Recent evidence suggests that cyclin-dependent kinase 4/6 (CDK4/6) inhibitors significantly improve progression-free survival and overall survival among metastatic breast cancer patients. However, given the effects on cell cycle arrest, there is potential for CDK4/6 inhibitors and radiotherapy (RT) to work synergistically, enhancing the effect and toxicities of RT. A comprehensive review of the literature on the combination of RT and CDK4/6 inhibitors was performed with 19 eligible studies included in the final analysis. A total of 373 patients who received radiotherapy combined with CDK4/6 inhibitors were evaluated across 9 retrospective studies, 4 case reports, 3 case series, and 3 letters to the editor. The CDK4/6 inhibitor used, RT target, and RT technique were assessed in terms of toxicities. This literature review demonstrates generally limited toxicities with the combination of CDK4/6 inhibitors and palliative radiotherapy to metastatic breast cancer patients. The current evidence is nonetheless limited, and further results of ongoing prospective clinical trials will help clarify whether these treatments can be safely combined.

SUMMARY INTRODUCTION Radiotherapy (RT) plays an important role in the treatment of patients with head and neck neoplasia, and is frequently used as postoperative adjuvant therapy. This study aimed to review the literature about timing factors that may influence the clinical outcomes of patients with advanced head and neck neoplasia treated with adjuvant RT. RESULTS Timing factors such as total treatment time, length of adjuvant RT, and the absence of interruptions during RT may influence the clinical outcome of these patients. CONCLUSIONS In the same way that certain tumor factors can affect the prognosis of patients with squamous cell carcinoma of the head and neck, some therapeutic timing factors are also prognostic factors and therefore, must be carefully orchestrated in order to avoid loss at therapeutic outcomes for these patients.

Introdução: O tratamento padrão da neoplasia prostática de alto risco e o uso combinado de radioterapia (RT) e hormonioterapia (HT). Em relação aos pacientes estratificados como risco intermediário, o tratamento hormonal associado a RT permanece controverso, devendo ter indicação criteriosa e baseada em evidencias disponíveis. Objetivo: Avaliar criticamente os resultados publicados na literatura com o uso de hormônio por curto tempo, período médio de seis meses, associado a RT no tratamento de pacientes com neoplasia prostática localizada e classificada como risco intermediário. Método: Revisão de literatura com estudos randomizados utilizando RT e HT para pacientes com câncer de próstata de risco intermediário foram encontrados e considerados. Busca estruturada por meio do ‘PubMed’ com os termos ‘androgen supression therapy’, ‘radiotherapy’, ‘randomized trials’, ‘phase 3 trial’, ‘prostate cancer’ e ‘intermediate risk’. Resultados: Quatro estudos randomizados comparando RT versus RT e HT de curta duração foram considerados. A maioria agrupa pacientes com riscos intermediário e alto e não os separa exclusivamente pela estratificação do risco intermediário. Os dados encontrados, no entanto, sugerem beneficio significativo de sobrevida livre de doença, sobrevida livre de falha bioquímica e sobrevida global para o uso do tratamento combinado. Conclusão: Por meio dos estudos publicados ate o momento, observaram-se melhores resultados para o grupo de tratamento combinado de RT com HT. Dados de estudos randomizados comparando RT isolada versus RT e HT de curta duração avaliando apenas pacientes com risco intermediário estão sendo realizados.