The introduction of innovative therapies has changed the scenario of complications. The delay in the recognition of kidney adverse effects is partly due to the timing of the development of the kidney damage which occurs later than the observation period of registration studies, and partly to the exclusion of patients with known kidney impairment from registration trials.
Renal disease has a significant impact on the management of cancer patients and often leads to discontinuation of therapy. Histological evaluations of kidney disorders induced by targeted/immunotherapy are very limited. Renal biopsy is critical for the management of renal toxicities and should be especially encouraged for patients showing adverse renal effects to novel cancer agents.
We recently examined the histological features of patients treated with new cancer agents who underwent renal biopsy for new onset renal failure and/or urinary abnormalities. The cohort included 42 patients. The most frequently administered therapies were immunotherapy (54.8%) and anti-angiogenic treatments (45.2%). The most common adverse effect was tubular interstitial nephritis in the first group and thrombotic microangiopathy in the second one. Based on histological findings, definitive discontinuation of treatment could be restricted to a very limited number of patients. All of them had anti-VEGF-related TMA. Treatment discontinuation was unneeded in patients treated with ICIs. In patients treated with multidrug therapy, the histological findings made it possible to identify the weight of drug-related specific injury. Based on this data, renal biopsy should be considered in every cancer patient who develops urinary abnormalities or shows a worsening of renal function during treatment with immunotherapy or targeted therapy.
Keywords: Onconephrology, Immune checkpoint, Targeted Therapies, Renal biopsy in oncotherapy, Thrombotic Micro-angiopathy, Interstitial tubular nephritis