Abscopal effect is a rare phenomenon characterized by tumor regression of untreated metastatic lesions after a local therapy (eg, radiotherapy). We studied the probability of abscopal effect with radiotherapy associated with anti-programmed death cell 1 (PD1) therapy after progression on anti-PD1. This study is a retrospective analysis of patients treated with nivolumab or pembrolizumab for melanoma, non-small cell lung cancer (NSCLC) and renal cancer at Antônio Ermírio de Moraes Oncology Center, Brazil. To be eligible for this analysis, patients must have had unequivocal evidence of disease progression on anti-PD1 therapy and subsequent radiotherapy for any tumor site while still receiving anti-PD1. The abscopal effect was characterized as a response outside the irradiated field after radiotherapy plus anti-PD1. Sixteen patients were evaluated, including 12 metastatic melanoma, 2 metastatic NSCLC, and 2 metastatic renal cell carcinoma. The median time to disease progression on anti-PD1 was 3 months. The radiotherapy field included lung, lymph nodes, and bones, with a median total dose of 24 Gy (1-40 Gy), usually in 3 fractions (1-10 fractions). Three patients with melanoma developed an abscopal effect at a rate of 18.7% (25% among melanoma patients). Of note, one of them achieved a remarkable complete response lasting >6 months. Three patients with melanoma obtained a significant local response after radiotherapy, despite no response in distant metastases. Eleven patients presented disease progression after radiotherapy. No increased toxicity was observed. In conclusion, no patients with NSCLC or renal cancer showed abscopal effect, but 25% of patients with melanoma showed regression of nonirradiated lesions when anti-PD1 was continued after radiation to a tumor site that had progressed on anti-PD1 monotherapy.
Background: Cancer patients in general and glioblastoma patients, in particular, have an increased risk of developing complications from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and reaching a balance between the risk of exposure to infection and the clinical benefit of their treatment is ideal. The aggressive behavior of this group of tumors justifies the need for a multidisciplinary team to assist in clinical decisions during the current pandemic. Brazil is now ranked #2 in the number of cases and deaths from COVID-19 pandemic, and existing disparities in the treatment of neuro-oncology patients in Brazil will challenge the clinical and surgical decisions of this population, possibly affecting global survival. Objective: To search the literature about the management of glioblastomas during COVID-19 pandemic to guide surgical and clinical decisions in this population of patients in Brazil. Methods: We performed a systematic search on the PubMed electronic database targeting consensus statements concerning glioblastoma approaches during COVID-19 pandemic up to July 18, 2020. Results: When approaching glioblastoma during the COVID-19 pandemic, important parameters that help in the decision-making process are age, performance status, tumor molecular profile, and patient consent. Younger patients should follow the standard protocol after maximal safe resection, mainly those with MGMT methylated tumors. Aged and underperforming patients should be carefully evaluated, and probably a monotherapy scheme is to be considered. Centers are advised to engage in telemedicine and to elaborate means to reduce local infection. Conclusion: Approaching glioblastoma during the COVID-19 pandemic will be challenging worldwide, but particularly in Brazil, where a significant inequality of healthcare exists.
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