Open access peer-reviewed chapter

Recent Advances in Human Papillomavirus Infection and Management

Written By

Shailendra K. Saxena, Swatantra Kumar, Madhu Mati Goel, Apjit Kaur and Madan LB Bhatt

Submitted: 03 October 2018 Reviewed: 11 October 2018 Published: 28 November 2018

DOI: 10.5772/intechopen.81970

From the Edited Volume

Current Perspectives in Human Papillomavirus

Edited by Shailendra K. Saxena

Chapter metrics overview

1,738 Chapter Downloads

View Full Metrics

Abstract

Human papillomavirus (HPV) accounts for approximately 4.5% of all cancers which differs at the level of economic development and geographical regions. The life cycle of the HPV is completely dependent on the epithelium differentiation without the involvement of cell death and systemic viremia. Carcinogenesis is the consequence of viral gene expression, dysregulated cell proliferation, and genomic instability. Keratinocytes are the target cell for HPV which act as the physical and immunological barrier. In cervical carcinogenesis, the enhanced level of Th17 infiltration has been observed which increases with the disease progression and is coupled with CCL20 expression in the stromal mesenchymal compartment. IL-6 and M-CSF are known as “switch factors” which are imperative for pro-tumorigenic response in monocytes. Screening of cervical cancer includes three major procedures: cytology, nucleic acid test, and co-testing. For evaluating anal lesions, high-resolution anoscopy is performed which is similar to colposcopy. Prophylactic vaccination is the primary preventive measure to control the HrHPV infection and reduce the burden of HPV-related cancer. The precancerous stage of HPV infection includes excision, ablation, and immunotherapy. Radiotherapy is the acceptable primary treatment for the early stage of anogenital cancer, whereas for the advanced-stage metastatic cancer, palliative therapy is the only option.

Keywords

  • HPV
  • infection
  • management
  • prevention

1. Introduction

Human papillomavirus (HPV) attributes to approximately 4.5% of all cancers which differs at the level of economic development and geographical regions [1]. Papillomaviridae family comprises of more than 200 types of HPV which are classified into five genera: Alphapapillomavirus, Betapapillomavirus, Gammapapillomavirus, Mupapillomavirus, and Nupapillomavirus [2]. All the genera are responsible for the various types of HPV-associated cancers. Furthermore, on the basis of oncogenicity, the mucosal type (alpha) is grouped into two subtypes which are low risk (LR), HPV 6 and HPV 11, which are known to cause benign genital warts and high-risk (HR) cervical cancer [3]. HPV 6 and HPV 11 are also known to cause respiratory papillomatosis predominantly in children [4]. According to IARC classification, high-risk HPV (HrHPV) is of 14 types: HPV 16, HPV 18, HPV 31, HPV 33, HPV 35, HPV 39, HPV 45, HPV 51, HPV 52, HPV 56, HPV 58, HPV 59, HPV 66, and HPV 68 [5]. High-risk papillomavirus is responsible for causing cancer related to the cervix, vulva, vagina, anus, penis, and oropharynx [6]. HPV 16 and HPV 18 represent approximately 60% for adenocarcinoma of the endocervix (ADC-CX), and both are equally associated with 15% of adenosquamous carcinoma (ASC) of the endocervix [7]. Among the HrHPV, HPV 16 is the most efficient in evading the host immune response and responsible for persistent infection in the oropharynx, an imperative step in development of malignant lesion [8]. The mucosal HPV is transmitted by sexual contacts, and the transformation zone in females is characterized as the area adjacent to the border of the ecto- and endocervix which are the preferential sites of primary infection [9]. Approximately 80% of the sexually active women get HPV infection where most of them are asymptomatic with the immune system-mediated clearance of infection within 6–12 months [10]. With the impairment of immune function, the infection becomes symptomatic in a small number of individuals. Persistent infection of HPV and the development of cervical intraepithelial neoplasia (CIN) after the period of latency may lead to the regression or progression toward the development of invasive carcinoma [11]. The prevalence of HPV infection is higher in immunocompromised individuals such as HIV [12] and organ transplant recipients (OTRs) [13] suggesting the role of T cell in the clearance of HPV. Other factors including smoking, parity, sexual habits, genetic factors, oral-contraceptives have shown to increase the risk of progression of HPV-driven diseases [14].

Beta genus of HPV principally accounts for progression of nonmelanoma skin cancer (NMSC). The association of beta HPV types with skin cancer can be explained as the prevalence of epidermodysplasia verruciformis (EV). Patients diagnosed with EV are highly susceptible for HPV beta-type infection which results in flat warts and pityriasis versicolor-like lesions [15]. With the advancement detection methods, beta HPV types have been shown to be abundantly present in the skin of the asymptomatic HPV-infected individuals. So far, 43 HPV of beta genus have been isolated. Furthermore, beta HPV types have been speculated as HPV facilitates the accumulation of ultraviolet-mediated DNA damage [16]. In order to prevent the disease, the neutralizing antibody (nAb) has been shown to provide protection. However, immunization with attenuated or killed pathogen is imperative.

Advertisement

2. Global HPV epidemiology

The global burden of HPV-driven cervical cancer accounts for approximately 630,000 cases annually [1] where five other HPV-associated sites of cancer are responsible for further 113,400 cases [17]. In spite of the availability of several preventive strategies, HPV subtypes cause worldwide morbidity and mortality particularly in the less developed countries (Figure 1) [18]. Asia contributes to the immense majority of cervical cancer cases of 285,000 with 144,000 deaths followed by Africa where 99,000 cases with 60,000 deaths and America with 83,000 newer cases with 36,000 deaths. Asia, China, and India contribute to 62,000 and 123,000 cases along with 30,000 and 67,000 deaths, respectively [19]. Data from the meta-analysis and systemic reviews are suggesting that the vast majority of the infection is asymptomatic and transient. The incidence of HPV infection particularly cervical cancer is higher in sub-Saharan Africa (SSA) [20]. The worldwide distribution of age-specific HPV infection also varies with the predominance in young women of age less than 25 years in Europe and America [21]. However, in Africa and Asia no significant decline with the age has been observed. 3.2% of HPV 16 infected women shows normal cytology [22]. Cervical precancerous lesion is an imperative factor for HPV prevalence where HPV is detected in 52.5% of ascus lesion, 74.8% of low-grade cervical lesions, and 88.9% of high-grade cervical lesions. HPV 16 has been detected in 19.3% of low- and 45.1% of high-grade cervical lesions [23]. Furthermore, anal HPV infection is the most frequent HPV infection of other anogenital areas. The global burden of anogenital cancers caused by HPV is very high where 88% of anal and <50% of cases attribute to the lower genital tract [24]. About 30,000 cases are reported in men with the 56.56% attributed to the anus and 43.33% to penile origin. In the case of women, 38,500 cases are reported with 46.75% cases attributed to the anus, 22% to the vulva, and 31.16% from the vaginal origin [1]. Furthermore, the predominance of anal HPV infection that has been observed in the men sex with men (MSM) is 58.8% or HIV-infected individuals. The oral HPV infection significantly differs by gender and with higher incidence in men [19]. The worldwide prevalence of HPV-associated head and neck cancer is 8.15%, that is, 37,200 cases, where 77.95% of cases belong to the oropharynx, 11.82% of cases correspond to the oral cavity, and 10.21% of cases correspond to the larynx [1].

Figure 1.

Worldwide prevalence of HPV (n = 1938) [adapted from ref. 18].

Advertisement

3. HPV genome and replication

Human papillomavirus is a histone-bound double-stranded DNA virus of ~8 kb with either eight or nine open reading frames (ORFs) on the same DNA strand. HPV genome can be subdivided into three regions: coding region comprises of early genes such as E1, E2, E4, E5, E6, and E7; region encoding major (L1) and minor (L2) capsid proteins; and a noncoding region present between ORFs L1 and E6 known as long control region (LCR), involving in viral DNA replication and transcriptional regulation [25]. HPV genome is highly conserved; however, exclusive features are represented by different genera. As compared with the mucosal HPV types, beta HPV genome is relatively shorter due to reduced size of LCR (400 bp) which ranges from 7.4–7.7 kb, whereas the E2 ORF is relatively larger in beta HPV types (Figure 2) [26]. Apart from this, most of the beta HPV types lack E5 gene with the exception of HPV 14 [27]. An additional early protein, E8Ê2C, is expressed exclusively by some of the HrHPV types as HPV 16, HPV 18, and HPV 31 that repress the expression of viral oncoproteins E6 and E7 following proliferation [28]. Recently, three gamma HPV types (101, 103, and 108) have been isolated from the cervical specimens which lack the E6 ORF [29].

Figure 2.

HPV genome.

Epithelial abrasion is the typical site of HPV infection where the squamocolumnar junction (SCJ) of the cervix is susceptible to HPV transformation [9]. The life cycle of the HPV is completely dependent on the epithelium differentiation without the involvement of cell death and systemic viremia. Heparan sulfate proteoglycans (HPSGs) are exposed by the epithelial abrasion which is the binding site for L1 and defined as the extracellular event of HPV replication [30]. Upon binding the conformational changes in the capsid expose the N terminus of L2 which gets cleaved by extracellular furin, a prerequisite for the virus internalization [31]. Virus uptake is mediated by L1 and endosomal vesicles, following transport of endosomal virus to the nucleus along with the retromer. L1 is degraded, whereas L2 forms the complex with viral genome following the escape from endosome to the trans-Golgi networks [32]. L2 entry into the nucleus is dependent on the cell cycle progression and transpired upon transient nuclear membrane breakdown [33]. The L2 genome complex interacts with ND-10, a promyelocytic leukemia nuclear bodies following initiation of early viral transcripts [34]. The host DNA replication machinery system is utilized by the viral early proteins E1 and E2 to establish 50–100 episomal copies per cells [35]. Dependence on host DNA replication system is the reason for the slow rate of virus evolution due to proofreading mechanism. The productive phase of HPV life cycle exhibits a unique spatial and temporal regulation and differentiation of keratinocyte in squamous epithelium. Upon leaving the basal membrane, HPV enters into the productive phase of life cycle which can be characterized as high copy number (1000 copies per cell) of HPV genome along with the late viral capsid expression for assembly transpired only in the upper terminally differentiated epithelial layer (Figure 3) [36].

Figure 3.

HPV life cycle.

Several of the host factors also play an imperative role in HPV replication where HPV drives the keratinocytes into S phase of the cell cycle mediated by E5, E6, and E7 viral oncoproteins [37]. E5 increases the expression of epidermal growth factor receptor (EGFR) which promotes the progression toward G1 phase [38]. E6 mediates proteasomal degradation upon binding with p53, a PDZ protein to promote de-differentiation of cells and other pro-apoptotic factors to promote the cell survival [39]. Moreover, MYC expression and telomerase get activated by E6 protein [40]. E7 protein is known to bind with multiple targets specifically RB to overcome the restriction points [41]. Primary keratinocytes get immortalized due to ectopic expression of E6 and E7 which also induces the genomic instability [42]. Carcinogenesis is the consequence of viral gene expression, dysregulated cell proliferation, and genomic instability; however, the progression of cancer is not beneficial to the virus.

Advertisement

4. Immunopathogenesis during HPV infection

The skin and mucosal surfaces act as the first line of defense during infection; however, cutaneous and mucosal HPV are known to diminish the recognition process mediated by TLR9 [43]. Mucosal HPV is known to inhibit the IFN signaling and expression which is mediated by both E6 and E7. HPV E6 protein interacts with IFN regulatory factor 3 (IRF3) [44], whereas E7 interferes with pro-apoptotic factor IRF1 and antiviral [45]. Keratinocytes are the target cell for HPV which act as the physical and immunological barrier. The activation of inflammasome in keratinocytes by other DNA viruses results in acute inflammatory responses; however, diminished inflammatory response has been observed in mucosal HPV infection. Mucosal HPV oncoproteins are responsible for abrogated posttranslational modification and secretion of IL-1β via targeting p300/CBP-associated factors/NF-κB pathway [46]. Upon infection the epithelial cells release chemotactic factors for recruiting, differentiation, and activation of Langerhans cells which are the professional antigen-presenting cells (APCs). HPV infection interferes with homeostasis of Langerhans cells in the epidermal compartment. Low levels of chemokines (CCL20 and CCL2) are mediated by HPV oncoproteins which result in the reduced level of APC recruitment toward the epithelium [47]. HPV infection during the progression of an invasive form of cancer results in expansion of epithelial stem cell compartments.

The increased level of stromal infiltration with the immune cells is associated with the increasing dysplasia. Secretion of chemoattractants is upregulated by HPV-transformed cells, specifically the CCL2 production by monocytes which attracts myelomonocytic cells following maintenance of inflammatory microenvironment via CCR-2 dependent pathway. Remarkably, CCL-2 secretion results in higher production of MMP-9 via intracellular Ca2+ signaling by monocytes [48]. MMP-9 has been shown to be involved in the progression toward malignancy where monocytes become infiltrating into high-grade cervical lesions. In cervical carcinogenesis, the enhanced level of Th17 infiltration has been observed which increases with the disease progression and is coupled with CCL20 expression in the stromal mesenchymal compartment [49]. Most importantly, IL-6 and monocyte colony-stimulating factors (M-CSF) are known as “switch factors” which are imperative for pro-tumorigenic response in monocytes and are highly upregulated during the late stage of human cervical cancer which results in activation of JAK/STAT3 signaling pathway in monocytes [46]. In cervical cancer, inhibition of NF-κB in CD83+ dendritic cells is the consequence of the diminished CCR7 expression that leads to interrupted dendritic cell migration to the lymph node-homing chemokine. Antigen transport to the secondary lymphoid tissue by stromal dendritic cells gets impaired due to diminished CCR7 expression. Cervical cancer cell-derived IL-6 immobilizes the dendritic cells in the tumor stroma via suppression of CCR7 resulting in local MMP-9 production [50]. Furthermore, the low level of IFN-γ production by M2-polarized macrophages causes a reduced level of T-cell proliferation in cervical cancer stroma [51]. The programmed cell death ligand-1 (PD-1) is expressed by most of the CD8+ T cells in cervical cancer, and the suppressed cytotoxic cell response is probably due to M2-macrophages [52].

Advertisement

5. Diagnosis for HPV

Screening of cervical cancer includes three major procedures: cytology (microscopic evaluations of sample acquired from cervical regions), nucleic acid test (detection of HrHPV DNA or RNA), and co-testing (combination of microscopy and nucleic acid test) [53]. In the clinical settings, some of the routine tests for HPV detection are biopsy, DNA-based test, Pap smear, colposcopy, and acetic acid test. Colposcopy is the clinical examination of the cervix, vagina, and vulva upon application of acetic acid solution which is known as visual inspection with acetic acid (VIA) and is mostly coupled with biopsy of regions suspected of neoplasia [54]. Colposcopy findings are evaluated and represented on the basis of acetowhite lesion, mosaic pattern, punctuation, and surface contour [55]. Due to the higher chance of false-positive results, colposcopy screening is recommended for various conditions such as HIV-infected individuals, dyskaryosis, borderline nuclear change in endocervical cells, and cervical cytology positive for malignant [56].

For evaluating anal lesions, high-resolution anoscopy is performed which is similar to colposcopy. However, anoscopy is more complex since it requires manipulation to visualize the entire SCJ along with lower accuracy. High-resolution anoscopy is performed as a first-line test for HPV surveillance in MSM population to follow up anal cytological findings [57]. Histopathological evaluations are considered as the reference standards for deciding the treatment in precancerous or cancerous stages of HPV [58]. CIN3 is considered as the precancerous stage of the HPV infection and can be treated, whereas CIN1 is the morphological representation of HPV infection and cannot be treated [59]. The CIN2 lesions are considered as severe appearing HPV infection rather than a precancerous one. Several of the biomarkers have been developed to screen CIN2 form of HPV infection. p16 staining can be used to discriminate among the p16-positive CIN2 with CIN3 and p16-negative with CIN1 [60]. DNA-based test utilizes the principle of direct probe hybridization such as dot blot and Southern blot which are associated with disadvantages as low sensitivity and requirement of large amount of DNA sample. Currently, hybrid capture HPV DNA test 2 (HC2) and PCR-based test have been approved by the FDA [61]. HC2 test can be used to detect as low as 1 pg. of HPV DNA/ml and its sensitivity is comparable with PCR. HC2 can detect both low-risk (6, 11, 42, 43, 44) and high-risk (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68) HPV. PCR-based diagnosis of HPV is more accurate and robust as compared to the Pap smear test which is a screening test for HPV detection.

Advertisement

6. Prevention and treatment

Prophylactic vaccination is the primary preventive measure to control the HrHPV infection and reduce the burden of HPV-related cancer [62]. Currently available vaccine for HPV comprises viruslike particles (VLPs) which is the major HPV coat protein L1. VLPs are noninfectious in nature which lacks DNA and have similar geometry to the native virus [63]. Currently, three prophylactic VLP vaccines have been licensed, namely, as the bivalent Cervarix, the nonavalent Gardasil, and the quadrivalent Gardasil [64]. Cervarix is based on the HPV 16 and HPV 18 antigens and proprietary adjuvants for enhancement of immunogenicity [65]. While Gardasil provides protection against wide range of HPV such as HPV 6, HPV 11, HPV 18, HPV 31, HPV 33, HPV 45, HPV 52, and HPV 52 [66]. All the vaccines are intended to provide complete protection against HPV if administered before the exposure and have been shown to be highly efficacious without any adverse effects. More than 64 countries have introduced the HPV vaccination program primarily targeting girls of age 9–13 and boys of higher age group [67]. In both males and females, systemic immunization with HPV vaccine results in higher amount of antibody generation as 1–1000 times higher than the natural infection.

The management of HPV infection depends on the type and severity of the HPV infection. For the precancerous stage of HPV infection, it includes treatment strategies as excision, ablation, and immunotherapy. The gold standard for the management of HPV treatment is various excisional procedures of the transformation zone where the extent of excision depends on the lesion size [68]. Ablation procedures are less invasive and include cold coagulation, laser therapy, and cryotherapy with the disadvantage of procurement of tissue sample for confirmatory diagnosis. The immunotherapy has shown to be effective but is still present in the clinical trial stages [69]. Anogenital cancers are treated by radical local excision and by regional lymphadenectomy during the spread of infection to the lymphatic system [70]. During cervical cancer radical hysterectomy which is the removal of the whole uterus including the upper vagina and supporting ligaments along with excision of paracervical soft tissue is performed. Surgical intervention not only defines the involvement of lymph nodes but also suggests the treatment alternatives as radiotherapy and chemoradiotherapy.

Radiotherapy is the acceptable primary treatment for the early stage of anogenital cancer, whereas for the advanced-stage metastatic cancer, palliative therapy is the only option. In the recurrent cervical cancer, the anti-angiogenic treatment such as bevacizumab along with cisplatin and paclitaxel can prolong the survival [71]. In case of invasive form of cervical cancer, treatment is based on surgery, brachytherapy, external beam radiation, and cisplatin-based chemotherapy [72]. In case of oropharyngeal squamous cell cancer, cisplatin-based chemotherapy has been the primary therapeutic approach [73]. Radiotherapy or surgical intervention is the choice of treatment during the primary early stage of oropharyngeal cancer.

Advertisement

7. Conclusions

Globally, over 4.6% of all the cancer cases are attributed to HPV each year where vast majority of the cases are of cervical cancer. HPV 16 and HPV 18 are predominantly responsible for progression toward cancer development. The greatest burden of HPV infection comes in the form of cervical cancer and can be prevented. The burden of cervical cancer in the form of high toll number can be reduced via vaccination, screening programs, and implementation of the early treatment along with palliation. Vaccination is the ultimate preventive strategy for all the forms of HPV-associated cancers, and the evidences are suggesting the safety of the strategy.

Advertisement

8. Future perspectives

From the last 36 years, the research in the area of HPV focuses on the prevention strategies and led to the development of vaccine and screening programs. However, new treatment for HPV infection and HPV-related cancer is still under investigation. Immunotherapy for the systemic treatment of HPV infection is the most promising area research worldwide, but none of them have been FDA approved. In order to reduce the burden of HPV-associated cancer, global implementation of vaccination and risk-based screening programs must be followed. The use of HPV-FASTER should be compelled to exemplify the current need of vaccination and screening among the higher prevalence of HPV in young generation. Currently, preventive vaccines are being developed targeting a wide range of HPV subtypes which might reduce and eventually eliminate the need of cervical cancer screening.

References

  1. 1. de Martel C, Plummer M, Vignat J, Franceschi S. Worldwide burden of cancer attributable to HPV by site, country and HPV type. International Journal of Cancer. 2017;141(4):664-670
  2. 2. Kocjan BJ, Bzhalava D, Forslund O, Dillner J, Poljak M. Molecular methods for identification and characterization of novel papillomaviruses. Clinical Microbiology and Infection. 2015;21(9):808-816
  3. 3. de Sanjosé S, Brotons M, Pavón MA. The natural history of human papillomavirus infection. Best Practice & Research. Clinical Obstetrics & Gynaecology. 2018;47:2-13
  4. 4. Carifi M, Napolitano D, Morandi M, Dall’Olio D. Recurrent respiratory papillomatosis: Current and future perspectives. Therapeutics and Clinical Risk Management. 2015;11:731-738
  5. 5. Kelly H, Mayaud P, Segondy M, Pant Pai N, Peeling RW. A systematic review and meta-analysis of studies evaluating the performance of point-of-care tests for human papillomavirus screening. Sexually Transmitted Infections. 2017;93(S4):S36-S45
  6. 6. Tommasino M. The human papillomavirus family and its role in carcinogenesis. Seminars in Cancer Biology. 2014;26:13-21
  7. 7. Molijn A, Jenkins D, Chen W, Zhang X, Pirog E, Enqi W, et al. The complex relationship between human papillomavirus and cervical adenocarcinoma. International Journal of Cancer. 2016;138(2):409-416
  8. 8. Lorenzi A, Rautava J, Kero K, Syrjänen K, Longatto-Filho A, Grenman S, et al. Physical state and copy numbers of HPV16 in oral asymptomatic infections that persisted or cleared during the 6-year follow-up. The Journal of General Virology. 2017;98(4):681-689
  9. 9. Mirkovic J, Howitt BE, Roncarati P, Demoulin S, Suarez-Carmona M, Hubert P, et al. Carcinogenic HPV infection in the cervical squamo-columnar junction. The Journal of Pathology. 2015;236(3):265-271
  10. 10. Ginindza TG, Dlamini X, Almonte M, Herrero R, Jolly PE, Tsoka-Gwegweni JM, et al. Prevalence of and associated risk factors for high risk human papillomavirus among sexually active women, Swaziland. PLoS One. 2017;12(1):e0170189
  11. 11. Lee CH, Peng CY, Li RN, Chen YC, Tsai HT, Hung YH, et al. Risk evaluation for the development of cervical intraepithelial neoplasia: Development and validation of risk-scoring schemes. International Journal of Cancer. 2015;136(2):340-349
  12. 12. Lin C, Franceschi S, Clifford GM. Human papillomavirus types from infection to cancer in the anus, according to sex and HIV status: A systematic review and meta-analysis. The Lancet Infectious Diseases. 2018;18(2):198-206
  13. 13. Chockalingam R, Downing C, Tyring SK. Cutaneous squamous cell carcinomas in organ transplant recipients. Journal of Clinical Medicine. 2015;4(6):1229-1239
  14. 14. Ribeiro AA, Costa MC, Alves RR, Villa LL, Saddi VA, Carneiro MA, et al. HPV infection and cervical neoplasia: Associated risk factors. Infectious Agents and Cancer. 2015;10:16
  15. 15. McLaughlin-Drubin ME. Human papillomaviruses and non-melanoma skin cancer. Seminars in Oncology. 2015;42(2):284-290
  16. 16. Hufbauer M, Cooke J, van der Horst GT, Pfister H, Storey A, Akgül B. Human papillomavirus mediated inhibition of DNA damage sensing and repair drives skin carcinogenesis. Molecular Cancer. 2015;14:183
  17. 17. Roden RBS, Stern PL. Opportunities and challenges for human papillomavirus vaccination in cancer. Nature Reviews. Cancer. 2018;18(4):240-254
  18. 18. Clifford GM, Gallus S, Herrero R, Muñoz N, Snijders PJ, Vaccarella S, et al. Worldwide distribution of human papillomavirus types in cytologically normal women in the International Agency for Research on Cancer HPV prevalence surveys: A pooled analysis. Lancet. 2005;366(9490):991-998
  19. 19. Serrano B, Brotons M, Bosch FX, Bruni L. Epidemiology and burden of HPV-related disease. Best Practice & Research. Clinical Obstetrics & Gynaecology. 2018;47:14-26
  20. 20. De Vuyst H, Alemany L, Lacey C, Chibwesha CJ, Sahasrabuddhe V, Banura C, et al. The burden of human papillomavirus infections and related diseases in sub-saharan Africa. Vaccine. 2013;31(05):F32-F46
  21. 21. Human Papillomavirus and related diseases report Americas. http://www.hpvcentre.net/statistics/reports/XMX.pdf
  22. 22. Bruni L, Diaz M, Castellsagué X, Ferrer E, Bosch FX, de Sanjosé S. Cervical human papillomavirus prevalence in 5 continents: Meta-analysis of 1 million women with normal cytological findings. The Journal of Infectious Diseases. 2010;202(12):1789-1799
  23. 23. Guan P, Howell-Jones R, Li N, Bruni L, de Sanjosé S, Franceschi S, et al. Human papillomavirus types in 115,789 HPV-positive women: A meta-analysis from cervical infection to cancer. International Journal of Cancer. 2012;131(10):2349-2359
  24. 24. Giuliano AR, Nyitray AG, Kreimer AR, Pierce Campbell CM, Goodman MT, Sudenga SL, et al. EUROGIN 2014 roadmap: Differences in human papillomavirus infection natural history, transmission and human papillomavirus-related cancer incidence by gender and anatomic site of infection. International Journal of Cancer. 2015;136(12):2752-2760
  25. 25. Doorbar J, Egawa N, Griffin H, Kranjec C, Murakami I. Human papillomavirus molecular biology and disease association. Reviews in Medical Virology. 2015;25(Suppl 1):2-23
  26. 26. Bernard HU. Regulatory elements in the viral genome. Virology. 2013;445(1-2):197-204
  27. 27. Howley PM, Pfister HJ. Beta genus papillomaviruses and skin cancer. Virology. 2015;479-480:290-296
  28. 28. Straub E, Dreer M, Fertey J, Iftner T, Stubenrauch F. The viral E8^E2C repressor limits productive replication of human papillomavirus 16. Journal of Virology. 2014;88(2):937-947
  29. 29. Nguyen HP, Ramírez-Fort MK, Rady PL. The biology of human papillomaviruses. Current Problems in Dermatology. 2014;45:19-32
  30. 30. Giroglou T, Florin L, Schäfer F, Streeck RE, Sapp M. Human papillomavirus infection requires cell surface heparan sulfate. Journal of Virology. 2001;75(3):1565-1570
  31. 31. Day PM, Schiller JT. The role of furin in papillomavirus infection. Future Microbiology. 2009;4(10):1255-1262
  32. 32. Popa A, Zhang W, Harrison MS, Goodner K, Kazakov T, Goodwin EC, et al. Direct binding of retromer to human papillomavirus type 16 minor capsid protein L2 mediates endosome exit during viral infection. PLoS Pathogens. 2015;11(2):e1004699
  33. 33. Aydin I, Weber S, Snijder B, Samperio Ventayol P, Kühbacher A, Becker M, et al. Large scale RNAi reveals the requirement of nuclear envelope breakdown for nuclear import of human papillomaviruses. PLoS Pathogens. 2014;10(5):e1004162
  34. 34. Wang JW, Roden RB. L2, the minor capsid protein of papillomavirus. Virology. 2013;445(1-2):175-186
  35. 35. McLaughlin-Drubin ME, Christensen ND, Meyers C. Propagation, infection, and neutralization of authentic HPV16 virus. Virology. 2004;322(2):213-219
  36. 36. Bienkowska-Haba M, Luszczek W, Myers JE, Keiffer TR, DiGiuseppe S, Polk P, et al. A new cell culture model to genetically dissect the complete human papillomavirus life cycle. PLoS Pathogens. 2018;14(3):e1006846
  37. 37. Bergner S, Halec G, Schmitt M, Aubin F, Alonso A, Auvinen E. Individual and complementary effects of human papillomavirus oncogenes on epithelial cell proliferation and differentiation. Cells, Tissues, Organs. 2016;201(2):97-108
  38. 38. Wasson CW, Morgan EL, Müller M, Ross RL, Hartley M, Roberts S, et al. Human papillomavirus type 18 E5 oncogene supports cell cycle progression and impairs epithelial differentiation by modulating growth factor receptor signalling during the virus life cycle. Oncotarget. 2017;8(61):103581-103600
  39. 39. Martinez-Zapien D, Ruiz FX, Poirson J, Mitschler A, Ramirez J, Forster A, et al. Structure of the E6/E6AP/p53 complex required for HPV-mediated degradation of p53. Nature. 2016;529(7587):541-545
  40. 40. Katzenellenbogen RA. Activation of telomerase by HPVs. Virus Research. 2017;231:50-55
  41. 41. White EA, Münger K, Howley PM. High-risk human papillomavirus E7 proteins target PTPN14 for degradation. MBio. 2016;7(5):e01530-e01516
  42. 42. Choi M, Lee C. Immortalization of primary keratinocytes and its application to skin research. Biomolecules & Therapeutics (Seoul). 2015;23(5):391-399
  43. 43. Hasan UA, Bates E, Takeshita F, Biliato A, Accardi R, Bouvard V, et al. TLR9 expression and function is abolished by the cervical cancer-associated human papillomavirus type 16. Journal of Immunology. 2007;178(5):3186-3197
  44. 44. Shah M, Anwar MA, Park S, Jafri SS, Choi S. In silico mechanistic analysis of IRF3 inactivation and high-risk HPV E6 species-dependent drug response. Scientific Reports. 2015;5:13446
  45. 45. Park JS, Kim EJ, Kwon HJ, Hwang ES, Namkoong SE, Um SJ. Inactivation of interferon regulatory factor-1 tumor suppressor protein by HPV E7 oncoprotein. Implication for the E7-mediated immune evasion mechanism in cervical carcinogenesis. The Journal of Biological Chemistry. 2000;275(10):6764-6769
  46. 46. Smola S. Immunopathogenesis of HPV-associated cancers and prospects for immunotherapy. Viruses. 2017;9(9):E254
  47. 47. Bashaw AA, Leggatt GR, Chandra J, Tuong ZK, Frazer IH. Modulation of antigen presenting cell functions during chronic HPV infection. Papillomavirus Research. 2017;4:58-65
  48. 48. Schröer N, Pahne J, Walch B, Wickenhauser C, Smola S. Molecular pathobiology of human cervical high-grade lesions: Paracrine STAT3 activation in tumor-instructed myeloid cells drives local MMP-9 expression. Cancer Research. 2011;71(1):87-97
  49. 49. Woodby B, Scott M, Bodily J. The interaction between human papillomaviruses and the stromal microenvironment. Progress in Molecular Biology and Translational Science. 2016;144:169-238
  50. 50. Pahne-Zeppenfeld J, Schröer N, Walch-Rückheim B, Oldak M, Gorter A, Hegde S, et al. Cervical cancer cell-derived interleukin-6 impairs CCR7-dependent migration of MMP-9-expressing dendritic cells. International Journal of Cancer. 2014;134(9):2061-2073
  51. 51. Allavena P, Sica A, Solinas G, Porta C, Mantovani A. The inflammatory micro-environment in tumor progression: The role of tumor-associated macrophages. Critical Reviews in Oncology/Hematology. 2008;66(1):1-9
  52. 52. Zhang Y, Zhu W, Zhang X, Qu Q, Zhang L. Expression and clinical significance of programmed death-1 on lymphocytes and programmed death ligand-1 on monocytes in the peripheral blood of patients with cervical cancer. Oncology Letters. 2017;14(6):7225-7231
  53. 53. Burd EM. Human papillomavirus laboratory testing: The changing paradigm. Clinical Microbiology Reviews. 2016;29(2):291-319
  54. 54. Tebeu PM, Fokom-Domgue J, Crofts V, Flahaut E, Catarino R, Untiet S, et al. Effectiveness of a two-stage strategy with HPV testing followed by visual inspection with acetic acid for cervical cancer screening in a low-income setting. International Journal of Cancer. 2015;136(6):E743-E750
  55. 55. Sellors JW, Sankaranarayanan R. Colposcopic Assessment of Cervical Intraepithelial Neoplasia. Colposcopy and Treatment of Cervical Intraepithelial Neoplasia: A Beginners’ Manual. http://screening.iarc.fr/colpochap.php?chap=7.php&lang=1 [Accessed on: 15-05-2018]
  56. 56. Dixit R, Bhavsar C, Marfatia YS. Laboratory diagnosis of human papillomavirus virus infection in female genital tract. Indian Journal of Sexually Transmitted Diseases. 2011;32(1):50-52
  57. 57. Leeds IL, Fang SH. Anal cancer and intraepithelial neoplasia screening: A review. World Journal of Gastrointestinal Surgery. 2016;8(1):41-51
  58. 58. Jenkins D. Histopathology and cytopathology of cervical cancer. Disease Markers. 2007;23(4):199-212
  59. 59. Khan MJ, Smith-McCune KK. Treatment of cervical precancers: Back to basics. Obstetrics and Gynecology. 2014;123(6):1339-1343
  60. 60. Benevolo M, Mottolese M, Marandino F, Vocaturo G, Sindico R, Piperno G, et al. Immunohistochemical expression of p16(INK4a) is predictive of HR-HPV infection in cervical low-grade lesions. Modern Pathology. 2006;19(3):384-391
  61. 61. Kulmala SM, Syrjänen S, Shabalova I, Petrovichev N, Kozachenko V, Podistov J, et al. Human papillomavirus testing with the hybrid capture 2 assay and PCR as screening tools. Journal of Clinical Microbiology. 2004;42(6):2470-2475
  62. 62. Poljak M. Prophylactic human papillomavirus vaccination and primary prevention of cervical cancer: Issues and challenges. Clinical Microbiology and Infection. 2012;18(Suppl 5):64-69
  63. 63. Mohsen MO, Zha L, Cabral-Miranda G, Bachmann MF. Major findings and recent advances in virus-like particle (VLP)-based vaccines. Seminars in Immunology. 2017;34:123-132
  64. 64. Capra G, Giovannelli L, Matranga D, Bellavia C, Guarneri MF, Fasciana T, et al. Potential impact of a nonavalent HPV vaccine on HPV related low-and high-grade cervical intraepithelial lesions: A referral hospital-based study in Sicily. Human Vaccines & Immunotherapeutics. 2017;13(8):1839-1843
  65. 65. Monie A, Hung CF, Roden R, Wu TC. Cervarix: A vaccine for the prevention of HPV 16, 18-associated cervical cancer. Biologics. 2008;2(1):97-105. PubMed PMID: 19707432; PubMed Central PMCID: PMC2727782
  66. 66. Mejilla A, Li E, Sadowski CA. Human papilloma virus (HPV) vaccination: Questions and answers. Canadian Pharmacicts Journal (Ott). 2017;150(5):306-315
  67. 67. Bruni L, Diaz M, Barrionuevo-Rosas L, Herrero R, Bray F, Bosch FX, et al. Global estimates of human papillomavirus vaccination coverage by region and income level: A pooled analysis. The Lancet Global Health. 2016;4(7):e453-e463
  68. 68. Srivastava M, Srivastava A. Excisional procedures for treatment of intraepithelial lesions. In: Colposcopy of Female Genital Tract. Singapore: Springer; 2017. pp. 183-196
  69. 69. Lee SJ, Yang A, Wu TC, Hung CF. Immunotherapy for human papillomavirus-associated disease and cervical cancer: Review of clinical and translational research. Journal of Gynecologic Oncology. 2016;27(5):e51
  70. 70. Wakeham K, Kavanagh K. The burden of HPV-associated anogenital cancers. Current Oncology Reports. 2014;16(9):402
  71. 71. Banerjee S. Bevacizumab in cervical cancer: A step forward for survival. Lancet. 2017;390(10103):1626-1628
  72. 72. Chuang LT, Temin S, Camacho R, Dueñas-Gonzalez A, Feldman S, Gultekin M, et al. Management and care of women with invasive cervical cancer: American Society of Clinical Oncology resource-stratified clinical practice guideline. Journal of Global Oncology. 2016;2(5):311-340
  73. 73. Perez CA, Wu X, Amsbaugh MJ, Gosain R, Claudino WM, Yusuf M, et al. High-dose versus weekly cisplatin definitive chemoradiotherapy for HPV-related oropharyngeal squamous cell carcinoma of the head and neck. Oral Oncology. 2017;67:24-28

Written By

Shailendra K. Saxena, Swatantra Kumar, Madhu Mati Goel, Apjit Kaur and Madan LB Bhatt

Submitted: 03 October 2018 Reviewed: 11 October 2018 Published: 28 November 2018