Study On The Relationship Between Periprostatic Fat Thickness And Prostate Cancer

Background and significanceProstate cancer(PCa)is the second most common malignancy in men in the world.Its incidence is increasing year by year,and it has ranked first in most countries in the world.The incidence of PCa in China is also increasing significantly.The metabolism of visceral fat is active and it is of great importance to affect tumor microenvironment.Periprostatic fat is the visceral fat that surrounds the prostate gland.The relationship between the measurement including thickness,area,volume and ratio of periprostatic fat and the development risk of PCa in the epidemiology remains controversial.Therefore,it is necessary to study the relationship between the two,in order to get more scientific and more convincing results,thus providing more specific guidance for the diagnosis and treatment of prostate cancer.Methods1.Systemic search was conducted on the studies on the correlation between periprostatic fat and PCa in six databases from the time when was built up to June 30,2020.Literature screening was conducted according to inclusion criteria.After inclusion,quality assessment,data extraction,combined effect size,sensitivity analysis,publication bias analysis,and subgroup analysis were performed,and Stata software was used to analyze the results.Meta-analysis was performed on the relationship between periprostatic fat thickness(PPFT)and high-grade prostate cancer(HG PCa).2.Retrospective analysis of the clinical and imaging data of 223 patients undergoing prostate biopsy in Nanfang Hospital from July 2018 to July 2020.According to the results of prostate biopsy,they were divided into prostate biopsy positive(+)group and negative(-)group,then the positive prostate biopsy(+)group was divided into high-grade prostate cancer group(GS>7)and low-grade group(GS≤7)according to Gleason score.The relationship between PPFT measured on MRI images and prostate biopsy results,high and low grade prostate cancer was analyzed by statistical methods,and PPFT was included to construct a predictive model for predicting prostate biopsy results,and a nomogram was formed.Results1.A total of 5 documents that meet the requirements were included.Through the combined effect size,the OR value was 1.27,the 95%CI was(1.17-1.37),and the heterogeneity test(I2=20.9%,P=0.282).Through sensitivity analysis,removing any of the studies will not affect our research results.Analysis of publication biass Begg’s Test(Pr>lzl=0.462)and Egger’s Test(P>ltl=0.390).Subgroup analysis(sample size,measurement tools,diagnosis and treatment methods,definition of high-grade prostate cancer),the OR value and 95%CI in the 4 subgroups are all greater than 1.2.Retrospective studies can confirm that PPFT is correlated with HG PCa(r=0.225,P=0.038),and is one of the independent risk factors for HG PCa(OR=1.753,95%CI 1.214-2.533,P=0.003).The increase in available PPFT was positively correlated with positive prostate biopsy(r=0.451,P<0.001),and it was one of the independent predictors of positive prostate biopsy(OR=2.686,95%CI was 1.712-4.212,P<0.001).When the cut-off of PPFT is 5.955mm,the sensitivity of predicting a positive biopsy result is 70.9%and the specificity is 86.1%.The nomogram for predicting a positive prostate biopsy(the area under the curve is 0.964,P<0.001).The calibration curve shows that the predicted results of prostate biopsy are in good agreement with the actual results.ConclusionCombining the content of the two parts,we can clarify that PPFT on MRI images is one of the independent risk factors for prostate cancer,especially HG PCa.In clinical diagnosis and treatment,the measurements of PPFT can not only provide clinical reference for prostate biopsy,but also can assess the risk of prostate cancer and provide guidance for prognosis.