Human Papillomavirus Testing in Head and Neck Squamous Cell Carcinoma: Best Practice for Diagnosis

Human papilloma virus detection in oropharyngeal carcinomas with in situ hybridisation using hand crafted morphological features and deep central attention residual networks

Human Papilloma Virus (HPV) is a major risk factor for the development of oropharyngeal cancer. Automatic detection of HPV in digitized pathology tissues using in situ hybridisation (ISH) is a difficult task due to the variability and complexity of staining patterns as well as the presence of imaging and staining artefacts. This paper proposes an intelligent image analysis framework to determine HPV status in digitized samples of oropharyngeal cancer tissue micro-arrays (TMA). The proposed pipeline mixes handcrafted feature extraction with a deep learning for epithelial region segmentation as a preliminary step. We apply a deep central attention learning technique to segment epithelial regions and within those assess the presence of regions representing ISH products. We then extract relevant morphological measurements from those regions which are then input into a supervised learning model for the identification of HPV status. The performance of the proposed method has been evaluated on 2009 TMA images of oropharyngeal carcinoma tissues captured with a ×20 objective. The experimental results show that our technique provides around 91% classification accuracy in detecting HPV status when compared with the histopatholgist gold standard. We also tested the performance of end-to-end deep learning classification methods to assess HPV status by learning directly from the original ISH processed images, rather than from the handcrafted features extracted from the segmented images. We examined the performance of sequential convolutional neural networks (CNN) architectures including three popular image recognition networks (VGG-16, ResNet and Inception V3) in their pre-trained and trained from scratch versions, however their highest classification accuracy was inferior (78%) to the hybrid pipeline presented here.

The role of tumour morphology in assigning HPV status in oropharyngeal squamous cell carcinoma

OBJECTIVES

There is no consensus on the optimal approach to human papilloma virus (HPV) testing in oropharyngeal squamous cell carcinoma (OPSCC). Our objective was to classify OPSCC as HPV positive or negative based on (1) morphology alone, (2) p16 status alone, (3) combined morphology and p16 status with additional HPV testing in discordant cases in keeping with 2012 College of American Pathologists (CAP) guidelines (combined approach), and to evaluate and compare survival outcomes.

MATERIALS AND METHODS

Retrospective review of 168 patients, 146 with OPSCC and 22 with cervical SCC of unknown primary site (SCCUP). Morphology was classified as keratinizing or non-keratinizing, p16 immunohistochemistry (IHC) performed and additional HPV DNA PCR testing undertaken in cases in which morphology and p16 status were discordant. Survival statistics were evaluated and compared for the 3 different approaches to classification.

RESULTS

On univariate analysis all 3 classification methods significantly predicted for overall survival (OS). Both p16 status and the combined approach also predicted for disease specific survival (DSS), whereas morphology fell just outside significance (p = 0.06). On multivariate analysis only the combined approach retained significance for both OS and DSS, whilst morphology was also significant for DSS.

CONCLUSIONS

Our findings confirm that tumour morphology significantly predicts for survival in OPSCC. However, we found combined tumour morphology and p16 IHC, with additional testing for discordant cases to be superior to either morphology or p16 IHC alone. Further study is required to establish the optimal testing method for HPV in OPSCC particularly in low prevalence populations.

Discrimination of HPV status using CT texture analysis: tumour heterogeneity in oropharyngeal squamous cell carcinomas

PURPOSE

To evaluate the diagnostic performance of texture analysis for discriminating human papillomavirus (HPV) status in patients with oropharyngeal squamous cell carcinoma (OPSCC) in the primary tumours and metastatic lymph nodes.

METHODS

Ninety-five patients with primary tumour and 91 with metastatic lymph nodes with confirmed HPV status, who underwent pretreatment contrast-enhanced CT (CECT), were included as the discovery population. CT texture analysis was performed using commercially available software. Differences between HPV-positive and HPV-negative groups were analysed using the χ² test (or Mann-Whitney U test) and independent t test (or Fisher's exact test). ROC curve analysis was performed to discriminate HPV status according to heterogeneity parameters. Diagnostic accuracy was evaluated in the separate validation population (n = 36) from an outside hospital.

RESULTS

HPV positivity was 52.6% for primary tumours and 56.0% for metastatic lymph nodes. The entropy and standard deviation (SD) values in the HPV-positive group were significantly lower. Entropy using the medium filter was the best discriminator between HPV-positive and HPV-negative primary OPSCCs (AUC, 0.85) and SD without the filter for metastatic lymph nodes (AUC, 0.82). Diagnostic accuracy of entropy for the primary tumour was 80.0% in the discovery group and 75.0% in the validation group. In cases of metastatic lymph node, the accuracy of SD was 79.1% and 78.8%, respectively.

CONCLUSION

Significant differences were found in heterogeneity parameters from texture analysis of pretreatment CECT, according to HPV status. Texture analysis could be used as an adjunctive tool for diagnosis of HPV status in clinical practice.

Expression of p-16, Ki-67 and p-53 markers in dysplastic and malignant lesions of the oral cavity and oropharynx

Background:

Understanding the markers for predicting degree of dysplasia and progression to malignancy can help early identification and prompt treatment of patients with oral cancers. In this study, we aim to identify and characterize different tumor suppressor genes such as p-53 and p-16 and proliferation marker Ki-67 in defining stages of dysplasia of oral mucosa and grading of tumor.

Settings and Design:

Oral biopsy tissues (for neoplastic lesions) received for histopathological evaluation were included in the study. The sections were processed for H&E staining, and 112 cases were chosen for immunohistochemical study. The data were analyzed by Chi-square and z-tests using software SPSS.

Results:

We found significant correlation between degree of dysplasia and p-16 immunoexpression with 16.7% of cases showing positivity in oral intraepithelial neoplasia (OIN) I cases as compared to 25% in OIN II and 77.8% in OIN III. Ki-67 immunoexpression correlated significantly with both histological type and grade of tumor with increased expression and intensity seen in malignant cases (66.3%) as compared to benign (10%) and premalignant cases (37%) and higher Ki-67 immunoexpression in poorly differentiated tumors (75%) than well-differentiated tumors (12.2%). Regarding p-53 immunoexpression, positive staining was seen in only malignant cases and premalignant cases.

Conclusions:

Ki-67 and p-16 can be useful as a marker of degree of dysplasia and transformation to malignancy. Ki-67 can also serve as a marker of degree of differentiation of tumors. Hence, they can serve as important ancillary markers to analyze the transition to carcinoma, dysplasia and progression of tumor.

HR-HPV E6/E7 mRNA In Situ Hybridization: Validation Against PCR, DNA In Situ Hybridization, and p16 Immunohistochemistry in 102 Samples of Cervical, Vulvar, Anal, and Head and Neck Neoplasia

Dysregulated expression of oncogenic types of E6 and E7 is necessary for human papillomavirus (HPV)-driven carcinogenesis. An HPV E6/E7 mRNA in situ hybridization (ISH) assay covering 18 common high-risk types ("HR-RISH," aka HR-HPV RNA18 ISH) has not been extensively studied in the anogenital tract or validated on automated technology. We herein compare HR-RISH to DNA polymerase chain reaction (PCR), p16 immunohistochemistry, and a previously available HPV DNA ISH assay in HPV-related anogenital and head and neck (H&N) neoplasia. A total of 102 squamous intraepithelial lesions (16 CIN1, 25 CIN3, 3 AIN1, 12 AIN3, 9 VIN3)/invasive squamous cell carcinomas (17 cervical, 2 anal, 18 H&N) as well as 10 normal and 15 reactive cervix samples were collected. HR-RISH, DNA ISH, and p16 immunohistochemistry were performed on whole formalin-fixed, paraffin-embedded sections. RNA ISH for 6 low-risk HPV types (LR-RISH) was also performed. RNA and DNA ISH assays used automated systems. HR-HPV PCR was performed on morphology-directed formalin-fixed, paraffin-embedded punches. HR-RISH was ≥97% sensitive for PCR+ and p16+ neoplasia, as well as morphologically defined anogenital high grade squamous intraepithelial lesion/invasive squamous cell carcinoma. HR-RISH was also positive in 78% of anogenital low grade squamous intraepithelial lesion, including 81% of CIN1. Furthermore, a subset of PCR-negative/invalid and p16-negative lesions was positive for HR-RISH. Only 1 problematic reactive cervix sample and no normal cervix samples stained. These results demonstrate that HR-RISH is a robust method for the detection of HR-HPV-related neoplasia and provides insight into HPV pathobiology. Performance meets or exceeds that of existing assays in anogenital and H&N lesions and may play a role in resolving diagnostically challenging CIN1 versus reactive cases.

HPV Testing of Head and Neck Cancer in Clinical Practice

The pathology laboratory has a central role in providing human papillomavirus (HPV) tests for patients with head and neck cancer. There is an extensive literature around HPV testing and a large number of proprietary HPV tests, which makes the field difficult to navigate. This review provides a concise contemporary overview of the evidence around HPV testing in head and neck cancer and signposts key publications, guideline documents and the most commonly used methods in clinical practice.

Prognostic significance of non-HPV16 genotypes in oropharyngeal squamous cell carcinoma

OBJECTIVES

Recent studies have found that cases with oropharyngeal squamous cell carcinoma (OPSCC) positive for HPV16 genotype have better overall survival compared with cases positive for other HPV genotypes. We sought to further replicate these studies and determine if this relationship is modified by expression of p16 tumor suppressor protein.

MATERIAL AND METHODS

We identified 238 OPSCC cases from the Carolina Head and Neck Cancer Study (CHANCE) study, a population based case-control study. Tumors that tested positive solely for HPV16 genotype and no other genotypes with PCR were classified as HPV16-positive. Tumors positive for any other high-risk HPV genotype were classified as non-HPV16-positive. Expression of p16 in the tumor was determined with immunohistochemistry. Follow-up time was calculated from the date of diagnosis to date of death or December 31, 2013. Overall survival was compared with the Kaplan-Meier curves and log-rank test. Hazard ratios (HR) adjusted for smoking, alcohol use, sex, race, and age was calculated with the Cox proportional hazard regression.

RESULTS

Cases with HPV16-positive OPSCC had better overall survival than cases with non-HPV16-positive OPSCC (log-rank p-value: 0.010). When restricted to OPSCC cases positive for p16 expression, the same trend continued (log-rank p-value: 0.002). In the adjusted model, cases with non-HPV16-positive OPSCC had greater risk of death compared to cases with HPV16-positive tumors (HR: 1.92; 95% CI: 1.03, 3.60).

CONCLUSIONS

This finding indicates that HPV genotyping carries valuable prognostic significance in addition to p16 status and future survival studies of OPSCC should take into account differing HPV genotypes.

The Genomics, Epigenomics, and Transcriptomics of HPV-Associated Oropharyngeal Cancer--Understanding the Basis of a Rapidly Evolving Disease

Human papillomavirus (HPV) has been shown to represent a major independent risk factor for head and neck squamous cell cancer, in particular for oropharyngeal carcinoma. This type of cancer is rapidly evolving in the Western world, with rising trends particularly in the young, and represents a distinct epidemiological, clinical, and molecular entity. It is the aim of this review to give a detailed description of genomic, epigenomic, transcriptomic, and posttranscriptional changes that underlie the phenotype of this deadly disease. The review will also link these changes and examine what is known about the interactions between the host genome and viral genome, and investigate changes specific for the viral genome. These data are then integrated into an updated model of HPV-induced head and neck carcinogenesis.