Diagnostic Histopathology
Assessment of human papillomavirus (HPV) status is a requirement for the diagnosis of HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) and metastatic squamous cell carcinoma in cervical lymph nodes where the location of the primary neoplasm is unknown. Within the diagnostic histopathology laboratory, there should be a validated and reproducible HPV testing strategy that can provide HPV status within a reasonable timeframe to inform patient care. Although these requirements are recognized by the head and neck oncology community, there is no internationally accepted standard for HPV testing. A two-tiered approach incorporating p16 immunohistochemistry with specific HPV testing by DNA in situ hybridization is a pragmatic way of providing HPV testing in clinical practice. A novel RNA in situ hybridization methodology targeting E6 and E7 mRNA has been validated and is likely to be available as an in vitro diagnostic device soon. This review will outline the current concepts around the diagnosis of HPV-associated head and neck SCC and suggest a diagnostic algorithm that can be instituted in most diagnostic cellular pathology laboratories.
Oral oncology, 50(1):1–9.
Mirghani H1, Amen F2, Moreau F3, Guigay J4, Ferchiou M5, Melkane AE6, Hartl DM7, Lacau St Guily J (2014).
PMID: 24169585 | DOI: 10.1016/j.oraloncology.2013.10.008.
High risk Human Papilloma virus (HR-HPV) associated oropharyngeal cancers are on the increase. Although, the scientific community is aware of the importance of Human Papilloma Virus (HPV) testing, there is no consensus on the assays that are required to reliably identify HR-HPV related tumors. A wide range of methods have been developed. The most widely used techniques include viral DNA detection, with polymerase chain reaction (PCR) or In Situ Hybridization, and p16 detected by immunohistochemistry. However, these tests provide different information and have their own specific limitations. In this review, we summarize these different techniques, in light of the recent literature. p16 Overexpression, which is an indirect marker of HPV infection, is considered by many head and neck oncologists to be the most important marker for patient stratification. We describe the frequent lack of concordance of this marker with other assays and the possible reasons for this. The latest developments in HPV testing are also reported, such as the RNAscope™ HPV test, and how they fit into the existing framework of techniques. HPV testing must not be considered in isolation, as there are important interactions with other parameters, such as tobacco exposure. This is an important and rapidly evolving field and is likely to become pivotal to staging and choice of treatment of oropharyngeal carcinoma in the future.
Head and neck pathology, 1–7.
Chernock RD, Nussenbaum B, Thorstad WL, Luo Y, Ma XJ, El-Mofty SK, Lewis JS Jr (2013).
PMID: 24151062.
Over the past several decades, it has become clear that human papillomavirus (HPV) is important for the development and progression of many head and neck squamous cell carcinomas, particularly those arising in the oropharyngeal tonsillar crypts. Yet, our understanding of HPV's role in premalignant squamous lesions remains relatively poor. This is in part because premalignant lesions of the oropharyngeal tonsillar crypt tissue, where most HPV-related carcinomas arise, are difficult if not impossible to identify. Recent evidence does suggest a role for HPV in a subset of premalignant lesions of the surface epithelium, especially the oral cavity, despite the rarity of HPV-related invasive squamous cell carcinomas at this site. Furthermore, these HPV-related oral cavity dysplasias appear to have unique, bowenoid histologic features described as 'basaloid' with full-thickness loss of squamous maturation, mitotic figures and apoptosis throughout. Here, we present a unique case of an HPV-related premalignant lesion (squamous cell carcinoma in situ) extensively involving the surface epithelium of the oral cavity, oropharynx and larynx that had 'nonkeratinizing' histologic features typical of HPV-related invasive squamous cell carcinoma. This case was strongly p16 positive by immunohistochemistry and harbored transcriptionally active HPV as demonstrated by E6/E7 RNA in situ hybridization. Furthermore, the patient had an excellent response to radiation treatment.
The Journal of Molecular Diagnostics, 14(1), 22–29.
Wang, F, Flanagan, J, Su N, Wang LC, Bui S, Nielson A, Wu X, Vo HT, Ma XJ, Luo Y. (2012).
PMID: 22166544 | DOI: 10.1016/j.jmoldx.2011.08.002.
In situ analysis of biomarkers is highly desirable in molecular pathology because it allows the examination of biomarker status within the histopathological context of clinical specimens. Immunohistochemistry and DNA in situ hybridization (ISH) are widely used in clinical settings to assess protein and DNA biomarkers, respectively, but clinical use of in situ RNA analysis is rare. This disparity is especially notable when considering the abundance of RNA biomarkers discovered through whole-genome expression profiling. This is largely due to the high degree of technical complexity and insufficient sensitivity and specificity of current RNA ISH techniques. Here, we describe RNAscope, a novel RNA ISH technology with a unique probe design strategy that allows simultaneous signal amplification and background suppression to achieve single-molecule visualization while preserving tissue morphology. RNAscope is compatible with routine formalin-fixed, paraffin-embedded tissue specimens and can use either conventional chromogenic dyes for bright-field microscopy or fluorescent dyes for multiplex analysis. Unlike grind-and-bind RNA analysis methods such as real-time RT-PCR, RNAscope brings the benefits of in situ analysis to RNA biomarkers and may enable rapid development of RNA ISH-based molecular diagnostic assays.
Case Reports in Otolaryngology
Brobst T, García J, Rowe Price KA, Gao G, Smith DI, Price D.
PMID: - | DOI: -
Abstract
Background:
Although alcohol and tobacco use are known risk factors for development of squamous cell carcinoma in the head and neck, human papillomavirus (HPV) has been increasingly associated with this group of cancers. We describe the case of a married couple who presented with HPV-positive oropharynx squamous cell carcinoma within two months of each other.
Methods:
Tumor biopsies were positive for p16 and high-risk HPV in both patients. Sanger sequencing showed a nearly identical HPV16 strain in both patients. Both patients received chemoradiation, and one patient also underwent transoral robotic tongue base resection with bilateral neck dissection.
Results:
Both patients showed no evidence of recurrent disease on follow-up PET imaging.
Conclusions:
New head and neck symptoms should be promptly evaluated in the partner of a patient with known HPV-positive oropharynx cancer. This case expands the limited current literature on concurrent presentation of HPV-positive oropharynx squamous cell carcinoma in couples.
Bishop JA, Westra WH.
PMID: 26457358 | DOI: 10.1097/PAS.0000000000000521.
Although human papillomavirus (HPV)-related oropharyngeal carcinomas (HPV-OPCs) are generally regarded as "poorly differentiated," they actually maintain a close resemblance to the lymphoepithelium of the tonsillar crypts from which they arise: they are basaloid, exhibit minimal keratinization, and are often permeated by lymphocytes. In rare cases, the presence of cilia in a primary HPV-OPC and their persistence in lymph node metastasis can confound the distinction between a benign and malignant process. Three cases of ciliated HPV-OPCs were identified from the archives of The Johns Hopkins Head and Neck Pathology consultation service. HPV status was determined using p16 immunohistochemistry and high-risk HPV in situ hybridization. All 3 patients presented with a cystic lymph node metastasis without a known primary carcinoma. One metastasis was originally diagnosed as a branchial cleft cyst only to regionally recur 7 years later. In 2 cases, a primary HPV-OPC was found in the tonsil. The carcinomas exhibited both nonkeratinizing squamous epithelium and cystic/microcystic spaces lined by ciliated columnar cells. Both the squamous and ciliated cells were HPV positive. This report draws attention to a novel variant of HPV-related head and neck cancer that exhibits ciliated columnar cells. This variant challenges prevailing notions that: (1) HPV-OPCs are uniformly poorly differentiated cancers; (2) cilia are an infallible feature of benignancy; and (3) presence of cilia is a reliable criterion for establishing branchial cleft origin when dealing with cystic lesions of the lateral neck.
Journal of Medical Virology
Phusingha P, Ekalaksananan T, Vatanasapt P, Loyha K, Promthet S, Kongyingyoes B, Patarapadungkit N, Chuerduangphui J, Pientong C.
PMID: 27935063 | DOI: 10.1002/jmv.24744
Human papillomavirus (HPV) is an independent risk factor for development of oral squamous cell carcinoma (OSCC). This study aimed to investigate the role of HPV infection and the trend in percentage of HPV-associated OSCC over a five-year period in northeastern Thailand. In this case-control study, 91 exfoliated oral cell samples and 80 lesion cell samples from OSCC cases and exfoliated oral cells from 100 age/gender-matched controls were collected. HPV infection was investigated by PCR using GP5+/GP6+ primers followed by HPV genotyping using reverse line blot hybridization. Quantitative RT-PCR was used to evaluate HPV oncogene transcription. Temporal trends of HPVinfection were evaluated in archived formalin-fixed paraffin-embedded (FFPE) OSCC tissues using in situ hybridization. HPV DNA was found in 17.5% (14/80) of lesion samples from OSCC cases and 29.7% (27/91) of exfoliated oral cell samples from the same cases. These values were significantly higher than in exfoliated oral cell samples from controls (13%, 13/100). HPV-16 was the genotype most frequently found in OSCC cases (92.8%, 13/14 infected cases). Interestingly, HPV oncogene mRNA expression was detected and correlated with OSCC cases (P < 0.005). Of 146 archived FFPE OSCC samples, 82 (56.2%) were positive for high-risk HPV DNA and 64 (43.8%) cases were positive for HPV E6/E7 mRNA expression. There was a trend of increasing percentage of HPV-associated OSCC from 2005 to 2010. This was especially so for females with well-differentiated tumors in specific tongue sub-sites. We suggest that HPV infection plays an important role in oral carcinogenesis in northeastern Thailand.
Human papillomavirus (HPV) oncogenic activity is the result of viral oncogene E6 and E7 expression in infected cells. Oncogene expression analysis is however not part of the routine diagnostic evaluation of HPV-associated oropharyngeal squamous cell carcinoma (OPSCC) since it requires fresh tumor tissue. We compared the diagnostic accuracy of several methods commonly employed for HPV characterization in OPSCC with the results of the newly available HPV E6/E7 mRNA in situ hybridization (ISH) on formalin-fixed, paraffin-embedded biopsy samples, in order to establish if the latter should be introduced in the diagnostic routine to increase accuracy when fresh tissue is not available. p16 immunostain, DNA ISH for high risk (HR) HPV genotypes, SPF LiPA amplification and genotyping, and HPV16 E6 amplification were performed on 41 consecutive OPSCC samples. Twenty (48,7%) cases were positive by mRNA ISH; sensitivity and specificity were 100% and 90% for p16, 90% and 100% for DNA ISH, 70% and 76% for SPF10 LiPA, 90% and 76% for E6 amplification. A diagnostic algorithm considering p16 immunostain as first step followed by either HR HPV DNA ISH or HPV16 E6 amplification in p16-positive cases correctly characterized 90% of mRNA-positive and all mRNA-negative cases; combining the 3 tests correctly identified all cases. While no stand-alone test was sufficiently accurate for classifying HPV-associated OPSCC, the high sensitivity and specificity of the established combination of p16 immunostain, DNA ISH and HPV16 DNA amplification suggests that the introduction of labour- and cost-intensive mRNA ISH, is not necessary in the diagnostic routine of oropharyngeal tumors.
PLoS One. 2014 Mar 13;9(3):e91142
Evans MF, Peng Z, Clark KM, Adamson CSC, Ma XJ, Wu X, Wang H, Luo Y, Cooper K
PMID: 24625757 | DOI: 10.1371/journal.pone.0091142.eCollection2014.
Cervical lesion grading is critical for effective patient management. A three-tier classification (cervical intraepithelial neoplasia [CIN] grade 1, 2 or 3) based on H&E slide review is widely used. However, for reasons of considerable inter-observer variation in CIN grade assignment and for want of a biomarker validating a three-fold stratification, CAP-ASCCP LAST consensus guidelines recommend a two-tier system: low- or high-grade squamous intraepithelial lesions (LSIL or HSIL). In this study, high-risk HPV E6/E7 and p16 mRNA expression patterns in eighty-six CIN lesions were investigated by RNAscope chromogenic in situ hybridization (CISH). Specimens were also screened by immunohistochemistry for p16INK4a (clone E6H4), and by tyramide-based CISH for HPV DNA. HPV genotyping was performed by GP5+/6+ PCR combined with cycle-sequencing. Abundant high-risk HPV RNA CISH signals were detected in 26/32 (81.3%) CIN 1, 22/22 (100%) CIN 2 and in 32/32 (100%) CIN 3 lesions. CIN 1 staining patterns were typified (67.7% specimens) by abundant diffusely staining nuclei in the upper epithelial layers; CIN 2 lesions mostly (66.7%) showed a combination of superficial diffuse-stained nuclei and multiple dot-like nuclear and cytoplasmic signals throughout the epithelium; CIN 3 lesions were characterized (87.5%) by multiple dot-like nuclear and cytoplasmic signals throughout the epithelial thickness and absence/scarcity of diffusely staining nuclei (trend across CIN grades: P<0.0001). These data are consistent with productive phase HPV infections exemplifying CIN 1, transformative phase infections CIN 3, whereas CIN 2 shows both productive and transformative phase elements. Three-tier data correlation was not found for the other assays examined. The dual discernment of diffuse and/or dot-like signals together with the assay’s high sensitivity for HPV support the use of HPV E6/E7 RNA CISH as an adjunct test for deciding lesion grade when CIN 2 grading may be beneficial (e.g. among young women) or when ‘LSIL vs. HSIL’ assignment is equivocal.
Am J Surg Pathol. Dec;36(12):1874–1882.
Bishop JA, Ma XJ, Wang H, Luo Y, Illei PB, Begum S, Taube JM, Koch WM, Westra WH (2012).
PMID: 23060353 | DOI: 10.1097/PAS.0b013e318265fb2b.
Evidence for transcriptional activation of the viral oncoproteins E6 and E7 is regarded as the gold standard for the presence of clinically relevant human papillomavirus (HPV), but detection of E6/E7 mRNA requires RNA extraction and polymerase chain reaction amplification-a challenging technique that is restricted to the research laboratory. The development of RNA in situ hybridization (ISH) probes complementary to E6/E7 mRNA permits direct visualization of viral transcripts in routinely processed tissues and has opened the door for accurate HPV detection in the clinical care setting. Tissue microarrays containing 282 head and neck squamous cell carcinomas from various anatomic subsites were tested for the presence of HPV using p16 immunohistochemistry, HPV DNA ISH, and an RNA ISH assay (RNAscope) targeting high-risk HPV E6/E7 mRNA transcripts. The E6/E7 mRNA assay was also used to test an additional 25 oropharyngeal carcinomas in which the HPV status as recorded in the surgical pathology reports was equivocal due to conflicting detection results (ie, p16 positive, DNA ISH negative). By the E6/E7 mRNA method, HPV was detected in 49 of 282 (17%) HNSCCs including 43 of 77 (56%) carcinomas from the oropharynx, 2 of 3 (67%) metastatic HNSCCs of an unknown primary site, 2 of 7 (29%) carcinomas from the sinonasal tract, and 2 of 195 (1%) carcinomas from other head and neck sites. p16 expression was strongly associated with the presence of HPV E6/E7 mRNA: 46 of 49 HPV-positive tumors exhibited p16 expression, whereas only 22 of 233 HPV-negative tumors were p16 positive (94% vs. 9%, P<0.0001). There was also a high rate of concordance (99%) between the E6/E7 mRNA method and HPV DNA ISH. For the selected group of discordant HNSCCs (p16/HPV DNA), the presence of E6/E7 transcripts was detected in 21 of 25 (84%) cases. The E6/E7 mRNA method confirmed the presence of transcriptionally active HPV-related HNSCC that has a strong predilection for the oropharynx and is strongly associated with high levels of p16 expression. Testing for HPV E6/E7 transcripts by RNA ISH is ideal because it confirms the presence of integrated and transcriptionally active virus, permits visualization of viral transcripts in tissues, and is technically feasible for routine testing in the clinical laboratory.
Am J Pathol. 2015 Jan 5. pii: S0002-9440(14)00688-9.
Miller DL, Davis JW, Taylor KH, Johnson J, Shi Z, Williams R, Atasoy U, Lewis JS Jr, Stack MS.
PMID: 25572154 | DOI: 10.1016/j.ajpath.2014.11.018.
High-risk human papillomavirus (HPV) is a causative agent for an increasing subset of oropharyngeal squamous cell carcinomas (OPSCCs), and current evidence supports these tumors as having identifiable risk factors and improved response to therapy. However, the biochemical and molecular alterations underlying the pathobiology of HPV-associated OPSCC (designated HPV+ OPSCC) remain unclear. Herein, we profile miRNA expression patterns in HPV+ OPSCC to provide a more detailed understanding of pathologic molecular events and to identify biomarkers that may have applicability for early diagnosis, improved staging, and prognostic stratification. Differentially expressed miRNAs were identified in RNA isolated from an initial clinical cohort of HPV+/- OPSCC tumors by quantitative PCR-based miRNA profiling. This oncogenic miRNA panel was validated using miRNA sequencing and clinical data from The Cancer Genome Atlas and miRNA in situ hybridization. The HPV-associated oncogenic miRNA panel has potential utility in diagnosis and disease stratification and in mechanistic elucidation of molecular factors that contribute to OPSCC development, progression, and differential response to therapy.
Seminars in Diagnostic Pathology
During the last few decades a phenotypically distinct type of head and neck squamous cell carcinoma (SCC), that is etiologically related to human papillomavirus(HPV), has emerged and its prevalence continues to increase. The tumors are site-specific with special predilection for the oropharynx. They are morphologically and molecularly distinct and are responsive to different types of treatment modalities, with excellent clinical outcome, in spite of early lymph node metastasis. Microscopically, the carcinomas are nonkeratinizing SCCs. More recently, other variants that are believed to be etiologically related to HPV are reported. As a result, several clinical and pathologic questions have emerged. Importantly, whether the virus is biologically active in these tumors and involved in their pathogenesis, and second, what are the clinical implications with regard to patient management and outcome in these HPV-related variants. This review is an attempt to answer some of these questions based on information derived from available yet limited number of publications. The variants to be discussed include; nonkeratinizing SCC (NKSCC), NKSCC with maturation (hybrid type), keratinizing SCC (KSSC), basaloid squamous carcinoma (BSCC), undifferentiated carcinoma (UC), papillary SCC (PSCC), small cell carcinoma, adenosquamous carcinoma (AdSCC) and spindle cell (sarcomatoid) carcinoma.
