Patient Selection in Human Papillomavirus Related Oropharyngeal Cancer: The Added Value of Prognostic Models in the New TNM 8th Edition Era

Advances and residual knowledge gaps in the neck management of head and neck squamous cell carcinoma patients with advanced nodal disease undergoing definitive (chemo)radiotherapy for their primary

PURPOSE

Substantial changes have been made in the neck management of patients with head and neck squamous cell carcinomas (HNSCC) in the past century. These have been fostered by changes in cancer epidemiology and technological progress in imaging, surgery, or radiotherapy, as well as disruptive concepts in oncology. We aimed to review changes in nodal management, with a focus on HNSCC patients with nodal involvement (cN+) undergoing (chemo)radiotherapy.

METHODS

A narrative review was conducted to review current advances and address knowledge gaps in the multidisciplinary management of the cN+ neck in the context of (chemo)radiotherapy.

RESULTS

Metastatic neck nodes are associated with poorer prognosis and poorer response to radiotherapy, and have therefore been systematically treated by surgery. Radical neck dissection (ND) has gradually evolved toward more personalized and less morbid approaches, i.e., from functional to selective ND. Omission of ND has been made feasible by use of positron-emission tomography/computed tomography to monitor the radiation response in cN+ patients. Human papillomavirus-driven oropharyngeal cancers and their cystic nodes have shown dramatically better prognosis than tobacco-related cancers, justifying a specific prognostic classification (AJCC) creation. Finally, considering the role of lymph nodes in anti-tumor immunity, de-escalation of ND and prophylactic nodal irradiation in combination are intense areas of investigation. However, the management of bulky cN3 disease remains an issue, as aggressive multidisciplinary strategies or innovative combined treatments have not yet significantly improved their prognosis.

CONCLUSION

Personalized neck management is an increasingly important aspect of the overall therapeutic strategies in cN+ HNSCC.

Role of TORS as De-Escalation Strategy in HPV-Related Oropharyngeal Cancer, What We Need to Know

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) presents unique challenges and opportunities for treatment, particularly regarding de-escalation strategies to reduce treatment morbidity without compromising oncological outcomes. This paper examines the role of Transoral Robotic Surgery (TORS) as a de-escalation strategy in managing HPV-related OPSCC. We conducted a comprehensive literature review from January 2010 to June 2023, focusing on studies exploring TORS outcomes in patients with HPV-positive OPSCC. These findings highlight TORS's potential to reduce the need for adjuvant therapy, thereby minimizing treatment-related side effects while maintaining high rates of oncological control. TORS offers advantages such as precise tumor resection and the ability to obtain accurate pathological staging, which can guide the tailoring of adjuvant treatments. Some clinical trials provide evidence supporting the use of TORS in specific patient populations. The MC1273 trial demonstrated promising outcomes with lower doses of adjuvant radiotherapy (RT) following TORS, showing high locoregional tumor control rates and favorable survival outcomes with minimal side effects. ECOG 3311 evaluated upfront TORS followed by histopathologically directed adjuvant therapy, revealing good oncological and functional outcomes, particularly in intermediate-risk patients. The SIRS trial emphasized the benefits of upfront surgery with neck dissection followed by de-escalated RT in patients with favorable survival and excellent functional outcomes. At the same time, the PATHOS trial examined the impact of risk-adapted adjuvant treatment on functional outcomes and survival. The ongoing ADEPT trial investigates reduced-dose adjuvant RT, and the DART-HPV study aims to compare standard adjuvant chemoradiotherapy (CRT) with a reduced dose of adjuvant RT in HPV-positive OPSCC patients. These trials collectively underscore the potential of TORS in facilitating treatment de-escalation while maintaining favorable oncological and functional outcomes in selected patients with HPV-related OPSCC. The aim of this scoping review is to discuss the challenges of risk stratification, the importance of HPV status determination, and the implications of smoking on treatment outcomes. It also explores the evolving criteria for adjuvant therapy following TORS, focusing on reducing radiation dosage and volume without compromising treatment efficacy. In conclusion, TORS emerges as a viable upfront treatment option for carefully selected patients with HPV-positive OPSCC, offering a pathway toward treatment de-escalation. However, selecting the optimal candidate for TORS-based de-escalation strategies is crucial to fully leverage the benefits of treatment de-intensification.

Biplex quantitative PCR to detect transcriptionally active human papillomavirus 16 from patient saliva

Head and neck cancers, particularly oropharyngeal cancers (OPC), have been increasingly associated with human papillomavirus (HPV) infections, specifically HPV16. The current methods for HPV16 detection primarily rely on p16 staining or PCR techniques. However, it is important to note the limitations of conventional PCR, as the presence of viral DNA does not always indicate an ongoing viral infection. Moreover, these tests heavily rely on the availability of tissue samples, which can present challenges in certain situations. In this study, we developed a RT-qPCR biplex approach to detect HPV16 oncogenes E6 and E7 RNA in saliva samples from OPC patients. Salivary supernatant was used as the liquid biopsy source. We successfully obtained RNA from salivary supernatant, preserving its integrity as indicated by the detection of several housekeeping genes. Our biplex approach accurately detected E6 and E7 RNA in HPV16-positive cell lines, tissues, and finally in OPC salivary samples. Importantly, the assay specifically targeted HPV16 and not HPV18. This biplexing technique allowed for reduced sample input without compromising specificity. In summary, our approach demonstrates the potential to detect viable HPV16 in saliva from OPC patients. Since the assay measures HPV16 RNA, it provides insights into the transcriptional activity of the virus. This could guide clinical decision-making and treatment planning for individuals with HPV-related OPC.

Combining the radiomics signature and HPV status for the risk stratification of patients with OPC

OBJECTIVE

The objective was to perform risk stratification of oropharyngeal cancer (OPC) for treatment de-escalation based on the radiomics analysis and human papillomavirus (HPV) status.

METHODS

A total of 265 patients with OPC who underwent baseline contrast-enhanced computed tomography were analyzed, and the patients were grouped into the training (n = 133) and test (n = 132) cohorts at a ratio of 1:1. Intratumoral and peritumoral radiomics features were extracted, and the radiomics signature (Rscore) was calculated using least absolute shrinkage and selection operator regression (LASSO) and Cox regression analyses.

RESULTS

Twelve features were selected to establish the radiomics signature (Rscore) of intratumoral regions +10-mm peritumoral regions, which yielded maximum AUCs of 0.835, 0.798, and 0.784 in the training, test, and validation cohorts, respectively. Patients with OPC were divided into the high-risk group, intermediate-risk group, and low-risk group based on the Rscore and HPV status and had different prognoses. Patients in the low-risk group benefit from radiotherapy alone, and patients in the intermediate-risk group only benefitted from chemoradiotherapy.

CONCLUSION

The radiomics signature appears to improve the predictive performance of clinical characteristics for oropharyngeal cancer. The combined stratification of the radiomics signature and HPV status might be preferred to select patients for de-escalated treatment.

External validation of a CT-based radiomics signature in oropharyngeal cancer: Assessing sources of variation

BACKGROUND AND PURPOSE

Radiomics is a high-throughput approach that allows for quantitative analysis of imaging data for prognostic applications. Medical images are used in oropharyngeal cancer (OPC) diagnosis and treatment planning and these images may contain prognostic information allowing for treatment personalization. However, the lack of validated models has been a barrier to the translation of radiomic research to the clinic. We hypothesize that a previously developed radiomics model for risk stratification in OPC can be validated in a local dataset.

MATERIALS AND METHODS

The radiomics signature predicting overall survival incorporates features derived from the primary gross tumor volume of OPC patients treated with radiation +/- chemotherapy at a single institution (n = 343). Model fit, calibration, discrimination, and utility were evaluated. The signature was compared with a clinical model using overall stage and a model incorporating both radiomics and clinical data. A model detecting dental artifacts on computed tomography images was also validated.

RESULTS

The radiomics signature had a Concordance index (C-index) of 0.66 comparable to the clinical model's C-index of 0.65. The combined model significantly outperformed (C-index of 0.69, p = 0.024) the clinical model, suggesting that radiomics provides added value. The dental artifact model demonstrated strong ability in detecting dental artifacts with an area under the curve of 0.87.

CONCLUSION

This work demonstrates model performance comparable to previous validation work and provides a framework for future independent and multi-center validation efforts. With sufficient validation, radiomic models have the potential to improve traditional systems of risk stratification, treatment personalization and patient outcomes.

Radiomics-guided radiation therapy: opportunities and challenges

Radiomics is an advanced image-processing framework, which extracts image features and considers them as biomarkers towards personalized medicine. Applications include disease detection, diagnosis, prognosis, and therapy response assessment/prediction. As radiation therapy aims for further individualized treatments, radiomics could play a critical role in various steps before, during and after treatment. Elucidation of the concept of radiomics-guided radiation therapy (RGRT) is the aim of this review, attempting to highlight opportunities and challenges underlying the use of radiomics to guide clinicians and physicists towards more effective radiation treatments. This work identifies the value of RGRT in various steps of radiotherapy from patient selection to follow-up, and subsequently provides recommendations to improve future radiotherapy using quantitative imaging features.

Non-Robustness of Ang’s Risk Classification in Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma in Japanese Patients

Background: Validity of the risk classification by Ang for human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) remains to be studied in the patients treated by modalities other than chemoradiotherapy and in Japanese patients. Materials and Methods: Between 2010 and 2018, 122 patients with HPV-related OPSCC in stages III and IV by the TNM classification 7th edition (TNM-7) were treated curatively at a single institution in Japan. The median age was 62.7 years. Over 50% of the patients underwent surgery with or without adjuvant therapy. The influence of multiple factors on survival was analyzed. Results: The amount of smoking dichotomized at 10 pack-year, which was used in Ang’s risk classification, was not predictive of prognosis, and Ang’s risk classification was not significantly influential on prognosis in multivariate analysis. In the patients treated with definitive radiation therapy, Ang’s risk classification was not predictive of the prognosis in univariate analysis. The impact of smoking was significant only in the patients undergoing the definitive operation. Conclusions: Ang’s risk classification was not robust in predicting the prognosis of general Japanese HPV-related OPSCC patients. The amount of smoking might have different prognostic influences depending on the therapeutic method.

Human papillomavirus-related oropharyngeal carcinoma

It was not until around 2000 that human papillomavirus-related oropharyngeal carcinoma was recognized as carcinoma with clinical presentations different from nonrelated head and neck carcinoma. Twenty years after and with the revision of the tumor-node-metastasis classification in 2017, various clinical trials focused on human papillomavirus-related oropharyngeal carcinoma to improve the prognosis and quality of life of patients with this disease. However, the incidence of human papillomavirus-related cancers is increasing, which is expected to be particularly prominent in Japan, where human papillomavirus vaccination is not widely available. In this review, we describe the current status of clinical trials (mainly focused on initial surgery and radiation dose reduction) for, primary and secondary prevention of, and the present status of human papillomavirus-related oropharyngeal carcinoma in Japan.

MicroRNA-182-5p and microRNA-205-5p as potential biomarkers for prognostic stratification of p16-positive oropharyngeal squamous cell carcinoma

BACKGROUND

MicroRNAs constitute promising biomarkers.

OBJECTIVE

The aim was to investigate diagnostic and prognostic implications of miR-182-5p and miR-205-5p in p16-positive and p16-negative oropharyngeal squamous cell carcinomas (OPSCCs).

METHODS

Expression of miR-182-5p, miR-205-5p were determined via quantitative real-time-PCR in fresh frozen tissues of 26 p16-positive, 19 p16-negative OPSCCs and 18 HPV-negative oropharyngeal controls. Associations between miRNA-expression, clinicopathological characteristics and prognosis were analyzed.

RESULTS

Higher miR-182-5p expression was associated with significant inferior disease-specific survival for p16-positive OPSCCs (HR = 1.98E+09, 95% CI 0-Inf; P= 0.028) and a similar trend was observed for p16-negative OPSCCs (HR = 1.56E+09, 95% CI 0-Inf; P= 0.051). Higher miR-205-5p expression was associated with an inferior progression-free survival (HR = 4.62, 95% CI 0.98-21.83; P= 0.034) and local control rate (HR = 2.18E+09, 95% CI 0-Inf; P= 0.048) for p16-positive OPSCCs.

CONCLUSIONS

Results indicate that miR-182-5p and miR-205-5p can further stratify patients with p16-positive OPSCC into prognostic groups.

Improvement of patient stratification in human papilloma virus-associated oropharyngeal squamous cell carcinoma by defining a multivariable risk score

BACKGROUND

Precise risk stratification models are necessary to determine patient selection for deintensifying treatment trials in human papilloma virus (HPV)-associated oropharyngeal squamous cell cancer (HPV+ OPSCC).

METHODS

We examined 526 cases with OPSCC treated at our department between 2002 and 2017. Every patient was classified after the 7th and 8th edition UICC staging manual. For HPV+ OPSCC, we calculated a simple risk score with four risk groups based on multivariable Cox regression analysis of clinical and lifestyle parameters (UICC 8th edition stage, tobacco/alcohol abuse, age, gender).

RESULTS

Two hundred and thirty-nine patients with OPSCC (45.4%) showed a positive histological HPV status. In comparison to UICC 8th edition stages, our proposed risk model showed a tendency for better stratification between risk strata I/III, I/IV, and II/IV (each p < 0.002) and I/II, II/III, and III/IV (each p < 0.09).

CONCLUSION

Age, gender, tobacco, and alcohol abuse should be added to the current UICC staging system in order to improve risk stratification in HPV+ OPSCC.

[Prognostic factors for overall survival in oropharyngeal carcinoma depending on HPV status]

Hintergrund

Aufgrund der unterschiedlichen Karzinogenese, Prognose und klinischen Manifestation werden seit der 8. Auflage des TNM-Klassifikationssystems der UICC/AJCC (UICC 8) humane Papillomavirus (HPV)-assoziierte und HPV-negative oropharyngeale Plattenepithelkarzinome (OSCC) als 2 Entitäten separat klassifiziert.

Material und Methoden

Insgesamt 524 Patienten mit einem im Zeitraum von 2000–2016 in der HNO-Klinik des Universitätsklinikums Münster behandelten OSCC wurden hinsichtlich des Nachweises von HPV-Typ-16-spezifischer DNA (HPV16-DNA), des Nikotin- und Alkoholkonsums sowie des Therapieeinflusses auf das Gesamtüberleben (GÜ) untersucht.

Ergebnisse

Ein signifikanter Anstieg der jährlichen Prävalenz der HPV16-DNA-positiven OSCC von 40 % (n = 12/30) im Jahr 2000 auf 46 % (n = 18/39) im Jahr 2016 wurde verzeichnet (p = 0,025, β = 0,539). 89 % (n = 212) der HPV16-DNA-positiven OSCC wurden anhand der UICC 8 gegenüber der UICC 7 herabgestuft. Im Gesamtkollektiv zeigten der häufige Alkohol- und Nikotinkonsum (≥ 10 Packungsjahre) einen statistisch relevanten negativen Einfluss auf das GÜ (p = 0,004 und p = 0,009). Auch häufiger Alkoholkonsum war in der HPV16-DNA-negativen Gruppe prognoserelevant (p = 0,049). In der HPV16-DNA-positiven Gruppe zeigte sich bezüglich des GÜ zwischen den UICC-Stadien I und II (p = 0,481) sowie zwischen III und IV (p = 0,439) gemäß UICC 8 kein statistischer Unterschied.

Schlussfolgerungen

Die UICC 8 verbessert zwar die Prognosestratifikation der OSCC durch die Trennung von HPV-positiven und HPV-negativen Tumoren im Vergleich zu UICC 7, die prognostische Aussagekraft der UICC 8 für die HPV-assoziierten OSCC ist jedoch weiterhin unzureichend. Der Noxenkonsum könnte zukünftig Einfluss auf die UICC-Klassifikation nehmen, um die prognostische Aussagekraft weiter zu verbessern.

Clinical efficacy of an antibody-based detection system for human papilloma virus infection in oral squamous cell carcinoma

OBJECTIVES

There is an increasing number of oral squamous cell carcinoma (OSCC) associated with HPV-16. However, p16 expression by immunohistochemistry as the current gold standard for a surrogate marker for virus infection reveals unsatisfying diagnostic accuracy. The aim of this study was to investigate a new rapid test for L1 antibody detection (Prevocheck®) and to validate its diagnostic performance.

MATERIALS AND METHODS

In a prospective study, the HPV 16 association of all consecutive patients with an OSCC treated between 2015 and 2019 were analyzed by L1 seropositivity (via PrevoCheck®), p16 immunostaining, and partly multiplex PCR for subtype analysis.

RESULTS

Overall (n = 107), p16 expression was positive in 17 cases (15.9%), and L1 antibody seropositivity in 7 cases (6.5%). In PCR analysis, two cases of HPV35 and 50 were found. Total HPV prevalence was 8.4% overall and 6.5% for HPV-16. An inferior diagnostic accuracy for HPV-16-associated OSCC in comparison to PrevoCheck® was revealed.

CONCLUSION

The rapid test for L1 antibodies showed an optimal sensitivity and specificity, positive and negative predictive value, and an overall diagnostic accuracy of 100%. However, HPV prevalence seems low in OSCC.

CLINICAL RELEVANCE

L1 rapid test may represent an additional diagnostic staging method to detect HPV-16 association rather than p16 immunohistochemistry.

Improved survival prediction for oropharyngeal cancer beyond TNMv8

PURPOSE

For oropharynx squamous cell carcinoma (OPSCC) this study aimed to: (i) compare 5-year overall survival (OS) stratification by AJCC/UICC TNM versions 7 (TNMv7) and 8 (TNMv8), (ii) determine whether changes to T and N stage groupings improve prognostication and (iii) develop and validate a model incorporating additional clinical characteristics to improve 5-year OS prediction.

MATERIAL AND METHODS

All OPSCC treated with curative-intent at our institution between 2011 and 2017 were included. The primary endpoint was 5-year OS. Survival curves were produced for TNMv7 and TNMv8. A three-way interaction between T, N stage and p16 status was evaluated for improved prognostication. Cox proportional hazards modelling was used to derive a new predictive model.

RESULTS

Of 750 OPSCC cases, 574 (77%) were p16-positive. TNMv8 was more prognostic than TNMv7 (concordance probability estimate [CPE] ± SE = 0.72 ± 0.02 vs 0.53 ± 0.02). For p16-positive disease, TNMv8 discriminated stages II vs I (HR 2.32, 95% CI 1.47-3.67) and III vs II (HR 1.75, 95% CI 1.13-2.72). For p16-negative disease, TNMv7 and TNMv8 demonstrated poor hazard discrimination. Different T, N stage and p16-status combinations did not improve prognostication after adjusting for other factors (CPE = 0.79 vs 0.79, p = 0.998). A model for p16-positive and p16-negative OPSCC including additional clinical characteristics improved 5-year OS prediction beyond TNMv8 (c-index 0.76 ± 0.02).

CONCLUSIONS

TNMv8 is superior to TNMv7 for p16-positive OPSCC, but both performed poorly for p16-negative disease. A novel model incorporating additional clinical characteristics improved 5-year OS prediction for both p16-positive and p16-negative disease.

Early T1-T2 stage p16+ oropharyngeal tumours. Role of upfront transoral robotic surgery in de-escalation treatment strategies. A review of the current literature

Human papillomavirus is responsible of approximately 70% oropharyngeal tumours and is related with more favourable outcomes. It has led to an increasing interest for de-escalation treatment strategies such as Trans Oral Robotic Surgery (TORS). A literature review was performed searching for the role of TORS as de-escalation modality of treatment in patients with p16 positive oropharyngeal squamous cell carcinoma (OPSCC). Special attention was paid to the potential advantage offered by TORS in reducing adjuvant radiation therapy. Six questions were formulated. 67 studies were selected. Several trials analysing the role of upfront TORS to treat early stage p16+ OPSCC and the possibility of reducing the adjuvant radiotherapy were founded. A lot of studies based on the experience of single centres show promising results. Nevertheless to date no definitive data can be extrapolated. The continued investigation of this line of de-escalation therapy with randomized prospective clinical trials is needed.

Potential Added Value of PET/CT Radiomics for Survival Prognostication beyond AJCC 8th Edition Staging in Oropharyngeal Squamous Cell Carcinoma

Accurate risk-stratification can facilitate precision therapy in oropharyngeal squamous cell carcinoma (OPSCC). We explored the potential added value of baseline positron emission tomography (PET)/computed tomography (CT) radiomic features for prognostication and risk stratification of OPSCC beyond the American Joint Committee on Cancer (AJCC) 8th edition staging scheme. Using institutional and publicly available datasets, we included OPSCC patients with known human papillomavirus (HPV) status, without baseline distant metastasis and treated with curative intent. We extracted 1037 PET and 1037 CT radiomic features quantifying lesion shape, imaging intensity, and texture patterns from primary tumors and metastatic cervical lymph nodes. Utilizing random forest algorithms, we devised novel machine-learning models for OPSCC progression-free survival (PFS) and overall survival (OS) using “radiomics” features, “AJCC” variables, and the “combined” set as input. We designed both single- (PET or CT) and combined-modality (PET/CT) models. Harrell’s C-index quantified survival model performance; risk stratification was evaluated in Kaplan–Meier analysis. A total of 311 patients were included. In HPV-associated OPSCC, the best “radiomics” model achieved an average C-index ± standard deviation of 0.62 ± 0.05 (p = 0.02) for PFS prediction, compared to 0.54 ± 0.06 (p = 0.32) utilizing “AJCC” variables. Radiomics-based risk-stratification of HPV-associated OPSCC was significant for PFS and OS. Similar trends were observed in HPV-negative OPSCC. In conclusion, radiomics imaging features extracted from pre-treatment PET/CT may provide complimentary information to the current AJCC staging scheme for survival prognostication and risk-stratification of HPV-associated OPSCC.

Prognostic Significance of Smoking in Human Papillomavirus-Positive Oropharyngeal Cancer Under American Joint Committee on Cancer Eighth Edition Stage

OBJECTIVE

To determine the prognostic significance of smoking in human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) when considering American Joint Committee on Cancer eighth edition (AJCC-8) stage.

STUDY DESIGN

Retrospective cohort study.

METHODS

Three hundred seventeen HPV-positive OPSCC patients with known AJCC-8 stage and smoking status (<10 or ≥10 pack-years) seen at a tertiary center from 1997 to 2017 were studied. We used the Kaplan-Meier method to compare 5-year overall survival (OS) by smoking status and by clinical AJCC-8 stage and smoking status combined. Hazard ratios (HRs) were estimated with Cox proportional hazard regression for the independent effects of smoking and AJCC-8 stage. We also studied pathologic stage and estimated the combined effects of smoking and clinical stage.

RESULTS

The ≥10 pack-years smokers had worse 5-year OS than <10 pack-years smokers (93.6%; 95% confidence interval (CI): 89.7-97.8 vs. 82.3%; 95% CI: 76.0%-89.1%). When stratified by AJCC-8 clinical stage, only stage I <10 pack-years smokers (98.7%; 95% CI: 96.3%-100.0%) had significantly better 5-year OS than their ≥10 pack-years (84.8%; 95% CI: 76.4%-94.1%) counterparts. In a multivariable analysis, ≥10 pack-years smoking was associated with increased hazard of death when adjusting for AJCC-8 clinical (HR: 2.52; 95% CI: 1.16-5.46) and pathologic (HR: 5.21; 95% CI: 1.47-18.5) stage. In both analyses, stage III patients demonstrated worse survival than stage I, and smoking had greater impact at lower stages.

CONCLUSIONS

Smoking is a negative prognosticator in HPV-positive OPSCC and interacts with AJCC-8 clinical stage. It is important to understand the impact of smoking in HPV-positive disease when considering treatment plans and deintensification trials.

LEVEL OF EVIDENCE

2b Laryngoscope, 130: 1961-1966, 2020.

Poorly differentiated neuroendocrine carcinoma of the head and neck: human papillomavirus tumour status/p16 status and impact on overall survival

AIMS

Poorly differentiated neuroendocrine carcinoma (PDNEC) of the head and neck is a rare high-grade neuroendocrine neoplasm. Human papillomavirus (HPV) status and p16 status are as yet unclear among PDNECs, owing to a lack of statistical analysis. The objective of the present study was therefore to evaluate their potential clinicopathological associations, and their prognostic impact on overall survival in PDNECs of the head and neck, regardless to HPV genotype.

METHODS AND RESULTS

All cases of PDNEC of the head and neck between 1998 and 2019 were identified from the database of the Lyon university hospital pathology department (n = 21); for these cases, p16 immunohistochemistry and HPV in-situ hybridisation were performed. Published cases of PDNEC of the head and neck with assessment of HPV status and p16 status were identified in PubMed (n = 57). Local and published cases were pooled for analysis. HPV positive (HPV+) tumour status was found to be significantly associated with oropharyngeal localisation (P < 0.001) and overexpression of p16 (P < 0.001). Multivariate analysis, adjusted on tumour site, histological subtype, p16 status, HPV status, and source of the case, showed that oropharyngeal localisation [hazard ratio (HR) 3.031, 95% confidence interval (CI) 1.257-7.310] and being a small-cell variant (HR 2.859, 95% CI 1.150-7.109) were significant predictors of worse overall survival; HPV+ tumour status was associated with better overall survival (HR 0.388, 95% CI 0.146-0.995).

CONCLUSIONS

HPV+ tumour status was associated with oropharyngeal PDNECs and with a better prognosis.

Prevalence of Human Papillomavirus (HPV) Infection and the Association with Survival in Saudi Patients with Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) shows wide disparities, association with human papillomavirus (HPV) infection, and prognosis. We aimed at determining HPV prevalence, and its prognostic association with overall survival (OS) in Saudi HNSCC patients. The study included 285 oropharyngeal and oral-cavity HNSCC patients. HPV was detected using HPV Linear-Array and RealLine HPV-HCR. In addition, p16INK4a (p16) protein overexpression was evaluated in 50 representative cases. Oropharyngeal cancers were infrequent (10%) compared to oral-cavity cancers (90%) with no gender differences. Overall, HPV-DNA was positive in 10 HNSCC cases (3.5%), mostly oropharyngeal (21%). However, p16 expression was positive in 21 cases of the 50 studied (42%) and showed significantly higher OS (p = 0.02). Kaplan–Meier univariate analysis showed significant associations between patients’ OS and age (p < 0.001), smoking (p = 0.02), and tumor stage (p < 0.001). A Cox proportional hazard multivariate analysis confirmed the significant associations with age, tumor stage, and also treatment (p < 0.01). In conclusion, HPV-DNA prevalence was significantly lower in our HNSCC patients than worldwide 32–36% estimates (p ≤ 0.001). Although infrequent, oropharyngeal cancer increased over years and showed 21% HPV-DNA positivity, which is close to the worldwide 36–46% estimates (p = 0.16). Besides age, smoking, tumor stage, and treatment, HPV/p16 status was an important determinant of patients’ survival. The HPV and/or p16 positivity patients had a better OS than HPV/p16 double-negative patients (p = 0.05). Thus, HPV/p16 status helps improve prognosis by distinguishing between the more favorable p16/HPV positive and the less favorable double-negative tumors.