Population: Adults with small renal masses.
Organizations
ASCO 2017, AUA 2021
Recommendations
–Based on tumor-specific findings and competing risks of mortality, consider renal tumor biopsy (RTB) for all patients with a small renal mass (SRM) (<4 cm in size).
–Manage initially with active surveillance for patients who have significant comorbidities and limited life expectancy (end-stage renal disease, SRM < 1 cm, life expectancy < 5 y).
–Offer partial nephrectomy (PN) for SRM to all patients for whom an intervention is indicated and who have a tumor that is amenable to this approach.
–Consider percutaneous thermal ablation for patients whose tumors can be ablated completely. Obtain a biopsy before or at the time of ablation.
–Reserve radical nephrectomy only for patients whose tumor is of significant complexity that is not amenable to PN or where PN may result in unacceptable morbidity even when performed at centers of excellence. Consider referral to experienced surgeon and a center with experience.
–Consider referral to a nephrologist if CKD (GFR < 45 mL/min/1.73 m2) or progressive CKD develops after treatment, especially if associated with proteinuria.
Practice Pearls
• SRMs are commonly discovered incidentally during diagnostic evaluation for other medical conditions. A significant number of SRMs are benign. As the size increases (especially >4 cm), the likelihood of malignancy increases. Imaging with MRI, CT scans, and ultrasound cannot make an absolute diagnosis of malignancy, necessitating a core biopsy if possible. About 10%–15% of patients will have a nondiagnostic biopsy and must be followed closely and rebiopsied if the mass is growing. Radiofrequency ablation (RFA) is commonly used to ablate small cancers but should have a biopsy done first to document malignancy.
• Decision regarding therapy in patients with significant comorbidities is difficult. The Charleston Comorbidity Index (CCI) is a tool that can predict 1-y mortality. In patients with a short life expectancy, surveillance and supportive care is the best approach for this population. Partial nephrectomy is the treatment of choice for SRM that are amenable to nephron-sparing surgery. Radical nephrectomy in the past has been the procedure of choice in managing small RCC. Today partial nephrectomy is preferred and radical nephrectomy now is the treatment of choice in <30% of patients with SRM.
Sources
–J Clin Oncol. 2017;35:668-680.
–N Engl J Med. 2010;362:624.
–Eur Urol. 2016;69:116.
–JAMA. 2015;150:664.
–Eur Urol. 2015;67.