Use of in situ hybridization to detect human papillomavirus in head and neck squamous cell carcinoma patients without a history of alcohol or tobacco use

Targeted Inhibition of Mammalian Target of Rapamycin (mTOR) Signaling Pathway Inhibits Proliferation and Induces Apoptosis of Laryngeal Carcinoma Cells in vitro

Aim and Objective

Laryngeal carcinoma is one of the most aggressive cancers of the head and neck region. The survival rate of patients with laryngeal carcinoma is low due to its late metastases and resistance to chemotherapy and radiotherapy. It was reported that mTOR was involved in the growth and apoptosis of various cancer cells. The aim of this study was to detect the effects of mTOR inhibition by mTOR shRNA on the proliferation, apoptosis and invasive ability of Hep-2 human laryngeal carcinoma cells in vitro.

Methods and Study Design

mTOR shRNA was designed and transfected into Hep-2 human laryngeal carcinoma cells. Untreated cells and cells treated with control vector (non-targeted shRNA) were used as control. The proliferation and apoptosis of Hep-2 cells were detected by MTT and flow cytometry. A transwell assay was used to measure the invasive ability of Hep-2. The inhibition effects on the mTOR signaling pathway by mTOR shRNA were studied using RT-PCR and Western blot.

Results

Our results showed that the mRNA and protein expression of mTOR and Akt were high in laryngeal carcinoma cells and could be inhibited by mTOR shRNA. At the same time, low expression of PTEN mRNA and protein was observed in Hep-2 cells. The expression increased when the cells were transfected with mTOR shRNA. This showed that mTOR shRNA could inhibit the proliferation and invasive ability of Hep-2 cells. It also could induce the apoptosis of Hep-2 cells in vitro.

Conclusions

The mTOR signaling pathway plays an important role in the development of laryngeal carcinoma. The mTOR shRNA we designed in this experiment effectively inhibited the mTOR signaling pathway. It inhibited the proliferation and invasive ability of the studied laryngeal carcinoma cells and induced their apoptosis in vitro. mTOR might therefore be a useful target in the therapy of laryngeal carcinoma.

Human Papillomavirus Status and the Risk of Cerebrovascular Events Following Radiation Therapy for Head and Neck Cancer

Background

Radiation therapy (RT) is a standard treatment for head and neck cancer; however, it is associated with inflammation, accelerated atherosclerosis, and cerebrovascular events (CVEs; stroke or transient ischemic attack). Human papillomavirus (HPV) is found in nearly half of head and neck cancers and is associated with inflammation and atherosclerosis. Whether HPV confers an increased risk of CVEs after RT is unknown.

Methods and Results

Using an institutional database, we identified all consecutive patients treated with RT from 2002 to 2012 for head and neck cancer who were tested for HPV. The outcome of interest was the composite of ischemic stroke and transient ischemic attack, and the association between HPV and CVEs was assessed using Cox proportional hazard models, competing risk analysis, and inverse probability weighting. Overall, 326 participants who underwent RT for head and neck cancer were tested for HPV (age 59±12 years, 75% were male, 9% had diabetes mellitus, 45% had hypertension, and 61% were smokers), of which 191 (59%) were tumor HPV positive. Traditional risk factors for CVEs were similar between HPV‐positive and ‐negative patients. Over a median follow‐up of 3.4 years, there were 18 ischemic strokes and 5 transient ischemic attacks (event rate of 1.8% per year). The annual event rate was higher in the HPV‐positive patients compared with the HPV‐negative patients (2.6% versus 0.9%, P=0.002). In a multivariable model, HPV‐positive status was associated with a >4 times increased risk of CVEs (hazard ratio: 4.4; 95% confidence interval, 1.5–13.2; P=0.008).

Conclusions

In this study, HPV‐positive status is associated with an increased risk of stroke or transient ischemic attack following RT for head and neck cancer.

Prognostic significance of p16 in squamous cell carcinoma of the larynx and hypopharynx

PURPOSE

To evaluate the prognostic significance of p16 expression among patients with squamous cell carcinoma of the larynx (LSCC) and hypopharynx (HSCC).

METHODS

The medical records of all patients with locally advanced, non-metastatic LSCC/HSCC were reviewed. p16^INK4A (p16) protein expression was evaluated on pathological specimens by immunohistochemistry (IHC), and the Kaplan-Meier method was used to estimate overall survival (OS) and locoregional control (LRC). In select cases, p16 expression was correlated to high-risk and low-risk HPV genotypes using in situ hybridization (ISH).

RESULTS

Thirty-one patients (23 LSCC; 8 HSCC) were identified. Seventeen (54.8%) patients were p16 negative; 14 (45.2%) were p16-positive. The primary treatment modality was radiation therapy for 22 (71.0%) patients and surgery for 9 (29.0%). Nineteen (61.3%) patients were evaluated for high-risk HPV and low-risk HPV genotypes by IHC, of whom 2 (10.5%) patients were positive for high-risk HPV and 1 (5.3%) was positive for low-risk HPV. For high-risk HPV, the positive predictive value (PPV), sensitivity, and specificity of p16 was 20.0%, 100%, and 52.9%. There was no significant difference in the 2-year actuarial rates of OS (91% vs. 64%, p=0.34) or LRC (51% vs. 46%, p=0.69) between the p16-positive and p-16 negative patients.

CONCLUSION

In this small cohort of 31 LSCC and HSCC patients, p16 was not a significant predictive of either LRC or OS. Furthermore, p16 was poorly correlated with HPV genotyping as identified by ISH.

Automated in situ hybridization for human papilloma virus

With the increased number of requests for high-risk human papilloma virus in situ hybridization (HPV ISH), not only for uterine cervical squamous cell carcinoma (SCC) but also for biopsies and resections of oropharyngeal SCC, and fine needle aspiration cell blocks of metastatic SCC in cervical lymph nodes, we optimized an automated method to replace the manual one we had used. The new technique used the Leica BOND-maX or III immunostainer, already in use for immunohistochemical analysis, with the Enzo HPV type 16/18 and 6/11 probes. We stained 55 surgical biopsies and 41 cell blocks of oropharyngeal SCC. Sensitivity was 90% and 73% for biopsies and cell blocks, respectively, with a specificity of 100% in both. Stain is strong and crisp with no background. Turnaround time is short as runs are performed daily, with up to 30 slides per run. Technologists become trained in a few days, and the repeat rate is low. The only disadvantage is that ISH and IHC cannot be performed simultaneously. We highly recommend this automated technique for high-risk and low-risk HPV ISH and probably with other probes.

Virology and molecular pathogenesis of HPV (human papillomavirus)-associated oropharyngeal squamous cell carcinoma

The current literature fully supports HPV (human papillomavirus)-associated OPSCC (oropharyngeal squamous cell carcinoma) as a unique clinical entity. It affects an unambiguous patient population with defined risk factors, has a genetic expression pattern more similar to cervical squamous cell carcinoma than non-HPV-associated HNSCC (head and neck squamous cell carcinoma), and may warrant divergent clinical management compared with HNSCC associated with traditional risk factors. However, a detailed understanding of the molecular mechanisms driving these differences and the ability to exploit this knowledge to improve clinical management of OPSCC has not yet come to fruition. The present review summarizes the aetiology of HPV-positive (HPV+) OPSCC and provides a detailed overview of HPV virology and molecular pathogenesis relevant to infection of oropharyngeal tissues. Methods of detection and differential gene expression analyses are also summarized. Future research into mechanisms that mediate tropism of HPV to oropharyngeal tissues, improved detection strategies and the pathophysiological significance of altered gene and microRNA expression profiles is warranted.

Detection of high-risk HPV in head and neck squamous cell carcinomas: comparison of chromogenic in situ hybridization and a reverse line blot method

Human papillomaviruses (HPVs) have been etiologically linked to a subset of head and neck squamous cell carcinomas (HNSCCs), generally arising in young patients without a history of tobacco smoking or alcohol use. These tumors typically lack mutations in TP53 and may show enhanced sensitivity to chemoradiation therapy with a correspondingly better overall prognosis. The determination of the HPV status in HNSCC therefore has therapeutic implications. We compared the Ventana ISH iView Blue Plus Detection Kit in situ hybridization (ISH) system and the Roche Linear Array HPV Genotyping Test for the detection of HPV in 98 formalin-fixed, paraffin-embedded HNSCC samples. A moderate concordance rate (70.4%) was observed between ISH and the Linear Array assays. ISH detected HPV in 39.8% of cases, whereas Linear Array detected HPV in 57.1% of cases. Sensitivity and specificity of ISH for detecting HPV in HNSCC specimens were determined to be 58.9% and 85.7%, respectively, using the Linear Array as the method of comparison (McNemar test, P=0.003). ISH offers the advantage of visual cell-type localization of viral infection but overall it is less sensitive than the polymerase chain reaction-based detection of HPV in HNSCC.

Intended single-modality management of T1 and T2 tonsillar carcinomas: retrospective comparison of radical tonsillectomy vs radiation from a single institution

BACKGROUND

T1 and T2 tonsillar squamous cell cancer with limited neck disease can be managed with single-modality radiation or surgery. Over 11 years, 17 patients underwent radical tonsillectomies; and 33 patients underwent radiation-based treatments for T1 and T2 and N0 to N2a tonsil cancer. Patients were intended to receive single-modality treatment based on presentation; however, some ultimately received adjuvant treatments.

METHODS

A retrospective chart review to compare overall survival (OS), disease-specific survival (DSS), and locoregional control (LRC) between the groups was used.

RESULTS

In surgical group, of 17 patients, 11 underwent surgery alone, 3 underwent surgery and radiation, and 3 underwent surgery with concurrent chemoradiation. Five-year OS for the surgical and radiation groups was 93% and 72%, respectively (no significance achieved). Five-year DSS rates (93% and 80%) and LRC (69% and 89%) similarly did not yield any significant difference.

CONCLUSION

Surgery remains a viable option in the management of T1 and T2 tonsillar cancers with comparable LRC, OS, and DSS.

Is p16 immunohistochemistry a more cost-effective method for identification of human papilloma virus-associated head and neck squamous cell carcinoma?

Tobacco and alcohol use are established risk factors for head and neck squamous cell carcinoma (HNSCC). However, patients with a unique subset of human papilloma virus (HPV)-associated HNSCC have been documented to have a better survival outcome. These tumors occur more frequently in the tonsils and oropharyngeal sites, among younger patients, higher socioeconomic group, and those exposed to more sexual partners and oral sex compared with HPV-negative HNSCC. Although tobacco- and alcohol-related HNSCCs appear to be on the decline, tonsillar and oropharyngeal HPV-associated tumors seem to be on the rise, and their prevalence varies widely in published reports, ranging from 20% to 60%. Human papilloma virus detection methods in tumor tissue vary and include polymerase chain reaction, in situ hybridization (ISH) technique for HPV DNA, and E6/E7 messenger RNA, with p16 immunohistochemistry (IHC) as a surrogate marker. The sensitivity and specificity of the different methods used are likely contributory factors to this wide variation. This study compares the p16 IHC staining patterns in HNSCC and laryngeal papillomas and assesses the concordance of p16 and high-risk HPV-ISH to determine the usefulness of p16 as a first-line marker. Using an objective criterion of diffuse intense confluent staining pattern as definite positive (akin to the 3+ of HER2/neu in breast cancer) and focal scattered staining pattern as equivocal reaction requiring confirmatory HPV assay, p16 IHC expression shows good concordance with high-risk HPV-ISH and can be used as a first-line marker. We propose p16 overexpression as a suitable surrogate and screening marker, with high potential of impacting the standard of care.

Papillary squamous cell carcinoma of the head and neck: a clinicopathologic series

PURPOSE

Papillary squamous cell carcinoma (PSCC) is a rare malignancy that has been associated with human papillomavirus. We present all cases of this disease at a single academic teaching hospital over the last 30 years.

MATERIALS AND METHODS

A retrospective chart review was performed for all patients with a diagnosis of PSCC. Of 65 patients identified, 52 were included after meeting established diagnostic criteria. Chart reviews were performed for patient demographics, overall survival, and disease-free survival.

RESULTS

Mean age at diagnosis was 65 years, with a male to female ratio of 2.3:1. The majority of lesions (n = 34, 65.4%) arose in areas commonly affected by benign squamous papillomas, with the laryngopharynx the most commonly affected (n = 19, 36.5%), followed by the oral cavity (n = 18, 34.6%), sinonasal tract (n = 8, 15.4%), and oropharynx (n = 7, 13.5%). Two- and 5-year disease-free survival rate was 68% and 46%, respectively. Overall survival rate was 90% and 72% at 2 and 5 years, respectively.

CONCLUSIONS

Papillary squamous cell carcinoma of the head and neck is a distinct variant of conventional squamous cell carcinoma with a good prognosis despite high locoregional recurrence rates. Histology and subsite localization corroborate existing evidence that human papillomavirus may be involved.

Assessing for primary oropharyngeal or nasopharyngeal squamous cell carcinoma from fine needle aspiration of cervical lymph node metastases

In fine needle aspirates of cervical lymph nodes with metastatic squamous cell carcinoma (SCC), the site of origin may not be clinically evident. The distinction between oropharyngeal and nasopharyngeal primary SCC has important management consequences. In the current study, we evaluated metastatic SCC for HPV types 16, 18, 31, 33, 51 (by in situ hybridization[ISH]), p16 and ProExC (surrogate HPV markers), and Epstein Barr Virus reported in nasopharyngeal SCC. Forty patients diagnosed between 2004 and 2008, with adequate cell block material were identified. ISH for high risk HPV and EBV (EBER), and immunohistochemistry for p16 and ProExC were performed. Primary site was designated in 31 cases with 26 head and neck including 11 oropharyngeal and 2 nasopharyngeal, and 5 other sites. High risk HPV was detected in 9 cases (22.5%), p16 in 16 (40%), ProExC in 35 (87.5%), and EBER in 2 (5%). All cases with high risk HPV ISH also showed overexpression of p16. The sensitivity for HPV infection by both surrogate markers was 100%; specificity for p16 and ProExC was 78.7 and 16.1%, respectively. Seven (63.6%) oropharyngeal SCC were positive for HPV ISH and negative for EBV; one nasopharyngeal SCC (50%) was EBER positive and HPV negative. HPV and EBER detection can serve as indicators for oropharyngeal and nasopharyngeal primary SCC, respectively, however our data show that only a subset (63.6%) of oropharyngeal SCC are high risk HPV-related. Additionally, despite their high sensitivity for HPV infection, surrogate markers, especially ProExC, lack specificity.

Human papillomavirus detection in head and neck squamous cell carcinomas

Squamous cell carcinomas of the head and neck (HNSCC) are a frequent diagnosis in anatomic pathology practice. Tobacco use and heavy alcohol consumption are known risk factors for HNSCC but in other cases human papillomavirus (HPV) is linked to carcinogenesis. HPV proteins E6 and E7 promote oncogenesis by blocking the action of p53 and pRB, respectively. An absence of p53 mutations in addition to expression of p16 are part of the distinct molecular profile identified in the subset of HNSCCs because of HPV. Various methods are available for HPV detection but polymerase chain reaction and in situ hybridization techniques are commonly used. Both methods are amenable for testing formalin-fixed paraffin-embedded tissue that is a sample type readily available to the pathologist. HPV is detectable in approximately a quarter of all HNSCCs, and is particularly prevalent in the oropharynx in which the positivity rates approach 40%. A vast majority of HPV-related HNSCCs are owing to HPV type 16 with types 18, 31, and 33 accounting for almost all of the remaining cases. HPV-related HNSCCs are associated with better prognosis for both recurrence and survival. This group of tumors has also been shown to respond well to radiation treatment. As the clinical relevance of HPV in HNSCCs continues to emerge, anatomic pathologists are likely to receive increasing requests for testing. Herein, the authors review the biological and clinical aspects of HPV-associated HNSCC and review techniques for HPV detection.

Polymerase chain reaction detection of HPV in squamous carcinoma of the oropharynx

Human papillomavirus (HPV) testing is routinely performed on oropharyngeal carcinomas. We compared the Access Genetics (Minneapolis, MN) polymerase chain reaction (PCR) assay (AGPCR), DNA-DNA in situ hybridization (ISH; Ventana, Tucson, AZ), and HPV-16 E7 PCR amplification in consecutively accessioned oropharyngeal cancers. We tested 126 cases by both PCR methods; 102 were positive by either for a maximum positive rate (MPR) of 81.0%. Relative to the MPR, the sensitivities of AGPCR and E7 PCR were 90.2% and 72.5%, respectively. Of 17 AGPCR+ cases tested by ISH, 14/14 unequivocally positive/negative were concordant. All cases (97/97) positive by either PCR assay were positive for p16. There was no relationship between level of histologic differentiation and HPV status. ISH and AGPCR have comparable performance for the detection of HPV in oropharyngeal carcinomas. PCR is a suitable and economical assay that is comparable to ISH in sensitivity and may provide logistical advantages relative to ISH for assessing HPV status in oropharyngeal malignancies. However, it is imperative that appropriate sensitivity controls be in place for such assays.

Survey on human papillomavirus/p16 screening use in oropharyngeal carcinoma patients in the United States

BACKGROUND

Patients with human papillomavirus (HPV)-positive oropharyngeal carcinoma (OC) have better prognosis than patients with HPV-negative OC. The objective of the current study was to assess how different practices across the United States treat patients with OC with respect to screening for HPV DNA or p16.

METHODS

Five hundred forty-two randomly selected radiation oncologists were sent an 11-question survey by email regarding the use of HPV/p16 screening in OC. The questionnaire addressed demographics of the practice, intensity-modulated radiotherapy (IMRT) use, screening practices for HPV DNA or p16, which year this began, the use of HPV or p16 data to direct patient care, and future plans for its use if it had not already been instituted.

RESULTS

One hundred ninety-two responses (39.6%) were received. Thirty-five percent of respondents (67 of 188) reported screening for HPV DNA routinely, whereas 4.8% of respondents (9 of 188) reported screening for p16. Of the physicians who did not use screening techniques, 37.2% (44 of 118 respondents) reported future plans to institute these screening techniques, 20% (9 of 45 respondents) stated plans to institute these techniques in the next 6 months, 55.5% (25 of 45 respondents) stated plans to institute these techniques within 6 months to 1 year, and 22.2% (10 of 45 respondents) stated plans to institute these techniques within 1 to 2 years. Academic physicians were more likely to use screening techniques (62.7%; P < .001) compared with private practitioners (31.4%). Only 12.4% of respondents reported using HPV or p16 data to direct care.

CONCLUSIONS

Approximately 40.4% of radiation oncology practices that responded to a survey in the United States screened for HPV DNA or p16 in OC, whereas only 12.4% used it to further direct care. This number appears to be growing rapidly. Clinical trials to further elucidate how HPV or p16 status should direct care in OC are warranted.

Papillomas of the external ear canal: report of ten cases in Chinese patients with HPV in situ hybridization

Squamous papilloma is a benign exophytic proliferation which can occur occasionally in the external ear canal. It is widely assumed that the Human Papilloma Virus (HPV) is an etiologic factor of papillomas. Available techniques for detection of HPV genomes include immunohistochemistry, Southern blot hybridization, in situ hybridization (ISH), and polymerase chain reaction. To our knowledge, HPV typing has not been reported on tissue sections of papillomas in the external ear canal. We report HPV ISH analysis in ten cases of papillomas, involving the external ear canal in Chinese patients. These papilloma excrescences were less than 1 cm in diameter, and were benign morphologically. Automated HPV ISH analysis was performed for the hybridization of DNA probes, including both low-risk and high-risk HPV subtypes. HPV ISH results revealed that seven out of ten cases were positive for low-risk HPV (6, 11), three cases demonstrated no hybridization for low-risk HPV probe, and none of the cases revealed any detection of high-risk HPV (16, 18, 31, 33, 35, 39, 51, 52, 56, 58, and 66). On follow-up after 18-29 months (average 24.5 months), eight patients were doing well, with no local recurrence after excision. Two patients were lost to follow-up. Our results confirm that benign papillomas of the external ear canal are associated with low-risk HPV infection with benign behavior and neither recurrence nor high grade dysplasia.

Role of human papillomavirus and its detection in potentially malignant and malignant head and neck lesions: updated review

Head and neck malignancies are characterized by a multiphasic and multifactorial etiopathogenesis. Tobacco and alcohol consumption are the most common risk factors for head and neck malignancy. Other factors, including DNA viruses, especially human papilloma virus (HPV), may also play a role in the initiation or development of these lesions. The pathways of HPV transmission in the head and neck mucosal lesions include oral-genital contact, more than one sexual partner and perinatal transmission of HPV to the neonatal child. The increase in prevalence of HPV infection in these lesions may be due to wider acceptance of oral sex among teenagers and adults as this is perceived to be a form of safe sex. The prevalence of HPV in benign lesions as well as malignancies has been assessed by many techniques. Among these, the polymerase chain reaction is the most sensitive method. Review of literature reveals that HPV may be a risk factor for malignancies, but not in all cases. For confirmation of the role of HPV in head and neck squamous cell carcinoma, large population studies are necessary in an assortment of clinical settings. Prophylactic vaccination against high-risk HPV types eventually may prevent a significant number of cervical carcinomas. Of the two vaccines currently available, Gardasil (Merck & Co., Inc.) protects against HPV types 6, 11, 16 and 18, while the other vaccine, Cervarix (GlaxoSmithKline, Rixensart, Belgium) protects against HPV types 16 and 18 only. However, the HPV vaccine has, to the best of our knowledge, not been tried in head and neck carcinoma. The role of HPV in etiopathogenesis, prevalence in benign and malignant lesions of this area and vaccination strategies are briefly reviewed here.