Multivariable Analysis On Prognostic Factors Of Non-clear Cell Renal Cell Carcinoma

Objectives: Conduct a retrospective study to explore the possible prognostic factors of patients with nonclear cell renal cell carcinoma(nccRCC)treated by surgury.Material and methods: 212 cases of nonclear cell renal cell carcinoma that treated in the Urology Center of First Affiliated Hospital of Xinjiang Medical University from April 2003 to September 2019 was collected retrospectively.Due to the poor number of cases for some subtypes,histological subtypes grouped as: papillary RCC(type I and II,98 cases in total),chromophobe RCC(64 cases),unclassified RCC(29cases)and other nccRCC(9 cases of MiT family translocation RCC,9 cases of clear cell papillary renal carcinoma,3 cases of renal collecting duct carcinoma,21 cases in total).In addition to the tumor size,pathological types and stage,Fuhrman grade,presence of tumor necrosis,sarcomatoid differentiation and tumor thrombus were also recorded.Beside the patient’s basic information,Preoperative clinicopathological factors and postoperative management were explored.Hematological parameters prior to surgery were recorded where available,including the neutrophil-to-lymphocyte ratio(NLR)and published biomarkers predictive for patient outcomes: hemoglobin,platelet,neutrophil,lactate dehydrogenase and calcium.All laboratory values were treated as continuous variables,described with the median and interquartile range(IQR).One way ANOVA was used for intra group differences.The main study outcome was OS.All possible factors evaluated univariately via a Cox proportional hazards model.Time from the procedure to death from kidney cancer or last follow-up was recorded.Death from kidney cancer was considered as the event,and patients were censored at the date of last follow-up.Significant univariate predictors and clinically significant factors for OS were added into a multivariate model,and step-wise regression was employed until all variables were independently significant.For each significant variable,a Kaplan-Meier curve was used to illustrate the estimated effect on OS,with survivors censored at theirlast follow-up date.Continuous variables were stratified by their median value,and the log-rank test was used to compare the estimated survival.All statistical analyses were 2sided and a P value of <0.05 was considered significant..SPSS 20.0 statistical software was used for data processing.Results: There were 212 nccRCC patients treated with surgery.Median age was 61 years(IQR: 41-61)and 53.8% were male.the median follow-up time was 37.5 months(20.3-70.8,the mean was 50.8).Up to the last follow-up time,25 patients died from renal cell carcinoma,the 5-year survival was 94.34%,and the total survival was 88.21%.Most of the patients had a good performance status,with96.7% having a Karnofsky performance status ≥ 80.Significant univariate predictors are age,tumor size,TNM stage,Fuhrman grade,presence of sarcomatoid differentiation,lymphocyte count,NLR,LDH.Combine the result of multivariate Cox-regression analysis,TNM stage,Fuhrman grade,sarcomatoid differentiation or not,NLR value are independent prognostic factors.Conclusions: nccRCC pations with higher TNM stage,Fuhrman grade,NLR and presence of sarcomatoid feature had worse prognosis,whereas the prognosis was better.