Kidney cancer (RCC) accounts for 2-3% of all malignancies in adults. 57,760 new cases of kidney cancer were estimated to be diagnosed nationwide in 2009, and 12,980 deaths were attributed to kidney cancer [1]. 20% had metastases at the time of initial diagnosis, and 30% had metastases after surgery, making it the second most common malignancy in the urinary tract. The incidence of kidney cancer is increasing at a rate of about 2% per year, the proportion of asymptomatic kidney cancer is increasing year by year, and the trend of metastatic kidney cancer is decreasing. One group of reports showed that the incidence rate decreased from 23.8% in the United States between 1988-1992 to 16.5% in 2003-2006 [2]. Some of the consensus and controversies in the diagnosis and treatment of kidney cancer in recent years are described below. Daxin Gong, Department of Urology, The First Hospital of China Medical University Relevant issues in tumor staging.RCC staging directly affects the prognosis of patients, and accurate preoperative staging helps in the selection of surgical modality and postoperative adjuvant therapy. There is now a new understanding of the role of tumor size, adrenal involvement, lymph nodes and renal vein tumor emboli in staging. The 2002 TNM staging system uses 4 cm as the cut-off point for T1a and T1b. It was found that there was a large difference in prognosis between the 7-10 cm group and the >10 cm group, and it was proposed that T2 stage tumors were divided into T2a (7-10 cm) and T2b (>10 cm). Several studies have shown that tumor size and lymph node involvement, distant metastasis and tumor aggressiveness are closely related [3,4]. Therefore, the latest TNM staging classifies tumors >10 cm into T2a and T2b. The current 2002 version of the TNM staging system classifies adrenal involvement as stage T3a. There is a correlation between adrenal involvement and high tumor grade, lymph node metastasis and distant metastasis, with a poor prognosis. Patients with direct adrenal invasion were found to have the same prognosis as stage T4 [5], therefore the latest TNM staging classifies direct adrenal invasion as stage T4 and adrenal metastasis as stage M1. No statistically significant difference in 3-year tumor-specific survival was found between patients with renal vein tumor embolism and patients with perirenal fat involvement. Therefore, the new TNM staging reduced renal vein tumor embolism from T3b to T3a [6]. 2002 TNM staging required the number of detected lymph nodes to be at least 8. Recent studies found no difference in survival between patients with N1 and N2 stages in patients with locally progressive and metastatic renal cancer, and the new TNM staging took the above factors into account and revised the N stage to N0 (0 lymph node involvement) and N1 (≥1 lymph node involvement). Perinephric fat involvement was defined as T3a in the 2002 version, and several studies have now shown that patients with sinus involvement have a poorer prognosis than those with perinephric fat involvement due to abundant lymphatic blood flow in the renal sinus [7,8], so it is necessary to take the above factors into account when considering tumor staging. As research continues to progress, more accurate staging systems will emerge and will require constant revision to provide a basis for clinical treatment and to assess prognosis. It is well known that the prognosis of disease is not solely determined by tumor staging, but by a variety of factors. Many scholars have proposed various prediction systems, such as Sloan-Kettering Cancer Center (MSKCC), University of California Integrated Staging System (UISS), Karakiewicz Postoperative Prediction System, etc., which vary in complexity and simplicity and contain different factors, and there is no universally accepted prediction system. Although a variety of molecular marker prediction models are available, it will take time to apply them to clinical practice. With the accumulation of clinical data and the continuous progress of medical informatics, a prediction system integrating TNM stage, genes, molecular biological markers and many other factors will surely emerge, which will provide a basis for patients to choose the appropriate surgical modality and adjuvant treatment methods. Issues related to radical nephrectomy for kidney cancer. Classically, the scope of radical nephrectomy includes the affected kidney, perirenal fascia, perirenal fat, ipsilateral adrenal glands, lymph nodes from the foot of the diaphragm to the bifurcation of the abdominal aorta, and the ureter above the bifurcation of the iliac vessels. In recent years, there has been a conceptual change regarding the extent of surgery and whether to perform lymph node dissection. (1) Should lymph node dissection be performed? In the past, it was thought that regional or expanded lymph node dissection should be performed during radical nephrectomy to achieve the following objectives: (1) reduce the rate of local tumor recurrence; (2) contribute to proper clinical staging; and (3) improve the survival rate. There is no dispute about the significance of regional or expanded lymph node dissection in determining the lymph node staging of tumors, but there is controversy about the therapeutic value. Recent findings have shown that lymph node metastases detected by surgery through correct preoperative staging techniques are rare [9]. Several studies have shown that lymph node dissection is of limited value for survival and treatment of disease recurrence in patients with kidney cancer with no lymph node metastases proven by preoperative examination [10,11]. For patients with clear preoperative lymph node metastases, regional lymph node dissection may improve patient survival [12]. The European Association for Research and Treatment of Cancer conducted a prospective phase 3 clinical study from 1988 in which 383 cases underwent radical kidney cancer surgery and lymph node dissection and 389 cases underwent lymph node dissection alone. The study showed a lymph node metastasis rate of only 4%, with no significant difference between the two groups in terms of overall survival, or survival without disease progression. Due to the low rate of lymph node metastasis, performing lymph node bacillary dissection is of limited value in low-risk patients [9]. For some progressive patients or high-risk patients, there may be benefit from lymph node dissection [12-14]. Given that lymph node dissection has fewer complications, is not disabling, and does not significantly increase operative time, regional or standard lymph node dissection is currently favored for limited renal cancer, and expanded lymph node dissection is not favored. (2) Should ipsilateral adrenalectomy be performed? In the past, it was believed that ipsilateral adrenalectomy should be performed routinely, and the adrenal metastasis of renal cancer could be as low as 1.2-4.3% [15,16], and routine adrenalectomy could lead to adrenal hypofunction in some patients, which seriously affects the quality of life. Currently, there is a preference for elective adrenalectomy, which is only considered for patients with large upper pole renal tumors or preoperative imaging suggestive of adrenal metastases [16-18]. Issues related to the treatment of metastatic renal cancer. (1) Is there value in tumor-reducing surgery? Previously, metastatic renal cancer was considered a contraindication to surgery, but recently it is believed that patients with isolated metastases can undergo simultaneous metastasectomy. Surgical treatment is only one of the adjuvant treatments for metastatic kidney cancer. Recent studies have found that tumor-reducing surgery with interferon therapy can improve median survival time [19]. Several international studies have evaluated the role of tumor-reducing surgery with targeted agents (sorafenib, sunitinib, temsirolimus, bevacizumab combined with interferon-α, pazopanib, and everolimus) in the treatment of metastatic kidney cancer, with some showing preliminary efficacy [20-22]. However, how to select patients, whether to apply preoperatively or postoperatively, so that they can really benefit from the treatment is currently difficult. (2) How to select targeted therapeutic agents? The appropriate therapeutic drug should be selected according to the choice of tumor pathology type and whether it is progressive or not. For clear cell carcinoma, sorafenib, sunitinib, tesirimus, pazopanib, bevacizumab combined with interferon-alpha or high-dose IL-2 can be used as first-line therapy. For non-clear cell carcinoma, tesiramos, sorafenib, sunitinib, pazopanib, erlotinib, and chemotherapeutic agents may be used. Second-line treatment can also choose drugs such as sorafenib, sunitinib, tesilomos, and everolimus. Due to the poor treatment effect of metastatic kidney cancer, there are also studies related to the combination of targeted drugs and immunotherapy, with sorafenib combined with interferon showing good therapeutic effect [23,24] and also the orderly use of targeted drugs [25]. With the development of basic research, the treatment of kidney cancer, especially metastatic kidney cancer, will have more and more effective therapeutic tools. The search for biomarkers of advanced kidney cancer for guiding species-based targeted therapy, the exploration of systematic and accurate prognostic assessment systems for selecting appropriate treatment modalities, and the development of large-scale prospective data studies for resolving the current controversies will benefit more patients.