Strengthening the foundation of kidney cancer treatment and research: revising the AJCC staging system

A 25 year perspective on the evolution and advances in an understanding of the biology, evaluation and treatment of kidney cancer

The diagnosis, evaluation and management of patients with renal cell carcinoma has transformed in the 21st century. Utilizing biological discoveries and technological advances, the field has moved from blunt surgical and largely ineffective medical treatments, to nuanced and fine-tuned approaches based on biology, extent of disease and patient preferences. In this review we will summarize the last 25 years of progress in kidney cancer.

Dissecting the role of lymphadenectomy in the management of renal cell carcinoma: past, present, and future

Lymph node involvement in renal cell carcinoma (RCC) portends a poor prognosis. However, the role of lymph node dissection (LND) at the time of tumor resection is not fully understood. Conflicting data have been published regarding the survival implications of LND during RCC surgery, and the optimal patient population for which LND might be beneficial has yet to be identified. Based on recent data characterizing the outcomes of node-positive RCC, some have advocated for revising the current staging guidelines to better reflect these findings. Given the paucity of high-quality evidence supporting or refuting the routine use of LND in RCC, further research is needed to shed light on this important topic. There are a number of ongoing clinical trials evaluating the role of perioperative (neoadjuvant and adjuvant) systemic therapy, which include patients with node-positive RCC, and will serve to guide changes in treatment practices for this patient population moving forward.

Impact of pathologic lymph node-positive renal cell carcinoma on survival in patients without metastasis: Evidence in support of expanding the definition of stage IV kidney cancer

BACKGROUND

Stage III renal cell carcinoma (RCC) encompasses both lymph node-positive (pT1-3N1M0) and lymph node-negative (pT3N0M0) disease. However, prior institutional studies have indicated that among patients with stage III disease, those with lymph node disease have worse oncologic outcomes and experience survival that is similar to that of patients with American Joint Committee on Cancer (AJCC) stage IV disease. The objective of the current study was to validate these findings using a large, nationally representative sample of patients with kidney cancer.

METHODS

Patients with AJCC stage III or stage IV RCC were identified using the National Cancer Data Base (NCDB). Patients were categorized as having lymph node-positive stage III (pT1-3N1M0), lymph node-negative stage III (pT3N0M0), or stage IV metastatic (pT1-3 N0M1) disease. Cox proportional hazards models compared outcomes while adjusting for comorbidities. Kaplan-Meier estimates illustrated relative survival when comparing staging groups.

RESULTS

A total of 8988 patients met the inclusion criteria, with 6587 patients classified as having lymph node-negative stage III disease, 2218 as having lymph node-positive stage III disease, and 183 as having stage IV disease. Superior survival was noted among patients with lymph node-negative stage III disease, but similar survival was noted between patients with lymph node-positive stage III and stage IV RCC, with 5-year survival rates of 61.9% (95% confidence interval [95% CI], 60.3%-63.4%), 22.7% (95% CI, 20.6%-24.9%), and 15.6% (95% CI, 11.1%-23.8%), respectively.

CONCLUSIONS

Current RCC staging systems group pT1-3N1M0 and pT3N0M0 disease as stage III disease. However, the results of the current validation study suggest the need for further stratification and even placement of patients with pT1-3N1M0 disease into the stage IV category. Staging that accurately reflects oncologic prognosis may help clinicians better counsel and select patients who might derive the most benefit from lymphadenectomy, adjuvant systemic therapy, more rigorous imaging surveillance, and clinical trial participation.

To Be or "Node" to Be: Nodal Disease and the Role of Lymphadenectomy in the Treatment of Renal Cell Carcinoma

Lymph node involvement in renal cell carcinoma (RCC) correlates with poor oncologic outcomes. However, current RCC staging guidelines may not fully reflect the survival impact of lymph node positive disease. Recent data demonstrates that nodal disease has significant impact on survival and modifications to current staging guidelines have been proposed. Lymph node dissection (LND) at the time of surgical intervention for RCC remains controversial. While clinical trial data have demonstrated conflicting evidence for LND, some institutional studies suggests that carefully selected patients at high-risk for recurrence may benefit from LND. Prospectively, clinical trials are examining treating nodal disease and disease at high-risk of recurrence in the neoadjuvant and/or adjuvant setting at the time of nephrectomy. These promising trials are poised, if successful, to influence the treatment paradigm for localized RCC.

Reassessment of American Joint Committee on Cancer Staging for Stage III Renal Cell Carcinoma With Nodal Involvement: Propensity Score Matched Analyses of a Large Population-Based Study

Background: To assess the role of nodal involvement in stage III renal cell carcinoma (RCC) according to the American Joint Committee on Cancer (AJCC) 8th staging system. We compared the survival outcomes of RCC patients with pT1-3N1M0 disease and those with pT3N0M0 or stage IV (stratified as pT4NanyM0 and pTanyNanyM1) disease in a large population-based cohort. Methods: A cohort of 3,112 eligible patients with RCC was identified from the Surveillance, Epidemiology, and End Results (SEER) database, registered between January 2004 and December 2015. Kaplan-Meier and Cox proportional hazards models were used to evaluate the overall survival (OS), and cancer-specific survival (CSS). The prognostic value of the modified stage for pT1-3N1M0 disease was assessed by nomogram-based analyses. Propensity score matching (PSM) was used to adjust for potential baseline confounding. Results: Patients with pT1-3N1M0 disease showed similar survival outcomes (median OS 41.0 vs. 38.0 months, P = 0.77; CSS 45.0 vs. 39.0 months, P = 0.59) to pT4NanyM0 patients, whereas the significantly better survival outcome was found for pT3N0M0 patients. After PSM, comparable survival rates were observed between pT1-3N1M0 group and pT4NanyM0 group, which were still significantly worse than the survival of pT3N0M0 patients. The modified stage IIIA (pT3N0M0), IIIB (pT1-3N1M0, pT4NanyM0), and IV (pTanyNanyM1) showed higher predictive accuracy than AJCC stage system in the nomogram-based analyses (concordance index: 0.70 vs. 0.68, P < 0.001 for OS; 0.71 vs. 0.69, P < 0.001 for CSS). Conclusions: The pT1-3N1M0 RCC might be reclassified as stage IIIB together with pT4NanyM0 disease for better prediction of prognosis, further examination and validation are warranted.

circPRRC2A promotes angiogenesis and metastasis through epithelial-mesenchymal transition and upregulates TRPM3 in renal cell carcinoma

Background: Circular RNAs (circRNAs) have been identified as essential regulators in a plethora of cancers. Nonetheless, the mechanistic functions of circRNAs in Renal Cell Carcinoma (RCC) remain largely unknown.

Methods: In this study, we aimed to identify novel circRNAs that regulate RCC epithelial-mesenchymal transition (EMT), and to subsequently determine their regulatory mechanisms and clinical significance.

Results: circPRRC2A was identified by circRNA microarray and validated by qRT-PCR. The role of circPRRC2A in RCC metastasis was evaluated both in vitro and in vivo. We found that increased expression of circPRRC2A is positively associated with advanced clinical stage and worse survivorship in RCC patients. Mechanistically, our results indicate that circPRRC2A prevents the degradation of TRPM3, a tissue-specific oncogene, mRNA by sponging miR-514a-5p and miR-6776-5p. Moreover, circPRRC2A promotes tumor EMT and aggressiveness in patients with RCC.

Conclusions: These findings infer the exciting possibility that circPRRC2A may be exploited as a therapeutic and prognostic target for RCC patients.