This study, published in the international journal Cancer Immunology, Immunotherapy in November 2025, analyzed the use of pembrolizumab, an immunotherapy drug, as adjuvant treatment in patients with clear cell renal cell carcinoma (ccRCC), the most common type of kidney cancer. Adjuvant therapy is given after surgical removal of the tumor with the goal of reducing the risk of the disease returning. Previous clinical trials had already shown that pembrolizumab can improve both disease-free survival and overall survival in patients at high risk of recurrence. However, there is still limited information on how this treatment performs in everyday clinical practice.
To address this gap, researchers analyzed data from the international ARON database, which collects clinical information from multiple hospital centers. The study included 311 patients from 40 hospitals across 12 countries, all diagnosed with clear cell renal cell carcinoma and considered at intermediate-high or high risk of recurrence after surgery. Patients received up to 17 cycles of pembrolizumab as adjuvant therapy.
After a median follow-up of about 15 months, the results showed that 95% of patients were still alive at two years, while 69% had no signs of disease recurrence. Nevertheless, about one in five patients experienced a recurrence of the tumor. The most common sites of relapse were the lungs and the bones.
The analysis also identified several factors associated with a higher risk of recurrence. In particular, outcomes were worse in patients younger than 65 years, in those with lymph node involvement, and in tumors with more aggressive histological features, such as sarcomatoid differentiation.
Regarding treatment safety, serious side effects led to treatment discontinuation in about 19% of patients. The most common adverse events included inflammation of the intestine (colitis), elevated liver enzymes, and inflammation of the kidneys (nephritis). Despite these events, the overall safety profile of the drug was considered manageable.
In summary, this large real-world study confirms that pembrolizumab can be an effective and relatively safe treatment after surgery for patients with clear cell renal cell carcinoma who are at high risk of recurrence. However, the authors emphasize that further studies with longer follow-up are needed to better identify which patients benefit the most from this therapy and to evaluate long-term outcomes.
