Kidney Cancer Research Network of Canada (KCRNC) consensus statement on the role of renal mass biopsy in the management of kidney cancer

Diagnostic accuracy and safety of renal tumour biopsy in patients with small renal masses and its impact on treatment decisions

OBJECTIVE

To assess the safety and diagnostic accuracy of renal tumour biopsy (RTB) in patients with small renal masses (SRM) and to assess if RTB prevents overtreatment in patients with benign SRM.

MATERIAL AND METHODS

In a retrospective, single-centre study from Västmanland, Sweden, 195 adult patients (69 women and 126 men) with SRM ≤ 4 cm who had undergone RTB during 2010-2023 were included. The median age was 70 years (range 23-89). The sensitivity, specificity and predictive values of RTB were calculated using the final diagnosis as the reference standard. Treatment outcomes were recorded for a median 42-month follow-up. Complications following the biopsies were assessed according to the Clavien-Dindo system.

RESULTS

The overall sensitivity of RTB was 95% (95% confidence interval [CI] 90% - 98%) and specificity was 100% (95% CI 95% - 100%). The positive predictive value was 100% and negative predictive value was 92%. The rate of agreement between RTB and the final diagnosis measured using kappa statistics was 0.92. Of the 195 patients, 62 underwent surgery and 48 were treated with ablation. The concordance rate between the RTB histology and final histology after surgery was 89%. Treatment was withheld in 67 of 195 patients with a benign or inconclusive RTB. No patients developed renal cell carcinoma or metastasis during follow-up. Complications occurred in two patients that were classified with Clavien-Dindo grades I and IV.

CONCLUSIONS

Percutaneous renal tumour biopsy appears to be a safe diagnostic method that provides accurate histopathological information about small renal masses and reduces overtreatment of benign SRM.

CT and MRI findings of cystic renal cell carcinoma: comparison with cystic collecting duct carcinoma

BACKGROUND

Cystic renal cell carcinoma (CRCC) and cystic collecting duct carcinoma (CCDC) share similar oncogeni and some imaging findings. The aim of this study was to characterize the clinical and CT imagings features of CRCC and CCDC.

METHODS

Thirty-three patients with CRCC and thirteen patients with CCDC with pathologically proven were retrospectively studied. Tumor characteristics were assessed.

RESULTS

On CT imaging, 33 patients(100 %) with CRCC and 13 patients(100 %) with CCDC, tumors calcifications (8 vs. 9, P < 0.0001), had a clear boundary (capsule sign, 30 vs. 2, P < 0.0001), infiltrative appearance (1 vs. 13, P < 0.0001), exogenous appearance (29 vs. 3, P < 0.0001), invaded the renal pelvis or ureter (1 vs. 10, P < 0.0001), hemorrhage (1 vs. 10, P < 0.0001), had retroperitoneal lymph node or distant metastasis (2 vs. 10, P < 0.0001), thickened enhancing internal septations (31 vs. 2, P < 0.0001), and mural soft-tissue nodules (21 vs. 1, P < 0.0001). On MR imaging,13 patients(39 %) with CRCC and 4 patients(31 %) with CCDC, all CRCCs appeared hypointense on T1-weighted images and hyperintense on T2-weighted images, however, all CCDCs appeared hypointense on T1-weighted images and hypointense on T2-weighted images(P < 0.0001). 33 patients with CRCC, they were all alive from3 years to 10 years follow-up, however, 13 patients with CCDC, of which 11 patients were able to be followed up, and 9 patients expired within 5 years of the initial diagnosis and the others are currently still alive.

CONCLUSIONS

Distinguishing features of CRCC and CCDC included calcifications, capsule signs, infiltrative appearance, metastasis, internal septations, mural nodules and signal on CT or MR images. These imaging features may help in differentiating the two renal tumor types.

Evolving Role of Urologists in the Management of Advanced Renal Cell Carcinoma

Advanced renal cell carcinoma is not uncommon, but necessitates a multidisciplinary approach for optimal treatment. Targeted therapy has increased the likelihood of urologists managing patients in all disease stages. Neoadjuvant therapy is currently experimental. Systemic therapy for metastatic disease demonstrates survival benefits. The role of cytoreductive nephrectomy and adjuvant therapy is dependent on patient selection. Management of advanced renal cell carcinoma involves continued optimization of available agents and biomarker development. This article reviews the role of the urologist in medical and surgical therapies, including prognostication, management of locally advanced and metastatic disease, and provides the most recent clinical trial data.