Clinical implications of human papillomavirus in head and neck cancers

Malignancies in women with HIV infection

Women with HIV infection have an increased risk of developing certain malignancies. These malignancies are commonly human papillomavirus (HPV)-related, reflecting the high rate of coinfection with HPV in women with underlying HIV infection. These women also have a high incidence of premalignant HPV-related changes, such as high-grade squamous intraepithelial lesions as diagnosed on Pap smears and cervical intraepithelial neoplasia on cervical biopsy. Screening recommendations for HIV-infected women reflect the need for vigilance in detecting and treating these lesions early. In addition, recent interest has focused on the use of cervical cancer screening, employing HPV-testing techniques, and on HPV vaccination in younger women to prevent initial infection and the subsequent development of cervical and other HPV-related cancers. The incidence of other types of malignancies, such as Hodgkin's and non-Hodgkin's lymphoma, is also increased in HIV-infected individuals. When these lymphomas occur, they tend to be of advanced stage and high-grade histologies. The advent of highly active antiretroviral therapy has been associated with a marked decrease in the incidence of some of these cancers. The use of therapy has been associated with marked improvement in response rates and overall survival of affected patients.

Molecular biology of head and neck cancer: risks and pathways

Patients present with a differential baseline risk of cancer based on normal and expected variations in genes associated with cancer. The baseline risk of developing cancer is acted on throughout life as the genome of different cells interacts with the environment in the form of exposures (eg, toxins, infections). As genetic damage is incurred throughout a lifetime (directly to DNA sequences or to the epigenome), events are set in motion to progressively disrupt normal cellular pathways toward tumorigenesis. This article attempts to characterize broad categories of genetic aberrations and pathways in a manner that might be useful for the clinician to understand the risk of developing cancer, the pathways that are disrupted, and the potential for molecular-based diagnostics.

Prospective trial incorporating pre-/mid-treatment [18F]-misonidazole positron emission tomography for head-and-neck cancer patients undergoing concurrent chemoradiotherapy

PURPOSE

To report the results from a prospective study of a series of locoregionally advanced head-and-neck cancer patients treated with platinum-based chemotherapy and intensity-modulated radiotherapy and to discuss the findings of their pre-/mid-treatment [(18)F]-misonidazole ((18)F-FMISO) positron emission tomography (PET) scans.

METHODS AND MATERIALS

A total of 28 patients agreed to participate in this study. Of these 28 patients, 20 (90% with an oropharyngeal primary cancer) were able to undergo the requirements of the protocol. Each patient underwent four PET scans: one pretreatment fluorodeoxyglucose PET/computed tomography scan, two pretreatment (18)F-FMISO PET/computed tomography scans, and a third (18)F-FMISO PET (mid-treatment) scan performed 4 weeks after the start of chemoradiotherapy. The (18)F-FMISO PET scans were acquired 2-3 h after tracer administration. Patients were treated with 2-3 cycles of platinum-based chemotherapy concurrent with definitive intensity-modulated radiotherapy.

RESULTS

A heterogeneous distribution of (18)F-FMISO was noted in the primary and/or nodal disease in 90% of the patients. Two patients had persistent detectable hypoxia on their third mid-treatment (18)F-FMISO PET scan. One patient experienced regional/distant failure but had no detectable residual hypoxia on the mid-treatment (18)F-FMISO PET scan.

CONCLUSION

Excellent locoregional control was observed in this series of head-and-neck cancer patients treated with concurrent platinum-based chemotherapy and intensity-modulated radiotherapy despite evidence of detectable hypoxia on the pretreatment (18)F-FMISO PET/computed tomography scans of 18 of 20 patients. In this prospective study, neither the presence nor the absence of hypoxia, as defined by positive (18)F-FMISO findings on the mid-treatment PET scan, correlated with patient outcome. The results of this study have confirmed similar results reported previously.

HPV-16 infection predicts treatment outcome in oropharyngeal squamous cell carcinoma

Objective: To determine if patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) treated with chemoradiation have improved outcomes.

Study Design: A retrospective search was used to identify patients with OPSCC treated with concurrent chemoradiation. Pretreatment biopsy specimens were tested for HPV-16 infection and p16 expression.

Methods: Forty-four patients with OPSCC treated with concurrent chemotherapy and intensity-modulated radiation therapy were identified. Eligibility criteria included a minimum two years of follow-up, or biopsy-proven recurrence. In situ hybridization was applied to archival tumor specimens, with HPV-16-positive status defined as positive staining of tumor cell nuclei. p16 expression was assessed by immunohistochemistry.

Results: Twenty-seven tumors (61%) were positive for HPV-16 and 29 tumors (66%) expressed p16. HPV-16 infection was highly correlated with p16 expression ( P < 10−7). Three-year disease-free and overall survival for all patients was 66 percent and 79 percent respectively. Patients with tumors infected with HPV-16 had improved overall (OS) and disease-free survival (DFS) after chemoradiation (OS: hazard ratio [HR] = 0.21, P = 0.01; DFS: HR = 0.30, P = 0.02).

Conclusion: Patients with OPSCC tumors that are infected with HPV-16 have improved survival after treatment with concurrent chemoradiation.

p73 G4C14-to-A4T14 polymorphism and risk of human papillomavirus-associated squamous cell carcinoma of the oropharynx in never smokers and never drinkers

BACKGROUND

The p53 tumor suppressor protein homolog p73 can be inactivated by oncoprotein E6 of human papillomavirus (HPV). Variation in p73 may alter the interaction between the E6 protein and p73 and, thus, alter the risk for HPV-associated carcinogenesis. It is believed that the p73 G4C14-to-A4T14 polymorphism affects p73 function by altering gene expression; however, whether that polymorphism also alters the risk of HPV type 16 (HPV-16)-associated squamous cell carcinoma of the oropharynx (SCCOP) is unknown.

METHODS

The current case-control study included a case group of 188 non-Hispanic white patients with newly diagnosed SCCOP and a control group of 349 healthy individuals. Logistic regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for cases and controls stratified by p73 genotype, age, sex, smoking status, alcohol use, and HPV-16 status. The effects of p73 genotypes on the risk of HPV-16-associated SCCOP were explored with further stratification by smoking and drinking status.

RESULTS

HPV-16 seropositivity was associated with an increased risk of SCCOP (adjusted OR, 5.98; 95% CI, 3.89-9.20), especially among never smokers (adjusted OR, 13.8; 95% CI, 5.91-32.1), never drinkers (adjusted OR, 14.9; 95% CI, 5.24-42.4), and individuals with p73 variant genotypes (GC/AT and AT/AT; adjusted OR, 7.96; 95% CI, 3.83-16.5). Moreover, the risk of HPV-16-associated SCCOP for individuals who had p73 variant genotypes was particularly high in never smokers and never drinkers.

CONCLUSIONS

The p73 G4C14-to-A4T14 polymorphism may modulate the risk of HPV-16-associated SCCOP, and the p73 variant genotypes may be markers of genetic susceptibility to HPV-16-associated SCCOP, particularly in never smokers and never drinkers.

Integrating biologically targeted therapy in head and neck squamous cell carcinomas

The integration of targeted therapies such as cetuximab to radiation therapy has revolutionized the management of head and neck cancers in the last decade. However, the use of targeted therapies raised several clinically relevant questions that have yet to be answered. These questions include the optimal patient and tumor profile for biologically targeted therapy, the optimal radiation fractionation to use with targeted therapies, how to integrate them into standard or new chemoradiation regimens, their schedule and duration of administration, their toxicity, and which direction to consider for novel targeted treatment. In this review, we highlight several of these important issues, discuss the clinical trials that are designed to address these issues, and introduce some novel targeted therapies that may contribute to the improvement of the therapeutic ratio for head and neck cancer therapy.

Focus on TILs: prognostic significance of tumor infiltrating lymphocytes in head and neck cancers

The expanding and established literature that correlates tumor infiltrating lymphocytes (TILs) with outcomes of patients with solid tumors has contributed greatly to the appreciation of the interaction between the host immune system with neoplastic growth. This analysis has been limited to specific tumors, such as melanoma and ovarian cancer, and our understanding of TILs in relation to many other malignancies has yet to be explored. We review one less well studied malignancy, head and neck squamous cell carcinoma (HNSCC), and the initial attempts to examine the impact of TILs on outcomes of these patients. To provide a context for the discussion of TILs and HNSCC, we first review the epidemiology, relevant head and neck anatomy, immune responses and discuss the historical data regarding the unique immunobiology of these tumors. Finally, with this perspective, we describe our current understanding of tumor infiltrating lymphocyte data for head and neck cancers.

Oropharyngeal carcinoma in non-smokers and non-drinkers: a role for HPV

Incidence of oropharyngeal squamous cell carcinoma (OSCC) increased 3% annually from 1973 to 2001. OSCC's can be attributed to tobacco and alcohol, but 25% are unlinked to typical risks. Case-control studies on HPV detection in non-smoking/non-drinking (NS/ND) OSCC patients have not previously been performed. The primary objective of this study was to determine whether high-risk HPV infection was significantly associated with development of oral squamous malignancy in non-smokers/non-drinkers. A chart review of 802 OSCC patients from the UNC Pathology Archives (1995-2006) yielded 40 non-smoker/non-drinker subjects. Utilizing a case-control design, 18 cancer cases and 22 benign biopsy controls were consecutively identified. Biopsy tissue was subjected to (i) HPV-L1 consensus PCR and sequencing (ii) real-time PCR. Chi-square and logistic regression analysis was employed. Logistic regression analysis determined that cases were 6.1 (OR 95% CI, 1.3-28) times more likely to have HPV infection in their tumors than controls. High-risk HPV-DNA was readily detected in the tonsils and base of tongue (oropharynx) of 14/18 cases and 6/22 controls by both consensus and real-time PCR. Of high-risk HPV containing lesions, 85% (17/20) originated in the oropharynx (chi-square, p=0.03). High risk HPV was also detected in benign biopsies of the oropharynx in 30% (3/10) of individuals who had a previous oral cancer (chi-square, p=0.006). The infectious nature of OSCC in NS/ND was revealed by consistent detection of HPV, suggesting HPV's potential role in transforming oral epithelium, providing further evidence of the need to screen the oropharynx for HPV in NS/ND.

The role of viruses in squamous cell carcinoma of the oropharyngeal mucosa

The development of squamous cell carcinomas of the oropharyngeal mucosa may involve many factors, including viruses. This review examines the evidence that viruses could be involved in the etiology of oral cancer, and shows that the evidence for a role of different viruses varies from very weak to very persuasive. Papillomaviruses are probably involved in the etiology of some carcinomas, particularly those of the oropharynx, and some herpes viruses may be involved as well. On the other hand some viruses can cause cancer in experimental situations but not in humans. Thus the importance of viruses in oral cancer is not always clear and must be evaluated with care. Those viruses that are associated with the disease provide targets for therapy and for diagnostic assays.

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

CONTEXT

Head and neck squamous cell carcinoma is commonly associated with tobacco and alcohol use. There are, however, a group of patients without a significant history of tobacco or alcohol use, and the etiology of these tumors is incompletely understood.

OBJECTIVE

To examine tumors in this subpopulation for association with human papillomavirus (HPV) using newly available in situ hybridization probes.

DESIGN

Between October 2004 and October 2005, 22 patients who did not use alcohol or tobacco were included. Formalin-fixed, paraffin-embedded tissue sections were used to perform in situ hybridization using newly available probe sets (Ventana Medical Systems, Tucson, Ariz). The slides were examined for the presence of integrated HPV using light microscopy. Positive and negative xenograft controls were run with the assay. Results.-The mean age of the patients was 64 years. There were 14 men and 8 women. The most common anatomic sites included tongue (n = 8), tonsil (n = 7), and larynx (n = 7). All cases and controls were successfully stained. Only 2 cases were positive for high-risk HPV, and both demonstrated an integrated pattern. Both cases were tumors of the tonsil. No cases were positive for low-risk HPV.

CONCLUSIONS

These results demonstrate that the new probe sets for HPV can be used very efficiently in clinical pathology material of head and neck squamous cell carcinoma. Our data show that high-risk HPV is an uncommon finding in head and neck squamous cell carcinoma from patients who do not have a history of tobacco or alcohol use; low-risk HPV was not seen in any case.

HPV E6, E6AP and cervical cancer

Every year, approximately 470,000 new cases of cervical cancer are diagnosed and approximately 230,000 women worldwide die of the disease, with the majority (approximately 80%) of these cases and deaths occurring in developing countries. Human papillomaviruses (HPVs) are the etiological agents in nearly all cases (99.7%) of cervical cancer, and the HPV E6 protein is one of two viral oncoproteins that is expressed in virtually all HPV-positive cancers. E6 hijacks a cellular ubiquitin ligase, E6AP, resulting in the ubiquitylation and degradation of the p53 tumor suppressor, as well as several other cellular proteins. While the recent introduction of prophylactic vaccines against specific HPV types offers great promise for prevention of cervical cancer, there remains a need for therapeutics. Biochemical characterization of E6 and E6AP has suggested approaches for interfering with the activities of these proteins that could be useful for this purpose. PUBLICATION HISTORY : Republished from Current BioData's Targeted Proteins database (TPdb; http://www.targetedproteinsdb.com).

Fatal fast-evolution of nasopharyngeal squamous cell carcinoma in an HIV patient with EBV and HPV (-16 AND -33) in blood serum

Our case illustrates the first report of an HIV-infected patient with a nasopharyngeal squamous cell carcinoma with viremia by one Epstein-Barr virus (EBV) and seropositivity by two high risk oncogenic human papilloma viruses (HPV)-types (HPV-16 and HPV-33), previous to his death. This patient presented a fatal fast-evolution.

HPV antibody levels and clinical efficacy following administration of a prophylactic quadrivalent HPV vaccine

The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti-HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day 1 and at 6-12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine subjects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5-100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers.

Human papillomavirus-related diseases: oropharynx cancers and potential implications for adolescent HPV vaccination

Molecular and epidemiological data now support an etiologic role for oncogenic human papillomavirus (HPV) in oral cancers in women and men. Recent studies have demonstrated an increase in the incidence of HPV-associated oral cancers in the United States. Moreover, the incidence rates for these cancers are higher in men than women. Oral HPV infections acquired through oral sex appear to be the principal risk factor for HPV-associated oral cancers. Despite reports in the popular press that the prevalence of oral sexual behaviors is increasing in the adolescent population, trends in these behaviors over time are largely unavailable. However, data indicate that oral-genital contact is frequently practiced among adolescents; adolescents do not typically consider this a risky behavior. The majority of oral cancers (approximately 90%) caused by HPV are identified as HPV 16 positive. Therefore, HPV-associated oral cancers could be prevented by a prophylactic vaccine if the vaccine were demonstrated to be capable of preventing oral HPV 16 infection. These findings have created new potential opportunities for the primary prevention of oral cancers.

Combined effects of the p53 codon 72 and p73 G4C14-to-A4T14 polymorphisms on the risk of HPV16-associated oral cancer in never-smokers

Because p53 and p73 are associated with critical cellular processes and can be inactivated or degraded by the human papillomavirus (HPV) E6 oncoprotein, we investigated the combined effects of p53 codon 72 and p73 G4C14-to-A4T14 polymorphisms on the risk of HPV16-associated oral cancer. We analyzed genotype data from 326 patients with squamous cell carcinoma of the oral cavity or oropharynx and 349 cancer-free controls. We found that HPV16 seropositivity was associated with an increased risk of oral cancer [adjusted odds ratio (OR), 3.42; 95% confidence interval (CI), 2.28-5.13], especially among never-smokers (adjusted OR, 8.20; 95% CI, 3.66-18.4) and subjects with variant genotypes [adjusted OR for p53 Arg/Pro + Pro/Pro (Pro carriers), 5.00; 95% CI, 2.72-9.21; adjusted OR for p73 GC/AT + AT/AT (AT carriers), 3.83; 95% CI, 1.98-7.41]. HPV16 seropositivity was also associated with an significantly increased risk of oral cancer in all three risk groups with combined genotypes [adjusted ORs (95% CIs) were 2.28 (1.15-4.54) for p53 Arg/Arg and p73 GC/GC, the low-risk group; 3.97 (2.14-7.36) for p53 Arg/Arg and p73 AT carriers or p53 Pro carriers and p73 GC/GC, the medium-risk group and 5.11 (2.00-13.0) for p53 Pro carriers and p73 AT carriers, the high-risk group]. Moreover, HPV16-seropositive never-smokers in the high-risk group exhibited an approximately 11-fold greater risk of oral cancer (adjusted OR, 11.3; 95% CI, 1.22-106.0) than did HPV16-seronegative never-smokers in the low-risk group. These findings suggest that the combined variants of p53 and p73 significantly increase the risk of HPV16-associated oral cancer, especially among never-smokers.

Chemotherapy in the treatment of locally advanced head and neck cancer

Three decades of collaborative research have led to the integration of platinum-based chemotherapy into the curative management of squamous cell carcinoma of the head and neck and gains in local-regional control, organ preservation and survival endpoints. Concomitant cisplatin-based chemotherapy and radiotherapy is the strategy that has proven most effective for organ preservation for larynx and oropharynx cancers, the treatment of unresectable disease, nasopharyngeal cancer and the post-operative adjuvant treatment of patients at high risk of recurrence. The evolution of current indications for this multimodality approach is reviewed and current areas of investigation discussed. Nearly all patients with locally advanced head and neck cancer receive chemotherapy as part of initial curative treatment. The focus of future trials should be on survival improvement, toxicity reduction and risk stratification for treatment decision making.

Molecular pathogenesis of head and neck cancers

Head and neck cancers represent a progressive genetic malady, with genetic aberrations accumulating in response to carcinogen exposure. Although individual genomic aberrations develop at specific time points in the progression axis, the precise role of these abnormalities in tumor progression and cancer behavior remain to be elucidated. This article will give an overview of the current knowledge on the molecular basis for the development of head and neck cancers.

Current status of biomarkers in head and neck cancer

As our understanding of HNSCC increases so has biomarker development. HPV16 integration is a significant marker of favorable prognosis and response to therapy for HNSCC. EGFR-amplification and overexpression is a poor-prognostic indicator. For premalignant lesions, LOH of 3p&9p21 loci confers an elevated risk of malignant transformation. As molecular targets are identified, these will be candidates for biomarkers for detection, diagnosis, prognosis, and therapy. Validation of these biomarkers requires demonstration of independence of significance beyond known biomarkers.

Ku70 predicts response and primary tumor recurrence after therapy in locally advanced head and neck cancer

5-Fluorouracil and cisplatin-based induction chemotherapy (IC) is commonly used to treat locally advanced head and neck squamous cell carcinoma (HNSCC). The role of nonhomologous end joining (NHEJ) genes (Ku70, Ku80 and DNA-PKcs) in double-strand break (DSB) repair, genomic instability and apoptosis suggest a possible impact on tumor response to radiotherapy, 5-fluorouracil or cisplatin, as these agents are direct or indirect inductors of DSBs. We evaluated the relationship between Ku80, Ku70 or DNA PKcs mRNA expression in pretreatment tumor biopsies, and tumor response to IC or local recurrence, in 50 patients with HNSCC. Additionally, in an independent cohort of 75 patients with HNSCC, we evaluated the relationship between tumor Ku70 protein expression and the same clinical outcomes or patient survival. Tumors in the responder group had significantly higher mRNA levels for Ku70, Ku80 and DNA-PKcs than those in the nonresponder group. Ku70 mRNA was the marker most significantly associated with response to IC. Moreover, high tumor Ku70 mRNA expression was associated with significantly longer local recurrence-free survival (LRFS). Ku70 protein expression was also significantly related to response, and patients with higher percentage of tumor cells expressing Ku70 had longer LRFS. In addition, the percentage of Ku70 positive cells, tumor localization and node involvement were significantly associated with overall survival of patient. Therefore, Ku70 expression is a candidate predictive marker that could distinguish patients who are likely to benefit from chemoradiotherapy or radiotherapy after the induction chemotherapy treatment, suggesting a contribution of the NHEJ system in HNSCC clinical outcome.

A genotype-phenotype examination of cyclin D1 on risk and outcome of squamous cell carcinoma of the head and neck

PURPOSE

The variant allele of CCND1 G870A encodes a splice variant of the cyclin D1 protein, which possesses an increased half-life. To confirm the phenotypic effect of the variant allele, we examined the immunohistochemical staining pattern of the protein in tumors from a case population of head and neck squamous cell carcinoma (HNSCC) and compared it with the genotype of these individuals. We also examined how this genotype was associated with the risk of HNSCC and if this genotype-phenotype association was related to patient outcome.

EXPERIMENTAL DESIGN

In a population-based case-control study of 698 cases and 777 controls, we both genotyped all participants for the CCND1 gene and did immunohistochemical staining of the cyclin D1 protein in the HNSCC tumors.

RESULTS

The variant AA genotype was significantly associated with positive immunohistochemical staining (P < 0.02), and this variant genotype was associated with a significantly elevated odds ratio of 1.5 (95% confidence interval, 1.1-2.0) for HNSCC overall, with risk greatest in oral and laryngeal sites. Positive immunohistochemical staining was inversely related to human papillomavirus 16 DNA present in the tumor (P < 0.03). The AA genotype and superpositive immunohistochemical staining for cyclin D1 also had independent and significant effects on patient survival.

CONCLUSIONS

These results strongly suggest that this splice variant, when present in two copies, is a significant predictor of both the occurrence of HNSCC as well as patient survival after treatment. These data further indicate that this variant protein is an important determinant of individual response to therapy for this disease.

Chemoselection as a strategy for organ preservation in advanced oropharynx cancer: response and survival positively associated with HPV16 copy number

PURPOSE

To test induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CRT) or surgery/radiotherapy (RT) for advanced oropharyngeal cancer and to assess the effect of human papilloma virus (HPV) on response and outcome.

PATIENTS AND METHODS

Sixty-six patients (51 male; 15 female) with stage III to IV squamous cell carcinoma of the oropharynx (SCCOP) were treated with one cycle of cisplatin (100 mg/m(2)) or carboplatin (AUC 6) and with fluorouracil (1,000 mg/m(2)/d for 5 days) to select candidates for CRT. Those achieving a greater than 50% response at the primary tumor received CRT (70 Gy; 35 fractions with concurrent cisplatin 100 mg/m(2) or carboplatin (AUC 6) every 21 days for three cycles). Adjuvant paclitaxel was given to patients who were complete histologic responders. Patients with a response of 50% or less underwent definitive surgery and postoperative radiation. Pretreatment biopsies from 42 patients were tested for high-risk HPV.

RESULTS

Fifty-four of 66 patients (81%) had a greater than 50% response after IC. Of these, 53 (98%) received CRT, and 49 (92%) obtained complete histologic response with a 73.4% (47 of 64) rate of organ preservation. The 4-year overall survival (OS) was 70.4%, and the disease-specific survival (DSS) was 75.8% (median follow-up, 64.1 months). HPV16, found in 27 of 42 (64.3%) biopsies, was associated with younger age (median, 55 v 63 years; P = .016), sex (22 of 30 males [73.3%] and five of 12 females [41.7%]; P = .08), and nonsmoking status (P = .037). HPV titer was significantly associated with IC response (P = .001), CRT response (P = .005), OS (P = .007), and DSS (P = .008).

CONCLUSION

Although the numbers in this study are small, IC followed by CRT is an effective treatment for SCCOP, especially in patients with HPV-positive tumors; however, for patients who do not respond to treatment, alternative treatments must be developed.

EGFR, p16, HPV Titer, Bcl-xL and p53, sex, and smoking as indicators of response to therapy and survival in oropharyngeal cancer

PURPOSE

To prospectively identify markers of response to therapy and outcome in an organ-sparing trial for advanced oropharyngeal cancer.

PATIENTS AND METHODS

Pretreatment biopsies were examined for expression of epidermal growth factor receptor (EGFR), p16, Bcl-xL, and p53 as well as for p53 mutation. These markers were assessed for association with high-risk human papillomavirus (HPV), response to therapy, and survival. Patient variables included smoking history, sex, age, primary site, tumor stage, and nodal status.

RESULTS

EGFR expression was inversely associated with response to induction chemotherapy (IC) (P = .01), chemotherapy/radiotherapy (CRT; P = .055), overall survival (OS; P = .001), and disease-specific survival (DSS; P = .002) and was directly associated with current smoking (P = .04), female sex (P = .053), and lower HPV titer (P = .03). HPV titer was significantly associated with p16 expression (P < .0001); p16 was significantly associated with response to IC (P = .008), CRT (P = .009), OS (P = .001), and DSS (P = .003). As combined markers, lower HPV titer and high EGFR expression were associated with worse OS (rho(EGFR) = 0.008; rho(HPV) = 0.03) and DSS (rho(EGFR) = 0.01; rho(HPV) = 0.016). In 36 of 42 biopsies, p53 was wild-type, and only one HPV-positive tumor had mutant p53. The combination of low p53 and high Bcl-xL expression was associated with poor OS (P = .005) and DSS (P = .002).

CONCLUSION

Low EGFR and high p16 (or higher HPV titer) expression are markers of good response to organ-sparing therapy and outcome, whereas high EGFR expression, combined low p53/high Bcl-xL expression, female sex, and smoking are associated with a poor outcome. Smoking cessation and strategies to target EGFR and Bcl-xL are important adjuncts to the treatment of oropharyngeal cancer.

The biomarkers of human papillomavirus infection in tonsillar squamous cell carcinoma-molecular basis and predicting favorable outcome

Presence of human papillomavirus (HPV) in variable proportions in tonsillar squamous cell carcinoma tissues has been demonstrated by several worldwide studies. Some reports emphasized the significance of HPV in predicting a better prognosis, as well as ethnic differences between Chinese and Caucasians. In order to understand the biological role of HPV and find out clinically accessible methods to determine its prognostic significance in primary tonsillar squamous cell carcinoma, we collected 92 patients with primary tonsillar squamous cell carcinoma diagnosed or treated in National Taiwan University Hospital, for whom archival tumor tissue were available. Immunohistochemical stains of p16(INK4A), high-risk HPV in situ hybridization, and nested polymerase chain reaction (PCR)-based genechips were performed to detect HPV infection and determine its genotype. Clinical data were compared with HPV infection detected by the different methods mentioned above. Real-time PCR was also performed on the HPV16-positive [HPV16(+)] lesions to understand viral integration status. The positive rates of nested PCR-based genechips, overexpression of p16(INK4A), and high-risk HPV in situ hybridization were 75% (69/92), 53% (49/92), and 44% (40/92), respectively. Both overexpression of P16(INK4A) and high-risk HPV in situ hybridization positivity were associated with favorable prognoses (P=0.004 and 0.001, respectively) and also independent prognostic factors in multivariate analyses (P=0.01 and 0.01, respectively). The positivity of nested PCR-based genechips was not statistically significant. From our data, primary tonsillar squamous cell carcinoma with positive immunohistochemical stains of p16(INK4A) and/or high-risk HPV in situ hybridization is associated with a better outcome, and both methods may serve as clinically accessible markers.

Incidence trends for human papillomavirus-related and -unrelated oral squamous cell carcinomas in the United States

PURPOSE

To investigate the impact of human papillomavirus (HPV) on the epidemiology of oral squamous cell carcinomas (OSCCs) in the United States, we assessed differences in patient characteristics, incidence, and survival between potentially HPV-related and HPV-unrelated OSCC sites.

PATIENTS AND METHODS

Data from nine Surveillance, Epidemiology, and End Results program registries (1973 to 2004) were used to classify OSCCs by anatomic site as potentially HPV-related (n = 17,625) or HPV-unrelated (n = 28,144). Joinpoint regression and age-period-cohort models were used to assess incidence trends. Life-table analyses were used to compare 2-year overall survival for HPV-related and HPV-unrelated OSCCs.

RESULTS

HPV-related OSCCs were diagnosed at younger ages than HPV-unrelated OSCCs (mean ages at diagnosis, 61.0 and 63.8 years, respectively; P < .001). Incidence increased significantly for HPV-related OSCC from 1973 to 2004 (annual percentage change [APC] = 0.80; P < .001), particularly among white men and at younger ages. By contrast, incidence for HPV-unrelated OSCC was stable through 1982 (APC = 0.82; P = .186) and declined significantly during 1983 to 2004 (APC = -1.85; P < .001). When treated with radiation, improvements in 2-year survival across calendar periods were more pronounced for HPV-related OSCCs (absolute increase in survival from 1973 through 1982 to 1993 through 2004 for localized, regional, and distant stages = 9.9%, 23.1%, and 18.6%, respectively) than HPV-unrelated OSCCs (5.6%, 3.1%, and 9.9%, respectively). During 1993 to 2004, for all stages treated with radiation, patients with HPV-related OSCCs had significantly higher survival rates than those with HPV-unrelated OSCCs.

CONCLUSION

The proportion of OSCCs that are potentially HPV-related increased in the United States from 1973 to 2004, perhaps as a result of changing sexual behaviors. Recent improvements in survival with radiotherapy may be due in part to a shift in the etiology of OSCCs.

p53 codon 72 polymorphism associated with risk of human papillomavirus-associated squamous cell carcinoma of the oropharynx in never-smokers

The tumor suppressor p53 protein can be bound, degraded and inactivated by the human papillomavirus (HPV) E6 oncoprotein. The p53 protein's susceptibility to this oncoprotein may be influenced by the p53 codon 72 polymorphism, but the role of such a polymorphism in the development of HPV16-associated squamous cell carcinoma of the oropharynx (SCCOP) has not been established. To investigate the role of the p53 codon 72 polymorphism in the risk of HPV16-associated SCCOP, we conducted a hospital-based case-control study of 188 non-Hispanic white patients with newly diagnosed SCCOP and 342 cancer-free control subjects frequency matched by age (+/-5 years), sex, tobacco smoking status and alcohol drinking status. We found that HPV16 seropositivity was associated with an increased risk of SCCOP [adjusted odds ratio (OR), 5.7; 95% confidence interval (CI), 3.7-8.7], especially among never-smokers (adjusted OR, 14.1; 95% CI, 6.0-32.9) and among subjects with the p53 codon 72 variant genotypes [Arginine (Arg)/Proline (Pro) and Pro/Pro] (adjusted OR, 9.2; 95% CI, 4.7-17.7). A significant multiplicative interaction on the risk of SCCOP was also found between the p53 codon 72 polymorphism and HPV16 seropositivity (P = 0.05). Among never-smokers, the risk of SCCOP for those who had both HPV16 seropositivity and p53 codon 72 variant genotypes (Arg/Pro + Pro/Pro) was particularly high (adjusted OR, 22.5; 95% CI, 4.8-106.2). These findings suggest that p53 codon 72 variant genotypes modify the risk of HPV16-associated SCCOP and may be markers of genetic susceptibility to HPV16-associated SCCOP, especially among never-smokers.

Detection and genotyping of human papillomavirus DNA in samples from healthy Sardinian patients: a preliminary study

The human papillomavirus (HPV) is involved in the development of different benign and malignant lesions that include in particular squamous tumours of the cervix, skin and the respiratory tracts. In particular, the 'high risk' HPV type 16 (HPV 16) causes genito-rectal epithelial cancers and is suspected of causing epithelial cancers of the head and neck. To determine the presence and genotypes of HPV was determined in saliva samples from 164 subjects recruited from the Department of Surgery and Odontostomatological Sciences (University of Cagliari). For this study a sensitive seminested polymerase chain reaction (PCR) method was used to detect HPV-DNA; moreover in all positive samples, HPV genotyping was based on sequencing of the HPV genome L1 region. The results obtained with these patients (who were ethnically homogeneous), showed an interesting percentage of positive samples for HPV-DNA (30 samples out of 164-18.3%). Only two HPV genotypes have been identified in these patients, HPV 16 and HPV 31 with 76.7% and 23.3% of the positive specimens, respectively, both correlating with high carcinogenic risk. This preliminary result leads us to reflect on the presence of HPV in saliva, in particular in young asymptomatic subjects (15.38%), and its prognostic value for the possible incidence in Sardinia of oral carcinoma.

Expression of p53 and its homolog, p73, in HPV DNA positive oesophageal squamous cell carcinomas

Several studies have detected human papilloma virus (HPV) DNA in squamous cell carcinoma of the oesophagus (OSCC). In this study, we analysed OSCC specimens from 114 patients for the presence of HPV DNA, and p53 and p73 expression. HPV DNA was detected in 44.7% of cases, with the low risk HPV11 occurring most frequently. p53 and p73 expression was detected in 70% and 61.4% of cases, respectively. There was no correlation between expression of p53, p73 or HPV infection and tumour grade, or between p53 expression and the presence of HPV DNA. There was, however, significant correlation between p73 expression and the presence of HPV DNA (p<0.01) and p53 and p73 co-expression (p<0.001), as well as co-expression of p53 and p73 with HPV status (p<0.05). These data support previous studies suggesting a role for HPV infection in OSCC and also indicate that HPV infection and p53 and p73 overexpression are not mutually exclusive. In addition, the data implicate a role for p73 in OSCC and suggest a complex interaction between p53, p73 and HPV in the aetiology of the disease.

Response to therapy and outcomes in oropharyngeal cancer are associated with biomarkers including human papillomavirus, epidermal growth factor receptor, gender, and smoking

Induction chemotherapy and concurrent chemoradiation for responders or immediate surgery for non-responders is an effective treatment strategy head and neck squamous cell carcinoma (HNSCC) of the larynx and oropharynx. Biomarkers that predict outcome would be valuable in selecting patients for therapy. In this study, the presence and titer of high risk human papilloma virus (HPV) and expression of epidermal growth factor receptor (EGFR) in pre-treatment biopsies, as well as smoking and gender were examined in oropharynx cancer patients enrolled in an organ sparing trial. HPV16 copy number was positively associated with response to therapy and with overall and disease specific survival, whereas EGFR expression, current or former smoking behavior, and female gender (in this cohort) were associated with poor response and poor survival in multivariate analysis. Smoking cessation and strategies to target EGFR may be useful adjuncts for therapy to improve outcome in the cases with the poorest biomarker profile.

Assessment of epidermal growth factor receptor (EGFR, ErbB1) and HER2 (ErbB2) protein expression levels and response to lapatinib (Tykerb, GW572016) in an expanded panel of human normal and tumour cell lines

OBJECTIVE

Lapatinib (Tykerb, GW572016), a potent inhibitor of the catalytic activities of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) (ErbB2), inhibits population growth of selected EGFR and HER2 overexpressing cell lines. Previous studies with a small number of cell lines suggest a correlation between overexpression of EGFR and/or HER2 and sensitivity to growth inhibition by lapatinib; however, the precise determinants of lapatinib selectivity for tumour and/or other cells remain unclear.

MATERIALS AND METHODS

To clarify the determinants of its selectivity in cultured cells, lapatinib-induced cell population growth inhibition and relative EGFR and HER2 protein expression were quantified in 61 different human tumour cell lines from 12 tumour types, two oncogene transformed human cell lines and two normal human cell cultures. Using statistical tools to analyse the data, a model describing the relationship between lapatinib IC(50) (the response variable) and EGFR and HER2 expression and tissue type (explanatory variables) was derived.

CONCLUSION

The results suggest that simultaneous consideration of EGFR and HER2 expression, as well as tissue type yields the best determinant of lapatinib selectivity in cultured cells.

Chemoprevention of squamous cell carcinoma of the head and neck

PURPOSE OF REVIEW

The aim of this article is to summarize progress in understanding of the biology of squamous cell carcinoma of the head and neck and of trials to prevent malignant conversion of oral premalignant lesions and the development of second primary tumors in those already treated for squamous cell carcinoma of the head and neck.

RECENT FINDINGS

The understanding of squamous cell carcinoma of the head and neck biology is rapidly evolving. Clinical trials for chemoprevention are involving more diverse regimens, following disappointing results of retinoid monotherapy. In-vitro and animal studies form the rationale for the next generation of studies, employing combination, synergistic treatments.

SUMMARY

Based on trial data to date, no recommendation for intervention with a chemopreventive agent can be made. It is clear, however, that smoking cessation is an effective intervention for preventing oral premalignant lesions and second primary tumors. Promising trials are being conducted and designed currently. The future of this area of study will involve rational choice of multidrug regimens based on current understanding of the biology of squamous cell carcinoma of the head and neck.

Human papillomavirus therapeutic vaccines in head and neck tumors

Head and neck cancer represents one of the most challenging diseases as the mortality remains high despite advances in early diagnosis and treatment. Human papillomavirus has been implicated in a third of head and neck squamous cell carcinomas and human papillomavirus type 16 is strongly associated with carcinomas arising from the oropharynx, the tonsil being the preferred infected site. Novel therapeutic approaches including immunotherapy are currently under investigation. Immune vaccines developed against human papillomavirus in the genital area are already available and could simultaneously protect other anatomical localizations; however, prophylactic vaccines are expected to be effective in reducing the incidence of tumors after many years and, therefore, there is an urgent need to improve therapeutic interventions, such as immunotherapy. To date, human papillomavirus therapeutic vaccines are either at the preclinical level or at early phase human trials for genital pathologies. Nevertheless, accumulating evidence from animal and clinical studies suggests that the enhancement of specific and innate immune responses is effective in clearance of the human papillomavirus infection, promoting a cautious optimism regarding the achievement of an efficacious immunotherapy. This article reviews what has been achieved and what remains to be done in the field for the development of future viral vaccines in head and neck tumors.

Induction of immune memory following administration of a prophylactic quadrivalent human papillomavirus (HPV) types 6/11/16/18 L1 virus-like particle (VLP) vaccine

BACKGROUND

The duration of protection afforded by vaccines represents a critical test of their utility as public health interventions. Some vaccines induce long-term immunity, while others require booster doses. Vaccines that induce long-term protection are usually characterized by the generation of immune memory. Recent trials of a quadrivalent (types 6, 11, 16, 18) human papillomavirus (HPV) vaccine have demonstrated high efficacy through 5 years of follow-up. We evaluated the extent to which the vaccine is able to generate HPV type-specific immune memory.

METHODS

A total of 552, 16-23-year-old women were enrolled in a double-blind, placebo-controlled study. At enrollment, subjects were randomized in a 1:1 ratio to receive three-dose regimens of quadrivalent HPV vaccine or placebo with 3 years' follow-up. A subset of 241 subjects (n=114 in the quadrivalent HPV vaccine group and n=127 in the placebo group) underwent 2 further years of follow-up. All extension subjects received quadrivalent HPV vaccine at month 60 to examine the extent of immune memory in response to the primary vaccination series.

RESULTS

Serum anti-HPV levels declined post-vaccination, but reached a plateau at month 24 that remained stable through month 60. Administration of a challenge dose of vaccine induced a classic anamnestic response, with anti-HPV levels 1 week post-challenge reaching levels observed 1 month following the completion of the three-dose primary series. At 1 month post-challenge, anti-HPV responses were higher than those observed 1-month post-dose 3.

DISCUSSION

A three-dose regimen of quadrivalent HPV vaccine induces high efficacy and stable anti-HPV levels for at least 5 years. Vaccination also induces robust immune memory. These findings suggest that the efficacy of this vaccine will be long lasting.

Lower prevalence but favorable survival for human papillomavirus-related squamous cell carcinoma of tonsil in Taiwan

Human papillomavirus (HPV) is frequently detected in squamous cell carcinoma of tonsil (TSCC) among the Western population. However, the only reported study on Chinese patients in the English literature demonstrated absence of HPV in TSCC. To evaluate the prevalence and clinical significance of HPV-related TSCC in Taiwan, we performed PCR with MY09/MY11 consensus primers and in situ hybridization to study 111 TSCC samples. The results showed that only 12.6% TSCC were HPV-positive. The favorable 5-year survival rate correlated significantly with HPV positivity (p=0.007), female (p=0.046), and early tumor (T) stage (p<0.001), but Cox's regression analysis revealed that only the status of HPV (p=0.04) and T stage (p=0.004) were independent prognostic factors for survival. In conclusion, the prevalence of HPV-related TSCC is much lower in Taiwan comparing with the Western population, and the prognosis of HPV-positive TSCC is better than that of HPV-negative TSCC.

Molecular and cytogenetic subgroups of oropharyngeal squamous cell carcinoma

PURPOSE

The aim of this study was to acquire further insights into the pathogenetic pathways of head and neck squamous cell carcinomas (HNSCC) that may be useful for identifying new biomarkers instrumental in developing more specific treatment approaches.

EXPERIMENTAL DESIGN

Cell cycle regulators and epidermal growth factor receptor (EGFR) and BRAF genes were analyzed in a series of 90 oropharyngeal SCCs of a cohort of surgically treated patients from a single institution, and the results were matched with the presence of high-risk human papillomavirus (HR-HPV) DNA and the TP53 status.

RESULTS

At least four distinct groups of tumors were identified sharing a common histology but displaying different molecular/cytogenetic patterns: (a) 19% were HPV-positive SCCs whose lack of alterations of the investigated genes could explain their particular natural history, which requires less aggressive treatment; (b) 37% were HPV-negative SCCs carrying TP53 mutations, which may be more effectively treated by drugs acting through p53-independent apoptosis; (c) 34% were HPV-negative SCCs carrying wild-type TP53 and loss of 9p21 (p16INK4a and p15INK4b) and/or cyclin D1 overexpression that justify treatment with DNA-damaging drugs followed by cell cycle inhibitors; and (d) 10% were HPV-negative lacking tumor suppressor genes and cell cycle alterations. The second, third, and fourth groups also showed an increased copy number of EGFR and chromosome 7 (43%) that might justify the additional or alternative use of EGFR inhibitors.

CONCLUSIONS

Our findings suggest that assessing HPV, TP53, 9p21, and EGFR status may be crucial to finding more tailored and beneficial treatments for oropharyngeal SCCs.

Role of sentinel lymph node biopsy in oral cancer

Squamous cell carcinoma of the oral cavity represents about 2% of all malignant neoplasms and 47% of those developing in the head and neck area. The tongue is the most common site involved, and this incidence is increasing mainly in young people, possibly related to human papilloma virus infections. Prognosis depends on the stage: the 5-year survival rate of tongue squamous cell carcinoma, whatever the T stage, is 73% in pN0 cases, 40% in patients with positive nodes without extracapsular spread (pNl ECS-), and 29% when nodes are metastatic with extracapsular spread (pNl ECS+: p > or = 0.0001). Nodal micrometastases (cN0 pN1) are found in up to 50% of cN0 tongue squamous cell carcinoma patients operated on the neck. At present, no clinical, imaging staging modalities or biological markers are available to diagnose nodal micrometastases. The sentinel node biopsy has been tested since 1996 in order to find a solution to this problem. The sentinel node is the first node reached by the lymphatic stream, assuming an orderly and sequential drainage from the tumour site, and should be predictive of the nodal stage. According to the literature, sentinel node biopsy is a reliable technique in selected cN0 cases, but the procedure is still experimental and should not be performed outside validation trials. Successful application of sentinel node biopsy in the head and neck region requires surgical experience and specific technical devices, including pre-operative lymphoscintigraphy and intra-operative gamma-probe. Moreover, dynamic lymphoscintigraphy seems to be able to show the lymphatic stream from the primary tumour and could allow a selective neck dissection to be tailored thus reducing the related morbidity.