Molecular Human Papillomavirus Testing Research Articles

Endocervical adenocarcinomas. Cytological, histological, and molecular diagnostics

This study was undertaken to analyze the effectiveness of cytological diagnostics of endocervical adenocarcinomas. We compared conventional liquid-based cytology, histology, immunohistochemistry, and molecular testing. A total of 25 endocervical adenocarcinomas, including endocervical adenocarcinomas in situ, were diagnosed using cytological methods over a year. Liquid-based cytology ensured better detection of glandular differentiation signs than conventional cytology. After molecular testing for human papillomavirus (HPV), we performed retrospective analysis of cytological characteristics of all endocervical adenocarcinomas (n = 15).We identified specific cellular characteristics of HPV-associated typical and mucinous adenocarcinomas. We also observed 1 case of non-HPV-related clear-cell and 1 case of non-HPV-related mesonephral adenocarcinoma.Our findings suggest that endocervical adenocarcinomas are a heterogeneous group of tumors. Endocervical adenocarcinomas accounted for 10.7 % of all primary cervical carcinomas (n = 214). Eighty percent of all endocervical adenocarcinomas were HPV-related, whereas the remaining 20 % were HPV-negative. We found no cytological differences between invasive endocervical adenocarcinomas and adenocarcinomas in situ.Mutations detected in some of the patients are an important diagnostic criterion that specifies whether the tumor is rare.

Modeling Cervical Cancer Screening Strategies With Varying Levels of Human Papillomavirus Vaccination

Cervical cancer screening is a lifesaving intervention, with an array of approaches, including liquid-based cytology (LBC), molecular testing for human papillomavirus (HPV) infection, and combinations via parallel cotesting or sequential triage. Maximizing screening efficacy while minimizing overtreatment is vital, especially when considering how the HPV vaccine will affect the interpretation of results. To estimate the likely outcomes of different screening modalities and to model how the increasing uptake of the HPV vaccine could affect the interpretation of screening results. This decision analytic model established a simple Markov model to compare the outcomes of different cervical cancer screening modalities on a simulated population of women (aged ≥25 years), considering different levels of HPV vaccination. The number of cases of cervical intraepithelial neoplasia (CIN) grade 2 and 3 detected and missed, the number of false positives, and the number of tests required to achieve a given level of accuracy. Positive and negative predictive values of different modalities were simulated under varying levels of HPV vaccination and therefore HPV prevalence. In a simulated population of 1000 women aged 25 years and older with an HPV prevalence of 2%, HPV-based modalities outperformed LBC-based approaches, detecting 19% more true positives (HPV test sensitivity, 89.9% [95% CI, 88.6%-91.1%]; LBC test sensitivity, 75.5% [95% CI, 66.6%-82.7%]). While cotesting markedly reduced missed cases, detecting 29% more true positives than LBC alone (19.5 [95% CI, 19.3-19.7] per 1000 women screened vs 15.1 [95% CI, 13.3-16.5] per 1000 women screened), it unacceptably increased excess colposcopy referral by 94% (184.4 [95% CI, 181.8-188.0] false positives per 1000 women screened vs 95.1 [95% CI, 93.1-97.0] false positives per 1000 women screened). By contrast, triage testing with reflex screening substantially reduced false positives by a factor of approximately 10 (eg, HPV with LBC triage, 9.6 [95% CI, 9.3-10.0] per 1000 women screened). Over a lifetime of screening, reflex approaches with appropriate test intervals maximized therapeutic efficacy; as HPV vaccination rates increased, HPV-based screening approaches resulted in fewer unnecessary colposcopies than LBC approaches (HPV testing, 80% vaccine coverage: 44.1 [95% CI, 40-45.9] excess colposcopies; LBC testing, 80% vaccine coverage: 96.9 [95% CI, 96.8-97.0] excess colposcopies). In this decision analytic model, the effectiveness of cervical cancer screening was dependent on the prevalence of cervical dysplasia and/or HPV infection or vaccination in a population as well as the sensitivity and specificity of various modalities. Although screening is lifesaving, overtesting or modalities inappropriate to the target population may cause significant harm, including overtreatment.

Defining benchmarks for tolerable risk thresholds in cancer screening: Impact of HPV vaccination on the future of cervical cancer screening

The performance of cervical cancer screening will decline as a function of lower disease prevalence—a consequence of successful human papillomavirus (HPV) vaccination. Replacement of cytology with molecular HPV testing as the primary screening test and adoption of risk‐based screening, with less intense screening of vaccinated individuals and initiated at older ages is expected to improve efficiency. However, policy officials may decide to further reduce or eliminate screening as the ratio of benefits to harms continues to decline. To evaluate the level of risk currently tolerated for different cancers in the United States (ie, for which clinical guidelines do not recommend secondary prevention though effective screening methods exist), we used US cancer registry data to compare incidence (2008‐2012) and survival (1988‐2011) associated with different cancers for which organized screening is recommended and not recommended. The most common cancer at ages 70 to 74 years (ie, age group with highest cancer incidence and reasonable life expectancy to consider screening in the US) satisfying Wilson and Jungner's classic screening criteria was vulvar cancer (incidence = 9/100 000 females). In comparison, the incidence of cervical cancer among females 65 years of age (the upper recommended age limit for screening) was 13 cases per 100 000 females (low as a reflection of effective screening), whereas 10‐year survival was 66% (similar to vulvar cancer at 67%). Our approach of defining tolerable risk in cancer screening could help guide future decisions to modify cervical screening programs.

Ensuring quality in cervical screening programmes based on molecular human papillomavirus testing.

The increased use of human papillomavirus testing within cervical screening programmes necessarily brings about changes to the laboratory services required to support them. A crucial element of such services is to demonstrate initial and ongoing quality of the test (and associated processes). In this review, we outline some of the quality considerations and challenges with an emphasis on the laboratory including assay and platform validation, internal quality control selection and strengths and weaknesses of external quality assurance schemes. The influence and role of key external entities, including regulatory agencies, guideline groups, programme commissioners and commercial providers, are also discussed.

Approaches for triaging women who test positive for human papillomavirus in cervical cancer screening.

Substantial evidence exists to support the introduction of molecular testing for human papillomavirus (HPV) as the primary technology in cervical cancer screening. While HPV testing is much more sensitive than cytology for detection of high-grade precancerous lesions, it is less specific. To improve efficiency, it is therefore recommended that a specific test (like cytology) be used in triaging HPV positive women to colposcopy. A number of studies have been conducted that support the use of cytology alone or in conjunction with HPV genotyping for triage. The decision to incorporate genotyping also depends on the commercial HPV test that is selected since not all tests provide results for certain individual high-risk types. Regardless of whether policy officials decide to adopt a triage approach that incorporates genotyping, the use of liquid based cytology (LBC) may also improve screening performance by reducing diagnostic delays. With LBC, the same cell suspension from a single collection may be used for HPV testing and a smear can be immediately prepared if HPV status is positive. This was a critical lesson from a community based demonstration project in Montreal (VASCAR study), where conventional cytology exists and specimen co-collection was not permitted for ethical reasons, requiring HPV positive women to return for an additional screening visit prior to colposcopy.

Introduction of molecular HPV testing as the primary technology in cervical cancer screening: Acting on evidence to change the current paradigm.

Since being introduced in the 1940s, cervical cytology - despite its limitations - has had unequivocal success in reducing cervical cancer burden in many countries. However, we now know that infection with human papillomavirus (HPV) is a necessary cause of cervical cancer and there is overwhelming evidence from large-scale clinical trials, feasibility studies and real-world experience that supports the introduction of molecular testing for HPV as the primary technology in cervical cancer screening (i.e., "HPV primary screening"). While questions remain about the most appropriate age groups for screening, screening interval and triage approach, these should not be considered barriers to implementation. Many countries are in various stages of adopting HPV primary screening, whereas others have not taken any major steps towards introduction of this approach. As a group of clinical experts and researchers in cervical cancer prevention from across Canada, we have jointly authored this comprehensive examination of the evidence to implement HPV primary screening. Our intention is to create a common understanding among policy makers, agencies, clinicians, researchers and other stakeholders about the evidence concerning HPV primary screening to catalyze the adoption of this improved approach to cervical cancer prevention. With the first cohort of vaccinated girls now turning 21, the age when routine screening typically begins, there is increased urgency to introduce HPV primary screening, whose performance may be less adversely affected compared with cervical cytology as a consequence of reduced lesion prevalence post-vaccination.

Human papillomavirus and oropharyngeal squamous cell carcinoma: a New Zealand cohort study.

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinomas (OPSCC) are clinically, epidemiologically and prognostically distinct from other OPSCCs. The incidence of HPV-related OPSCCs has increased significantly worldwide over the past few decades. However, no studies of OPSCC with direct molecular HPV testing has been conducted in New Zealand. To estimate the proportion of OPSCCs attributable to HPV infections in a New Zealand population with a validated HPV testing algorithm. HPV-status was determined by p16 immunohistochemistry and polymerase chain reaction (PCR) of both L1 and E6/7 genes on 55 OPSCCs diagnosed in 2010 and 2011 in Central and South Auckland. Baseline and survival analyses were performed according to HPV status. Forty-one (75%) of OPSCC tumours had HPV infections. There was 98% concordance between p16 immunohistochemistry and real-time E6/E7 PCR. After a median follow-up period of 2.6 years, patients with OPSCC of HPV aetiology had more favourable outcomes compared to patients with HPV-negative OPSCC (hazard ratio 0.14, P = 0.02) after adjustment for other variables. This study highlights the significant role that HPV plays in the aetiology of OPSCC in New Zealand, and confirms the high rate of accuracy of p16 immunostaining.

Human papillomavirus detection using in situ hybridization and correlations with histological and cytological findings

Background and objectiveThe human papillomavirus (HPV) is the main causative agent of cancerous and precancerous lesions in cervical cancers. The infection detection is performed by cytological and histological examination. However, molecular testing for HPV infection remains necessary to distinguish nonspecific inflammatory lesions from HPV-related lesions. We aimed to compare cytological and histological diagnosis of HPV lesions and to confront histological findings with molecular detection of HPV by in situ hybridization (ISH). Material and methodsA total of 2399 pap smears were collected between 1997 and 2002. Twenty-nine of them presented with lesions indicative of HPV infection. Colposcopy and biopsy were performed on 23 of these 29 pap smears, with a comparison of the cytological and histological findings. Molecular testing for HPV by ISH was performed on 11 pap smears. ResultsA 79% cytological and histological agreement was observed. ISH revealed the presence of the virus in seven case patients, amounting to a 63% histological and molecular agreement. Seven HPV genotypes were categorized (6-11-16-18-31-33-51). ConclusionHPV detection by ISH adds little to the diagnosis of HPV-associated lesions based on cytological and histological features. It, however, helps improve the specificity of the diagnosis and determine the viral genotype which, in turn, helps better define the lesion prognosis.

Molecular testing and cervical screening: will one test fit all?

Cervical screening has undergone significant changes in recent years, with molecular human papillomavirus (HPV) testing for HPV 16 and 18 at the forefront of clinical practice. But is molecular testing more effective than morphologic testing for cervical screening? Does current information on HPV hold true across all populations? As a public health laboratory serving high-risk, underserved populations, these remain important considerations for our practice. The subject population largely consisted of young women within 200% or less of the poverty line. Correlation of Papanicolaou and HPV results was performed via retrospective review, focusing on Papanicolaou cases with high-grade diagnoses and an associated HPV test using the cobas 4800 HPV test. Secondary HPV testing and typing was performed via PCR at an outside laboratory for 205 cases with sufficient residual material and negative for HPV 16/18 by cobas. Of 20,211 cytology tests reviewed from July 2013 to May 2015, 521 were diagnosed as high-grade; 387 had concurrent HPV tests. Of those with concurrent HPV tests, 58% (225 of 387) of the high-grade Papanicolaou cases were not HPV 16/18 positive; furthermore, no HPV was detected in 14% (55 of 387) of these cases. Secondary testing revealed the presence of 25 unique genotypes. With recent emphasis on molecular HPV testing, the results of this review are concerning. As we move forward with evolution of cervical screening practices, it will be important to explore these questions for the continued quality and integrity of women's health services.

Hybrid Capture 2 human papillomavirus testing of fine needle aspiration cytology of head and neck squamous cell carcinomas.

Human papillomavirus (HPV) positive head and neck squamous cell carcinoma (HNSCC) accounts for 25% of HNSCCs and frequently presents with neck lymph node metastases. We investigated utilizing cytology needle rinse material for HPV DNA testing by Hybrid Capture 2 molecular testing (HC2) as an alternative to p16 immunohistochemistry. Twenty-two cases of HNSCC presenting with neck lymph node metastasis were prospectively identified by assessment of Diff Quik stained cytology smears. An aliquot of the needle rinse material from the lymph node was analyzed for HPV status using standard HC2 protocol. P16 status was determined with immunohistochemistry on the cell block and/or surgically obtained tumor. The mean age of patients with p16 negative HNSCC was 7 years older than p16 positive disease (Table ). Primary tumor subsites were as follows: 17 oropharynx, 1 hypophayrnx, 3 larynx, and 1 oral cavity (Table ). All ten p16 negative patients had a history of smoking compared with 33% of p16 positive. Only 3 (25%) of p16 positive tumors demonstrated keratinization, whereas 90% of the p16 negative tumors keratinized (Fig. 1). Twelve of 22 HNSCC cases (55%) were p16 positive, of which 7 (58%) tested positive for HPV by HC2. Ten cases (45%) were negative for p16, all of which were negative for HPV by HC2 (Table ). Molecular testing for HPV using HC2 on needle rinse material of FNA of HNSCC is a useful method of determining HPV status in HNSCC.

Can HPV Testing Be Used as a First-line Screening Test for Cervical Cancer Prevention? Three-year Cumulative Risk of CIN2+ In Women Aged 30 Years and Older Screened by Pap and HPV Co-testing

Introduction: Over time, cervical screening has evolved from a simple glass-slide smear to a sophisticated test involving liquid-based processing, automated screening, and molecular human papillomavirus (HPV) testing. Recent emphasis on molecular testing seeks to identify HPV strains considered “high-risk” for carcinogenesis, with HPV 16 & 18 being the main focus of research and clinical practice. But is molecular testing more effective and efficient than morphologic testing for cervical screening? Does current data on HPV hold true across all populations? As a public health laboratory serving high-risk, underserved populations, these remain important considerations for our practice. Materials and Methods: Correlation of Pap and HPV results was performed via retrospective review, focusing on Pap cases with high-grade diagnoses and an associated HPV test using the cobas 4800 HPV platform from Roche Diagnostics. HPV results included HPV 16, HPV 18, HPV Other High-Risk, a combination of two or more groups, or HPV Not Detected. The subject population consisted mostly of young women within 200% or less of the poverty line. Results: Of 2,818 cytology test cases reviewed from July 2013-March 2014, 74 were diagnosed as high-grade. HPV was not detected in 10 (13.51%) of these cases. Of the 64 positive HPV tests, 25 (39.06%) fell in the Other High-Risk category. In total, 35 (52.57%) of the high-grade Pap cases were not HPV 16/18 positive. Conclusions: With recent changes to cervical screening practices and guidelines, namely the emphasis on molecular HPV testing, the results of this review are concerning. How will these changes in screening affect our bottom line, both financially and prognostically? Is our patient population substantially different from those used to develop popular testing algorithms? As we move forward with evolution of cervical screening practices, it will be important to explore these questions for the continued quality and integrity of women’s health services.

Adequacy of fine-needle aspiration specimens for human papillomavirus infection molecular testing in head and neck squamous cell carcinoma

Background:Head and neck squamous cell carcinoma is often associated with human papillomavirus (HPV) infection. Positive HPV status has been associated with increased response to treatment and improved prognosis in terms of recurrence-free and overall survival. In certain instances, diagnosis is performed through fine-needle aspiration of lymph nodes with metastatic carcinoma, often demonstrating extensive tumor necrosis. We evaluated the effect of tumor necrosis on deoxyribonucleic acid (DNA) adequacy for HPV molecular testing.Materials and Methods:Retrospective review of the pathology files at our institution identified cases of squamous cell carcinoma (SCC) diagnosed by fine-needle aspiration (FNA) on which HPV DNA molecular testing was performed. The cases were classified according to percent tumor necrosis into three categories (<10% necrosis, 10-70% necrosis and >70% necrosis) and the percentage of cases with adequate HPV DNA for molecular testing in each of the categories was compared. When available, p16 immunohistochemistry performed on the cases was compared with HPV status by molecular testing.Results:A total of 70 cases from 67 patients were included in the study. Adequate DNA for molecular HPV testing was obtained from samples of 47 cases (67%) while samples from 23 cases (33%) were inadequate for molecular testing. Of the adequate samples, 36 (77%) were positive and 11 (23%) were negative for high-risk HPV. Adequate DNA for testing was obtained in 22 out of 33 cases showing no necrosis (67%), 10 out of 16 cases showing partial necrosis (63%) and in 13 out of 17 cases showing extensive necrosis (76%).Conclusion:Our study found that HPV molecular testing is not influenced by percent tumor necrosis or method by which FNA was performed. We believe that a portion of the FNA specimen obtained from head and neck lesions diagnosed as SCC during the rapid on-site evaluation should be sent for HPV DNA testing, independent of the amount of tumor necrosis, thus guaranteeing availability of specimen for HPV testing.

20. Utility of human papillomavirus (HPV) 16 E6 and L1 DNA levels for anal cancer screening in HIV-infected individuals

Background In this prospective study we evaluate the sampling performance of HPV16 DNA E6 and L1 levels in detecting anal intraepithelial neoplasm using either a moistened Dacron swab (DS) or cytobrush (CB). Methods: We recruited HIV-infected (n = 57) and organ-transplanted subjects (n = 3) with an abnormal anal Pap smear who presented for high-resolution anoscopy (HRA). Prior to HRA, the first 30 subjects underwent sampling with a moistened DS, and the next 30 with a CB. HRA was then performed in the usual fashion. Samples were tested for HPV16 DNA E6 and L1 DNA using a validated qPCR technique. Anal biopsies were taken as per standard-of-care and categorised as negative, AIN 1/warts, or AIN 2 or 3. Results: 59 of 60 samples had adequate DNA and were evaluated for the comparison of HPV16 E6 and L1 DNA levels. A CB performed better than the DS in detecting low positive and positive levels of HPV16 E6 DNA (P = 0.01). We then further evaluated the correlation of HRA-directed biopsies and HPV16 DNA E6 levels. There was a positive correlation of HRA-directed biopsy results stratified by increasing histological levels with HPV16 E6 DNA (P = 0.018, Kruskal–Wallis test). Conclusions: A CB performed better than DS for molecular HPV testing. If molecular testing is included in anal cancer screening, consideration should be made for co-sampling with both a DS for cytology and CB for HPV testing. Further studies evaluating the sample yields should be performed to assist in implementation of anal cancer screening programs in defined populations of at-risk individuals.

APTIMA HPV assay performance in women with atypical squamous cells of undetermined significance cytology results

The objective of the study was to determine the sensitivity and specificity of the APTIMA human papillomavirus (AHPV) assay for high-grade cervical intraepithelial neoplasia (CIN) in women 21 years old and older with atypical squamous cells of undetermined significance (ASC-US) cytology. Women 21 years old and older with ASC-US cytology had colposcopy/biopsy and molecular human papillomavirus testing. Performance of the AHPV and Hybrid Capture 2 assays was compared with a clinical diagnosis of CIN grade 2, CIN grade 3, or adenocarcinoma in situ (CIN2 or greater). Of 939 evaluable subjects, CIN2 or greater and CIN3 or greater prevalence was 9.7% and 4.4%, respectively. AHPV sensitivity and specificity was 86.8% and 62.9% for CIN2 or greater detection and 90.2% and 60.2% for CIN3 or greater, respectively. AHPV had a similar sensitivity to Hybrid Capture 2 but a significantly higher specificity (62.9% vs 55.8%, P < .001) for CIN2 or greater detection. Among women with ASC-US cytology, detection of high-risk human papillomavirus E6/E7 oncogenic messenger ribonucleic acid is an effective triage method for colposcopy referral.

A molecular monopoly? HPV testing, the Pap smear and the molecularisation of cervical cancer screening in the USA

DNA-based molecular testing for human papillomavirus has emerged as a novel approach to cervical cancer screening in the context of well-entrenched existing technology, the Pap smear. This article seeks to elucidate the process of molecularisation in the context of screening programmes. We illustrate how, although Pap has long been problematised and could be seen as a competing technological option, the existing networks and regime for Pap were important in supporting the entrenchment process for the artefacts, techniques and new diagnostics industry entrant, Digene, associated with the new test. The article provides insights into how the molecularisation of screening unfolds in a mainstream market. We reveal an incremental and accretive, rather than revolutionary, process led by new commercial interests in an era when diagnostic innovation is increasingly privatised. We show Digene's reliance on patents, an international scientific network and their position as an obligatory point of passage in the clinical research field with regard to the new technology's role, as well as on controversial new marketing practices. The article is based on a mixed method approach, drawing on a wide range of contemporary sources (including patents, statutory filings by companies, scientific literature and news sources) as well as interviews.

Cytologists battle cruel killer in Peru

Cytologists battle cruel killer in Peru

Understanding and incorporating human papillomavirus testing in cervical cancer screening: a South African perspective

The identification of human papillomavirus (HPV) as the aetiological agent for cervical cancer has important implications for the future of cervical cancer screening and prevention strategies. Despite the availability of HPV vaccines, regular and adequate screening will remain the mainstay of cervical cancer screening for some time to come. Molecular tests for high-risk HPV DNA and E6/E7 mRNA have the potential to improve cervical cancer screening in developed and developing countries. The latest international and South African private sector guidelines propose the incorporation of molecular testing for HPV in screening and patient management, backed by good scientific evidence. It is a time of transition for screening programmes; a move from the annual Pap test to a new viral paradigm. This review discusses the proper placement, advantages and disadvantages of cytology versus HPV-based screening tests from a South African perspective.

Human papillomavirus E6/E7 mRNA testing as a predictive marker for cervical carcinoma

Human papillomavirus (HPV) is necessary for the development of cervical carcinoma, and incorporation of molecular testing for HPV in screening and patient management has been proposed. Sufficient scientific evidence exists to recommend HPV DNA testing in the triage of women with equivocal cytology and in follow-up after the treatment of precursor lesions. However, due to a low clinical specificity and positive predictive value, HPV DNA testing has so far not been recommended as primary screening in Europe. In general, diagnostic HPV tests have to demonstrate accuracy, reproducibility and clinical utility before they can be used in patient management and implemented in cervical cancer screening programmes. In this article we give an overview of RNA-based HPV diagnostics and the role of E6/E7 mRNA detection as a predictive marker for the development of cervical carcinoma. HPV E6/E7 mRNA testing for high-risk types seems to correlate better with the severity of the lesion compared with HPV DNA testing, and is a potential marker for the identification of women at risk of developing cervical carcinoma. Commercial assays for simultaneous genotyping and detection of E6/E7 mRNA from the five most common high-risk HPV types are now available and require further evaluation for primary screening, triage and follow-up after treatment.

Human papillomavirus infection: biology, epidemiology, and prevention

Over the past several decades, knowledge of the biology and epidemiology of human papillomavirus (HPV) infection has increased tremendously. However, there are still many unanswered questions concerning the interaction of the virus with its host. The virus has been identified as a necessary causal agent for cervical squamous neoplasia and has been linked to the development of neoplasia in several other mucosal sites. The viral oncogenes E6 and E7 are the major players in the virus' scheme to evade the immune system and use the host cell replication machinery to survive. Many risk factors for infection with HPV have been identified; however, the focus now centers on identifying risk factors for persistence of the infection as it is likely that transient infections play a very small role in the overall development of clinical disease. Prevention measures to date have centered around screening programs, mostly for cervical cancer, including the perfection of screening techniques and inclusion of molecular testing for HPV into screening regimens. The development of prophylactic and therapeutic vaccines has also increased as primary prevention measures appear to have the best hope for long-term effects on cancer incidence.

Human papillomavirus infection: biology, epidemiology, and prevention

Over the past several decades, knowledge of the biology and epidemiology of human papillomavirus (HPV) infection has increased tremendously. However, there are still many unanswered questions concerning the interaction of the virus with its host. The virus has been identified as a necessary causal agent for cervical squamous neoplasia and has been linked to the development of neoplasia in several other mucosal sites. The viral oncogenes E6 and E7 are the major players in the virus' scheme to evade the immune system and use the host cell replication machinery to survive. Many risk factors for infection with HPV have been identified; however, the focus now centers on identifying risk factors for persistence of the infection as it is likely that transient infections play a very small role in the overall development of clinical disease. Prevention measures to date have centered around screening programs, mostly for cervical cancer, including the perfection of screening techniques and inclusion of molecular testing for HPV into screening regimens. The development of prophylactic and therapeutic vaccines has also increased as primary prevention measures appear to have the best hope for long-term effects on cancer incidence.