Partial p16 staining in oropharyngeal squamous cell carcinoma: extent and pattern correlate with human papillomavirus RNA status

Human Papillomavirus Testing in Head and Neck Carcinomas: Guideline Update

CONTEXT.—

In 2018, an evidence-based guideline was published by the College of American Pathologists to develop recommendations for the testing, application, interpretation, and reporting of high-risk human papillomavirus and surrogate marker tests in head and neck carcinomas. Substantial new evidence has prompted a review, including data on human papillomavirus (HPV) in nonoropharyngeal anatomic sites, HPV global rates, p16 immunohistochemistry, and HPV testing performance in cytology specimens, and performance of p16 immunohistochemistry as a surrogate marker.

OBJECTIVE.—

To assess research published since the release of the original 2018 guideline and to update evidence-based recommendations for HPV testing in head and neck carcinomas.

DESIGN.—

The College of American Pathologists convened a panel of experts to update the guideline following the standards established by the National Academy of Medicine for developing trustworthy clinical practice guidelines. The expert panel defined the key questions and performed a systematic review of the literature. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, recommendations were updated on the basis of available evidence, certainty of that evidence, and key judgments.

RESULTS.—

Seven strong recommendations, 4 conditional recommendations, and 5 good practice statements are offered in the guideline update.

CONCLUSIONS.—

The updated guideline statements provide direction on the nature of HPV testing in various head and neck specimens (including key updates based on new research on sinonasal squamous cell carcinoma) and expanded guidance on specific scenarios and practice settings. The goal is to improve and standardize, where possible, HPV testing across diverse pathology practice settings and different countries.

Does a Transcriptionally Active HPV Infection Affect the Invasiveness of Pituitary Neuroendocrine Tumors? A Case Series Study of 60 Patients in Krakow, Poland

BACKGROUND/OBJECTIVE

Pituitary neuroendocrine tumors (PITNETs) often show a tendency towards invasive behavior, i.e., an invasion towards the cavernous sinuses or destruction of the sella turcica. In the present study, we analyzed whether a transcriptionally active HPV infection affects the invasiveness of pituitary tumors.

METHODS

Sixty patients with different phenotypes of PITNETs who underwent neurosurgery were studied. The obtained postoperative material was analyzed histopathologically. For each patient, formalin-fixed paraffin-embedded blocks were cut into ultra-thin slices and two to three of them were designated for DNA extraction, while one was used for histological slides. Based on the isolated DNA, the presence of DNA from individual HPV types was determined by the real-time detection polymerase chain reaction using the REALQUALITY RQ-Multi HPV Detection reagent kit (AB ANALITICA, Italy). P16 protein expression was assessed by immunohistochemical staining on the histological slides. A transcriptionally active infection with individual HPV types was distinguished when HPV DNA and P16 protein overexpression were detected simultaneously for a given tumor.

RESULTS

In the group of the 60 analyzed PITNETs, a transcriptionally active high-risk HPV infection was detected in a subset of 11 tumors (18.3%). This infection was associated with a significantly lower probability of tumor invasiveness, measured on both the Knosp (OR = 0.11, 95% CI: 0.02-0.58) and Hardy scales (OR = 0.12 95% CI: 0.024-0.56).

CONCLUSIONS

Further studies are needed to confirm the prevalence of transcriptionally active HPV infections in pituitary adenomas and the role of these infections in the invasiveness of pituitary tumors.

Frequency and clinical significance of human papilloma virus in oral cancer - A study from Kerala

BACKGROUND

Oral cancer is a major health problem in India. Recently an increase in the oral cancer incidence among young individuals without any habits was observed, which may be due to Human Papilloma Virus (HPV). However, information on the prevalence of HPV in oral cancer in India is sparse. This study aims to document the frequency of HPV16 infection in oral squamous cell carcinoma (SCC) and to study its correlation with treatment outcome.

METHODS

Paraffin-embedded tissue blocks of 183 patients with SCC of the oral cavity were studied. HPV16 prevalence was detected by a polymerase chain reaction and expression of p16INK4a was analyzed by immunohistochemistry. This was correlated with clinical outcomes.

RESULTS

The prevalence of HPV 16 was 6.6% and all were carcinoma tongue. All HPV-positive patients showed intense expression of p16INK4a. The five-year overall survival (OS) and disease-free survival (DFS) for HPV positive patients were higher compared to HPV negative patients (100% versus 74.5% and 100% versus 70.8% respectively). The five-year OS and DFS for patients with p16INK4a intense expression were also higher compared to p16INK4a weak expression (91.2% versus 57.4% and 82% versus 22.5% respectively). Five-year OS and DFS of patients with HPV16 positivity and p16INK4a intense expression were significantly higher than patients with HPV negative and p16INK4a weak expression (100% versus 54.7% and 100% versus 22.5% respectively).

CONCLUSION

The frequency of HPV16 positivity in oral cancer was low in this study with a site predilection to the oral tongue. p16INK4a expression did not correlate with HPV status. A better treatment outcome was observed in HPV-positive cancers. We also observed better treatment outcomes in patients with p16INK4A overexpression irrespective of HPV status.

Differences between Squamous Cell Carcinomas of the Base of the Tongue and the Tonsils in Prevalence of HPV16 Infection, Its Type, and Clinical Features

Regarding attempts to find de-escalation methods of treatment for patients with HPV16-positive squamous cell carcinoma of the oropharynx (OPSCC), there is an urgent need to identify new prognostic factors which allow physicians to differentiate the prognosis of these patients. The aim of the study is to compare the incidence of transcriptionally active HPV16 infection and its type as well as other epidemiological, clinical, and histopathological features between SCC of the base of the tongue (BOTSCC) and tonsils (TSSCC). The analysis was performed in a group of 63 patients with OPSCC, for which, in our earlier studies, we assessed transcriptionally active HPV16 infection and its type (viral load and viral genome status). Transcriptionally active HPV16 infection was significantly more common in TSSCC (96.3%) than in BOTSCC (3.7%). Patients with TSSCC had significantly higher disease-free survival rates (84.1%) than those with BTSCC (47.4%); the same was true in the subgroup with HPV16 positivity. The obtained results are an important indication for further research on the development of new prognostic and/or predictive factors for patients with HPV16-positive squamous cell carcinomas of the oropharynx.

Positive Linear Relationship between Nucleophosmin Protein Expression and the Viral Load in HPV-Associated Oropharyngeal Squamous Cell Carcinoma: A Possible Tool for Stratification of Patients

Most oropharyngeal squamous cell carcinomas (OPSCCs) are human papillomavirus (HPV)-associated, high-risk (HR) cancers that show a better response to chemoradiotherapy and are associated with improved survival. Nucleophosmin (NPM, also called NPM1/B23) is a nucleolar phosphoprotein that plays different roles within the cell, such as ribosomal synthesis, cell cycle regulation, DNA damage repair and centrosome duplication. NPM is also known as an activator of inflammatory pathways. An increase in NPM expression has been observed in vitro in E6/E7 overexpressing cells and is involved in HPV assembly. In this retrospective study, we investigated the relationship between the immunohistochemical (IHC) expression of NPM and HR-HPV viral load, assayed by RNAScope in situ hybridization (ISH), in ten patients with histologically confirmed p16-positive OPSCC. Our findings show that there is a positive correlation between NPM expression and HR-HPV mRNA (Rs = 0.70, p = 0.03), and a linear regression (r² = 0.55; p = 0.01). These data support the hypothesis that NPM IHC, together with HPV RNAScope, could be used as a predictor of transcriptionally active HPV presence and tumor progression, which is useful for therapy decisions. This study includes a small cohort of patients and, cannot report conclusive findings. Further studies with large series of patients are needed to support our hypothesis.

A Case of HPV-Associated Oropharyngeal Squamous Cell Carcinoma with Block-Like, Partial Loss of p16 Expression

BACKGROUND

Oropharyngeal squamous cell carcinoma is frequently associated with high-risk HPV infection, which confers a good prognosis. Immunohistochemistry for p16 is used as a surrogate for HPV status, but discrepant results are occasionally seen. Here, we report a case with a unique pattern of partial loss of p16.

METHODS

A 63 year old male presented with a base of tongue nonkeratinizing squamous cell carcinoma and a large metastatic neck mass. The primary lesion and multiple regions of the metastatic mass were assessed with p16 immunohistochemistry, RNA in situ hybridization for high-risk HPV, and HPV16 genome sequencing.

RESULTS

The primary lesion was p16 negative, and the metastatic neck mass had large, confluent regions that were either strongly p16 positive or entirely p16 negative. All of these regions were positive for high-risk HPV with identical HPV16 genomes.

CONCLUSION

This unusual case illustrates a potential diagnostic pitfall, and it raises important questions regarding molecular mechanisms and prognostic implications of p16 staining in oropharyngeal squamous cell carcinoma.

Prevalence of human papillomavirus in head and neck cancers at tertiary care centers in the United States over time

BACKGROUND

Human papillomavirus (HPV) is responsible for a growing proportion of oropharyngeal squamous cell carcinomas (OPSCCs) among men and White individuals. Whether similar trends apply to women, non‐Whites, and non‐oropharyngeal squamous cell carcinomas (non‐OPSCCs) is unknown.

METHODS

This is a cross‐sectional analysis combining 2 multi‐institutional case series of incident head and neck squamous cell carcinoma (HNSCC) cases. Incident HNSCCs from 1995 to 2012 were enrolled retrospectively using banked tumor samples and medical record abstraction. Incident HNSCCs from 2013 to 2019 were enrolled prospectively. The prevalence of tumor HPV biomarkers was tested over 3 time periods (1995‐2003, 2004‐2012, and 2013‐2019). Centralized testing was done for p16 immunohistochemistry (p16) and oncogenic HPV in situ hybridization (ISH).

RESULTS

A total of 1209 incident cases of HNSCC were included. Prevalence of p16‐ and ISH‐positive tumors increased significantly for oropharynx cancers over time. The majority were positive after 2013 for White patients (p16, 92%; P < .001; ISH 94%; P < .001), Black patients (p16, 72%; P = .021; ISH 67%; P = .011), and Hispanic patients (p16, 100%; P = .04; ISH 100%; P = .013). For women with OPSCC, the prevalence of p16‐ and ISH‐positive tumors increased significantly to 82% (P < .001) and 78% (P = .004), respectively. For non‐OPSCCs, there was increased p16 and ISH positivity overall with 24% p16 and 16% ISH positivity in the most recent time period (P < .001 for both).

CONCLUSIONS

The majority of OPSCCs in US tertiary care centers are now p16 and ISH positive for all sex and race groups. In some populations in the United States, 91% of OPSCCs are now caused by HPV. Few non‐OPSCCs are p16 and ISH positive.

This study evaluates the prevalence of p16 and in situ hybridization positivity in head and neck cancers over time. This study shows an increase in prevalence over time among women and non‐Whites, 2 groups that are understudied in the epidemiology of human papillomavirus.

Low frequency of HPV positivity in breast tumors among patients from south-central Poland

Background

Some studies suggest that Human Papilloma Virus (HPV) infection is important factor in carcinogenesis of breast tumors. This study’ objective was to analyze HPV prevalence in breast cancers of patients from south-central Poland.

Materials and methods

The study was performed based on archival paraffin embebbed and formalin fixed blocks in the group of 383 patients with breast cancer. HPV prevalence and its genotype were assessed, respectively by: nested PCR (with two groups of primers: PGMY09/PGMY11 and GP5+/GP6+), quantitative PCR (qPCR). Tumors were classified as HPV positive in case of at least one positive result in nested PCR and positive results in genotyping procedure. For all HPV positive tissues P16 immunostaining was applied in order to confirm active viral infection.

Results

In the group of 383 breast cancers, HPV positivity was found in 17 samples (4.4%) in nested PCR. All these samples were subjected to HPV genotyping. This analysis revealed presence of HPV type 16 into two tumors (0.5%). In these two cancers, P16 overexpression was reported.

Conclusion

In breast tumors of patients from south-central Poland in Poland, HPV positivity is demonstrated in very low percentage of cases.

Accuracy of liquid-based brush cytology and HPV detection for the diagnosis and management of patients with oropharyngeal and oral cancer

Objectives

This study aims to evaluate the usefulness of liquid-based brush cytology for malignancy diagnosis and HPV detection in patients with suspected oropharyngeal and oral carcinomas, as well as for the diagnosis of tumoral persistence after treatment.

Material and methods

Seventy-five patients with suspicion of squamous cell carcinoma of the oropharynx or oral cavity were included. Two different study groups were analyzed according to the date of the sample collection: (1) during the first endoscopy exploration and (2) in the first control endoscopy after treatment for squamous cell carcinoma. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for malignancy diagnosis as well as for HPV-DNA detection on brush cytologies were assessed.

Results

Before treatment, the brush cytology showed a sensitivity of 88%, specificity of 100%, and accuracy of 88%. After treatment, it showed a sensitivity of 71%, specificity of 77%, and accuracy of 75%. HPV-DNA detection in cytology samples showed a sensitivity of 85%, specificity of 100%, and accuracy of 91% before treatment and an accuracy of 100% after treatment.

Conclusions

Liquid-based brush cytology showed good accuracy for diagnosis of oropharyngeal and oral squamous cell carcinoma before treatment, but its value decreases after treatment. Nevertheless, it is useful for HPV-DNA detection, as well as to monitor the patients after treatment.

Clinical relevance

Brush cytology samples are reliable for the detection of HPV-DNA before and after treatment and may be a useful method to incorporate in the HPV testing guidelines.

Oropharyngeal Squamous Cell Carcinoma With Discordant p16 and HPV mRNA Results: Incidence and Characterization in a Large, Contemporary United States Cohort

Early studies estimate that 5% to 10% of oropharyngeal squamous cell carcinomas overexpress p16 but are unassociated with transcriptionally-active high-risk human papillomavirus (HPV). Patients with discordant HPV testing may experience clinical outcomes that differ from traditional expectations. To document the rate of p16 and HPV mRNA positivity, characterize patients with discordant testing, and identify features that may warrant selective use of HPV-specific testing after p16 IHC, a multi-institutional, retrospective review of oropharyngeal squamous cell carcinoma patients with p16 IHC and HPV mRNA testing by reverse transcriptase polymerase chain reaction was performed. Of the 467 patients, most had T1 or T2 tumors (71%), 82% were p16 positive, and 84% were HPV mRNA positive. Overall, most tumors were nonkeratinizing (378, 81%), which was strongly associated with p16 and HPV positivity (93% and 95%, respectively). Overall, 81% of patients were double positive, 14% double negative, and 4.9% discordant (3.4% p16 negative/HPV mRNA positive and 1.5% p16 positive/HPV mRNA negative). The survival rates of these discordant patient groups fell squarely between the 2 concordant groups, although in multivariate analysis for both disease-free survival and overall survival, discordant patients were not found to have statistically significantly different outcomes. Reclassifying patients by applying HPV mRNA testing when p16 results and morphology do not match, or when p16 results are equivocal, improved prognostication slightly over p16 or HPV mRNA testing alone. Patients with discordant testing demonstrate a borderline significant trend toward survival differences from those with concordant tests. When evaluated independently, patients who were p16 negative but HPV mRNA positive had a prognosis somewhat closer to double-positive patients, while those who were p16 positive, but HPV mRNA negative had a prognosis closer to that of double-negative patients. We suggest an algorithm whereby confirmatory HPV mRNA testing is performed in patients where p16 status is not consistent with tumor morphology. This captures a majority of discordant patients and improves, albeit modestly, the prognostication.

Lack of CD44 overexpression and application of concurrent chemoradiotherapy with cisplatin independently indicate excellent prognosis in patients with HPV-positive oropharyngeal cancer

BACKGROUND

HPV-16 positivity in patients with squamous cell carcinoma of oropharynx (OPSCC) is associated with better prognosis. However, in more than 40% of HPV infected patients progression of cancer disease is observed, which indicates the presence of cancer cells resistant to therapy. Some studies suggest that there may be a subpopulation of cancer stem cells (CSCs), which simultaneously exhibit unlimited ability to self-renew and differentiate towards neoplastic cells. The relation between HPV16 infection and biomarkers of CSCs is unclear.

OBJECTIVE

The aim of the study was to compare the expression of CD44, CD98, ALDH1/2 and P16 in oropharyngeal cancer patients with or without HPV16 infection, as well as to analyze the prognostic potential of selected CSCs biomarkers in these two subgroups.

METHODS

The study was performed in a group of 63 patients. HPV16 infection status was analyzed by quantitative polymerase chain reaction, while CD44, CD98, ALDH1/2 and P16 expression by immunohistochemistry. In survival analysis, two endpoints were applied: overall survival (OS) and disease-free survival (DFS).

RESULTS

Among 63 cancers, HPV16 infection was found in 25 tumors (39.7%), overexpression of CD44, CD98, ALDH1/2 and P16 in 43 (68.2%), 30 (47.6%), 33 (52.4%) and 27 (42.9%) cancers, respectively. In the HPV16-positive subgroup, DFS rate of 100% was observed in patients with tumors characterized by lack of CD44 overexpression and those treated with concurrent chemoradiotherapy with cisplatin (CisPt-CRT). In the HPV16-negative subgroup 100% of DFS was noticed for patients (n = 6) with P16 immunopositive tumors. In this subgroup none of the CSCs biomarkers evaluated in the study had any impact on OS or DFS. In patients with HPV16-positive oropharyngeal cancer, lack of CD44 overexpression and application of CisPt-CRT were found to be positive prognostic factors.

Different patterns of p16INK4a immunohistochemical expression and their biological implications in laryngeal squamous cell carcinoma

Introduction: p16^INK4a immunohistochemistry (IHC) is widely used to facilitate the diagnosis of human papillomavirus (HPV)-associated neoplasia, when ≥70% of cells show strong nuclear and cytoplasmic positivity. In this study, we aim to compare partial expression patterns that do not fulfill the above criteria and seek biological implications in laryngeal squamous cell carcinoma (LSCC). Materials and Methods: p16^INK4a IHC staining was conducted on representative sections of archived tissue from 88 LSCCs. Immunoreactivity was described based on four parameters: intracellular localization of immunostaining, intensity of immunostaining, distribution pattern and percentage of positive cells. Results: Six patterns of p16^INK4a immunoexpression were observed and defined as: strong diffuse (strong immunostaining, expression in cytoplasm and nucleus in >70% of tumor cells), weak diffuse (moderate or weak immunostaining, expression in cytoplasm in >70% of tumor cells), marginal (strong cytoplasmic immunostaining, limited to the periphery of tumor islets), strong scattered (strong immunostaining, expression in cytoplasm and nucleus in <50% of tumor cells), weak scattered (moderate or weak immunostaining, expression in cytoplasm in <50% of tumor cells), negative (no expression). The pN stage of the patients was associated with p16^INK4a immunoexpression patterns, the marginal pattern was only found in the pN0-Nx stages, while the weak diffuse pattern was more frequently observed in pN2-N3 stages. Conclusions: Partial immunostaining with architecturally distinct p16^INK4a immunoexpression patterns may prove significant in stratifying characteristic clinicopathological subgroups among LSCC. Our observations may support the hypothesis that p16^INK4a has different roles in different subcellular locations, with tumorigenic molecular pathways unrelated to HPV infection.

Co-expression of fibroblast growth factor receptor 3 with mutant p53, and its association with worse outcome in oropharyngeal squamous cell carcinoma

Fibroblast growth factor receptor 3 (FGFR3) is expressed in squamous cell carcinoma of the head and neck (SCCHN) including oropharyngeal squamous cell carcinoma (OPSCC) and is a potential therapeutic target. However, information on its correlation with other relevant cancer related proteins stratified by p16 status and its prognostic significance in OPSCC is limited. We examined FGFR3 expression and its correlation with clinical characteristics, p16 status, and mutant p53 (mp53) among 220 retrospectively collected OPSCC cases and 40 prospectively collected SCCHN cases, including a majority of OPSCC. Correlations of FGFR3 Weighted Index (WI) with p16 status and mp53 WI as well as its association with disease-free survival (DFS) and overall survival (OS) were evaluated. FGFR3 expression was detected in 61% and 70% of cases in cohorts 1 and 2, respectively. FGFR3 level was significantly higher in p16-negative tumors in both cohorts (p<0.001 and 0.006). FGFR3 expression was highly correlated with mp53 expression in both p16 + and p16- OPSCC (p<0.0001 and p = 0.0006, respectively). In cohort 1, univariate analysis showed that FGFR3 was associated with DFS but not OS. Kaplan-Meier analysis showed that higher FGFR3 and mp53 level correlated with worse DFS (p = 0.025) and OS (p = 0.009). As expected, p16 positive status was associated with improved OS and DFS (p<0.001 for both). Our results suggest that high FGFR3 expression is associated with p16 negative status and mp53 expression in OPSCC and correlates with a worse clinical outcome. The biological relationship between FGFR3 and mp53 in OPSCC deserves further investigation.

In situ hybridization for high risk HPV E6/E7 mRNA in oropharyngeal squamous cell carcinoma

OBJECTIVES

To report a single institution's experience using human papillomavirus (HPV) E6/E7 mRNA in-situ hybridization (mRNA ISH) for HPV detection in oropharyngeal squamous cell carcinoma (OPSCC). To review the literature on HPV detection methods.

STUDY DESIGN

Retrospective chart review, literature review.

SETTING

Tertiary care academic hospital.

SUBJECTS AND METHODS

We conducted a retrospective chart review of 122 OPSCC biopsy specimens. mRNA ISH was performed on formalin-fixed paraffin-embedded (FFPE) tissue with a pool of 18 high risk HPV probes using an automated stainer; p16 immunohistochemistry (IHC) was also performed. We conducted a literature review on HPV detection methods including p16 IHC, mRNA ISH, DNA ISH, and PCR.

RESULTS

In our cohort, mRNA ISH had a sensitivity and specificity of 100% and 100% with reference to p16 (100% concordance). 2-year OS was 87.5% vs. 94.5% for p16/HPV-negative vs. positive patients. 2-year DFS was 60.0% vs. 84.2%. On literature review, mRNA ISH demonstrated consistently high sensitivity and specificity ranging from 88-98% and 90-100% respectively. In comparison, the specificity of p16 was 85-95%.

CONCLUSIONS

Our report supports the use of mRNA ISH for HPV detection in OPSCC and validates its feasibility using automated tissue staining methods on FFPE tissue. Our findings and literature review support that mRNA ISH may have superior specificity and be easier to interpret than p16. Further study on the prognostic value and cost-effectiveness of mRNA ISH is warranted and may establish this HPV detection method as the "gold standard."

Quantitative assessment of p16 expression in FNA specimens from head and neck squamous cell carcinoma and correlation with HPV status

BACKGROUND

This study investigated p16 by immunohistochemistry (IHC) on cellblocks (CBs) and human papillomavirus (HPV) by polymerase chain reaction (PCR) in fine-needle aspiration (FNA) of head and neck squamous cell carcinoma (HNSCC).

METHODS

Receiver operating characteristic (ROC) curve analysis was used to assess test performance in CBs compared with p16 IHC in 42 surgical specimens from patients with HNSCC and in correlation with HPV by PCR in cytology specimens. The study assessed HPV by PCR in FNA specimens as a substitute for p16 IHC in surgical specimens.

RESULTS

Of 42 cases, 38 CBs showed malignant cells as cohesive clusters of viable cells with or without single tumor cells, whereas 4 specimens were composed exclusively of single tumor cells and degenerated cells. All p16-negative surgical specimens showed an absence of p16 staining in the corresponding CBs (n = 16). In the p16-positive surgical cases (n = 26), corresponding CBs with tumor clusters (n = 23) showed heterogeneous p16 expression ranging from 40% to 100%; however, scoring single cells was challenging and unreliable because of cellular degradation. ROC curve inspection showed the optimal threshold to be at least 40% p16 staining in tumor clusters with 100% sensitivity and specificity. In cases with inadequate CBs, HPV by PCR on needle rinse showed 88% sensitivity and 100% specificity for p16 expression in surgical specimens.

CONCLUSIONS

A cutoff of at least 40% p16 expression in tumor clusters may be appropriate for p16 positivity in cytology CB specimens. A positive HPV finding by PCR on needle rinse can be used as a substitute for p16 expression in surgical specimens.

Detection of human papillomavirus in oropharyngeal squamous cell carcinoma

Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) etiologically attributed to oncogenic human papillomavirus (HPV). Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise. Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity, specificity, and technical difficulty. This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC, including HPV DNA/RNA polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), p16 immunohistochemistry (IHC), and DNA/RNA in situ hybridization (ISH) assays. This summary may facilitate the selection of a suitable method for detecting HPV infection, and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality, incidence, and morbidity.

Correlation of p16 immunostaining in cell-blocks with corresponding tissue specimens for squamous cell carcinomas of the oropharynx

OBJECTIVE

The goal of this study was to evaluate the performance of p16 staining in cell-blocks vs tissue specimens as a surrogate marker for human papillomavirus (HPV) status in oropharyngeal squamous cell carcinomas.

METHODS

Head and neck squamous cell carcinoma cases presenting as a neck mass with a p16 result on cytology and corresponding tissue specimens (1 January 2014 to 30 June 1920) were included in the study. The following were assessed from cell-block material: number of tumour clusters, percentage of tumour cells with p16 staining, and presence of staining in clusters vs single cells. Results were compared to tissue p16 status. Results of any other ancillary HPV testing were also noted.

RESULTS

Forty-two head and neck squamous cell carcinoma neck metastases (35 oropharyngeal, five non-oropharyngeal, and 2 unknown primaries) were identified. The p16 staining pattern in cell-blocks was seen in single cells (27.6%), clusters (44.8%), or both (27.6%). The percentage of tumour cells staining for p16 in cell-blocks was much lower than in corresponding tissue specimens. There were four false negatives and one false positive (concurrent HPV DNA polymerase chain reaction testing was positive in cytology and surgical material).

CONCLUSIONS

Compared to tissue, the cut-off for p16 interpretation in cell-blocks is substantially lower and staining may be present in single cells or clusters. In 96.9% of cases, any p16 staining in cell-blocks correlated with positive p16 staining in surgical specimens. However, a negative or discrepant p16 result on cell-block should prompt confirmatory HPV studies, as false negative p16 staining in cell-blocks is high.

Validation of local p16 testing for determination of human papilloma virus status eligibility on a low risk oropharyngeal cancer trial - A Trans-Tasman Radiation Oncology Group study

OBJECTIVE

Accurate determination of human papilloma virus (HPV) status is critical when identifying patients with oropharyngeal squamous cell carcinoma (OPSCC) who may be candidates for de-escalation trials. In this study we investigated whether local p16 screening, by immunohistochemistry (IHC), has high positive predictive value (PPV) for HPV status in a good prognosis HPV positive OPSCC (HPVOPSCC) population treated on a clinical trial.

METHODS AND MATERIALS

Patients enrolled on the TROG 12.01 randomised trial for good prognosis HPVOPSCC were randomised based on local p16 IHC testing but subsequently had central p16 IHC and HPV RNA in situ hybridisation (HPV RNA ISH) testing. Correlations between the local and central p16 and central HPV RNA ISH were studied. The main outcome was the positive predictive value (PPV) of local pathology laboratory testing of p16.

RESULTS

176/182 patients had samples available for central testing. 172/176 were evaluable for central testing of p16, and all were confirmed to be p16 positive (172/172, 100%, 95% CI = [97.9%, 100%]). Similarly, 100% of those evaluable for HPV RNA ISH (155/155, 100%, 95% CI = [97.6%, 100%]) were confirmed HPV positive, indicating p16 overexpression driven by transcriptionally active HPV and a PPV of 100% for local p16 testing.

CONCLUSIONS

Our results validate the suitability of local pathology laboratory p16 testing alone, in populations with a high attributable fraction of OPSCC due to HPV, to screen and enrol low risk HPVOPSCC patients onto de-intensification trials. This obviates the need for upfront more complex and expensive HPV assays and/or central laboratory testing.

p16 Immunohistochemical Expression in Head and Neck Squamous Cell Carcinoma: Association With Prognostic Parameters

Background p16 is a tumor suppressor gene, over expression of which is considered as a surrogate marker of oncogenic human papillomavirus (HPV) infection. Moreover, p16 over expression correlates with good prognosis in head and neck squamous cell carcinoma (HNSCC). In the present study, we aimed to evaluate the frequency of p16 overexpression in HNSCC in our setup and its association with clinicopathologic parameters. Methods We performed p16 immunohistochemistry (IHC) on 144 cases of HNSCC. Association of p16 overexpression with various clinicopathologic parameters including T-stage, N-stage, grade, recurrence status, and risk factors was evaluated. Results p16 over expression was noted in 22.9% (33 cases), while 21.5% (31 cases) were focal positive and 55.6% (80 cases) were negative for p16 over expression. On the basis of percentage of expression; > 70% p16 expression was noted in 4.9% (7 cases), 9% (13 cases) showed 51% - 70% p16 expression, 9% (13 cases) revealed 11%-50% p16 expression, while 77.1% cases revealed no expression or < 10% p16 expression. Significant association of p16 expression was noted with nodal metastasis and extranodal spread while no significant association of p16 was noted with other prognostic parameters and risk factors. Conclusion Our data revealed that high expression (> 50%) of p16 is low in oropharyngeal squamous cell carcinoma in our setup. These finding suggest a low prevalence of HPV as a cause of HNSCC in our population. Moreover, p16 expression was found to be associated with some good prognostic parameters like lack of nodal metastasis, however, no significant association was noted with overall disease-free survival.

Epithelial-to-mesenchymal transition is a prognostic marker for patient outcome in advanced stage HNSCC patients treated with chemoradiotherapy

BACKGROUND

The prognosis of patients with HPV-negative advanced stage head and neck squamous cell carcinoma (HNSCC) remains poor. No prognostic markers other than TNM staging are routinely used in clinic. Epithelial-to-mesenchymal transition (EMT) has been shown to be a strong prognostic factor in other cancer types. The purpose of this study was to determine the role of EMT in HPV-negative HNSCC outcomes.

METHODS

Pretreatment tumor material from patients of two cohorts, totalling 174 cisplatin-based chemoradiotherapy treated HPV-negative HNSCC patients, was RNA-sequenced. Seven different EMT gene expression signatures were used for EMT status classification and generation of HNSCC-specific EMT models using Random Forest machine learning.

RESULTS

Mesenchymal classification by all EMT signatures consistently enriched for poor prognosis patients in both cohorts of 98 and 76 patients. Uni- and multivariate analyses show important HR of 1.6-5.8, thereby revealing EMT's role in HNSCC outcome. Discordant classification by these signatures prompted the generation of an HNSCC-specific EMT profile based on the concordantly classified samples in the first cohort (cross-validation AUC > 0.98). The independent validation cohort confirmed the association of mesenchymal classification by the HNSCC-EMT model with poor overall survival (HR = 3.39, p < 0.005) and progression free survival (HR = 3.01, p < 0.005) in multivariate analysis with TNM. Analysis of an additional HNSCC cohort from PET-positive patients with metastatic disease prior to treatment further supports this relationship and reveals a strong link of EMT to the propensity to metastasize.

CONCLUSIONS

EMT in HPV-negative HNSCC co-defines patient outcome after chemoradiotherapy. The generated HNSCC-EMT prediction models can function as strong prognostic biomarkers.

Childhood tonsillectomy alters the primary distribution of HPV-related oropharyngeal squamous cell carcinoma

OBJECTIVES

We investigated how tonsillectomy during childhood may influence the distribution of human papillomavirus (HPV) positive cancer of the tonsils in adult life using p16 as a surrogate marker for HPV infection.

STUDY DESIGN

Retrospective observational study.

METHODS

A total of 280 patients diagnosed with oropharyngeal squamous cell carcinoma (OPSCC) and known p16 status were eligible for this study. Each participant was called to obtain the childhood tonsillectomy history. Respondents were subgrouped by p16 status and the primary tumor location. Patient demographic and clinical information was analyzed for association with Fisher's exact and Wilcoxon rank sum tests. Location of tumor was modeled using univariate (UVA) and multivariate (MVA) logistic regression with associated odds ratios (OR) and 95% confidence intervals.

RESULTS

Of the 280 patients, 115 (41%) were respondents: 104 (90.4%) were p16 positive and 11 (9.6%) were p16 negative. For p16 positive patients, we observed a majority (93%) of intact tonsils in those with tonsil cancer, compared to 45% of intact tonsils in patients with p16 positive cancer elsewhere in the oropharynx (P < .001). MVA logistic regression showed that female gender (OR = 4.16, P = .0675), prior smoking history (OR = 2.6, P = .0367), and intact tonsils (OR = 15.2, P < .0001) were associated with tonsillar OPSCC.

CONCLUSION

We found that patients with p16 positive OPSCC at a non-tonsil site were much more likely to have had prior tonsillectomy vs those with p16 positive OPSCC arising within the tonsil. Nevertheless, we do not advocate tonsillectomies as a public health policy to reduce HPV-related OPSCC.

LEVEL OF EVIDENCE

6.

Biological Determinants of Chemo-Radiotherapy Response in HPV-Negative Head and Neck Cancer: A Multicentric External Validation

Purpose: Tumor markers that are related to hypoxia, proliferation, DNA damage repair and stem cell-ness, have a prognostic value in advanced stage HNSCC patients when assessed individually. Here we aimed to evaluate and validate this in a multifactorial context and assess interrelation and the combined role of these biological factors in determining chemo-radiotherapy response in HPV-negative advanced HNSCC. Methods: RNA sequencing data of pre-treatment biopsy material from 197 HPV-negative advanced stage HNSCC patients treated with definitive chemoradiotherapy was analyzed. Biological parameter scores were assigned to patient samples using previously generated and described gene expression signatures. Locoregional control rates were used to assess the role of these biological parameters in radiation response and compared to distant metastasis data. Biological factors were ranked according to their clinical impact using bootstrapping methods and multivariate Cox regression analyses that included clinical variables. Multivariate Cox regression analyses comprising all biological variables were used to define their relative role among all factors when combined. Results: Only few biomarker scores correlate with each other, underscoring their independence. The different biological factors do not correlate or cluster, except for the two stem cell markers CD44 and SLC3A2 (r = 0.4, p < 0.001) and acute hypoxia prediction scores which correlated with T-cell infiltration score, CD8⁺ T cell abundance and proliferation scores (r = 0.52, 0.56, and 0.6, respectively with p < 0.001). Locoregional control association analyses revealed that chronic (Hazard Ratio (HR) = 3.9) and acute hypoxia (HR = 1.9), followed by stem cell-ness (CD44/SLC3A2; HR = 2.2/2.3), were the strongest and most robust determinants of radiation response. Furthermore, multivariable analysis, considering other biological and clinical factors, reveal a significant role for EGFR expression (HR = 2.9, p < 0.05) and T-cell infiltration (CD8⁺T-cells: HR = 2.2, p < 0.05; CD8⁺T-cells/Treg: HR = 2.6, p < 0.01) signatures in locoregional control of chemoradiotherapy-treated HNSCC. Conclusion: Tumor acute and chronic hypoxia, stem cell-ness, and CD8⁺ T-cell parameters are relevant and largely independent biological factors that together contribute to locoregional control. The combined analyses illustrate the additive value of multifactorial analyses and support a role for EGFR expression analysis and immune cell markers in addition to previously validated biomarkers. This external validation underscores the relevance of biological factors in determining chemoradiotherapy outcome in HNSCC.

Human papilloma virus related squamous cell carcinomas of the head and neck: diagnosis, clinical implications and detection of HPV

High-risk human papillomavirus (HPV) positive squamous cell carcinoma (SCC) of the head and neck is reported most commonly in the oropharynx but can also uncommonly be found in other sites such as the anterior oral cavity and sinonasal tract. While HPV positive oropharyngeal squamous cell carcinoma (HPV-OPSCC) has been shown to have a more favourable prognosis than conventional smoking- and alcohol-related anterior oral cavity squamous cell carcinoma (OSCC), HPV positive SCC arising elsewhere in the head and neck region does not carry the same favourable prognosis. HPV-OPSCC often tends to present with large cystic metastases in the cervical lymph nodes, with a clinically and radiologically occult primary. Correct diagnosis of the initial biopsy/cytology specimen is critical for directing further investigations and management. In recognition of its distinct biological behaviour, the 8th edition of the American Joint Commission on Cancer (AJCC 8) has proposed a separate clinical and pathological staging system for HPV-OPSCC compared to that for a conventional primary OSCC or neck metastasis of similar size. The new AJCC staging does not apply to other HPV positive SCC of the head and neck. This review examines the current biology of HPV positive SCC, focusing on HPV-OPSCC. The value and pitfalls of current detection methods of HPV are discussed with an emphasis on the role of the pathologist in the diagnosis and management of HPV positive SCC of the head and neck.

Oropharyngeal Squamous Cell Carcinoma in 390 Patients: Analysis of Clinical and Histological Criteria Which Significantly Impact Outcome

This study evaluates the prognostic impact of several factors in oropharyngeal squamous cell carcinoma (OPSCC), controlling for human papillomavirus (HPV)-associated tumors and stage (American Joint Committee on Cancer 8th edition). All patients in Southern California Permanente Medical Group diagnosed with OPSCC between 2006 and 2012 tested for p16 immunohistochemistry were included. Review of all pathology materials was combined with central p16 testing. Multivariable analyses were performed. The cohort of 390 patients included 342 p16-positive and 48 p16-negative tumors. For all-comers, on univariate analysis, the following factors, when present, were associated with improved patient survival: p16-positive tumor (n = 324, p < 0.001); crypt versus surface tumor location (n = 312, p = 0.004); nonkeratinizing type (n = 309, p < 0.0001); nonkeratinizing with maturation type (n = 37, p < 0.0001); basaloid pattern (n = 284, p = 0.005); and a broad, pushing border of infiltration (n = 282, p = 0.004). Inferior survival outcomes were observed with: age ≥ 55 years (p < 0.0001); ≥ 10 pack-year smoking history (n = 183, p = 0.003); increasing tumor stage (p < 0.0001); overt radiographic extranodal extension (ORENE) (n = 58, p < 0.0001); low level IV/Vb lymph node involvement (n = 45, p = 0.0002); a jagged pattern of infiltration (n = 76, p = 0.0004); tumor ulceration (n = 76, p = 0.0004); absent lymphocytic infiltrate (p < 0.0001); and concurrent dysplasia (n = 125, p = 0.009). On multivariable analysis, accounting for patient age, smoking history ≥ 10 pack-years, and TNM stage, for patients with p16-positive disease, advanced TNM stage (p = 0.007), the presence of ORENE (p = 0.0002), and low-neck lymphadenopathy (p = 0.0001) were independent negative prognostic factors for disease free survival (DFS). Older age (p < 0.0001), smoking history ≥ 10 pack-years (p = 0.02), advanced TNM stage (p = 0.0002), ORENE (p = 0.004), and low-neck lymphadenopathy (p = 0.002) were independent negative prognostic factors for OS. Among patients with p16-positive OPSCC, older age, smoking history, advanced stage, ORENE, and low-neck lymphadenopathy were significant negative prognostic factors for DFS and/or OS. Further refinement of staging to incorporate additional lymph node findings may be warranted.

A proposal for classification of oropharyngeal squamous cell carcinoma: Morphology and status of HPV by immunohistochemistry and molecular biology

The current three-tier grading system (well, moderate and poorly differentiated) used to morphologically classify head and neck squamous cell carcinoma (HNSCC) is inadequate for categorisation of oropharyngeal squamous cell carcinoma (OPSCC) owing to the lack of prognostic value. The aim of this study was to assess the validity of a classification system for OPSCC based on morphology and human papilloma virus (HPV) infection status. Haematoxylin and eosin slides of 121 patients (100 M, 21 F, age range 40-89 years) with OPSCC were reviewed and categorised as histological types I, II and III. The presence of HPV was assessed by immunohistochemistry with p16 and RNAscope In situ hybridization (ISH). The follow-up period was 36 months. Ninety-six patients were p16+ and clinical stage I. Patient survival with types I, II and III was 93%, 50% and 96%, respectively. Twenty-five patients were p16-: 10 clinical stage I and 15 stage III. Amongst this group, no type I morphology was identified. At follow-up, 65% of type II and 75% of type III patients were alive. All p16+ cases were also positive for E6/E7 mRNA high-risk HPV by ISH, while 23 p16- cases were negative and two were positive. Cox regression identified three predictors of mortality: older age (HR = 1.14, 95% CI = 1.06-1.23, P = .001); female gender (HR = 0.22.95% CI 0.05-0.88, P = .033); and type II morphology (HR = 13.1, 95% CI = 1.09-157.0, P = .043). OPSCC morphological classification in three sub-types, along with HPV infection status, seems to reflect the outcome of patients with OPSCC.

The prevalence of HPV infection in rectal cancer - Report from South - Central Poland (Cracow region)

Some studies suggest that HPV infection may be important carcinogenic factor in development of some part of colorectal cancers. However, in the worldwide literature concerning this type of tumours, the great variability in HPV frequency is noticed. In Poland, the incidence of HPV infection in colorectal cancers was examined in five studies so far and their results are also conflicting. Therefore, the aim of the present study was to assess the HPV presence in the group of 120 patients with adenocarcinomas of rectum. HPV infection was assessed on the basis of DNA extracted from collected formalin fixed paraffin embedded tumour specimens. Viral presence was evaluated using two PCR based methods: nested PCR and quantitative PCR (qPCR) with primers specific for HPV16. All HPV positive samples were subjected to virus genotyping using AmoyDx^® Human papillomavirus (HPV) Genotyping Detection Kit and P16 immunostaining. Among 120 evaluated colorectal tumours, HPV DNA was detected in 2 cancers (1.67%) by nested PCR and in 2 (1.67%) tumours by qPCR, including 1 sample diagnosed as HPV positive on the basis of both PCR variants. Two HPV positive cancers had HPV16 infection and other one HPV18. All three tumours with positivity of HPV DNA were P16 negative. In south - central Poland, HPV infection in rectal cancers probably has not influence on rectal carcinogenesis.

HPV and Oropharyngeal Cancer in the Eighth Edition of the TNM Classification: Pitfalls in Practice

This review is a call for mindfulness and precision when applying TNM 8 in oropharyngeal cancers. Implications, intentions, and weaknesses of TNM 8 are addressed in light of our own investigations and the published literature. In TNM 8, the impact of p16^INK4A status on the staging of oropharyngeal SCC highlights i) that underlying evidence is scarce, ii) its stage grouping exclusively has prognostic intention, and iii) that a noncritical application of TNM 8 might negatively impact the patients' survival as the perception of TNM 8 as having therapeutic intention may lead to de-escalating treatment regimens in p16^INK4A-positive cases, specifically when grouped into stage I despite the presence of neck metastasis. If other parameters from HPV positivity that also have a negative impact on the patient's survival, such as smoking or the presence of comorbidity, are neglected in therapy planning, survival outcomes might even become worse. Future studies applying TNM 8 and further investigating the value of p16^INK4A as surrogate marker for active HPV infections will identify whether or not changes in TNM 8 should have therapeutic implications in HPV-associated, only p16^INK4A-positive cases or whether this impact additionally holds true for nontonsillar cancers.

Detection of High-Risk Human Papillomavirus in Oral Cavity Squamous Cell Carcinoma Using Multiple Analytes and Their Role in Patient Survival

PURPOSE

Accurate detection of human papillomavirus (HPV) in oral cavity squamous cell carcinoma (OSCC) is essential to understanding the role of HPV in disease prognosis and management of patients. We used different analytes and methods to understand the true prevalence of HPV in a cohort of patients with OSCC with different molecular backgrounds, and we correlated HPV data with patient survival.

METHODS

We integrated data from multiple analytes (HPV DNA, HPV RNA, and p16), assays (immunohistochemistry, polymerase chain reaction [PCR], quantitative PCR [qPCR], and digital PCR), and molecular changes (somatic mutations and DNA methylation) from 153 patients with OSCC to correlate p16 expression, HPV DNA, and HPV RNA with HPV incidence and patient survival.

RESULTS

High prevalence (33% to 58%) of HPV16/18 DNA did not correlate with the presence of transcriptionally active viral genomes (15%) in tumors. Eighteen percent of the tumors were p16 positive and only 6% were both HPV DNA and HPV RNA positive. Most tumors with relatively high copy number HPV DNA and/or HPV RNA, but not with HPV DNA alone (irrespective of copy number), were wild-type for TP53 and CASP8 genes. In our study, p16 protein, HPV DNA, and HPV RNA, either alone or in combination, did not correlate with patient survival. Nine HPV-associated genes stratified the virus-positive from the virus-negative tumor group with high confidence ( P < .008) when HPV DNA copy number and/or HPV RNA were considered to define HPV positivity, and not HPV DNA alone, irrespective of copy number ( P < .2).

CONCLUSION

In OSCC, the presence of both HPV RNA and p16 is rare. HPV DNA alone is not an accurate measure of HPV positivity and therefore may not be informative. HPV DNA, HPV RNA, and p16 do not correlate with patients' outcome.

A Comparison of E6H4 and G175-405 p16-specific Monoclonal Antibodies in Oropharyngeal Squamous Cell Carcinoma

The purpose of this investigation is to directly compare G175-405 and E6H4 p16-specific antibodies as immunomarkers of HPV-driven oropharyngeal carcinoma. The investigators designed a retrospective analysis using specimens from an archived tissue bank with known in situ hybridization and polymerase chain reaction status for HPV DNA. Fifty randomly selected oropharyngeal specimens were evaluated with both the G175-405 and E6H4 p16-specific monoclonal antibodies. Two pathologists, blinded to the HPV-specific testing status, evaluated p16 positivity for both antibody clones. Interrater agreement was determined using a Cohen κ coefficient. Sensitivity and specificity values were calculated using a standard 2×2 contingency table, then compared using McNemar test. Interrater agreement for interpretation of p16 expression was 92% (κ=0.84) for the G175-405 clone and 100% for the E6H4 clone (κ=1.0). The G175-405 stain had a sensitivity of 0.917 and specificity of 0.846. The E6H4 stain had a sensitivity of 1.000 and specificity of 0.769. Using McNemar test, there were no significant differences found for sensitivity (P=0.480) or specificity (P=0.480) values. The results of this study suggest that though both G175-405 and E6H4 antibody stains are statistically comparable immunomarkers for HPV-driven oropharyngeal carcinoma, the E6H4 clone offers improved interobserver reliability.

Radiographic nodal prognostic factors in stage I HPV-related oropharyngeal squamous cell carcinoma

BACKGROUND

The updated AJCC Cancer Staging Manual groups all p16-positive oropharyngeal squamous cell carcinoma (OPSCC) with unilateral nodal involvement within 6 cm into the new clinical N1 classification, consolidating a heterogeneous group of disease with varying radiographic findings.

METHODS

A central radiological review was conducted identifying 233 patients with stage I node-positive (cT1-2N1) disease who underwent definitive concurrent chemoradiation. Factors evaluated included lymph node size, low-neck lymphadenopathy, retropharyngeal lymphadenopathy, overt radiographic extracapsular extension, and matted lymphadenopathy.

RESULTS

On multivariate analysis adjusted for age, smoking history, and chemotherapy regimen, low-neck lymphadenopathy (hazard ratio (HR) = 6.55; P < .001) and retropharyngeal lymphadenopathy (HR = 3.36; P = .009) predicted for inferior progression-free survival (PFS). low-neck lymphadenopathy (HR = 6.38; P = .001) and retropharyngeal lymphadenopathy (HR = 3.32; P = .02) also predicted for inferior overall survival (OS). All other radiographic characteristics showed no prognostic impact for PFS or OS.

CONCLUSIONS

This analysis suggests that caution should be advised against de-intensification efforts among patients with stage I node-positive p16-positive OPSCC with low-neck lymphadenopathy or retropharyngeal lymphadenopathy.

A Retrospective 20-Year Analysis of Proliferative Verrucous Leukoplakia and Its Progression to Malignancy and Association with High-risk Human Papillomavirus

Proliferative verrucous leukoplakia (PVL) is defined as an aggressive, relentless and recalcitrant form of leukoplakia that has a high propensity for malignant transformation. The aim of this study was to evaluate the malignant potential of PVL and determine its possible association with high-risk human papillomavirus (HPV). Twenty cases with a clinical and biopsy proven diagnosis of PVL were collected from the University of Florida Oral Medicine clinic database. Immunohistochemistry was performed to evaluate the expression of p16INK4A and p53 genes in the PVL lesions. The lesions were also tested for high-risk HPV by DNA in-situ hybridization. The average age of the patients at the time of first biopsy was 62.7 years. Most patients had multiple sites of involvement, gingiva being the most common location. The lesions progressed to malignancy in approximately 50% of patients. The expression of p16INK4A gene was considered negative, with at least a 50-65% immunoreactivity observed in only three cases that progressed to malignancy. No expression of high-risk HPV was detected, whereas p53 staining was positive in less than 25% of the cells demonstrating gene expression. No definite association between PVL and high-risk HPV infection could be established. Due to the high transformation potential of PVL, early recognition with aggressive treatment, including multiple biopsies, and continued close clinical follow-up, remain the mainstay of favorable management of this condition.

Investigating Trk Protein Expression between Oropharyngeal and Non-oropharyngeal Squamous Cell Carcinoma: Clinical Implications and Possible Roles of Human Papillomavirus Infection

Purpose

The relationship between head and neck squamous cell carcinoma (HNSCC) and subtypes of tropomyosin-related kinase (Trk) has not been studied in-depth. In this study, we evaluated the expression patterns of TrkA, TrkB, and panTrk and their clinicopathological significance as well as association with p16 expression and human papilloma virus (HPV) status.

Materials and Methods

Total of 396 radically resected oropharyngeal (n=121) and non-oropharyngeal (n=275) HNSCCs were included. Immunohistochemistry for TrkA, TrkB, and panTrk was performed. In addition, p16 immunohistochemistry was performed to assess the HPV status. Using HPV-negative HNSCC cell lines, FaDu and CAL27, HPV type 16 E6/E7 gene was transfected, and then changes of TrkA and TrkB expression were analyzed.

Results

In the clinical samples of HNSCC, high expression of TrkA and panTrk were more associated with oropharyngeal and p16 positive squamous cell carcinoma (SCC). In patients with completely resected (R0-resected) oropharyngeal SCC, high TrkA expression was related to superior overall survival and recurrence-free survival (RFS). In patients with R0-resected oral cavity SCC, high panTrk was related to poor RFS. In HPV type E6/E7 gene-transfected FaDu and CAL27 cell lines, increase of TrkA expression was observed.

Conclusion

It seems that expression pattern of panTrk and TrkA differed according to anatomical sites of HNSCC and was closely related to p16 expression and patient prognosis. Trk expression should be considered in the context of anatomical site, p16 expression or HPV status and Trk subtypes.

Biomarker P16 predicts progression risk of anal low-grade squamous intraepithelial lesions

OBJECTIVES

The aim of this study was to determine whether biomarker P16 predicts progression risk for anal low-grade squamous intraepithelial lesions (LSILs).

DESIGN

A retrospective study.

METHODS

One hundred and nine HIV-infected and 18 HIV-uninfected patients with biopsy-proven anal LSIL at initial screening underwent surveillance high-resolution anoscopy and biopsy within 2 years of diagnosis. P16 immunohistochemistry was performed on index lesions and evaluated using a semi-quantitative scoring system. The association of predictors and lesional outcomes (progression, persistence or regression) was analysed using ordinal logistic regression models. A subset of p16-positive LSILs was tested for high-risk human papillomavirus (HR-HPV) DNA using real-time PCR.

RESULTS

Upon follow-up, 46 (36%) LSILs progressed to high-grade squamous intraepithelial lesion (HSIL), 50 (40%) persisted as LSIL and 31 (24%) regressed to benign mucosa (median 16 months, range 5-24 months). Age, sex, race, history of condylomata, CD4 T-cell count and HIV plasma viral load were similar regardless of clinical outcome. P16 immunoreactivity of index lesion was classified as block-positive (n = 36), focal-positive (n = 49) or negative (n = 42). Sixty-four percent of block-positive lesions progressed, as opposed to 35% of focal-positive and 14% of negative lesions (P < 0.001). HR-HPV DNA was detected in 90% of p16 block-positive lesions vs. 55% of focal-positive lesions. In unadjusted analyses, positive p16, HIV and former smoker status were significantly associated with lesional persistence and progression. P16 remained the only significant predictor in an adjusted model.

CONCLUSION

Biomarker p16 is the strongest predictor for anal LSIL-to-HSIL progression, outperforming other risk factors. To enhance the overall effectiveness of surveillance, we propose using p16 immunohistochemistry to help stratify patients at high vs. low risk of progression.

Examining the contribution of smoking and HPV towards the etiology of oral cavity squamous cell carcinoma using high-throughput sequencing: A prospective observational study

Oral cavity Squamous Cell Carcinoma (OCSCC) is a common form of head and neck cancer throughout the developed and developing world. However, the etiology of OCSCC is still unclear.

Here, we explored the extent to which tobacco use, Human Papillomavirus (HPV) infection and genetic and transcriptomic changes contributed to the oncogenesis of OCSCC. In a prospective observational study, we analysed fresh tissue biopsies from 45 OCSCC collected from 51 subjects presenting with OCSCC to the Brisbane Head and Neck Clinics between 2013 and 2015. Exploration of the genetic and transcriptomic landscape of the biopsies were performed using RNA sequencing (RNA-seq) and whole exome sequencing. HPV associated tumours were determined using p16 staining of histological sections and RNA sequencing. Patient demographics including tumor location within the oral cavity, and history of tobacco and alcohol use were correlated with genomic and transcriptomics analyses. About 4.5% of OCSCC were HPV associated. The most frequent mutations in the OCSCC samples were in the TP53 and CDKN2A genes, but no association of specific mutations with HPV or tobacco use was observed. Using weighted gene co-expression network analysis to explore the RNA-seq data, tumors from participants with a history of tobacco use showed a significant trend towards increased mammalian target of Rapamycin (mTOR) signaling and decreased mitochondrial respiration. In conclusion, HPV was shown to be an uncommon association with OCSCC and changes in TP53 transcriptional regulation, mTOR signaling and mitochondrial function were associated with a history of tobacco use. Larger data sets will be required to enable detection of differences which may help with development of personalized therapeutics in the future.

Comparison of high-dose Cisplatin-based chemoradiotherapy and Cetuximab-based bioradiotherapy for p16-positive oropharyngeal squamous cell carcinoma in the context of revised HPV-based staging

AIM

To perform a comparison of Cisplatin vs. Cetuximab in p16-positive oropharyngeal squamous cell carcinoma (OPSCC) in the context of the revised HPV-based staging.

BACKGROUND

Previous reports comparing these agents in head and neck cancer have included heterogenous disease and p16-status.

MATERIALS AND METHODS

A retrospective review was conducted from 2006 to 2016 of patients with p16-positive OPSCC who underwent definitive radiotherapy concurrent with either triweekly Cisplatin (n = 251) or Cetuximab (n = 40). AJCC 8th Edition staging was adapted.

RESULTS

Median follow-up for surviving patients was 40 months. On multivariate analysis for all-comers, comparing Cisplatin and Cetuximab, 3-year locoregional recurrence (LRR): 6% vs. 16% (p = 0.07), 3-year distant metastasis (DM): 8% vs. 21% (p = 0.04), 3-year overall recurrence rate (ORR): 11% vs. 29% (p = 0.01), and 3-year cause-specific survival (CSS): 94% vs. 79% (p = 0.06), respectively. On stage-based subgroup analysis, for stage I-II disease, 3-year LRR: 5% vs. 10% (p = 0.51), 3-year DM: 7% vs. 16% (p = 0.32), 3-year ORR: 10% vs. 23% (p = 0.15), and 3-year CSS: 95% vs. 82% (p = 0.38). For stage III disease, 3-year LRR: 10% vs. 40% (p = 0.07), 3-year DM: 9% vs. 43% (p = 0.07), 3-year ORR: 15% vs. 55% (p = 0.04), and 3-year CSS: 94% vs. 57% (p = 0.048).

CONCLUSIONS

When given concurrently with radiotherapy, Cetuximab and triweekly Cisplatin demonstrated comparable efficacy for AJCC 8th Edition stage I-II p16-positive OPSCC. However, Cetuximab appeared to be associated with higher rates of treatment failure and cancer-related deaths in stage III disease. Upon availability of the RTOG 1016 trial results, analysis based on the revised HPV-based staging should be performed to confirm these findings.

Human Papillomavirus Testing in Head and Neck Carcinomas: Guideline From the College of American Pathologists

Context Human papillomavirus (HPV) is a major cause of oropharyngeal squamous cell carcinomas, and HPV (and/or surrogate marker p16) status has emerged as a prognostic marker that significantly impacts clinical management. There is no current consensus on when to test oropharyngeal squamous cell carcinomas for HPV/p16 or on which tests to choose. Objective To develop evidence-based recommendations for the testing, application, interpretation, and reporting of HPV and surrogate marker tests in head and neck carcinomas. Design The College of American Pathologists convened a panel of experts in head and neck and molecular pathology, as well as surgical, medical, and radiation oncology, to develop recommendations. A systematic review of the literature was conducted to address 6 key questions. Final recommendations were derived from strength of evidence, open comment period feedback, and expert panel consensus. Results The major recommendations include (1) testing newly diagnosed oropharyngeal squamous cell carcinoma patients for high-risk HPV, either from the primary tumor or from cervical nodal metastases, using p16 immunohistochemistry with a 70% nuclear and cytoplasmic staining cutoff, and (2) not routinely testing nonsquamous oropharyngeal carcinomas or nonoropharyngeal carcinomas for HPV. Pathologists are to report tumors as HPV positive or p16 positive. Guidelines are provided for testing cytologic samples and handling of locoregional and distant recurrence specimens. Conclusions Based on the systematic review and on expert panel consensus, high-risk HPV testing is recommended for all new oropharyngeal squamous cell carcinoma patients, but not routinely recommended for other head and neck carcinomas.

CDKN2A Copy Number Loss Is an Independent Prognostic Factor in HPV-Negative Head and Neck Squamous Cell Carcinoma

Background

HPV infection is associated with high p16 expression and good prognosis in head and neck squamous cell carcinomas (HNSCCs). Analysis of CDKN2A, the gene encoding p16, may further elucidate the association between p16 expression and prognosis. We sought to determine whether CDKN2A copy number loss was associated with poor survival in HPV-negative HNSCCs.

Methods

The Cancer Genome Atlas HNSCC clinical and genomic data were obtained and integrated. Patients <80 years old with a primary tumor in the oral cavity, oropharynx, hypopharynx, or larynx were included. Stratifying by copy number loss status, CDKN2A mRNA and p16 protein expression levels were examined and overall survival (OS) and disease-free survival (DFS) were evaluated.

Results

401 patients with HPV-negative HNSCC were identified. 146 patients demonstrated CDKN2A copy number loss. The CDKN2A copy number loss group expressed significantly lower levels of CDKN2A mRNA and p16 protein than did the non-copy number loss group. Median OS for patients with and without CDKN2A copy number loss was 16.5 and 46.6 months, respectively (p = 0.007). Median DFS for both groups was 11.6 and 19.2 months, respectively (p = 0.03). In both univariate and multivariable analyses, stage IV designation, receipt of chemotherapy and CDKN2A copy number loss were predictive of OS.

Conclusion

CDKN2A copy number loss predicted poor survival independently of other patient and treatment factors and may be a clinically useful prognostic factor.

Evaluation of Diagnostic Utility of a High-Risk Human Papillomavirus PCR Test on Formalin-Fixed, Paraffin-Embedded Head and Neck Tumor Tissues

The increasing prevalence of high-risk human papillomavirus (HR-HPV)-associated head and neck squamous cell carcinoma (HNSCC) has prompted strong clinical demands for detecting HR-HPV directly in the tumor. Although p16 immunohistochemistry (IHC) has been the standard testing method, it has limitations including false positivity, lack of sensitivity in low tumor cell samples such as fine-needle aspirate (FNA), and its subjectivity. We developed a modified method based on a commercial automated HR-HPV PCR assay and evaluated the performance characteristics and the diagnostic utility of this assay for direct HR-HPV detection in the HNSCC samples. HNSCC formalin-fixed, paraffin-embedded blocks were retrieved from archives including 44 excisions, 63 biopsies, and 16 FNAs. Tissue slices were trimmed from the blocks, deparaffinized, lysed, and loaded on the commercial automated platform for HR-HPV PCR. All specimens had a concurrent p16 IHC performed. The PCR assay showed high concordance with the p16 IHC (96%; 99/103) and excellent positive agreement (91.5%) and negative agreement (100%). In addition, the PCR assay provided more conclusive results in samples with equivocal p16 IHC results. The modified commercial automated HR-HPV PCR test is a labor-efficient, quick, reliable, sensitive, and specific method for detecting HR-HPV in formalin-fixed, paraffin-embedded samples. This assay also showed excellent diagnostic utility in samples with equivocal p16 IHC results, including FNA cell blocks.

Correlation between HPV status at T and N sites of oropharyngeal squamous cell carcinomas

OBJECTIVES

Human papilloma virus (HPV) is known to be associated with oropharyngeal squamous cell carcinomas (OPSCC) and may potentially play a vital role in tumor metastasis. The purpose of this study was to correlate HPV status of cervical lymph node metastases with their respective primary OPSCC tumor.

METHODS

Formalin-fixed, paraffin-embedded (FFPE) tissue samples obtained from 34 patients with cervical lymph node metastases were analyzed with HPV 16 DNA polymerase chain reaction (PCR), p16 immunohistochemistry and HPV typing. The results were correlated with the HPV status and type found in the primary tumors of OPSCC.

RESULTS

Comparing HPV DNA status with p16 we found that 21 primary tumors and lymph node metastases were HPV positive (61.8%) and seven primary tumors and lymph node metastases were HPV negative (20.6%). Six patient samples differed when correlating the primary tumor and lymph node metastasis (17.6%).

CONCLUSIONS

In this study, HPV status in OPSCCs and their cervical lymph node metastases correlated in the vast majority of cases. However, HPV detection methods may have certain limitations resulting in varying degree of non-correlation. This should be taken into account when stratifying treatment in regard to HPV status.

The prevalence of human papillomavirus in oropharyngeal cancer in a New Zealand population

BACKGROUND

The incidence of oropharyngeal cancer (OPC) in New Zealand (NZ) has more than doubled over the last 14 years with 126 cases in 2010. Overseas studies have shown that human papillomavirus (HPV) plays a significant role in the development of these cancers. However, the role of HPV in OPC and the burden on the NZ health system is unclear.

AIM

The aim of the study was to determine the prevalence and the genotypes of HPV associated with OPC in New Zealand.

METHODS

In this study, 621 OPC were identified from cancer registry data from 1996-98, 2003-05, and 2010-12. Biopsies of 267 cases were then retrieved from laboratories throughout New Zealand. p16 immunohistochemistry and a human beta globin PCR were performed on all specimens. HPV genotyping was performed on all beta globin positive specimens using real-time PCR with melt analysis.

RESULTS

Using a p16/PCR algorithm, 77.9% (95% CI: 71.1-83.5%) of cases were attributable to HPV. Of these, 98.5% were HPV 16 positive. There was also one case each of HPV 33 and 35. The percentage of HPV positive cases increased from 61.9% (95% CI: 40.9%- 79.2%) in 1996-98 to 87.5% (95% CI: 79.8%- 92.5%) in 2010-12. Results from the multivariable model, adjusted for sex and ethnicity found statistically significant associations between HPV positivity and timeframe (OR: 5.65, 95% CI: 2.60-12.30, 2010-12 vs 1996-98), and between HPV positivity and patient age (OR: 0.55, 95% CI: 0.33-0.99, ≥61 years vs ≤60 years).

CONCLUSIONS

This data is consistent with data from other developed countries showing an increase in cases of HPV positive OPC in New Zealand, and the majority of cases being attributable to HPV 16. These results support the recent inclusion of males into the nationally funded immunization schedule for Gardasil® 9.

Differences in the prognosis of HPV16-positive patients with squamous cell carcinoma of head and neck according to viral load and expression of P16

Purpose

To evaluate the impact of HPV16 load (VL—the number of virus genome copies per cell) and P16 expression on prognosis of patients with squamous cell carcinomas (SCCs) of head and neck (HN).

Materials and methods

HPV16 presence was assessed in the group of 109 patients with HNSCCs by quantitative polymerase chain reaction (qPCR). VL (assessed by qPCR) and P16 expression (evaluated by immunohistochemistry) were analysed only in the subgroup of HPV16-positive tumours. These features were correlated with 5-year overall survival (OS) and disease-free survival (DFS).

Results

HPV16 infection was found in 36 tumours (33.0%). Virus-positive patients had better OS and DFS than those without infection (P = 0.041 and 0.005). Among HPV16-positive HNSCCs, 18 (50.0%) had higher VL (median value > 6764.3 copies/cell) and 25 (73.5%) P16 over expression. The significant differences in OS and DFS (P = 0.008 and 0.004) were noticed according to VL, wherein 100% DFS was found for patients with higher VL. According to P16 expression, significant difference was found only for OS (P = 0.020). In multivariate analysis, VL (P = 0.045; HR = 2.795; CI 0.121–1.060) and the level of smoking (P = 0.023, HR = 2.253; CI 1.124–4.514) were independent factors affecting DFS of HPV16-positive patients.

Conclusion

On the basis of viral load, it is possible to differentiate prognosis of patients with HPV16-positive HNSCCs. In this subgroup, viral load has stronger prognostic potential than P16 expression.

p16 immunohistochemistry in oropharyngeal squamous cell carcinoma: a comparison of antibody clones using patient outcomes and high-risk human papillomavirus RNA status

High-risk human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas have a more favorable prognosis than HPV-negative ones. p16 immunohistochemistry has been recommended as a prognostic test in clinical practice. Several p16 antibodies are available, and their performance has not been directly compared. We evaluated three commercially available p16 antibody clones (E6H4, JC8 and G175-405) utilizing 199 cases of oropharyngeal squamous cell carcinoma from a tissue microarray, read by three pathologists with three different cutoffs for positivity: any staining, >50% and >75%. Positive predictive values for high-risk HPV status by RNA in situ hybridization for the E6H4, JC8 and G175-405 clones were 98%, 100% and 99% at the 75% cutoff, but negative predictive values were much more variable at 86%, 69% and 56%, respectively. These improved using the 50% cutoff, becoming similar for all three antibodies. Intensity varied substantially, with 85% of E6H4, 72% of JC8 and 67% of G175-405 showing strong (3+) intensity. With Kaplan-Meier survival plots at the 75% cutoff, the E6H4 clone showed the largest differential in disease specific and overall survival between p16-positive and -negative results. Decreasing the cutoff to 50% increased correlation with HPV in situ hybridization and improved the survival differential for the JC8 and G175-405 clones without worsening of performance for the E6H4 clone. Interobserver agreement was also assessed by kappa scores and was highest for the E6H4 clone. Overall, these study results show modest but important performance differences between the three different p16 antibody clones, suggesting that the E6H4 clone performs best because of strongest staining intensity, greatest differential in outcomes between positive and negative results, lowest interobserver variability, and lowest background, nonspecific staining. The results also suggest that a 75% cutoff is very functional but that, in this patient population with high HPV incidence, 50% and any staining cutoffs may be more effective, particularly for the non-E6H4 clones.

Immunohistochemistry Analysis of CD44, EGFR, and p16 in Oral Cavity and Oropharyngeal Squamous Cell Carcinoma

Objectives We analyze the relationship between CD44, epidermal growth factor receptor (EGFR), and p16 expression in oral cavity and oropharyngeal cancers in a diverse population. We also describe whether particular patterns of staining are associated with progression-free survival and overall survival. Study Design Prospective study, single-blind to pathologist and laboratory technologist. Setting Hospital based. Subjects and Methods Immunohistochemistry, comprising gross staining and cellular expression, was performed and interpreted in a blinded fashion on 24 lip/oral cavity and 40 oropharyngeal cancer specimens collected between 2007 and 2012 from participants of a larger study. Information on overall survival and progression-free survival was obtained from medical records. Results Nineteen cases were clinically p16 positive, 16 of which were oropharyngeal. Oral cavity lesions were more likely to exhibit strong CD44 membrane staining ( P = .0002). Strong CD44 membrane and strong EGFR membrane and/or cytoplasmic staining were more common in p16-negative cancers ( P = .006). Peripheral/mixed gross p16 staining pattern was associated with worse survival than the universal staining on univariate and multivariate analyses ( P = .006, P = .030). This held true when combining gross and cellular localization for p16. For CD44, universal gross staining demonstrated poorer overall survival compared with the peripheral/mixed group ( P = .039). CD44 peripheral/mixed group alone and when combined with universal p16 demonstrated the best survival on multivariate analysis ( P = .010). Conclusion In a diverse population, systematic analysis applying p16, CD44, and EGFR gross staining and cellular localization on immunohistochemistry demonstrates distinct patterns that may have prognostic potential exceeding current methods. Larger studies are warranted to investigate these findings further.