The Complete Response of a Renal Cell Carcinoma Metastatic to Brain, Lungs, and Liver to Second-Line Nivolumab: A Case Report

Metastatic renal cell carcinoma (RCC) is a therapeutic challenge to clinicians since it shows significant resistance to chemotherapy and radiation therapy. With the introduction of immunotherapy, the treatment paradigm for RCC has evolved. Here, we describe the case of a 55-year-old male who presented with flank pain. An abdominal-pelvic computed tomography (CT) scan revealed a right renal mass. Following open right radical nephrectomy, first-line treatment with sunitinib was administered. After four months he developed multiple metastases to the liver, lungs, abdominal wall, and brain. He initiated second-line treatment with nivolumab and also received whole brain radiation therapy (WBRT). Six months following combined treatment with nivolumab and WBRT, a CT scan revealed complete radiologic response in the lungs, abdominal wall, brain, and liver except for the persistence of a subhepatic mass. Despite the discontinuation of nivolumab and starting bevacizumab due to financial problems, the patient was stable for 22 months, and after this, he was hospitalized with high bilirubin levels. An abdominal CT scan detected the development of the necrotic subhepatic mass compressing the common bile duct (CBD), with no other sign of metastatic disease. We believe that the explanation for this long-term disease control could be the combination of immune-checkpoint-inhibitor (ICI) with WBRT resulting in significant cranial and extracranial immune response, known as "the abscopal effect". This report highlights the importance of local therapy combined with ICI-based therapy in metastatic RCC.