Resident Groupe Jolimont Etterbeek, Brussels Hoofdstedelijk Gewest, Belgium
Background Immune checkpoint inhibitors (ICI) significantly improve the outcome of patients with metastatic renal cell carcinoma. Two strategies are currently approved: tyrosine kinase inhibitors plus ICI or ICI plus ICI. Response evaluation is sometimes challenging based on conventional imaging as response are sometimes delayed or mixed response can occur.
Methods In a retrospective cohort, we evaluated the response profile in patients treated with ICI + ICI or TKI + ICI with a follow-up of at least 6 months, including the occurrence of dissociated response and the change it could induce in treatment strategy. Response status was evaluated based on Immune RECIST criteria at 9 months.
Results Between 2018 and 2022, 20 patients were included in the analysis; 10 patients treated with ICI + ICI (group A) and 10 patients treated with TKI + ICI (Group B). In group A, complete response (CR) occurred in 1 patient, partial response (PR) in 3 patients, stable disease (SD) in 4 patients and progressive disease (PD) in 2 patients. In Group B, CR was observed in 1, PR in 4, SD in 3 and PD in 2 patients. Dissociated response was observed in 5 patients of Group A and in 2 patients of group B. In patients with dissociated response, radiotherapy or surgery was performed in 3 patients of group A and 2 patients of group B. These radical treatments resulted in disappearance, decrease or stability of all non-responding lesions, allowing prolongation of the systemic treatment.
Conclusion Dissociated response was observed in 50% of patients treated with ICI + ICI and in 20% of patients treated with TKI + ICI, allowing radical treatment in significant proportion of patients.
