Evaluation of individual and cumulative sites of extrarenal tumor invasion in pT3a clear cell renal cell carcinoma

Development and validation of a nomogram to predict postoperative cancer-specific survival of patients with nonmetastatic T3a renal cell carcinoma

PURPOSE

To establish a nomogram for the prediction of postoperative cancer-specific survival (CSS) in patients with nonmetastatic T3a renal cell carcinoma (RCC).

METHODS

The Surveillance, Epidemiology, and End Results database were searched for patients with pT3aN0-1M0 RCC between 2010 and 2018. The patients were randomly stratified into the training and verification group (7:3 ratio). Using Cox regression analysis, the predictors for the CSS in the training group were integrated to establish the nomogram for predicting the 3-year and 5-year CSS. Harrell's concordance index (C-index), time-dependent receiver operating characteristic curve, decision curve analysis, and Kaplan-Meier survival analysis were used to evaluate the nomogram performance.

RESULTS

A total of 5,791 pT3aN0-1M0 RCC cases with eligible data were selected from the Surveillance, Epidemiology, and End Results database. Age, tumor size, surgery type, Fuhrman grade, histological type, sarcomatoid, N stage, and invasion patterns were identified as the significant predictors for CSS to establish the nomogram. The C-indices of the nomogram were 0.774 (95% CI: 0.753-0.795) and 0.777 (95% CI: 0.745-0.809) for the training and verification group, respectively. The calibration of the nomogram revealed consistency between the predicted and observed survival. The area under the 3-year and 5-year CSS receiver operating characteristic curves were 0.773 and 0.786 in the training group, respectively. Decision curve analysis showed the optimal application of the model in clinical decision-making. According to the cutoff values of prognostic indices, patients with low-risk showed better CSS than those with high-risk in both training and verification groups (both P< 0.0001).

CONCLUSION

The current nomogram could effectively predict the CSS of patients with nonmetastatic T3a RCC, and could be used to identify patients who might need a compact interval of follow-up and postoperative adjuvant systemic treatment. The limitations included the retrospective nature, absence of external validation, and several unmeasured variables related to the selection bias of surgery type. The results should be interpreted with caution.

Oncological Outcomes of Patients With Different Pathological Features of pT3a Renal Tumor: A Systematic Review and Quantitative Synthesis

Purpose

To identify the differences in oncological outcomes for patients with different pT3a renal tumor invasion patterns and pathological features.

Methods

The protocol of this study was registered on PROSPERO (CRD42021234475). Relevant studies were identified by searching the PubMed, Cochrane library, Embase, and Web of Science databases. Cancer-specific survival (CSS) was selected as the endpoint. Pooled hazard ratio (HR) and 95% confidence interval (CI) extracted from multivariate Cox models were evaluated to identify the hazard association.

Results

A total of 22 studies, which enrolled 12384 patients were included for quantitative synthesis. Sinus fat invasion (SFI) + perinephric fat invasion (PFI) was associated with inferior CSS compared to SFI only (p = 0.02). Comparable CSS was observed between SFI and PFI (p = 0.57). SFI ± PFI showed inferior CSS compared to PFI only (p = 0.0002). The presence of pelvicalyceal system invasion significantly increased the risk of cancer-specific mortality (p = 0.0005). Renal vein invasion (RVI) indicated poor oncological outcomes in terms of CSS (p = 0.002). The concomitant RVI and fat invasion (FI) significantly increased the risk of deterioration of CSS compared to RVI or FI (p < 0.0001). Multiple invasion patterns translated into a significantly decreased CSS (p < 0.0001). Aggressive tumor behavior, including lymph node involvement (p = 0.006), distant metastases (p < 0.00001), sarcomatoid differentiation (p < 0.0001), necrosis (p < 0.0001), Fuhrman grade III or IV (p < 0.0001), positive margin (p < 0.0001), and tumor size >7cm (p < 0.0001) were the predictors of inferior CSS. The lymphovascular invasion (p = 0.67) was indolent in terms of CSS.

Conclusion

This study confirmed the heterogenicity of pT3a renal tumors. Multiple invasion patterns could translate into a significantly decreased CSS, and SFI should not be merged in the SFI + PFI group. The presence of PSI or RVI could significantly increase the risk of cancer-specific mortality. Lymph node involvement, distant metastases, sarcomatoid differentiation, necrosis, high Fuhrman grade, positive margin, and size >7cm were the predictors of inferior CSS. A precise-risk grade of CSS for different invasion patterns including comprehensive combinations may be useful for the further refinements of the TNM system.

Systematic Review Registration

The current study was registered on PROSPERO, and the registration numbers is CRD42021234475.

[Criteria for an improved prognostic stratification in category pT renal carcinoma]

Asymptomatic renal carcinomas are usually small and localized and thus, for the assessment of pT, precise criteria are required, able to identify the initial phases of a local extension and correlate them with current prognostic prospects. Various studies and consensus meetings have defined precisely how to measure tumoral nodules (solid, cystic and multiple). Furthermore, they have distinguished tumoral extension to the renal sinus, which has a worse prognosis, from that to the perirenal adipose tissue. They have also analyzed the clinical significance of invasion of the sinus vessels, the hilar veins and parenchymal vascular retroinvasion. Our aim is to revise and update the criteria of the different pT subcategories and consider those morphological aspects which could be clinically significant and that are not currently included in the TNM classification.