher in patients with Fuhrman grade 3-4 versus grade 1-2 patients (P = .010), though the investigators said no significant differences in the ratio were seen in patients stratified by age, body mass index, fatty liver, number of metastases, among other subgroup analyses.
Multivariate analysis revealed that the two independent prognostic factors for progression-free survival were preoperative apo B/A1 ratio and Fuhrman grade, with hazard ratios of 3.131 and 1.906, respectively (P less than .001 for both), while independent prognostic factors for overall survival also included the apo B/A1 ratio (hazard ratio, 2.173; P less than .001) and Fuhrman grade, along with tumor necrosis and receiving targeted therapy.
This retrospective study was limited by relatively small samples from a single center, and the prognostic value of the apo B/A1 ratio needs to be verified in other studies, investigators said.
“Peripheral blood biomarkers only provide a supplement to the traditional prognostic factors in the prediction of the prognosis for patients with metastatic RCC, and are still unable to replace it,” Dr. Zhang and associates said.
The Beijing Natural Science Foundation supported the study. Dr. Zhang and coauthors had no disclosed conflicts of interest related to the work.
SOURCE: Zhang F et al. . 2018 Nov 30. doi: 10.1016/j.urolonc.2018.11.010.