A recent study has shown that the risk of spread of cancer cells to the fat surrounding the kidney (perinephric fat) during a biopsy for renal cell carcinoma (RCC) is very small, and occurred in only 1.2% of cases. In these cases, a renal mass biopsy resulted in the stage of the cancer changing from T1a (low stage) to pT3a (advanced stage) involving the perinephric fat.
The study was conducted in the USA and using the National Cancer Database, researchers identified 24,548 patients who underwent surgery for T1a renal tumours. Of these, 1,827 underwent a renal mass biopsy. Perinephric fat invasion occurred in only 284 patients (1.2%).
The 5-year overall survival rates were 89% in the biopsy group and 91% in the group who did not have a biopsy.
The researchers said, “This effect is small and the clinical significance is unknown…….We also acknowledge that this finding, if real, is balanced by the importance of the information acquired from biopsies.”