Lung cancer continues to be the most common neoplasia and represents the leading cause of cancer-related death in the world. Nonetheless, contrary to expected projections, the decrease in incidence expected by decrease in tobacco exposure has been partially halted due to an increasing amount of lung cancer cases in nonsmokers, particularly in female patients. This led to the development of new hypotheses in terms of lung cancer etiology, including the involvement of oncogenic viruses such as the human papillomavirus (HPV). HPV role in the pathophysiology of lung cancer, including adenocarcinoma and squamous cell carcinoma, is currently under research. Exposure to HPV, and the resulting infection, can occur in several possible ways, including sexual transmission and airborne fomites. Main pathogenic occurrences include alterations in inhibition of p53 and retinoblastoma. This chapter presents the current evidence as to the role of HPV in the development of lung cancer, methods to establish HPV infection, and also explores the role of predisposing factors, as well as immunological and inflammatory factors in nonsmokers. Additionally, the role of other molecular factors, such as EGFR, interleukins 6 and 10, and others, is discussed. Finally, future perspectives in this new paradigm of lung cancer in nonsmokers are broadly reviewed.
Part of the book: Current Perspectives in Human Papillomavirus
The incidence of radiation necrosis has increased secondary to combined modality therapy for brain tumors and stereotactic radiosurgery. The pathology of progressive brain radiation necrosis (RN) primarily includes inflammation and angiogenesis in which cytokines, chemokines, and vascular endothelial growth factors are upregulated. Combined multiparametric imaging, including lesional metabolism, spectroscopy, and blood flow, could enhance diagnostic accuracy compared with a single imaging study. Nevertheless, a substantial risk of bias restricts firm conclusions about the best imaging technique for diagnosing brain RN. Bevacizumab shows promising results of improving radiographic edema and post-gadolinium enhancement with associated symptomatic improvement. However, this was based on small double-blinded randomized controlled trials, which introduces a high risk of bias due to the small sample size despite the high-quality trial design. Edaravone combined with corticosteroids also resulted in a more significant reduction in radiographic edema than corticosteroids alone but had no impact on reducing the enhancing lesion. There is a great need for further prospective randomized controlled trials (RCTs) to treat brain RN.
Part of the book: Central Nervous System Tumors