Immunotherapy in HPV-Related Oropharyngeal Cancers

Advances in human papillomavirus detection and molecular understanding in head and neck cancers: Implications for clinical management

Head and neck cancers (HNCs), primarily head and neck squamous cell carcinoma (HNSCC), are associated with high-risk human papillomavirus (HR HPV), notably HPV16 and HPV18. HPV status guides treatment and predicts outcomes, with distinct molecular pathways in HPV-driven HNSCC influencing survival rates. HNC incidence is rising globally, with regional variations reflecting diverse risk factors, including tobacco, alcohol, and HPV infection. Oropharyngeal cancers attributed to HPV have significantly increased, particularly in regions like the United States. The HPV16 genome, characterized by oncoproteins E6 and E7, disrupts crucial cell cycle regulators, including tumor protein p53 (TP53) and retinoblastoma (Rb), contributing to HNSCC pathogenesis. P16 immunohistochemistry (IHC) is a reliable surrogate marker for HPV16 positivity, while in situ hybridization and polymerase chain reaction (PCR) techniques, notably reverse transcription-quantitative PCR (RT-qPCR), offer sensitive HPV detection. Liquid-based RT-qPCR, especially in saliva, shows promise for noninvasive HPV detection, offering simplicity, cost-effectiveness, and patient compliance. These molecular advancements enhance diagnostic accuracy, guide treatment decisions, and improve patient outcomes in HNC management. In conclusion, advances in HPV detection and molecular understanding have significant clinical management implications. Integrating these advancements into routine practice could ultimately improve patient outcomes.

Transcriptomic profiling of peripheral blood cells in HPV-associated carcinoma patients receiving combined valproic acid and avelumab

Human papillomavirus (HPV)-associated cancer continues to evade the immune system by promoting a suppressive tumor microenvironment. Therefore, immunotherapy appears to be a promising approach for targeting HPV-associated tumors. We hypothesized that valproic acid (VA) as an epigenetic agent combined with avelumab may enhance the antitumor immunity in HPV-associated solid tumors. We performed bulk RNA-sequencing (RNA-Seq) on total peripheral blood mononuclear cells (PBMCs) of seven nonresponders (NRs) and four responders (Rs). A total of 39 samples (e.g., pretreatment, post-VA, postavelumab, and endpoint) were analyzed. Also, we quantified plasma analytes and performed flow cytometry. We observed a differential pattern in immune response following treatment with VA and/or avelumab in NRs vs. Rs. A significant upregulation of transcripts associated with NETosis [the formation of neutrophil extracellular traps (NETs)] and neutrophil degranulation pathways was linked to the presence of a myeloid-derived suppressor cell signature in NRs. We noted the elevation of IL-8/IL-18 cytokines and a distinct transcriptome signature at the baseline and endpoint in NRs. By using the receiver operator characteristics, we identified a cutoff value for the plasma IL-8/IL-18 to discriminate NRs from Rs. We found differential therapeutic effects for VA and avelumab in NRs vs. Rs. Thus, our results imply that measuring the plasma IL-8/IL-18 and bulk RNA-Seq of PBMCs may serve as valuable biomarkers to predict immunotherapy outcomes.

Human Papillomavirus-Induced Chromosomal Instability and Aneuploidy in Squamous Cell Cancers

Chromosomal instability (CIN) and aneuploidy are hallmarks of cancer. CIN is defined as a continuous rate of chromosome missegregation events over the course of multiple cell divisions. CIN causes aneuploidy, a state of abnormal chromosome content differing from a multiple of the haploid. Human papillomavirus (HPV) is a well-known cause of squamous cancers of the oropharynx, cervix, and anus. The HPV E6 and E7 oncogenes have well-known roles in carcinogenesis, but additional genomic events, such as CIN and aneuploidy, are often required for tumor formation. HPV+ squamous cancers have an increased frequency of specific types of CIN, including polar chromosomes. CIN leads to chromosome gains and losses (aneuploidies) specific to HPV+ cancers, which are distinct from HPV- cancers. HPV-specific CIN and aneuploidy may have implications for prognosis and therapeutic response and may provide insight into novel therapeutic vulnerabilities. Here, we review HPV-specific types of CIN and patterns of aneuploidy in squamous cancers, as well as how this impacts patient prognosis and treatment.

Molecular aspects of cervical cancer: a pathogenesis update

Cervical cancer (CC) is a significant health problem, especially in low-income countries. Functional studies on the human papillomavirus have generated essential advances in the knowledge of CC. However, many unanswered questions remain. This mini-review discusses the latest results on CC pathogenesis, HPV oncogenesis, and molecular changes identified through next-generation technologies. Interestingly, the percentage of samples with HPV genome integrations correlates with the degree of the cervical lesions, suggesting a role in the development of CC. Also, new functions have been described for the viral oncoproteins E5, E6, and E7, resulting in the acquisition and maintenance of cancer hallmarks, including proliferation, immune response evasion, apoptosis, and genomic instability. Remarkably, E5 oncoprotein affects signaling pathways involved in the expression of interferon-induced genes and EGFR-induced proliferation, while E6 and E7 oncoproteins regulate the DNA damage repair and cell cycle continuity pathways. Furthermore, next-generation technologies provide vast amounts of information, increasing our knowledge of changes in the genome, transcriptome, proteome, metabolome, and epigenome in CC. These studies have identified novel molecular traits associated with disease susceptibility, degree of progression, treatment response, and survival as potential biomarkers and therapeutic targets.

Immunotherapy for head and neck squamous cell carcinoma: current status and perspectives

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several solid cancers, including head and neck squamous cell carcinoma (HNSCC). First approved for second-line settings, ICIs are now used for the first-line treatment of HNSCCs, mainly in combination with standard chemotherapy. This review focuses on the results of the main phase III studies evaluating ICIs in recurrent or metastatic HNSCCs. The efficacy and indications according to the PD-L1 status, the main predictive biomarker, are discussed. The results of trials assessing ICI efficacy for locally advanced disease, including the neoadjuvant setting are also discussed. Finally, therapeutic combinations that are potential treatments for HNSCCs, including ICIs and targeted therapies such as anti-EGFR agents, are presented.

Vaccines for HPV-associated diseases

Human papillomavirus (HPV) infection represents a significant global health concern owing to its role in the etiology of conditions ranging from benign low-grade lesions to cancers of the cervix, head and neck, anus, vagina, vulva, and penis. Prophylactic vaccination programs, primarily targeting adolescent girls, have achieved dramatic reductions in rates of HPV infection and cervical cancer in recent years. However, there is a clear demand for a strategy to manage the needs of the many people who are already living with persistent HPV infection and/or HPV-associated conditions. Unlike prophylactic vaccines, which act to prevent HPV infection, therapeutic vaccination presents an opportunity to induce cellular immunity against established HPV infections and lesions and prevent progression to cancer. Several HPV vaccines are undergoing clinical development, using a range of platforms. Peptide- or protein-based vaccines, vector-based vaccines, whole-cell vaccines, and nucleic acid vaccines each offer relative merits and limitations for the delivery of HPV antigens and the subsequent generation of targeted immune responses. There has been particular interest in DNA-based vaccines, which elicit both cellular and humoral immune responses to provide long-lasting immunity. DNA vaccines offer several practical advantages over other vaccine platforms, including the potential for rapid and scalable manufacturing, targeting of many different antigens, and potential for repeat boosting. Furthermore, unlike vectored approaches, DNA vaccines are thermostable over extended time periods, which may enable shipping and storage. Several delivery strategies are available to address the main challenge of DNA vaccines, namely their relatively low transfection efficiency. We review the latest clinical data supporting the development of DNA vaccines and reflect on this exciting prospect in the management of HPV-related disease.

The combined HPV16-E2/E6/E7 T cell response in oropharyngeal cancer predicts superior survival

Tumor-infiltrating HPV16-E2-specific CD8+ T cells have been detected in HPV16-induced oropharyngeal squamous cell carcinoma (OPSCC). Whether intratumoral CD4+ T cells target HPV16 E2 and if HPV16-E2-specific immunity contributes to better clinical outcome is unknown. In a prospective HPV16+ OPSCC cohort, we regularly detect HPV16-E2-specific CD4+ and CD8+ intratumoral T cells, albeit at lower frequencies than the co-infiltrating HPV16-E6/E7-specific T cells. These HPV16-reactive T cells produce multiple cytokines when activated, indicating their polyfunctionality. Importantly, their combined intratumoral presence predicts superior survival, emphasizing the value of HPV16-E2-specific T cells in anti-tumor immunity and suggests its use as a target antigen for immunotherapy.

Clinical, morphologic and molecular heterogeneity of HPV-associated oropharyngeal cancer

The incidence of human papillomavirus-positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) is rising rapidly and has exceeded cervical cancer to become the most common HPV-induced cancer in developed countries. Since patients with HPV + OPSCC respond very favorably to standard aggressive treatment, the emphasis has changed to reducing treatment intensity. However, recent multi-center clinical trials failed to show non-inferiority of de-escalation strategies on a population basis, highlighting the need to select low-risk patients likely to respond to de-intensified treatments. In contrast, there is a substantial proportion of patients who develop recurrent disease despite aggressive therapy. This supports that HPV + OPSCC is not a homogeneous disease, but comprises distinct subtypes with clinical and biological variations. The overall goal for this review is to identify biomarkers for HPV + OPSCC that may be relevant for patient stratification for personalized treatment. We discuss HPV + OPSCC as a heterogeneous disease from multifaceted perspectives including clinical behavior, tumor morphology, and molecular phenotype. Molecular profiling from bulk tumors as well as single-cell sequencing data are discussed as potential driving factors of heterogeneity between tumor subgroups. Finally, we evaluate key challenges that may impede in-depth investigations of HPV + OPSCC heterogeneity and outline potential future directions, including a section on racial and ethnic differences.