Long-term Response After Stopping Immunotherapy in a Patient With Metastatic Renal Cancer

Successful long-term management of metastatic clear cell renal cell carcinoma with nivolumab: a case report and literature review

In Colombia, renal cancer is a rare condition, with clear cell renal cell carcinoma (ccRCC) being the most prevalent neoplasm. In recent years, immune checkpoint inhibitors (ICI) have been proposed for the management of metastatic disease, as they have shown improved rates of response and long-term survival. Furthermore, they exhibit a favourable tolerance profile, and adverse events causing significant morbidity are infrequent. We report the case of a 61-year-old male patient initially diagnosed with early-stage ccRCC who underwent right nephrectomy in 2009. Six years later, disease recurrence with metastatic compromise was documented, which led to the resection of the L1 vertebral body followed by radiotherapy and maintenance treatment with sunitinib. Due to disease progression, treatment with sunitinib was discontinued. Subsequently, everolimus was initiated as second-line immunotherapy, which was later discontinued due to the appearance of new metastatic lesions. In 2017, the patient was referred to our institution, where a third-line pharmacological treatment with nivolumab was initiated. In 2022, complete remission by positron emission tomography-computed tomography (PET-CT) was evidenced, which has been sustained to date. This case demonstrates the efficacy and safety of ICI in patients with metastatic ccRCC. The case presented is relevant in that it describes the achievement of complete remission in a patient who did not respond to the first two lines of immunotherapy. Given the limited literature regarding the discontinuation of therapy after achieving sustained remission, further research is warranted to explore this topic.

Spontaneous Regression of Metastatic Renal Cell Carcinoma after SARS-CoV-2 Infection: A Report of Two Cases

Spontaneous regression of metastatic renal cell carcinoma (mRCC) is a rare event, often associated with an activation of innate immunity by various triggers. SARS-CoV-2 infection induces a strong inflammatory response in some patients and a cytokine storm is one of the main causes of severe morbidity and mortality associated with the virus. Here, we describe two cases of patients with histologically and radiologically proven mRCC whose treatment was delayed due to COVID-19 and who experienced spontaneous tumour regression following the infection. Both patients reported here had predominantly pulmonary and mediastinal involvement and underwent nephrectomy. The interval between the diagnosis of COVID-19 and the detection of tumour regression was 3 and 4 months, respectively. Although approved vaccines and other measures are clearly the best way to prevent COVID-19-associated morbidity and mortality in cancer patients, we hypothesize that innate immunity activation by the infection can contribute to tumour regression in special circumstances.