DNA methylation as a triage tool for cervical cancer screening - A meeting report.

Introduction: DNA methylation is proposed as a novel biomarker able to monitor molecular events in human papillomavirus (HPV) infection pathophysiology, enabling the distinction between HPV-induced lesions with regression potential from those that may progress to HPV-related cancer. Methods: This meeting report summarises the presentations and expert discussions during the HPV Prevention and Control Board-focused topic technical meeting on DNA methylation validation in clinician-collected and self-collected samples, novel DNA methylation markers discovery, implementation in cervical cancer screening programs, and their potential in women living with human immunodeficiency virus (HIV). Results: Data presented in the meeting showed that HPV-positive, baseline methylation-negative women have a lower cumulative cervical cancer incidence than baseline cytology-negative women, making DNA methylation an attractive triage strategy. However, additional standardised data in different settings (low- versus high-income settings), samples (clinician-collected and self-collected), study designs (prospective, modelling, impact) and populations (immunocompetent women, women living with HIV) are needed. Conclusion: Establishing international validation guidelines were identified as the way forward towards accurate validation and subsequent implementation in current screening programs.

Effect of pneumococcal conjugate vaccines on viral respiratory infections: a systematic literature review.

BACKGROUND: In addition to preventing pneumococcal disease, emerging evidence indicates that pneumococcal conjugate vaccines (PCVs) might indirectly reduce viral respiratory tract infections (RTI) by affecting pneumococcal-viral interactions. METHODS: We performed a systematic review of interventional and observational studies published during 2000-2022 on vaccine efficacy/adjusted effectiveness (VE) and overall effect of PCV7, PCV9, PCV10, or PCV13 against viral RTI. RESULTS: Sixteen of 1671 records identified were included. Thirteen publications described effects of PCVs against viral RTIs in children. VE against influenza ranged between 41-86% (n=4), except for the 2010-2011 influenza season. In a randomized controlled trial, PCV9 displayed efficacy against any viral RTI, human seasonal coronavirus, parainfluenza, and human metapneumovirus. Data in adults were limited (n=3). PCV13 VE ranged between 4-25% against viral lower RTI, 32-35% against COVID-19 outcomes, 24-51% against human seasonal coronavirus, and 13-36% against influenza A lower RTI, with some 95%CI spanning zero. No protection was found against adenovirus or rhinovirus in children or adults. CONCLUSIONS: PCVs were associated with protection against some viral RTI, with the strongest evidence for influenza in children. Limited evidence for adults was generally consistent with pediatric data. Restricting public health evaluations to confirmed pneumococcal outcomes may underestimate the full impact of PCVs.

An update on one-dose HPV vaccine studies, immunobridging and humoral immune responses - A meeting report.

The 12th HPV Prevention and Control meeting was held on June 2-3, 2022, in Antwerp, Belgium. This technical meeting focused on several topics. This report summarises the discussions and lessons learned on two topics: an update on one-dose HPV vaccination studies and humoral immune responses upon HPV vaccination. Long-term follow-up studies from Costa Rica (eleven years) and India (ten years) report stable levels of antibodies after a single HPV vaccination. High vaccine effectiveness against incident persistent HPV 16/18 infection was seen in India (95.4%, 85.0-99.9) ten years postvaccination and in Kenya (97.5%, 81.7-99.7) eighteen months postvaccination, an important observation in a setting with a higher HPV prevalence. The potential impact of HPV vaccination using a one-dose schedule in India was modelled and showed that implementation of one-dose schedule can contribute towards achieving WHO Cervical Cancer elimination goals. These data support the WHO SAGE recommendations for adopting a one-dose schedule for females aged 9-20 years. Immunobridging studies were discussed during the meeting. General agreement was reached that when thoughtfully applied, they can support and accelerate the expanded use of HPV vaccine with new vaccine schedules, age cohorts, or vaccine formulations. Internationally standardised measurements of HPV immune responses important for the progress of HPV vaccinology field. Humoral immune responses upon HPV vaccination plateau at 24 months regardless of number of doses, therefore, data should be analysed after at least 24 months of follow-up to bridge studies accurately.

Prevention and control of HPV and HPV-related cancers in France: the evolving landscape and the way forward - a meeting report.

Misinformation regarding HPV vaccine safety and benefits has resulted in low coverage within the eligible French population. HPV vaccination is safe and efficacious in preventing HPV infections in adolescents. However, reaching optimal coverage in countries such as France is challenging due to misinformation, among other factors. Moreover, disparities exist in cervical cancer screening programs. To support the government health promotion policy aimed at improving prevention and control of HPV-related cancers in France, the Human Papillomavirus Prevention and Control Board (HPV-PCB), in collaboration with local experts, held a meeting in Annecy, France (December 2021).HPV-PCB is an independent, multidisciplinary board of international experts that disseminates relevant information on HPV to a broad array of stakeholders and provides guidance on strategic, technical and policy issues in the implementation of HPV control programs.After a one-and-a-half-day meeting, participants concluded that multi-pronged strategies are required to expand vaccination coverage and screening. Vaccine acceptance could be improved by: 1) strenghtening existing trust in clinicians by continuous training of current and upcoming/pre-service healthcare professionals (HCPs), 2) improving health literacy among adolescents and the public through school and social media platforms, and 3) providing full reimbursement of the gender-neutral HPV vaccine, as a strong signal that this vaccination is essential.The discussions on HPV infections control focused on the need to: 1) encourage HCPs to facilitate patient data collection to support performance assessment of the national cervical cancer screening program, 2) advance the transition from cytology to HPV-based screening, 3) improve cancer prevention training and awareness for all HCPs involved in screening, including midwives, 4) identifying patient barriers to invitation acceptance, and 5) promoting urine or vaginal self-sampling screening techniques to improve acceptability, while establishing appropriate follow-up strategies for HPV-positive women. This report covers some critical findings, key challenges, and future steps to improve the status of HPV prevention and control measures in the country.

Real-world impact and effectiveness of the quadrivalent HPV vaccine: an updated systematic literature review.

INTRODUCTION: Human papillomavirus (HPV) infection, which poses significant disease burden, is decreasing following implementation of vaccination programs. Synthesized evidence on HPV vaccine real-world benefit was published in 2016. However, long-term impact of vaccination, and how vaccination programs influence infection rates and disease outcomes, requires further examination. AREAS COVERED: We systematically reviewed observational studies on HPV vaccination within MEDLINE, EMBASE, and Google Scholar from 2016 to 2020, involving 14 years of follow-up data. We identified 138 peer-reviewed publications reporting HPV vaccine impact or effectiveness. Outcomes of interest included rates of infection at different anatomical sites and incidence of several HPV-related disease endpoints. EXPERT OPINION: The expansion of HPV vaccination programs worldwide has led to a reduction in genital infection and significant decreases in incidence of HPV-related disease outcomes. Therefore, the WHO has set goals for the elimination of cervical cancer as a public health concern. To track progress toward this requires an understanding of the effectiveness of different vaccination initiatives. However, the impact on males, and potential benefit of gender-neutral vaccination programs have not been fully explored. To present an accurate commentary on the current outlook of vaccination and to help shape policy therefore requires a systematic review of available data.

Real-world impact and effectiveness assessment of the quadrivalent HPV vaccine: a systematic review of study designs and data sources.

INTRODUCTION: Vaccine effectiveness and impact studies are typically observational, generating evidence after vaccine launch in a real-world setting. For human papillomavirus (HPV) vaccination studies, the variety of data sources and methods used is pronounced. Careful selection of study design, data capture and analytical methods can mitigate potential bias in such studies. AREAS COVERED: We systematically reviewed the different study designs, methods, and data sources in published evidence (1/2007-3/2020), which assessed the quadrivalent HPV vaccine effectiveness and impact on cervical/cervicovaginal, anal, and oral HPV infections, anogenital warts, lesions in anus, cervix, oropharynx, penis, vagina or vulva, and recurrent respiratory papillomatosis. EXPERT OPINION: The rapid growth in access to real-world data allows global monitoring of effects of different public health interventions, including HPV vaccination programs. But the use of data which are not collected or organized to support research also underscore a need to develop robust methodology that provides insight of vaccine effects and consequences of different health policy decisions. To achieve the WHO elimination goal, we foresee a growing need to evaluate HPV vaccination programs globally. A critical appraisal summary of methodology used will provide timely guidance to researchers who want to initiate research activities in various settings.

Human papillomavirus vaccination in adults: impact, opportunities and challenges - a meeting report.

For more than a decade human papillomavirus (HPV) vaccine have been implemented in most high-income countries, and more recently also in several low- and middle-income countries. The vaccines are safe and their impact and effectiveness in preventing HPV vaccine type infection and associated diseases has been thoroughly established. Currently, the primary recommended cohorts for immunisation are adolescents, 9-15 years of age but HPV is an ubiquitous infection that is mainly (but not exclusively) sexually transmitted. Sexually active adults remain susceptible to infection and continued transmission of the virus, representing a reservoir of infection in the population. A recent meeting, conducted by the HPV Prevention and Control Board (HPV-PCB), reviewed the current status of HPV vaccination of adults, discussed limitations, challenges and benefits of HPV vaccination of adults, evaluated the effectiveness of HPV vaccination after treatment of post cervical cancer and precancerous lesions, and discussed the potential impact of adult vaccination on cervical cancer elimination strategies in light of the current and future HPV vaccine shortage. HPV-PCB is an independent multidisciplinary board of international experts that disseminates relevant information on HPV to a broad array of stakeholders and provides guidance on strategic, technical and policy issues in the implementation of HPV prevention and control programs. The HPV-PCB concluded that, given the current data available on adult HPV vaccination and the ongoing vaccine supply constraints, it is too early to implement routine vaccination of adults. Many research gaps need to be filled before we have a better understanding of the efficacy and broader public health impact of HPV vaccination in adult women.

Impact of the COVID-19 pandemic on human papillomavirus-based testing services to support cervical cancer screening.

INTRODUCTION: The World Health Organization elimination goal for cervical cancer relies on screening 70% of women at ages 35 and 45, preferentially through molecular HPV testing. The SARS-CoV-2 pandemic has led to an unprecedented demand for molecular tests and platforms. Our objective was to gain insight into the impact of SARS-CoV-2 on the actual or anticipated shortage of tests, equipment, consumables, and staff required to deliver molecular HPV laboratory services and to consider the implications for the sustainability and development of cervical screening programs. METHODS: A 19-item online questionnaire was created and made available online between December 2020 and February 2021. Five companies with clinically validated HPV and SARS-CoV-2 tests in their portfolios were invited to provide a statement on the volumes of molecular COVID-19 tests produced, relevant changes to manufacturing capacity, and their current and post-pandemic strategy for HPV tests. RESULTS: We received responses from 57 laboratories representing 30 countries and six continents. Among these, 74% reported experiencing a supply shortage, 54% reported a shortage of personnel, and 33% reported delays in ordering equipment. Three companies described expansion of manufacturing lines, investment in diagnostic infrastructure, and scale-up of manufacturing capacity. Two companies specifically referred to opportunities for the use of platforms for COVID-19 testing to support HPV testing in time. CONCLUSIONS: The demand for SARS-CoV-2 testing is competing with HPV testing, compounded by a shortage of staff. This represents a challenge for existing laboratory services and for settings keen to implement HPV-based screening. However, supply challenges may be addressed in time, given the significant investment in manufacturing capacity. In addition, innovation around molecular COVID-19 testing systems may result in solutions that address the shortage of rapid low-cost HPV testing systems for low-resource settings. Finally, because the demand for COVID-19 testing is likely to decrease, this may release both workforce and platform capacity for high-throughput HPV testing. The global health community should be alert to the opportunities around innovation and capacity if cervical cancer elimination goals are to be reached.

Prevention and control of HPV infection and HPV-related cancers in Colombia- a meeting report.

The Human Papillomavirus (HPV) Prevention and Control Board is an independent multidisciplinary board of international experts that disseminates relevant information on HPV to a broad array of stakeholders and provides guidance on strategic, technical and policy issues in the implementation of HPV control programs. In response to drastic drop of vaccine coverage following the adverse event crisis in Carmen del Bolivar, Colombia, the HPV Prevention and Control Board in collaboration with the Colombian National Cancer Institute and Colombian League Against Cancer convened a meeting in Bogota, Columbia (November 2018). The goal of the meeting was to bring together national and international group of experts to report the disease burden, epidemiology and surveillance of HPV and HPV-related cancers, to discuss the successes and especially the challenges of HPV vaccination and screening in Colombia, as well as the lessons learnt from neighbouring countries. The meeting provided a platform to confer various stakeholder's perspectives, including the role of the Colombian healthcare system and to catalyse various parts of the public health community in Colombia into effective action. The conclusion of the meeting included following suggestions to strengthen HPV prevention and control: 1) Re-introducing school-based vaccine programs, 2) Integrating primary and secondary prevention programs, 3) Developing an innovative crisis communication plan targeting healthcare workers, teachers and general population, 4) Building trust through efficient and timely communication, 5) Building strong relationship with media to ensure a stable vaccination campaign support, and 6) Promoting empathy among healthcare professionals towards patients to build trust and communicate effectively.

The role of healthcare providers in HPV vaccination programs - A meeting report.

The Human Papillomavirus (HPV) Prevention and Control Board convened a meeting in Bucharest, Romania (May 2018), to discuss the role of healthcare providers (HCPs) in prevention programs, with a focus on HPV vaccination and cervical cancer screening. International and local experts discussed the role that HCPs can play to increase the uptake of HPV vaccine and screening. Experts recommended: 1) increasing HCP norms of getting vaccinated; 2) training providers to make effective recommendations; 3) making culturally appropriate materials available, in local languages; and 4) centralizing and coordinating education and information material, to direct both HCPs and the general public to the best material available.

Self-sampling for human papillomavirus DNA detection: a preliminary study of compliance and feasibility in BOLIVIA.

BACKGROUND: Cervical cancer incidence and mortality rates in Bolivia are among the highest in Latin America. This investigation aims to evaluate the possibility of using simple devices, e.g. a cotton swab and a glass slide, for self-sampling in order to detect human papillomavirus (HPV) DNA by PCR in cervico-vaginal cells. METHODS: In the first phase of our study we evaluated the use of a glass slide as a transport medium for cervical cells. A physician took paired-cervical samples from 235 women. One sample was transported in Easyfix® solution and the other sample was smeared over a glass slide. Both were further analyzed and compared for human DNA recovery and HPV detection. A kappa value was determined to evaluate the agreement between the HPV DNA detection rates. In the second phase of the study, 222 women from the urban, peri-urban and rural regions of Cochabamba were requested to perform self-sampling using the following devices: a cotton swab combined with a glass slide, and a vaginal tampon. Women gave their opinion about the self-sampling technique. Finally, the agreement for high risk-HPV detection between self- and physician-collected samples was performed in 201 samples in order to evaluate the self-sampling technique. RESULTS: Firstly, the comparison between Easyfix® solution and the glass slide to transport clinical samples gave a good agreement for HPV DNA detection (κ = 0.71, 95% CI 0.60-0.81). Secondly, self-sampling, especially with cotton swab combined with glass slide, would generally be preferred over clinician sampling for a screening program based on HPV detection. Finally, we showed a good agreement between self- and physician collected samples for high risk-HPV detection (κ = 0.71, 95% CI 0.55-0.88). CONCLUSIONS: Simple devices such as a cotton swab and a glass slide can be used to perform self-sampling and HPV DNA detection. Furthermore, most Bolivian women preferred self-sampling over clinician-sampling for cervical cancer screening.

Overcoming barriers in HPV vaccination and screening programs.

The Human Papillomavirus Prevention and Control Board brought together experts to discuss optimizing HPV vaccination and screening programs. Board members reviewed the safety profile of licensed HPV vaccines based on clinical and post-marketing data, reaching a consensus that current safety data is reassuring. Successful vaccination programs used well-coordinated communication campaigns, integrating (social) media to spread awareness. Communication of evidence supporting vaccine effectiveness had beneficial effects on the perception of the vaccine. However, anti-vaccination campaigns have threatened existing programs in many countries. Measurement and monitoring of HPV vaccine confidence over time could help understand the nature and scale of waning confidence, define issues and intervene appropriately using context-specific evidence-based strategies. Finally, a broad group of stakeholders, such as teachers, health care providers and the media should also be provided with accurate information and training to help support prevention efforts through enhanced understanding of the risks and benefits of vaccination. Similarly, while cervical cancer screening through population-based programs is highly effective, barriers to screening exist: awareness in countries with population-based screening programs, access for vulnerable populations, and access and affordability in low- and middle-income countries. Integration of primary and secondary prevention has the potential to accelerate the decrease in cervical cancer incidence.

High-risk human papillomavirus types in HIV-infected and HIV-uninfected young women in KwaZulu-Natal, South Africa: implications for vaccination.

BACKGROUND: High-risk human papillomavirus (hr-HPV) infections and low-grade squamous intraepithelial lesions occur frequently in young women. The available vaccines cover up to seven hr-HPV genotypes (HPV16, HPV18, HPV31, HPV33, HPV45, HPV52 and HPV58) and two low-risk HPV types (HPV6 and HPV11). The objective of this study was to describe the hr-HPV genotypes present among HIV-uninfected and HIV-infected young women in rural high schools. METHODS: Cervicovaginal lavages were obtained from sexually active young women recruited from high schools in KwaZulu-Natal (n = 1223). HPV testing was done by the polymerase chain reaction using GP5+/GP6 + primers and enzyme immunoassay. HIV testing was done using rapid test kits. RESULTS: Of the 1223 cervicovaginal lavages, 301 (25%) were positive for hr-HPV. The HPV prevalence was higher in HIV infected (32.20%, 95% CI: 0.27-0.38) than in HIV-uninfected women (22.50%, 95% CI: 0.21-0.26), (p = .001). Similarly, multiple infections were slightly more common in HIV infected (59.32%) than in HIV-uninfected women (53.51%), (p = .37). The nine predominant genotypes in descending order were HPV types 16 (n = 99, 22.10%), 51 (n = 58, 12.91%), 18 (n = 56, 12.50%), 35 (n = 50, 11.10%), 33 (n = 47, 10.82%), 56 (n = 42, 9.31%), 45 (n = 34, 7.60%), 52 (n = 32, 7.14%) and 59 (n = 31, 6.91%). HPV 35, 51, 56 and 59 (40.62%), which are not covered by any vaccine, were among the most prevalent in the schools of KwaZulu-Natal. CONCLUSION: Four of the most predominant high-risk HPV types in this region are not covered by the new nine-valent HPV vaccine.

Establishment and characterization of cetuximab resistant head and neck squamous cell carcinoma cell lines: focus on the contribution of the AP-1 transcription factor.

BACKGROUND: After an initial response to EGFR targeted therapy, secondary resistance almost invariably ensues, thereby limiting the clinical benefit of the drug. Hence, it has been recognized that the successful implementation of targeted therapy in the treatment of HNSCC cancer is very much dependent on predictive biomarkers for patient selection. METHODS: We generated an in vitro model of acquired cetuximab resistance by chronically exposing three HNSCC cell lines to increasing cetuximab doses. Gene expression profiles of sensitive parental cells and resistant daughter cells were compared using microarray analysis. Growth inhibitory experiments were performed with an HB-EGF antibody and the MMP inhibitor, both in combination with cetuximab. Characteristics of EMT were analyzed using migration and invasion assays, immunofluorescent vimentin staining and qRT-PCR for several genes involved in this process. The function of the transcription factor AP-1 was investigated using qRT-PCR for several genes upregulated or downregulated in cetuximab resistant cells. Furthermore, anchorage-independent growth was investigated using the soft agar assay. RESULTS: Gene expression profiling shows that cetuximab resistant cells upregulate several genes, including interleukin 8, the EGFR ligand HB-EGF and the metalloproteinase ADAM19. Cytotoxicity experiments with neutralizing HB-EGF antibody could not induce any growth inhibition, whereas an MMP inhibitor inhibited cell growth in cetuximab resistant cells. However, no synergetic effects combined with cetuximab could be observed. Cetuximab resistant cells showed traits of EMT, as witnessed by increased migratory potential, increased invasive potential, increased vimentine expression and increased expression of several genes involved in EMT. Furthermore, expression of upregulated genes could be repressed by the treatment with apigenin. The cetuximab resistant LICR-HN2 R10.3 cells tend to behave differently in cell culture, forming spheres. Therefore, soft agar assay was performed and showed more and larger colonies when challenged with cetuximab compared to PBS challenged cells. CONCLUSIONS: In summary, our results indicate that increased expression of the ligand HB-EGF could contribute to resistance towards cetuximab in our cetuximab resistant HNSCC cells. Furthermore, several genes upregulated or downregulated in cetuximab resistant cells are under control of the AP-1 transcription factor. However, more studies are warranted to further unravel the role of AP-1 in cetuximab resistance.

The hypoxic tumor microenvironment and drug resistance against EGFR inhibitors: preclinical study in cetuximab-sensitive head and neck squamous cell carcinoma cell lines.

BACKGROUND: Increased expression of the epidermal growth factor receptor (EGFR) is observed in more than 90% of all head and neck squamous cell carcinomas (HNSCC). Therefore, EGFR has emerged as a promising therapeutic target. Nevertheless, drug resistance remains a major challenge and an important potential mechanism of drug resistance involves the hypoxic tumor microenvironment. Therefore, we investigated the cytotoxic effect of the EGFR-targeting agents cetuximab and erlotinib under normoxia versus hypoxia. FINDINGS: Three cetuximab-sensitive HNSCC cell lines (SC263, LICR-HN2 and LICR-HN5) were treated with either cetuximab or erlotinib. Cells were incubated under normal or reduced oxygen conditions (<0.1% O2) for 24 or 72 h immediately after drug addition. Cell survival was assessed with the sulforhodamine B assay. Cetuximab and erlotinib established a dose-dependent growth inhibition under both normal and prolonged reduced oxygen conditions in all three HNSCC cell lines. However, a significantly increased sensitivity to cetuximab was observed in SC263 cells exposed to hypoxia for 72 h (p = 0.05), with IC50 values of 2.38 ± 0.59 nM, 0.64 ± 0.38 nM, and 0.10 ± 0.05 nM under normoxia, hypoxia for 24 h and hypoxia for 72 h, respectively. LICR-HN5 cells showed an increased sensitivity towards erlotinib when cells were incubated under hypoxia for 24 h (p = 0.05). CONCLUSIONS: Our results suggest that both EGFR-inhibitors cetuximab and erlotinib maintain their growth inhibitory effect under hypoxia. These results suggest that resistance to anti-EGFR therapy in HNSCC is probably not the result of hypoxic regions within the tumor and other mechanisms are involved.

Overcoming cetuximab resistance in HNSCC: the role of AURKB and DUSP proteins.

Unraveling the underlying mechanisms of cetuximab resistance in head and neck squamous cell carcinoma (HNSCC) is of major importance as many tumors remain non-responsive or become resistant. Our microarray results suggest that "resistant" cells still exhibit RAS-MAPK pathway signaling contributing to drug resistance, as witnessed by low expression of DUSP5 and DUSP6, negative regulators of ERK1/2, and increased expression of AURKB, a key regulator of mitosis. Therefore, interrupting the RAS-MAPK pathway by an ERK1/2 inhibitor (apigenin) or an AURKB inhibitor (barasertib) might be a new strategy for overcoming cetuximab resistance in HNSCC.

The radiosensitising effect of gemcitabine and its main metabolite dFdU under low oxygen conditions is in vitro not dependent on functional HIF-1 protein.

BACKGROUND: Regions within solid tumours often experience oxygen deprivation, which is associated with resistance to chemotherapy and irradiation. The aim of this study was to evaluate the radiosensitising effect of gemcitabine and its main metabolite dFdU under normoxia versus hypoxia and to determine whether hypoxia-inducible factor 1 (HIF-1) is involved in the radiosensitising mechanism. METHODS: Stable expression of dominant negative HIF-1α (dnHIF) in MDA-MB-231 breast cancer cells, that ablated endogenous HIF-1 transcriptional activity, was validated by western blot and functionality was assessed by HIF-1α activity assay. Cells were exposed to varying oxygen environments and treated with gemcitabine or dFdU for 24 h, followed by irradiation. Clonogenicity was then assessed. Using radiosensitising conditions, cells were collected for cell cycle analysis. RESULTS: HIF-1 activity was significantly inhibited in cells stably expressing dnHIF. A clear radiosensitising effect under normoxia and hypoxia was observed for both gemcitabine and dFdU. No significant difference in radiobiological parameters between HIF-1 proficient and HIF-1 deficient MDA-MB-231 cells was demonstrated. CONCLUSIONS: For the first time, radiosensitisation by dFdU, the main metabolite of gemcitabine, was demonstrated under low oxygen conditions. No major role for functional HIF-1 protein in radiosensitisation by gemcitabine or dFdU could be shown.

Mutation analysis of genes in the EGFR pathway in Head and Neck cancer patients: implications for anti-EGFR treatment response.

BACKGROUND: Targeted therapy against the Epidermal Growth Factor Receptor (EGFR) is among the most promising molecular therapeutics for Head and Neck Squamous Cell Carcinoma (HNSCC). However, drug resistance limits the clinical efficacy of anti-EGFR monoclonal antibodies and no predictive biomarker has entered the clinic yet. METHODS: A retrospective clinical study was performed utilizing pathological specimens from 52 newly diagnosed HNSCC patients. These patients were screened for mutations in EGFR and KRAS. Tyrosine kinase mutations in EGFR and KRAS mutations were evaluated by high resolution melting analysis (HRMA), whereas EGFRvIII was determined using one-step real-time PCR. Finally, patient samples were screened for HPV-DNA by GP5+/6+ PCR. Survival analysis was performed using Kaplan-Meier analysis and significance was calculated using log-rank statistic. RESULTS: In our study population no EGFRvIII mutations were present. However, two silent mutations were found; T785T in exon 20 and R836R in exon 21 of the EGFR gene. Additionally, HRMA revealed an abnormal KRAS melting pattern in 7.0% of the samples. However, the KRAS StripAssay could confirm only one sample with a G12S mutation and none of these samples could be confirmed by direct sequencing. HPV DNA was present in 3/25 larynx and 9/27 oropharynx tumors. CONCLUSION: The low rate of EGFR and KRAS mutations in this Belgian HNSCC population suggests that these genes will probably not play a major role in predicting response to anti-EGFR therapy in HNSCC. Hence, other predictive markers need to be discovered in order to optimize EGFR targeting therapy.

Anti-epidermal growth factor receptor therapy in head and neck squamous cell carcinoma: focus on potential molecular mechanisms of drug resistance.

Targeted therapy against the epidermal growth factor receptor (EGFR) is one of the most promising molecular therapeutics for head and neck squamous cell carcinoma (HNSCC). EGFR is overexpressed in a wide range of malignancies, including HNSCC, and initiates important signal transduction pathways in HNSCC carcinogenesis. However, primary and acquired resistance are serious problems and are responsible for low single-agent response rate and tumor recurrence. Therefore, an improved understanding of the molecular mechanisms of resistance to EGFR inhibitors may provide valuable indications to identify biomarkers that can be used clinically to predict response to EGFR blockade and to establish new treatment options to overcome resistance. To date, no predictive biomarker for HNSCC is available in the clinic. Therapeutic resistance to anti-EGFR therapy may arise from mechanisms that can compensate for reduced EGFR signaling and/or mechanisms that can modulate EGFR-dependent signaling. In this review, we will summarize some of these molecular mechanisms and describe strategies to overcome that resistance.

Probiotics enhance the clearance of human papillomavirus-related cervical lesions: a prospective controlled pilot study.

Probiotics have been proposed for a number of urogenital infectious conditions. In this study, we examine a possible effect on human papillomavirus (HPV)-related precancerous lesions in cervical cytology. We conducted a prospective controlled pilot study, in which 54 women with an HPV+low-grade squamous intraepithelial lesion diagnosis in their PAP smear were followed for 6 months. The intervention group consumed a daily probiotic drink during the study period; the control group received no treatment, according to common care policy. Outcome measures were the control PAP smear and HPV status after 6 months. Probiotic users had a twice as high chance of clearance of cytological abnormalities (60 vs. 31%, P=0.05). HPV was cleared in 19% of control patients versus 29% of probiotic users (P=0.41). This exploratory pilot study suggests that the probiotic studied promotes the clearance of HPV-related cytological abnormalities. If confirmed, this would represent an entirely new option to manage cervical cancer precursors.