Association of Apelin Levels with Lymph Node Invasion and Clinical Progression in Obese Patients Undergoing Radical Prostatectomy for Prostate Cancer

Objective: We aimed to determine the relationship between Apelin, an adipocytokine associated with neoangiogenesis, adverse histopathology such as extraprostatic extension, positive surgical margins, lymph node involvement, and high Gleason score, and survival in patients who underwent curative radical prostatectomy due to prostate cancer. Material and Methods: In this prospective cohort study, 88 patients who underwent radical prostatectomy with curative intent between March 2018 and January 2019 were included. Patients with any treatment for prostate cancer, including androgen deprivation therapy or radiotherapy, were excluded. In the study, Apelin levels in the serum samples of all patients were measured with commercially available ELISA kits (Elabscience, Houston, TX, USA) before radical prostatectomy was performed. The patients were divided into two groups: non-obese and obese, with a BMI of 30 kg/m2 as the limit. Patient characteristics, histopathological differences, prognosis, and Apelin levels were evaluated between the two groups. Results: In the study, 17 patients were obese, and 71 were non-obese; age, comorbidity index, lipid parameters, and PSA levels were similar. The mean Apelin levels were not different between the two groups (172.9 vs. 146.4, p=0.262). The clinical progression (CP) rate was higher in obese patients (29.4% vs. 2.8%, p=0.001), while the biochemical recurrence rates were similar between the groups. Higher Apelin levels were associated with lymph node invasion in obese patients (180.2 pN1 vs. 122.8 pN0, p=0.027), but this association was not observed in non-obese patients. Conclusion: The risk of CP following radical prostatectomy was higher in obese patients, and Apelin levels were associated with lymph node invasion in these individuals. Keywords: apelin, adipokine, biochemical recurrence, clinical progression, obesity, prostate cancer