HPV-related Head And Neck Squamous Cell Carcinomas Research Articles

Trends in incidence rates of head and neck squamous cell carcinomas overall and by potential relatedness to human papillomavirus, Costa Rica 2006 to 2015.

In Costa Rica (CR), only one report on head and neck cancer (HNC) incidence trends (1985-2007) has been published and no investigations on the epidemiology of potentially human papillomavirus (HPV)-related and HPV-unrelated HNCs have been done. We examined the age-standardized incidence rates (IRs) and trends of head and neck squamous cell carcinomas (HNSCC) and compared incidence trends of potentially HPV-related and HPV-unrelated HNSCCs. We obtained all available HNC cases for the period 2006-2015 from the Costa Rican National Cancer Registry of Tumors and the population estimates from the Costa Rican National Institute of Statistics and Census. The analysis was restricted to invasive HNSCCs (n=1577). IRs and incidence rate ratios were calculated using SEER*Stat software and were age-standardized for the 2010 Costa Rican population. Joinpoint regression analysis program was used to calculate trends and annual percent changes (APCs) in rates. For all HNSCCs, the age-standardized IR was 34.0/million person-years; 95% CI 32.4, 35.8. There was a significant decline in the incidence of nasopharyngeal cancer (APC: -5.9% per year; 95% CI -10.8, -0.7) and laryngeal cancer (APC: -5.4% per year; -9.2, 1.5). The incidence trends for hypopharyngeal, oropharyngeal and oral cavity cancers each remained stable over time. HNSCCs were categorized by their potential relatedness to HPV infection. Though the APCs were not statistically significant, IRs of potentially HPV-related HNSCCs trended upward, while HPV-unrelated HNSCCs trended downward. HNSCCs are uncommon in CR and decreased over time. We observed a divergent pattern of decreasing HPV-unrelated with increasing HPV-related HNSCCs that should be further informed by HPV genotyping tumor samples.

Combination Radiation Therapy and Selective TLR9 Agonist Improves Local Control in a Murine Model of HPV-Related HNSCC

<h3>Purpose/Objective(s)</h3> As novel immunotherapies emerge, it has become increasingly evident that personalized treatment combinations are necessary to improve outcomes in head and neck squamous cell carcinomas (HNSCC). Toll-like receptors (TLR) play a critical role in the activation of professional antigen presenting cells (APC). Given the increasing appreciation of the role of APC and B-cells in HPV+ HNSCC, we sought to evaluate the therapeutic role of selective TLR agonists in combination with radiation therapy (RT). <h3>Materials/Methods</h3> For human tumor RNA sequencing studies, we analyzed data from the TCGA and a separate independent validation cohort of HNSCC patients, cumulatively totaling nearly 600 patients. Single cell RNA sequencing (scRNA-seq) databases were analyzed using Seurat v4.0. For murine studies, wild type C3H mice were injected subcutaneously with 5 × 10⁵ cells of AT-84-E7-OVA syngeneic squamous cell carcinoma into the right flank. TLR agonists were administered intratumorally in 25 uL per published schedules for: TLR4 (MPLA-SM, 1 mg/ml), TLR7 (1V270, 2 mg/ml), and TLR9 (ODN 1826, 2 mg/ml). Control mice received PBS. Mice receiving RT were treated with 12 Gy in 1 fraction. Cell surface markers in the tumor draining lymph node (TDLN) and tumor were analyzed by flow cytometry. <h3>Results</h3> Treatment with TLR4, TLR7, and TLR9 agonists decreased the size of the primary tumor in our murine model of HPV+ HNSCC, with a B cell selective TLR9 agonist exhibiting the greatest therapeutic benefit. When analyzing transcriptomes of HPV- tumors, we found no correlation between high TLR4/7/9 expression and outcomes, however, in HPV+ tumors, among TLRs 4/7/9, only TLR9 had a significant correlation with overall survival (HR 0.38, P = 0.008). In an independent cohort of HPV+ HNSCC patients, the correlation between OS and high TLR9 expression was maintained. scRNA-seq of human HNSCC TILs revealed heterogeneity in TLR9 expression among various immune cells. In the TDLN, TLR9 agonist were shown to decrease the relative proportion of B cells and trended towards increased proportions of CD4+ T cells, which had decreased expression of CD44. In comparison, in the tumor, we observed increased CD8+ T cell infiltration but decreased proportions of B cells with TLR9 agonists. When evaluating TLR9 agonists in conjunction with RT, we found that the combination treatment led to the largest therapeutic benefit. <h3>Conclusion</h3> In HPV+ HNSCC, transcriptional analysis revealed a significant correlation between high TLR9 expression and overall survival. Concordantly, the combination of RT and TLR9 agonists lead to a significant reduction in the primary tumor, which may be driven by dynamic changes in B cell phenotype or migration patterns and CD8+ T cell tumor infiltration. These findings support the further investigation into the use of TLR9 agonists in combination with radiation therapy for the treatment of HPV+ HNSCC.

Abstract P011: B cell subsets that correlate with anti-PD-1 resistance in a preclinical model of HPV+ oropharyngeal cancer

Abstract A subset of head and neck squamous cell carcinomas (HNSCC) is associated with infection with oncogenic strains of human papillomavirus (HPV) and its prevalence continues to rise in the US. Cancer progression has been associated, in part, with an impaired immunity. Because of this, immunotherapies such as immune checkpoint blockade (ICB) have been FDA approved to treat different types of cancers, including HNSCC. The ICB targeting the molecule programmed death cell-1 (PD-1) is used as treatment for HPV-related HNSCC, however, only around 30% of patients respond. Most studies have focused on characterizing T cell responses, however, B cells, are also present in the tumor microenvironment of HPV-positive HNSCC. Interestingly, different B cell subsets with differential functions that may promote or prevent an effective anti-tumor response are present in tumors and tumor-draining lymph nodes. Therefore, fine regulation of anti-tumor and tumor-promoting B cell subsets may be necessary to promote an effective anti-tumor response and therefore prevent tumor progression. However, the B cells that may be associated with responsiveness to anti-PD-1 in HPV+ oropharyngeal cancer remain undefined. By using the preclinical model for HPV+ oropharyngeal cancer (named mEER) we have determined that tongue-implanted tumors are sensitive to anti-PD-1, where around 50% of the mice clear the tumors, whereas flank-implanted tumors are completely resistant to these treatments. By using this in vivo model, we were able to characterize B cell subsets in anti-PD-1 sensitive and anti-PD-1 resistant tumors. First, we compared B cell subsets in untreated mice between tongue (anti-PD-1 sensitive) and flank-implanted (anti-PD-1 resistant) tumors by flow cytometry. Interestingly, flank-implanted tumors contained more PD-1-expressing B cells, which have been identified as an immunosuppressive population in hepatocellular carcinoma. The presence of immunosuppressive B cells on flank tumors was also supported by our finding that flank implanted tumors grew at a slower rate in B cell-deficient mice compared to wild-type mice. When we compared tongue-bearing tumor mice that responded or not responded to anti-PD-1, we observed that mice that did not respond to anti-PD-1 had a higher frequency of antibody-secreting cells in tumor-draining lymph nodes compared to responders. Lastly, when we cultured naïve B cells with tumor cell supernatant from mEER cells, B cells upregulated PD-1 and were able to produce the immunosuppressive cytokine IL-10. Our data suggest that HPV+ oropharyngeal tumors modulate B cell functions and that a differential infiltration of B cell subsets into tumors and tumor-draining lymph nodes correlates with responsiveness to anti-PD-1 therapy in a preclinical model of HPV+ oropharyngeal cancer. These results will aid in our long-term goal to elucidate novel mechanisms for the modulation of anti-tumor responses by B cells and the development of novel B cell-specific therapies for HPV-related cancers and, therefore, improve clinical outcomes in these patients. Citation Format: Pamela A. Merheb, Daniel L. Castañón, Michael Rivera, Jorge Galán, Stephanie M. Dorta-Estremera. B cell subsets that correlate with anti-PD-1 resistance in a preclinical model of HPV+ oropharyngeal cancer [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P011.

Recurrent Human Papillomavirus-Related Head and Neck Cancer Undergoes Metabolic Reprogramming and Is Driven by Oxidative Phosphorylation.

Human papillomavirus (HPV) infection drives the development of some head and neck squamous cell carcinomas (HNSCC). This disease is rapidly increasing in incidence worldwide. Although these tumors are sensitive to treatment, approximately 10% of patients fail therapy. However, the mechanisms that underlie treatment failure remain unclear. We performed RNA sequencing (RNA-seq) on tissues from matched primary- (pHNSCC) and metachronous-recurrent cancers (rHNSCC) to identify transcriptional differences to gain mechanistic insight into the evolutionary adaptations of metachronous-recurrent tumors. We used HPV-related HNSCC cells lines to investigate the effect of (i) NRF2 overexpression on growth in vitro and in vivo, (ii) oxidative phosphorylation (OXPHOS) inhibition using IACS-010759 on NRF2-dependent cells, and (iii) combination of cisplatin and OXPHOS inhibition. The OXPHOS pathway is enriched in recurrent HPV-associated HNSCC and may contribute to treatment failure. NRF2-enriched HNSCC samples from The Cancer Genome Atlas (TCGA) with enrichment in OXPHOS, fatty-acid metabolism, Myc, Mtor, reactive oxygen species (ROS), and glycolytic signaling networks exhibited worse survival. HPV-positive HNSCC cells demonstrated sensitivity to the OXPHOS inhibitor, in a NRF2-dependent manner. Further, using murine xenograft models, we identified NRF2 as a driver of tumor growth. Mechanistically, NRF2 drives ROS and mitochondrial respiration, and NRF2 is a critical regulator of redox homeostasis that can be crippled by disruption of OXPHOS. NRF2 also mediated cisplatin sensitivity in endogenously overexpressing primary HPV-related HNSCC cells. These results unveil a paradigm-shifting translational target harnessing NRF2-mediated metabolic reprogramming in HPV-related HNSCC.

HPV-Related Oropharyngeal Cancer Metastatic to Small Bowel Presenting as Small Bowel Obstruction – A Case Report and Systematic Review

Squamous cell carcinomas (SCC) account for the majority of all primary oropharyngeal carcinomas. These tumors can progress locally as well as metastasize to lymph nodes, the lung, bone, and liver. Metastases of primary laryngeal SCC to the small bowel is exceedingly rare and portends a poor prognosis as they often present with catastrophic symptoms. HPV-related head and neck SCC (HNSCC) is a peculiar subset of all HNSCC, and available data from prospective studies suggest better survival outcomes with HPV-related HNSCC compared to non-HPV-related HNSCC. In this article, we report the case of a patient who was managed at a tertiary hospital for a HPV-related laryngeal SCC with metastases to the small bowel presenting as small bowel obstruction (SBO). We also conducted a systematic review of HNSCC metastatic to small bowel with a focus on relation to HPV. We identified 13 reported cases of HNSCC metastatic to the small bowel. Of these, only 1 case was positive for p16 (a marker of HPV infection in HNSCC). We present the second case of HPV-related HNSCC with metastases to the small bowel.

P16 immunostaining in cytology specimens: its application, expression, interpretation, and challenges

p16 immunostaining is considered as a surrogate marker for human papillomavirus (HPV)-related head and neck squamous cell carcinomas (HNSCC). Herein, the utility of p16 is evaluated in cytology specimens. The electronic data of a large academic institution was searched for cytology cases accompanied by p16 (2014-2018). Cases were categorized based on body sites. P16 staining was quantified (negative [0%], focal/patchy, or diffusely positive [>70%]). HPV testing was correlated where available. A total of 372 cases were included (male:female, 239:133). The largest differences in application of p16 between men and women were in head/neck cases (209 versus 59) and the abdominal cases (1 versus 33), respectively. p16 diffuse staining is seen in most squamous cell carcinomas, small cell carcinomas, and gynecologic serous carcinomas. p16 expression was patchy or negative in most adenocarcinoma, neuroendocrine carcinoma, spindle cell neoplasms, and benign conditions. HPV testing was done on 217 cases including 138 cases with strong p16 (127 HPV+/11 HPV-), 20 cases with focal/patchy P16 staining (6 HPV+/14 HPV-) and 59 cases with negative p16 staining (3 HPV+/56 HPV-). Diffuse p16 staining aids in the diagnosis of HPV-related carcinomas, particularly HPV-related HNSCC, across the body and according to sex. In contrast, focal/patchy p16 staining does not correlate with HPV status across various body sites. In conclusion, intensity of p16 matters and should be correlated with cytomorphology, clinical history, and ancillary studies (eg, p40 immunostaining) for an accurate diagnosis and preventing diagnostic pitfalls.

The frequency of high-risk human papillomavirus types, HPV16 lineages, and their relationship with p16INK4a and NF-κB expression in head and neck squamous cell carcinomas in Southwestern Iran.

High-risk human papillomaviruses (hr-HPVs) are the key risk factors implicated in the development of a significant proportion of head and neck squamous cell carcinomas (HNSCCs). We aimed to investigate the distribution of hr-HPV types and HPV16 lineages in a sample of patients with HNSCC and the possible association between HPV status and the expression of P16INK4A and NF-κB in Iranian HNSCC patients. We examined 108 formalin-fixed, paraffin-embedded (FFPE) histologically confirmed primary SCC tissue specimens of different head and neck anatomical sites. HPV types and HPV16 lineages were determined by nested PCR and overlapping nested PCR assays, respectively, followed by gene sequencing and phylogenetic analysis. The expression of p16INK4a and NF-κB was evaluated by immunohistochemistry. Twenty-five (23.1%) HNSCC tissue specimens were tested positive for HPV infection. The most prevalent HPV type was HPV-16, followed by HPV18 and HPV11. HPV16 variants belonged to the lineage A and lineage D which were further sorted into sublineages A1, A2, and D2. A significant association between HPV status and p16INK4a immunoreactivity was observed in more than 76% of the HPV-related HNSCCs (P < 0.0001). The overexpression of p16INK4a and cytoplasmic NF-κB was more common in low-grade HNSCC tumors. Our data highlights that HPV16, in particular the A2 sublineage, followed by A1 and D2 sublineages are the major agents associated with HNSCCs in Iran. Based on HPV16 predominance and its lineage distribution pattern, it seems that the prophylactic vaccines developed for cervical cancer prevention could also be applicable for the prevention of HPV-related HNSCCs in our population.

HPV Involvement in the Tumor Microenvironment and Immune Treatment in Head and Neck Squamous Cell Carcinomas.

Head and neck squamous cell carcinomas (HNSCC) are one of the most prevalent cancers worldwide. Active human papillomavirus (HPV) infection has been identified as an important additional risk factor and seems to be associated with a better prognosis in non-drinker and non-smoker young patients with oropharyngeal SCC. The better response of the immune system against the HPV-induced HNSCC is suspected as a potential explanation for the better prognosis of young patients. To further assess this hypothesis, our review aims to shed light the current knowledge about the impact of HPV infection on the immune response in the context of HNSCC, focusing on the innate immune system, particularly highlighting the role of macrophages, Langerhans and myeloid cells, and on the adaptative immune system, pointing out the involvement of T regulatory, T CD8 and T CD4 lymphocytes. In addition, we also review the preventive (HPV vaccines) and therapeutic (checkpoint inhibitors) strategies against HPV-related HNSCC, stressing the use of anti-CTLA4, PD-L1, PD-L2 antibodies alone and in combination with other agents able to modulate immune responses.

A Review of HPV-Related Head and Neck Cancer.

Head and neck squamous cell carcinomas (HNSCCs) arise in the mucosal lining of the upper aerodigestive tract. Tobacco and alcohol use have been reported to be associated with HNSCC. Infection with high-risk human papillomaviruses (HPVs) has recently been implicated in the pathogenesis of HNSCCs. It is now widely accepted that high-risk HPV is a cause of almost all cervical cancers as well as some forms of HNSCCs. HPV-related HNSCCs are increasing. HPV-related HNSCCs and HPV-unrelated HNSCCs differ with respect to the molecular mechanisms underlying their oncogenic processes. HPV-related HNSCCs are known to have a better prognosis response to treatment as compared with HPV-unrelated HNSCCs. Therefore, in recent years, it has been required to accurately discriminate between HPV-related and HPV-unrelated HNSCCs. To diagnose the HPV-related HNSCCs, various methods including P16 immunohistochemistry, FISH, and genetic analyses of the HPV gene from histopathological and liquid biopsy specimens have been employed. Based on the results of the differential diagnosis, various treatments employing EGFR TKI and low-dose radiation have been employed. Here, we review the involvement of the HPV virus in HNSCCs as well as the molecular mechanism of carcinogenesis, classification, prognosis, diagnostic procedures, and therapy of the disease.

Measures of economic advantage associated with HPV-positive head and neck cancers among non-Hispanic black and white males identified through the National Cancer Database

BackgroundNational trends show dramatic increases in the incidence of HPV-related head and neck squamous cell carcinomas (HNSCCs) among black and white males. Using cases identified through the National Cancer Data Base, we assessed factors associated with HPV 16- or 16/18 positive HNSCCs among non-Hispanic black and white males diagnosed in the U.S. between 2009 and 2013. MethodsThis sample included 21,524 HNSCCs with known HPV status. Adjusted relative risks (RRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression. ResultsCompared to those with HPV-negative tumors, male patients diagnosed with HPV-positive HNSCCs were non-Hispanic white, younger at diagnosis, lived in zip-code areas with higher median household income and higher educational attainment, had private health insurance and no reported comorbidities at diagnosis. Although the risk of HPV-positive HNSCCs increased with measures of higher area-level socioeconomic status, the effect was stronger for non-Hispanic black males (RRAdjusted=1.76, 95% CI 1.49–2.09) than for whites (RRAdjusted=1.12, 95% CI 1.08–1.16). The peak age for diagnosis of HPV-positive HNSCCs occurred in those diagnosed at 45–49 years (RRAdjusted=1.57, 95% CI 1.42–1.73). Oropharyngeal tumors were strongly associated with HPV-positivity (RRAdjusted=4.32, 95% CI 4.03–4.63). In the analysis restricted to oropharyngeal anatomic sites, similar patterns persisted. ConclusionIn our analysis, measures of economic advantage were associated with an increased risk of HPV-positive HNSCCs. In order to develop effective interventions, greater understanding of the risk factors for HPV-positive HNSCCs is needed among both high-risk males and their healthcare providers.

Human Papillomavirus Associated Cancers of the Head and Neck: An Australian Perspective.

Human papillomavirus (HPV) associated head and neck squamous cell carcinomas (HNSCCs), have become a serious global health problem. Despite decreases in HPV-negative HNSCCs, the prevalence of HPV-positive HNSCCs has significantly increased. HPV-positive cancers are associated with superior survival outcomes when compared to HPV-negative cancers, which appears likely to be associated with differences in the molecular pathogenesis of the two diseases. While therapies are still problematic, the current HPV vaccine programs hold a promise for the primary prevention of HPV-related HNSCCs and since Australia was the first to introduce a nationwide HPV vaccine program, it is in a unique position to observe the effects of the vaccine on HNSCCs. This review discusses the epidemiological trends associated with HPV in HNSCC, with reference to the differences between HPV-positive and HPV-negative HNSCCs and the prevention potential of HPV vaccines.

Abstract 2915: Identification of the mechanisms of radiosensitization by human papillomavirus (HPV) in head and neck cancer cell lines

Abstract Background: Several clinical studies have shown that HPV+ head and neck squamous cell carcinomas (HNSCC) present a more favorable outcome and greater response to radiotherapy. Although there are some data supporting the hypothesis that HPV-related HNSCC exhibit higher sensitivity to radiotherapy, it is difficult to conclude that the improved outcome of HPV-related HNSCC is only attributable to intrinsic radiosensitivity of the HPV+ cells. We postulate that a complex interaction occurs between intrinsic mechanisms of radio-response and the tumor micro-environment including cells of the immune system stimulated by the presence of HPV. The objectives of this work are to study mechanisms of radio-response in HPV+ cells and to investigate whether irradiated HPV+ cells exhibit increased immunogenic cell death signals including membrane exposure of endoplasmatic reticulum-resident chaperone calreticulin, secretion of High-Mobility-Group-Box 1 protein (HMGB1) and ATP release. Material and Methods: We determined radiosensitivity by clonogenic survival of two HPV+ HNSCC cell lines (UPCI-SCC-154 &amp; UPCI-SCC90) compared to two HPV- cells (SCC61 &amp; SQD9). Cell cycle distribution and G2/M checkpoint were assessed by flow cytometry. DNA damage repair was evaluated by gamma-H2Ax assay, HR and NHEJ reporter gene assay. In addition, cell death (apoptosis, necrosis and mitotic catastrophe) and senscence were measured in the four cell lines together with immunogenic cell death signals, through cytokines, HMGB1, and ATP-release as well as, membrane exposure of calreticulin. Results: The surviving fraction at 2Gy (SF2) for the two HPV+ cell lines was 0,13 and 0,15 for UPCI-SCC-90 and UPCI-SCC-154, respectively while SF2 for SQD9 was 0,49 and 0,16 for SCC-61 a cell line already described as radiosensitive. Cell cycle distribution indicated an important block in G2/M 24h after irradiation for the HPV+ cell lines together with a slower clearance of gamma-H2Ax for HPV+ cells, compared to HPV- cells. Furthermore, HPV+ cells showed decreased DNA repair capacity by NHEJ and HR. Apoptosis rate after irradiation (2Gy) was variable depending on the cell line, but remained overall under 5%. Senescence was not increased after irradiation (2Gy) whereas mitotic catastrophe increased in HPV-negative cell lines after 24h. Cytokine secretion was cell line dependent while HMGB1 and ATP release was increased in HPV+ cell lines compared to HPV- cell lines. Finally, calreticulin membrane exposure after irradiation detected by immunofluorescence was more frequent in HPV+ compared with HPV- cells. Conclusions: Our results confirm an increased radiosenstitivity of HPV+ cells after irradiation together with increased signals recognised as “immunogenic cell death” (calreticulin exposure, HMGB1 and ATP release) providing a rationale to investigate immune responses in HPV+ tumors after radiotherapy. Note: This abstract was not presented at the meeting. Citation Format: Vanesa Bol. Identification of the mechanisms of radiosensitization by human papillomavirus (HPV) in head and neck cancer cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2915. doi:10.1158/1538-7445.AM2015-2915

An updated overview of HPV-associated head and neck carcinomas.

Human papilloma virus (HPV)-associated head and neck carcinoma is quite heterogeneous and most of the tumors arise in the oral cavity, oropharynx, hypopharynx and larynx. HPV was just recently recognized as an emerging risk factor for oropharyngeal squamous cell carcinoma (OSCC). HPV(+) tumors represent 5-20% of all head and neck squamous-cell carcinomas (HNSCCs) and 40-90% of those arising from the oropharynx, with widely variable rates depending on the geographic area, population, relative prevalence of environment-related SCC and detection assay. Different carcinogenic mechanisms are most likely implicated in cervical and oropharyngeal carcinogenesis. The most certain carcinogenic genotype for the head and neck region and the most common high-risk HPV genotype, HPV-16, is frequently detected in OSCC. A combination of p16INK4A expression and molecular detection of HPV DNA is the gold standard for the viral identification in tissue and exfoliated cell samples. Differences in the biology of HPV(+) and HPV(-) OSCC may have implications for the management of patients. New immunotherapy drugs based on the release of the co-inhibitory receptors, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed-death 1 (PD-1) have currently emerged. The goal of therapeutic cancer vaccination is inculcation of a persistent, tumor antigen-specific T cell response which kills tumor cells. The efficacy of the current HPV vaccines, Cervarix and Gardasil, in preventing HPV-related HNSCC is at present unknown. Treatment de-escalation is recommended as the current management of HPV-induced HNSCCs.

Biological basis for increased sensitivity to radiation therapy in HPV-positive head and neck cancers.

Although development of head and neck squamous cell carcinomas (HNSCCs) is commonly linked to the consumption of tobacco and alcohol, a link between human papillomavirus (HPV) infection and a subgroup of head and neck cancers has been established. These HPV-positive tumors represent a distinct biological entity with overexpression of viral oncoproteins E6 and E7. It has been shown in several clinical studies that HPV-positive HNSCCs have a more favorable outcome and greater response to radiotherapy. The reason for improved prognosis of HPV-related HNSCC remains speculative, but it could be owned to multiple factors. One hypothesis is that HPV-positive cells are intrinsically more sensitive to standard therapies and thus respond better to treatment. Another possibility is that HPV-positive tumors uniquely express viral proteins that induce an immune response during therapy that helps clear tumors and prevents recurrence. Here, we will review current evidence for the biological basis of increased radiosensitivity in HPV-positive HNSCC.

The Morphologic Profile of HPV-Related Head and Neck Squamous Carcinoma: Implications for Diagnosis, Prognosis, and Clinical Management

Much recent attention has highlighted a subset of head and neck squamous cell carcinomas (HNSCCs) related to the human papillomavirus (HPV) that is characterized by an epidemiologic, demographic, and clinical profile that deviates from the profile of conventional non-HPV-related HNSCC. Lost in the dash to develop and implement diagnostic assays to detect the presence of HPV in HNSCCs is the unpretentious observation that these HPV-HNSCCs are also distinctive with respect to their microscopic appearance, and that an awareness of these characteristic morphologic features can facilitate the diagnosis of HPV-related HNSCC (HPV-HNSCC). This review will delineate the microscopic appearance of HPV-HNSCC, spotlight ways in which the misinterpretation of these microscopic features can lead to diagnostic confusion, and provide recommendations for appropriate terminology when diagnosing HPV-HNSCC.

MTOR as a Molecular Target in HPV-Associated Oral and Cervical Squamous Carcinomas

The incidence of head and neck squamous cell carcinomas (HNSCC) associated with human papillomavirus (HPV) infection has increased over the past decades in the United States. We aimed at examining the global impact of HPV-associated HNSCC and whether the established key role of mTOR activation in HNSCC is also observed in HPV(+) HNSCC lesions, thereby providing novel treatment options for HPV-associated HNSCC patients. An international HNSCC tissue microarray (TMA) was used to analyze the expression of p16(INK4A), a surrogate for HPV infection, and Akt-mTOR pathway activation. Results were confirmed in a large collection of HPV(-) and HPV(+) HNSCC cases and in a cervical cancer (CCSCC) TMA. Observations were validated in HNSCC and CCSCC-derived cell lines, which were xenografted into immunodeficient mice for tumorigenesis assays. Approximately 20% of all HNSCC lesions could be classified as HPV(+), irrespective of their country of origin. mTOR pathway activation was observed in most HPV(+) HNSCC and CCSCC lesions and cell lines. The preclinical efficacy of mTOR inhibition by rapamycin and RAD001 was explored in HPV(+) HNSCC and CCSCC tumor xenografts. Both mTOR inhibitors effectively decreased mTOR activity in vivo and caused a remarkable decrease in tumor burden. These results emphasize the emerging global impact of HPV-related HNSCCs and indicate that the activation of the mTOR pathway is a widespread event in both HPV(-) and HPV-associated HNSCC and CCSCC lesions. The emerging results may provide a rationale for the clinical evaluation of mTOR inhibitors as a molecular targeted approach for the treatment of HPV-associated malignancies.

Population-based evidence of increased survival in human papillomavirus-related head and neck cancer

BackgroundEvidence from clinical, population-based and molecular studies has shown that human papillomavirus (HPV) infection can be a causal risk factor for a subset of head and neck squamous cell carcinomas (HNSCC). It is proposed that HPV-associated oropharyngeal cancer is a new disease entity that requires treatment and prevention strategies distinct from present recommendations. MethodsIn our population-based study we estimated incidence and survival trends in 8270 patients with HPV-related HNSCC (HPV+HNSCC) and HPV-unrelated HNSCC (HPV–HNSCC) in Norway over the past three decades. ResultsIn the period 1981–1995, patients with HPV+HNSCC had poorer survival than HPV–HNSCC (adjusted hazard ratio (HR) 1.3, 95% confidence interval (CI): 1.14–1.44). By 1996–2007, survival had increased in both groups, but the increase was significantly greater among HPV+HNSCC patients (HR 0.57, 95% CI: 0.48–0.67). During the same period, incidence also increased, but only for HPV+HNSCCs. From 1981–1995 to 1996–2007, median age at diagnosis for HPV+HNSCC decreased from 63.2 to 59.8years, while for HPV–HNSCC median age at diagnosis of 66.6years remained unchanged. ConclusionsWe demonstrate a population level improvement in survival among patients with oropharyngeal squamous cell cancers commonly related to infection with HPV. In contrast, patients with HNSCC not related to HPV only showed a modest improvement in survival in the period 1981–2007. A concomitant increase in incidence and survival was observed for HPV-related cancers only. This trend cannot be explained by changes in treatment, cancer registration nor screening, but is most likely due to an increased prevalence of HPV-positive tumours.

Human papillomavirus (HPV)–related, p16 positive head and neck squamous cell carcinomas (HNSCCs) after stem cell transplantation (SCT) and solid organ transplantation (SOT).

5571 Background: It is well-recognized that patients who undergo SCT or SOT are at risk for second malignancies, including HNSCC. While viral oncogenes have a defined role in some post-transplant cancers, the link between HPV infection and HNSCC in immunosuppressed patients has not been well studied. Methods: We reviewed the Cleveland Clinic SCT and SOT databases and identified patients who developed HNSCC after transplantation. Demographics, primary site and stage were noted. In situ hybridization for high risk HPV subtypes (HPV-ISH) and p16 immunohistochemistry results were recorded if available, or were performed in patients with sufficient pathologic material. Results: Twenty-one patients with HNSCC after transplantation were identified; 9 (43%) after SCT and 12 (57%) after SOT. Eighteen patients (86%) were male, and all were Caucasian, with a median age at HNSCC diagnosis of 57 (range 31-72) years, and a median time from transplantation to HNSCC diagnosis of 6.1 (range 0.4-16.4) years. The primary site was in the oropharynx in 8 patients (38%), oral cavity in 6 (28%), larynx in 5 (24%), hypopharynx in 1 (5%), and unknown in 1 (5%). HNSCC stage was I in 4 (20%) patients, II in 4 (20%), III in 4 (20%), IVA in 5 (24%), and IVB in 1 (5%). Data on disease stage was not available in 3 patients. HPV-ISH and p16 status could be determined in 17 patients; 6 were both p16 and HPV-ISH positive, 1 was p16 positive but insufficient tissue was available for HPV-ISH testing, and 1 was p16 positive and HPV-ISH negative. Five of the p16 positive HNSCCs occurred in SOT recipients, 3 were diagnosed after SCT. The remaining 9 patients were both p16 and HPV negative. Among the 8 p16 positive patients, primary sites were in the oropharynx in 4, larynx in 2, and oral cavity in 2. Among the 9 p16 negative patients, primary sites included oral cavity in 3, oropharynx in 3, hypopharynx in 1, larynx in 1 and unknown in 1. Conclusions: In this small retrospective study, the HNSCCs that developed after SCT and SOT were frequently positive for HPV-ISH and p16. Unlike HPV-related HNSCCs in immunocompetent patients, HPV and p16 positivity was often identified outside of the oropharynx.

Abstract LB-7: HPV-associated HNSCC: Widespread mTOR pathway activity and preclinical evaluation of mTOR inhibitors rapamycin and RAD-001

Abstract Traditional risk factors for head and neck squamous cell carcinomas (HNSCCs) include tobacco and alcohol consumption and betel nut chewing. Over the past three decades, the United States has experienced a considerable increase in the incidence of HNSCCs associated with human papillomavirus (HPV) infection. HPV is now recognized as an important etiologic agent in HNSCCs, particularly those originating in the oropharynx. To investigate the molecular mechanisms underlying HNSCC progression, we established the International HNSCC Tissue Array Initiative, which includes hundreds of HNSCC lesions from around the world. Using immunodetection of the p16INK4a protein (p16) as a surrogate marker for HPV-related HNSCC, we found that approximately 20% of the HNSCC cores could be classified as HPV+, irrespective of the country of origin. These results emphasize the emerging global impact of HPV-related HNSCCs. On the basis of the results from these tissue array analyses, we designed studies aimed at elucidating dysregulated signaling networks in HPV+ HNSCCs. Surprisingly, although HPV+ HNSCCs represent a distinct clinicopathological subset of HNSCC lesions, we observed frequent Akt-mTOR pathway activation in HPV+ HNSCC, aligned with our previous studies documenting the activation of this signaling route in non-HPV related HNSCCs. Thus, activation of the Akt-mTOR pathway represents a widespread event in HNSCC, irrespective of HPV status. These findings were confirmed in an independent cohort of 48 HNSCC cases of oral and oropharyngeal tumors, 28 of which were determined to be HPV+ as judged by HPV DNA detection and p16 expression levels. We observed elevated expression of markers for Akt and mTOR activity (pAktS473, pS6) in all 28 of the HPV+ cases when compared to normal controls. These observations prompted us to investigate whether specific allosteric inhibitors of mTOR (rapamycin and RAD001) represent a valid therapeutic approach for HPV+ HNSCC. Initially, we observed that a panel of HPV+ human derived HNSCC cell lines (n=5) exhibited elevated levels of pS6 by Western blot, which was blocked upon treatment with rapamycin and RAD001 (100 nM, 30 min). Two representative human HNSCC HPV+ cell lines were used to establish HPV+ HNSCC xenografts in the flanks of athymic (nu/nu) mice. Tumor bearing mice were treated with vehicle, rapamycin, or RAD001. Both treatment groups showed rapid tumor collapse and a significant decrease in tumor burden when compared to vehicle treated mice (p&amp;lt;0.0001). Successful inhibition of Akt-mTOR pathway activation was confirmed by pS6 and pAktS473 immunostaining of the xenograft tissue. We can conclude that activation of the Akt-mTOR pathway is a widespread event in HPV-associated HNSCC, and that mTOR inhibitors may represent attractive candidates for the treatment of HPV-positive squamous neoplastic lesions. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-7. doi:10.1158/1538-7445.AM2011-LB-7

Meta-analysis of the impact of human papillomavirus (HPV) on cancer risk and overall survival in head and neck squamous cell carcinomas (HNSCC).

BackgroundHPV is important in a subset of HNSCC. Our meta-analysis determined the clinical characteristics of HPV-related HNSCC.MethodPubmed search terms "HPV" and "HNSCC" were used to identify 34 studies since 1980. We obtained pooled adjusted odds ratio (OR) or hazard ratio (HR) using random or fixed-effects model and compared OS depicted in forest plot.ResultsA total of 5681 patients were included. The prevalence of HPV+ tumors was 22%, with 86.7% of HPV16+ genotype. The OR for HNSCC in HPV16+ patients was 4.44 (95% CI = 2.87-6.02). HPV status was associated with p16 expression (adj OR = 3.00; 0.90-9.70), and HPV+ tumors were less likely to harbor p53 mutations (adj OR = 0.21; 0.04-0.38). The HR for death in HPV+ patients was 0.42 (0.27-0.57). HPV+ HNSCC also had a better response to therapy.ConclusionHPV+ HNSCC are established as a separate biologic entity. Prospective trials are needed to establish the optimal therapy for HPV+ HNSCC.