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.

Monitoring of chlorine decay in public swimming pools in Medellín (Colombia).

The present work shows the evaluation of the decay of free residual chlorine in several public swimming pools in the city of Medellín, observing that a decrease in residual chlorine does occur. Some factors accelerate the decrease in the concentration of free residual chlorine in recreational water, such as the number of bathers in the pool, the pH, and the temperature of the water. For this reason, the concentration of the disinfectant rapidly decreases to an extent that the health of swimmers could be put at risk. The Authority of Health of Medellín carries out inspection, surveillance and quality control activities of water for recreational use. These purposes of these include guaranteeing the reduction of risk factors to the health of the users of said pools.