Introduction: In kidney cancer, it is well known that tumor necrosis is associated with poor prognosis in recurrence free survival and overall survival. Tumor necrosis accompanies tubular necrosis which may induces albuminuria as seen in acute tubular necrosis. However, there was no study the association of tumor necrosis and albuminuria and its clinical implications. In this study we analyzed whether preoperative albuminuria is related to tumor necrosis and prognosis in terms of recurrence free survival. Methods: In this study, we retrospectively analyzed kidney cancer patients underwent partial or radical nephrectomy who is consequently enrolled in prospective patient registry system of Seoul National University, SUPER-RCC-Nx from March 2016 to August 2018. Statistical analysis was performed using XLSTAT. For the categorical variables chi-square test was conducted and for the numerical variables two-tailed t test was conducted. Kaplan-Meier analysis revealed recurrence free survival comparing two groups. Cox proportional hazards regression was conducted for multivariate analysis Results: In total of 674 enrolled patients, tumor necrosis was observed in 293 patients. Tumor necrosis was significantly associated with old age, higher pathologic T stage, and poor histologic grade. Notably preoperative albuminuria was observed in 55.6% of tumor necrosis group while only 25.5% exhibited albuminuria in tumor necrosis negative group (p < 0.0001). Furthermore, there was no difference in albuminuria patients between tumor necrosis positive and negative group after partial or radical nephrectomy (p = 0.11). In subgroup analysis conducted on tumor necrosis positive group, albuminuria was associated with higher pathologic T stage and Fuhrman grade. Moreover, Cox proportional hazard regression analysis revealed that albuminuria is independent prognostic factor associated with higher recurrence rate with hazard ratio of 2.433 (1.427 – 4.15, p = 0.001). Conclusions: In kidney cancer, tumor necrosis is associated with albuminuria which can be reversed after partial or radical nephrectomy. In subgroup analysis of tumor necrosis positive group, it is definite that higher tumor extent is associated with albuminuria. In tumor necrosis positive patients, albuminuria is worse prognosis factor. SOURCE OF Funding: This research was supported by a Basic Science Research Program through National Research Foundation of Korea, funded by the Ministry of Science and ICT (2022R1A2C1012657) and by Seoul National University Hospital (0320210060).
