The Current State of Biological and Clinical Implications of Human Papillomavirus-Related Oropharyngeal Cancer

Transformation zone at the vallate papillae: a significant source of papillomavirus infection at the base of the tongue?

OBJECTIVE

The aim of this study was to investigate whether the base of the tongue harbours a transformation zone (TZ), i.e., an initiation site for papillomavirus infection, analogous to that in the uterine cervix by examining the histological structure of Von Ebner's gland ducts in the vallate papillae.

METHODS

Immunohistochemical staining and immunofluorescence techniques were used to detect markers associated with the uterine cervical TZ in the vallate papillae, and these results were compared with those in uterine cervical tissue. Additionally, tongue samples from mouse papillomavirus (MmuPV1)-infected mice were analysed to test our hypothesis.

RESULTS

The specific expression of CK17 in the squamous epithelium of the vallate papillae indicated the presence of immature squamous epithelium, arising from the transformation of reserve cells in this region. Moreover, a s determined using virus-infected mice, the TZ at the base of the tongue was a significant site for papilloma virus infection.

CONCLUSIONS

This is the first study to reveal the presence of a TZ in the vallate papillae, as determined by the presence of reserve cells and immature squamous epithelium, suggesting that the base of the tongue is a significant site for papillomavirus infection. This finding provides an entry point for the early prevention and diagnosis of HPV-associated lesions in the oropharynx.

Are we ready for deintensification in human papillomavirus-positive oropharyngeal carcinomas?

PURPOSE OF REVIEW

Excellent outcomes following contemporary treatment of human papillomavirus (HPV)-positive oropharyngeal carcinoma (HPV+ OPC) have prompted the exploration of deintensification approaches to minimize treatment-related toxicities. This review describes the landscape of deintensification to date (up to November 2022).

RECENT FINDINGS

Although several deintensification trials have been published, none are practice changing. Three phase III randomized-controlled trials studying cetuximab and radiation therapy vs. standard chemoradiotherapy all showed inferior outcomes. Although some phase II trials reported favourable outcomes, they are often single-arm trials without an adequate control arm, thereby limiting the ability to modify practice.

SUMMARY

Substantial effort has been expended to explore deintensification options for selected HPV+ OPC patients aiming to avoid unnecessary toxicity. Strategies have included replacing cisplatin with cetuximab, reduced chemotherapy or radiotherapy intensity, reduction of radiotherapy volumes and risk stratification after trans-oral surgery or following induction chemotherapy. Challenges remain in the current deintensification landscape, including identifying the most suitable candidates along with a choice of most appropriate deintensification strategies. Promising selection criteria included either static baseline features or kinetic characteristics of clinical-biological parameters. Practice-changing trials remain elusive, and the search continues to attempt optimization of the therapeutic ratio for these patients.

Circulating HPV16 DNA in Blood Plasma as Prognosticator and Early Indicator of Cancer Recurrence in Radio-Chemotherapy for Anal Cancer

BACKGROUND

Implementation of anal squamous cell carcinoma (ASCC) treatment modifications requires reliable patient risk stratification. The circulating tumor-related human papillomavirus type 16 (ctHPV16) may play a role in predicting survival or assessing treatment response.

METHODS

The study included 62 ASCC patients treated with chemoradiotherapy. A threshold of 2.5 was used to determine the maximum standardized uptake value (SUVmax). The ctHPV16 viral load (VL) was quantified by qPCR.

RESULTS

In the multivariate Cox analysis, lower SUVmax (p = 0.047) and ctHPV16-positive (p = 0.054) proved to be independent prognostic factors for favorable overall survival (OS). In the subgroup with the higher SUVmax, ctHPV16 and nodal (N) status were independent prognostic factors with p = 0.022 for ctHPV16 and p = 0.053 for N. The best survival rate (95%) presented ctHPV16-positive/N-negative patients. High ctHPV16 VL tended to be slightly specific for patients younger than 63 years (p = 0.152). The decrease in ctHPV16 VL to undetectable level after the end of treatment correlated with the overall clinical response.

CONCLUSIONS

A prognostic stratification by SUVmax, ctHPV16 and N-positive status allows consideration of more aggressive treatment in high-risk patients (those with high SUVmax, ctHPV16-negative, and N-positive) or de-intensification of therapy in low-risk patients (those with low SUVmax, ctHPV16-positive and N-negative). However, prospective clinical trials on a large group are needed.

Multiparametric MRI Evaluation of Oropharyngeal Squamous Cell Carcinoma. A Mono-Institutional Study

The aim of this paper is to define the pre-treatment radiological characteristics of oropharyngeal squamous cell carcinoma (OPSCC) using morphological and non-morphological magnetic resonance imaging (MRI), based on HPV status, in a single-institution cohort. In total, 100 patients affected by OPSCC were prospectively enrolled in the present study. All patients underwent 1.5T MR with standard sequences, including diffusion-weighted imaging with and intravoxel incoherent motion (IVIM-DWI) technique and a dynamic contrast-enhanced (DCE) MRI. For all patients, human papillomavirus (HPV) status was available. No statistically significant differences in the volume of primary tumors (PTs) and lymph nodes (LNs) were observed based on HPV status. When comparing the two patient groups, no significant differences were found for the PT radiologic characteristics (presence of well-defined borders, exophytic growth, ulceration, and necrosis) and LN morphology (solid/cystic/necrotic). Tumor subsite, smoking status, and alcohol intake significantly differed based on HPV status, as well as ADC and D_t values of both PTs and LNs. We detected no significant difference in DCE-MRI parameters by HPV status. Based on a multivariate logistic regression model, the combination of clinical factors, such as tumor subsite and alcohol habits, with the perfusion-free diffusion coefficient D_t of LNs, may help to accurately discriminate OPSCC by HPV status.

Radiomics and radiogenomics in head and neck squamous cell carcinoma: Potential contribution to patient management and challenges

The application of imaging biomarkers in oncology is still in its infancy, but with the expansion of radiomics and radiogenomics a revolution is expected in this field. This may be of special interest in head and neck cancer, since it can promote precision medicine and personalization of treatment by overcoming several intrinsic obstacles in this pathology. Our goal is to provide the medical oncologist with the basis to approach these disciplines and appreciate their main uses in clinical research and clinical practice in the medium term. Aligned with this objective we analyzed the most relevant studies in the field, also highlighting novel opportunities and current challenges.

Transitions in oral and gut microbiome of HPV+ oropharyngeal squamous cell carcinoma following definitive chemoradiotherapy (ROMA LA-OPSCC study)

Background

Oral and gut microbiomes have emerged as potential biomarkers in cancer. We characterised the oral and gut microbiomes in a prospective observational cohort of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) patients and evaluated the impact of chemoradiotherapy (CRT).

Methods

Saliva, oropharyngeal swabs over the tumour site and stool were collected at baseline and post-CRT. 16S RNA and shotgun metagenomic sequencing were used to generate taxonomic profiles, including relative abundance (RA), bacterial density, α-diversity and β-diversity.

Results

A total of 132 samples from 22 patients were analysed. Baseline saliva and swabs had similar taxonomic composition (R² = 0.006; p = 0.827). Oropharyngeal swabs and stool taxonomic composition varied significantly by stage, with increased oral RA of Fusobacterium nucleatum observed in stage III disease (p < 0.05). CRT significantly reduced the species richness and increased the RA of gut-associated taxa in oropharyngeal swabs (p < 0.05), while it had no effect in stool samples. These findings remained significant when adjusted by stage, smoking status and antibiotic use.

Conclusions

Baseline oral and gut microbiomes differ by stage in this HPV+ cohort. CRT caused a shift towards a gut-like microbiome composition in oropharyngeal swabs. Stage-specific features and the transitions in oral microbiome might have prognostic and therapeutic implications.

Potential therapeutic implications of the new tumor, node, metastasis staging system for human papillomavirus-mediated oropharyngeal cancer

PURPOSE OF REVIEW

The 8th edition tumor, node, metastasis (TNM) classification (TNM-8) introduced a new classification for human papillomavirus (HPV)-mediated oropharyngeal carcinoma (HPV+ OPC). This review summarizes its potential therapeutic implications focusing on literature published since 2018.

RECENT FINDINGS

The following are active research areas involved in clinical care and therapy relevant to TNM-8: tumor HPV testing and its clinical implications; stage I disease: treatment selection and lessons learned from recent deintensification trials; emerging strategies addressing stage II and III disease.

SUMMARY

The TNM-8 classification depicts prognosis of HPV+ OPC much more reliably compared with TNM-7. Among the advantages in outcome comparison and stratification for clinical trial entry and conduct, it also enables more satisfactory individual patient consultation to adequately estimate prognosis, and facilitates clinical and translational research. However, clinicians must remain mindful that the TNM classification is not a guideline for treatment but, instead, provides a framework for clinical research and treatment decision-making. The TNM-8 has potential to improve risk-tailored treatment algorithms for HPV+ OPC including selection of treatment modality (primary trans-oral surgery vs. radiotherapy, addition of chemotherapy) and adjusting the intensity of approaches. To realize these goals fully, it is apparent that the TNM-8 needs to evolve further.

Immunotherapy in head and neck cancer: The great challenge of patient selection

The development of immune checkpoint inhibitors (ICIs) revolutionized the therapeutic landscape in head and neck cancer. However, the majority of patients present primary resistance to ICIs and do not benefit from use of these agents, highlighting the need of developing predictive biomarkers to better determine who will benefit from treatment with ICIs. Patient's related clinical characteristics, disease related features, pathological and molecular factors, as well as emerging immune predictive biomarkers can be considered for the selection of those patients who would be the best candidate for immunotherapy. We examined these factors, emerging from the results of currently available studies in head and neck squamous cell carcinoma (HNSCC), in order to provide a useful tool which could assist the oncologist in their clinical practice.

US oral health students' willingness to train and administer the HPV vaccine in dental practices

HPV oropharyngeal cancers have now surpassed cervical cancer rates in the US. Dental providers' engagement in HPV education and vaccination efforts may help reduce the burden of HPV oropharyngeal cancers. We examined factors associated with oral health students' willingness to train and administer the human papillomavirus (HPV) vaccine in dental settings. US students in 15 oral health programs participated in an online survey in 2016. Unadjusted and adjusted multivariable logistic regression were conducted and odds ratios (OR) and 95% confidence intervals (CI) were reported. Analyses were conducted in SAS Version 9.4. Data from a total of N = 306 students were analyzed to examine sociodemographic, educational, practice, and attitudinal factors associated with willingness to train and administer the HPV vaccine. Majority of the participants were female (70.3%), non-Hispanic/Latino (90.8%), and White (62.1%). Perceiving that HPV vaccination recommendation (OR = 1.95, 95% CI = 1.14-3.35) and administration (OR = 3.79, 95% CI = 1.63-8.81) was in the dental professional's scope was positively associated with outcome measures when other factors were held constant. Students with greater patient contact time (OR = 4.47, 95% CI = 1.14-17.58) and lower role conflict (agreed that HPV vaccine administration was in the dental professional's scope) had higher odds of willingness to administer the HPV vaccine when other factors were held constant (OR = 5.9, 95% CI = 2.27-15.3). The major barrier to engaging oral health students in HPV vaccination efforts was role conflict. Professional organizations and oral health programs should strongly support the role of oral health professionals in HPV oropharyngeal prevention.

Human papillomavirus genotypes and infection among women in Changzhou, China

Human papillomavirus (HPV) infection is a major cause of cervical cancer. HPV vaccine has been shown to be highly effective in preventing HPV infection, and understanding the genotypes of HPV infection can guide the utilization of HPV vaccine. This epidemiological study aimed to investigate the genotype distribution of HPV in HPV-positive female patients in Changzhou. This study enrolled HPV-positive female patients admitted at the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University were enrolled in this study. HPV genotypes were identified via standard HPV DNA testing. The cohort comprised 5738 patients, that the predominant genotypes were HPV52 (13.4%), HPV16 (9.6%), HPV58 (8.8%), HPV81 (8.6%), and HPV53 (7.7%). HPV infection prevalence was the highest among those aged 41-45 y (16.6%), followed by those aged 31-35 y (15.1%) and 36-40 y (15.1%). In total, 46.8% of infections were found in women aged 31-45 y. The main genotypes of HPV infection upon physical examination or diagnosis of cervicitis and cervical cancer were HPV52, 16, 58, 81, and 53. HPV52, 16, 58, 81, and 53 are the most predominant genotypes of HPV infection. Further, HPV infection is most prevalent among women aged 31-45 y. Our findings provide experimental evidence for guiding HPV vaccination policy.

Immune biomarkers of response to immune-checkpoint inhibitors in head and neck squamous cell carcinoma

Anti-programmed cell death protein 1 (PD-1) agents have become the standard of care for platinum-refractory recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) and are currently being evaluated in various disease settings. However, despite the gain in overall survival seen in some of the clinical trials, the majority of patients display primary resistance and do not benefit from these agents. Taking into consideration the potentially severe immune-related toxicities and their high cost, the search for predictive biomarkers of response is crucial. Besides Programmed death ligand-1 (PD-L1) expression, other biomarkers such as immune infiltration, tumor mutational burden or immune-gene expression profiling have been explored, but none of them has been validated in this disease. Among these, the microbiota has recently garnered tremendous interest since it has proven to influence the efficacy of PD-1 blockade in some tumor types. With the accumulating evidence on the effect of the microbiota in HNSCC tumorigenesis and progression, the study of its potential role as a predictive immune biomarker is warranted. This review examines the available evidence on emerging immune predictive biomarkers of response to anti-PD-1/PD-L1 therapy in HNSCC, introducing the microbiota and its potential use as a predictive immune biomarker in this disease.

The interplay of IMRT and transoral surgery in HPV-mediated oropharyngeal cancer: Getting the balance right

Transoral surgery (TOS) and IMRT represent two primary local ablative treatment modalities for oropharyngeal cancer (OPC). The choice of one over the other represents an interplay between the chance of cure vs risk of late sequelae. HPV-mediated (HPV+) OPC patients generally have excellent outcomes, especially in TNM-8 stage I disease. Controversies exist over which treatment has a more favorable toxicity profile and equal efficacy in the management of this population. Non-randomized retrospective data show comparable oncological and functional outcomes between TOS-based vs IMRT-based treatment for this disease. Several de-intensification concepts have been explored in this subset in both primary surgery-based vs primary radiotherapy-based trials. However, no robust mature trial data are available to convincingly guide treatment selection. TOS is often presented as one of the de-intensification options although the majority of series also describe the use of adjuvant treatments which inevitably result in non-negligible toxicities. Patient selection and surgeons' training are paramount. Understanding tumor biology and the prognostic value of traditional 'adverse' features will further guide trial design for refinement of risk tailored approach. In conclusion, comparative data suggests TOS and IMRT are both effective treatment for TNM-8 stage I HPV+ OPC with similar oncological and functional outcomes. TOS as a single modality has potential advantages in mitigating radiation included toxicities. TOS should be avoided in the presence of clinically overt extranodal extension or when negative margins are unlikely to be achieved. TOS is also less ideal for cases with radiological features predicting a high risk of distant metastasis.