Challenges in renal cancer: Small renal mass

Patient case and potential approaches

The patient is a 58-year old female of African descent who experienced a single episode of visible haematuria. In December 2021, the patient had an unintentional 3kg weight loss. By January 2022, she was diagnosed with bilateral renal tumours. She had relatively good kidney function with an eGFR (estimated glomerular filtration rate) of 61 ml/min and serum creatinine 100 umol/l. The patient has a sister with renal cell carcinoma (RCC).

Dr. Kuusk presented a CT scan wherein the left lower pole tumour is 7cm in size and with similar contrast enhancement, the completely endophytic tumour on the right side is 3cm. The lesion on the left appeared to have a central necrosis. She stated that the PADUA and RENAL scores show high complexity.

Prof. W. Marston Linehan (US) kickstarted the presentations on approaches with his pre-recorded lecture “When do we have to genetically screen in kidney cancer?”. He stated that germline testing is recommended in patients with clinical features such as early onset of RCC, bilateral and/or multifocal RCC (BMF), and/or familial RCC (FRC) (i.e. RCC in up to 2nd degree relative), as well as, patients with phenotypic features such as known FRC manifestations.

On opting for biopsy, Prof. Alessandro Volpe (IT) said that renal tumour biopsies (RTBs) can support treatment decisions for cT1 renal masses. In his presentation “When do we perform biopsy?”, he stated that the added value of RTBs is significant in the setting of bilateral tumours, especially in older patients and patients with less than 3 renal masses. In addition, RTBs are safe and should be proposed especially when different treatment approaches (including active surveillance) are reasonable options. Prof. Volpe added that genetic and molecular characterisation beyond traditional histology on RTBs will have the potential to further optimise patient decision making.

According to Dr. Oscar Rodriguez Faba (ES), percutaneous cryoablation (PCA) of completely endophytic tumours can be an alternative for selected patients with acceptable outcomes. In his lecture “Pro: Focal treatment”, he said that with the use of protection techniques, cryoablation can be carried out more safely, and the application range of this therapy would expand.

During his presentation on “Pro: Nephron-sparing surgery”, Prof. Andrea Minervini (IT) offered the following approaches and sequence:

1. Plan a two-stage partial nephrectomy (PN) approach
2. Start with the left side and go for a wedge resection/heminephrectomy

He stated, “Later on, proceed with a pure enucleation on-clamp (or even selective clamping if possible) PN on the right side (when planning to use the intraoperative ultrasound and 3D reconstruction).”

Actual approaches and sequence taken
During the panel discussion, Dr. Kuusk disclosed the actual approaches and sequence taken for the patient case. “For the tumour on the left side, we performed RAPN (robotic assisted partial nephrectomy). Histopathology revealed a pT1b WHO/ISUP grade 2, a margin negative clear-cell RCC, and a Leibovich score of 3 (intermediate risk group). The postoperative renal scintigraphy scan confirmed a 31% of the kidney function was spared,” said Dr. Kuusk.

She added, “For the tumour on the right side, we took a biopsy first. This confirmed a clear cell RCC WHO/ISUP grade 1. The patient preferred active treatment over active surveillance. A partial nephrectomy was considered challenging due to the complete endophytic nature and high PADUA and RENAL scores, therefore a cryoablation is scheduled.”

For additional expert insights on this patient case and to (re)watch the full presentations of and other patient cases of Plenary Session 1, please go to the EAU22 On Demand on the Virtual Platform.