HPV Infection-Associated Cancers: Next-Generation Technology for Diagnosis and Treatment

Effect of paiteling on the alteration of persistent HR-HPV infection after panhysterectomy

This study aims to determine the effect of paiteling by placing a vaginal stump on the outcome of persistent high-risk human papillomavirus (HR-HPV) infection after hysterectomy for cervical intraepithelial neoplasia (CIN). From January 2013 to December 2015, 125 patients were enrolled in the study. These patients were divided into groups, according to patient’s preference. There were 55 patients in the paiteling group, while there were 70 patients in the control group. At the end of the third and ninth month, Thinprep cytology test (TCT) and human papillomavirus (HPV) typing were reviewed to determine the changes in HR-HPV and its complications. The negative conversion rates of these two groups were observed. Patients in the control group were observed and followed up without treatment. At the third month after treatment, HPV negative rates were 83.64% and 34.29% in the paiteling group and control group, respectively (χ2 = 30.444, P < 0.01). In the ninth month, the rate of HPV negative conversion was 90.91% in the paiteling group and 48.57% in the control group (χ2 = 25.047, P < 0.01). The difference between the two groups was statistically significant, and patients in both groups had no obvious adverse reactions. Paiteling irrigation at the vaginal stump can accelerate the positive-to-negative conversion of HR-HPV infection after panhysterectomy.

Cervical Precancer Treatment in Low- and Middle-Income Countries: A Technology Overview

Cervical cancer is the fourth leading cause of cancer-related death in women worldwide, with 90% of cases occurring in low- and middle-income countries (LMICs). There has been a global effort to increase access to affordable screening in these settings; however, a corresponding increase in availability of effective and inexpensive treatment modalities for ablating or excising precancerous lesions is also needed to decrease mortality. This article reviews the current landscape of available and developing technologies for treatment of cervical precancer in LMICs. At present, the standard treatment of most precancerous lesions in LMICs is gas-based cryotherapy. This low-cost, effective technology is an expedient treatment in many areas; however, obtaining and transporting gas is often difficult, and unwieldy gas tanks are not conducive to mobile health campaigns. There are several promising ablative technologies in development that are gasless or require less gas than conventional cryotherapy. Although further evaluation of the efficacy and cost-effectiveness is needed, several of these technologies are safe and can now be implemented in LMICs. Nonsurgical therapies, such as therapeutic vaccines, antivirals, and topical applications, are also promising, but most remain in early-stage trials. The establishment of evidence-based standardized protocols for available treatments and the development and introduction of novel technologies are necessary steps in overcoming barriers to treatment in LMICs and decreasing the global burden of cervical cancer. Guidance from WHO on emerging treatment technologies is also needed.

Human papillomavirus-driven immune deviation: challenge and novel opportunity for immunotherapy

It is now recognized that the immune system can be a key component of restraint and control during the neoplastic process. Human papillomavirus (HPV)-associated cancers of the anogenital tract and oropharynx represent a significant clinical problem but there is a clear opportunity for immune targeting of the viral oncogene expression that drives cancer development. However, high-risk HPV infection of the target epithelium and the expression of the E6/E7 oncogenes can lead to early compromise of the innate immune system (loss of antigen-presenting cells) facilitating viral persistence and increased risk of cancer. In these circumstances, a succession of interacting and self-reinforcing events mediated through modulation of different immune receptors, chemokine and cytokine responses (CCL20; CCL2; CCR2; IL-6; CCR7; IL-12) further promote the generation of an immune suppressive microenvironment [increased levels of Tregs, Th17, myeloid-derived suppressor cells (MDSCs) and PD-L1]. The overexpression of E6/E7 expression also compromises the ability to repair cellular DNA, leading to genomic instability, with the acquisition of genetic changes providing for the selection of advantaged cancer cells including additional strategies for immune escape. Therapeutic vaccines targeting the HPV oncogenes have shown some encouraging success in some recent early-phase clinical trials tested in patients with HPV-associated high-grade anogenital lesions. A significant hurdle to success in more advanced disease will be the local and systemic immune suppressive factors. Interventions targeting the different immunosuppressive components can provide opportunity to release existing or generate new and effective antitumour immunity. Treatments that alter the protumour inflammatory environment including toll-like receptor stimulation, inhibition of IL-6-related pathways, immune-checkpoint inhibition, direct modulation of MDSCs, Tregs and macrophages could all be useful in combination with therapeutic HPV vaccination. Future progress in delivering successful immunotherapy will depend on the configuration of treatment protocols in an insightful and timely combination.

Is There Still Room for Cancer Vaccines at the Era of Checkpoint Inhibitors

Checkpoint inhibitor (CPI) blockade is considered to be a revolution in cancer therapy, although most patients (70%–80%) remain resistant to this therapy. It has been hypothesized that only tumors with high mutation rates generate a natural antitumor T cell response, which could be revigorated by this therapy. In patients with no pre-existing antitumor T cells, a vaccine-induced T cell response is a rational option to counteract clinical resistance. This hypothesis has been validated in preclinical models using various cancer vaccines combined with inhibitory pathway blockade (PD-1-PDL1-2, CTLA-4-CD80-CD86). Enhanced T cell infiltration of various tumors has been demonstrated following this combination therapy. The timing of this combination appears to be critical to the success of this therapy and multiple combinations of immunomodulating antibodies (CPI antagonists or costimulatory pathway agonists) have reinforced the synergy with cancer vaccines. Only limited results are available in humans and this combined approach has yet to be validated. Comprehensive monitoring of the regulation of CPI and costimulatory molecules after administration of immunomodulatory antibodies (anti-PD1/PD-L1, anti-CTLA-4, anti-OX40, etc.) and cancer vaccines should help to guide the selection of the best combination and timing of this therapy.

Leveraging premalignant biology for immune-based cancer prevention

Prevention is an essential component of cancer eradication. Next-generation sequencing of cancer genomes and epigenomes has defined large numbers of driver mutations and molecular subgroups, leading to therapeutic advances. By comparison, there is a relative paucity of such knowledge in premalignant neoplasia, which inherently limits the potential to develop precision prevention strategies. Studies on the interplay between germ-line and somatic events have elucidated genetic processes underlying premalignant progression and preventive targets. Emerging data hint at the immune system's ability to intercept premalignancy and prevent cancer. Genetically engineered mouse models have identified mechanisms by which genetic drivers and other somatic alterations recruit inflammatory cells and induce changes in normal cells to create and interact with the premalignant tumor microenvironment to promote oncogenesis and immune evasion. These studies are currently limited to only a few lesion types and patients. In this Perspective, we advocate a large-scale collaborative effort to systematically map the biology of premalignancy and the surrounding cellular response. By bringing together scientists from diverse disciplines (e.g., biochemistry, omics, and computational biology; microbiology, immunology, and medical genetics; engineering, imaging, and synthetic chemistry; and implementation science), we can drive a concerted effort focused on cancer vaccines to reprogram the immune response to prevent, detect, and reject premalignancy. Lynch syndrome, clonal hematopoiesis, and cervical intraepithelial neoplasia which also serve as models for inherited syndromes, blood, and viral premalignancies, are ideal scenarios in which to launch this initiative.