This Collection focuses on one of the most significant developments in oncology in recent years: the increase in head and neck cancers (HNC) related to the Human Papillomavirus (HPV). While some oropharyngeal cancers (posterolateral wall and tonsillar pillars) have traditionally been associated with smoking and alcohol, HPV infection, particularly by the HPV-16 type, has emerged as the predominant causative factor in many patients with other Oropharyngeal cancer (localized in tonsils and base if tongue) in Western countries. These latter account for approximately 70% of oropharyngeal cases in the US and about 50% in Italy. These HPV-positive tumors exhibit a distinctive clinical and molecular profile, often with a better prognosis and different sensitivity to standard treatments (surgery, radiotherapy, chemotherapy) compared to HPV-negative forms. Understanding viral biology, mechanisms of oncogenesis, and biomarkers (such as the p16 protein and TP53 status) is crucial for risk stratification and planning de-intensified and personalized therapies aimed at reducing long-term toxicity. This Collection brings together cutting-edge contributions on early diagnosis (including new methodologies such as liquid biopsy), innovative therapeutic approaches, and prevention strategies, particularly HPV vaccination, which is essential to stem this growing epidemic. The goal is to provide a comprehensive and critical overview for clinicians and researchers

Infectious agents cause approximately 20% of all human cancer cases worldwide, with higher rates in low-income countries. Six human viruses, including high-risk alpha human papillomaviruses (HPV), hepatitis B (HBV) and C (HCV) viruses, human T-cell lymphotropic virus 1 (HTLV-1), Epstein–Barr virus (EBV), and Kaposi sarcoma-associated herpesvirus (HHV-8), have been classified as class 1 carcinogens by the International Agency for Research on Cancer. In addition, the Helicobacter pylori bacterium as well as the Opisthorchis viverrini, Clonorchis sinensis, and Schistosoma haematobium helminths have been also defined as class 1 carcinogens to humans. All known oncogenic pathogens can promote cell survival and transformation because of their common abilities to cause chronic insults, genetic and epigenetic alterations, deregulated metabolic pathways, and immune escape.

The global burden of pathogen-related cancers is expected to grow with the identification of novel oncogenic microorganisms or uncommon tropism of known agents in the body sites. Paradigmatic is the role of HPV infection in oropharyngeal cancers and the clinical relevance of such association. The cooperation of viruses with environmental risk factors, such as cutaneous HPV types and ultraviolet radiation or HBV and aflatoxin, is another important emerging issue in cancer development. Furthermore, recent findings showed the intriguing effects of microbiota in cancer susceptibility, neoplastic progression, co-infections with carcinogenic agents, and response to therapy.

This collection aims to gather and share novel information focusing on epidemiology, molecular biology, cellular biology, genetics, and epigenetics as well as translational research of infectious agents causing cancer. All types of manuscripts in this scope will be welcome, including research articles, brief reports, and review articles.

All submissions in this collection undergo the journal’s standard peer review process. Similarly, all manuscripts authored by a Guest Editor(s) are handled by the Editor-in-Chief.