Clinical perspectives on the role of the human papillomavirus vaccine in the prevention of cancer

Fluorescence Imaging for Cancer Screening and Surveillance

The advent of fluorescence imaging (FI) for cancer cell detection in the field of oncology is promising for both cancer screening and surgical resection. Particularly, FI in cancer screening and surveillance is actively being evaluated in many new clinical trials with over 30 listed on Clinical Trials.gov . While surgical resection forms the foundation of many oncologic treatments, early detection is the cornerstone for improving outcomes and reducing cancer-related morbidity and mortality. The applications of FI are twofold as it can be applied to high-risk patients in addition to those undergoing active surveillance. This technology has the promise of highlighting lesions not readily detected by conventional imaging or physical examination, allowing disease detection at an earlier stage of development. Additionally, there is a persistent need for innovative, cost-effective imaging modalities to ameliorate healthcare disparities and the global burden of cancer worldwide. In this review, we outline the current utility of FI for screening and detection in a range of cancer types.

Safety and Efficacy Data on Vaccines and Immunization to Human Papillomavirus

Since the discovery of the causal association between human papillomavirus (HPV) and cervical cancer, efforts to develop an effective prophylactic vaccine to prevent high-risk HPV infections have been at the forefront of modern medical research. HPV causes 530,000 cervical cancer cases worldwide, which is the second most common cause of cancer deaths in women; a worldwide collaboration among epidemiologists, molecular biologists, vaccinologists, virologists, and clinicians helped lead to the development of two highly effective prophylactive HPV vaccines. The first, Gardasil, is a quadrivalent vaccine made up of recombinant HPV L1 capsid proteins from the two high-risk HPV types (16/18) responsible for 70% of cervical cancer cases as well as two low-risk HPV types (6/11) which are the causative agent for genital warts. The second, Cervarix, is a bivalent vaccine that was FDA approved three years after Gardasil and is also composed of L1 capsid proteins from HPV types 16/18. This review article focuses on the safety and efficacy data of both FDA-approved vaccines, as well as highlighting a few advances in future HPV vaccines that show promise in becoming additional treatment options for this worldwide disease.

Managing uncertainty: healthcare professionals' meanings regarding the HPV vaccine

BACKGROUND

New preventive technologies such as vaccines offer insight into psychological, social, and cultural landscapes. Providers have a key role in parents' decisions for vaccinating their children. Yet, perspectives from providers regarding the human papillomavirus (HPV) vaccine, or vaccination in general, are rarely sought

PURPOSE

Our objective in this paper is to understand how the HPV vaccine is perceived by health care providers and the multiple contextual meanings it elicits.

METHODS

We conducted interviews with 20 health care professionals in Bulgaria about their attitudes and practices related to HPV vaccination and their recommendations for policies. The verbatim-transcribed interviews were analyzed through narrative analysis, with a special focus on language.

RESULTS

We illustrate providers' contradictory and contextualized constructions of the vaccine and the narrative strategies they use to manage any uncertainty it elicits. These include being advocates and missionaries for preventive health, confirming their trust in the medical profession and professional organizations, challenging patients' concerns with rational explanations, normalizing the risk of medical innovations, and avoiding the sexual nature of HPV transmission.

CONCLUSIONS

The introduction of a vaccine to prevent HPV infection, and by implication, possibly cervical and other cancers, created hope, and at the same time, intensified confusion and uncertainty. Providers have been frustrated for years with the rising mortality from cervical cancer in Bulgaria, and their perceived powerlessness in affecting this. HPV vaccination, on the other hand, seems relatively simple and "taming uncertainty" positions them as instrumental in limiting (or even eliminating) morbidity and mortality in future generations.

Immunogenicity of bivalent human papillomavirus DNA vaccine using human endogenous retrovirus envelope-coated baculoviral vectors in mice and pigs

Human papillomavirus is known to be the major pathogen of cervical cancer. Here, we report the efficacy of a bivalent human papillomavirus type 16 and 18 DNA vaccine system following repeated dosing in mice and pigs using a recombinant baculovirus bearing human endogenous retrovirus envelope protein (AcHERV) as a vector. The intramuscular administration of AcHERV-based HPV16L1 and HPV18L1 DNA vaccines induced antigen-specific serum IgG, vaginal IgA, and neutralizing antibodies to levels comparable to those achieved using the commercially marketed vaccine Cervarix. Similar to Cervarix, AcHERV-based bivalent vaccinations completely blocked subsequent vaginal challenge with HPV type-specific pseudovirions. However, AcHERV-based bivalent vaccinations induced significantly higher cell-mediated immune responses than Cervarix, promoting 4.5- (HPV16L1) and 3.9-(HPV18L1) fold higher interferon-γ production in splenocytes upon stimulation with antigen type-specific pseudovirions. Repeated dosing did not affect the immunogenicity of AcHERV DNA vaccines. Three sequential immunizations with AcHERV-HP18L1 DNA vaccine followed by three repeated dosing with AcHERV-HP16L1 over 11 weeks induced an initial production of anti-HPV18L1 antibody followed by subsequent induction of anti-HPV16L1 antibody. Finally, AcHERV-based bivalent DNA vaccination induced antigen-specific serum IgG immune responses in pigs. These results support the further development of AcHERV as a bivalent human papillomavirus DNA vaccine system for use in preventing the viral infection as well as treating the infected women by inducing both humoral and cell-mediated immune responses. Moreover, the possibility of repeated dosing indicates the utility of AcHERV system for reusable vectors of other viral pathogen vaccines.

Costs associated with management of cervical human papillomavirus-related conditions

BACKGROUND

Oncogenic types of human papillomavirus (HPV) have been linked to 99.7% of cervical cancer cases worldwide.

METHODS

This retrospective claims-based analysis was conducted to assess patterns of use and costs associated with diagnostic and treatment procedures for disease attributed to HPV performed before the introduction of HPV vaccination (January 1, 2001-May 31, 2006). Percentages of commercially insured health plan enrollees who underwent each procedure of interest were calculated for each year. Annual costs (combined patient and health plan-paid amounts) were calculated from qualifying medical claims. Descriptive statistics were used to assess trends in procedure rates and costs.

RESULTS

Data for approximately 14.2 million enrollees were obtained. Hysterectomy was the most commonly administered treatment. With the exception of colposcopy with LEEP, all other treatment procedures experienced a decline in rate of use. The most frequently performed diagnostic procedure was colposcopy with endocervical curettage (ECC). With the exception of ECC, rates of diagnostic procedures reached a peak among 20- to 24-year-olds, and followed a downward trend across older groups. Hysterectomy was the most expensive treatment (median $7,383; mean $8,384) per procedure in 2006.

CONCLUSION

Results reveal high rates of use and high-associated costs of diagnostic procedures and treatments related to disease attributed to HPV.

IMPACT

The data presented may be useful in cost-effectiveness analyses and to guide decision makers evaluating how best to optimize prevention strategies.