Cervical cancer heterogeneity: a constant battle against viruses and drugs

Cervical cancer is the first identified human papillomavirus (HPV) associated cancer and the most promising malignancy to be eliminated. However, the ever-changing virus subtypes and acquired multiple drug resistance continue to induce failure of tumor prevention and treatment. The exploration of cervical cancer heterogeneity is the crucial way to achieve effective prevention and precise treatment. Tumor heterogeneity exists in various aspects including the immune clearance of viruses, tumorigenesis, neoplasm recurrence, metastasis and drug resistance. Tumor development and drug resistance are often driven by potential gene amplification and deletion, not only somatic genomic alterations, but also copy number amplifications, histone modification and DNA methylation. Genomic rearrangements may occur by selection effects from chemotherapy or radiotherapy which exhibits genetic intra-tumor heterogeneity in advanced cervical cancers. The combined application of cervical cancer therapeutic vaccine and immune checkpoint inhibitors has become an effective strategy to address the heterogeneity of treatment. In this review, we will integrate classic and recently updated epidemiological data on vaccination rates, screening rates, incidence and mortality of cervical cancer patients worldwide aiming to understand the current situation of disease prevention and control and identify the direction of urgent efforts. Additionally, we will focus on the tumor environment to summarize the conditions of immune clearance and gene integration after different HPV infections and to explore the genomic factors of tumor heterogeneity. Finally, we will make a thorough inquiry into completed and ongoing phase III clinical trials in cervical cancer and summarize molecular mechanisms of drug resistance among chemotherapy, radiotherapy, biotherapy, and immunotherapy.

HPV Status and Individual Characteristics of Human Papillomavirus Infection as Predictors for Clinical Outcome of Locally Advanced Cervical Cancer

This study is aimed at searching for an informative predictor of the clinical outcome of cervical cancer (CC) patients. The study included 135 patients with locally advanced cervical cancer (FIGO stage II-III) associated with human papillomavirus (HPV) 16/18 types or negative status of HPV infection. Using logistic regression, we analyzed the influence of the treatment method, clinical and morphological characteristics, and the molecular genetic parameters of HPV on the disease free survival (DFS) of patients treated with radiotherapy or chemoradiotherapy. Multivariate analysis revealed three factors that have prognostic significance for DFS, i.e., HPV-related biomarker (HPV-negativity or HPV DNA integration into the cell genome) (OR = 9.67, p = 1.2 × 10^-4), stage of the disease (OR = 4.69, p = 0.001) and age (OR = 0.61, p = 0.025). The predictive model has a high statistical significance (p = 5.0 × 10^-8; Nagelkirk's R² = 0.336), as well as sensitivity (Se = 0.74) and specificity (Sp = 0.75). Thus, simultaneous accounting for the clinical and molecular genetic predictors (stage of the disease, patient age and HPV-related biomarker) makes it possible to effectively differentiate patients with prognostically favorable and unfavorable outcome of the disease.

Integration rates of human papilloma virus genome in a molecular survey on cervical specimens among Iranian patients

The human papilloma virus (HPV) as a major causative agent of different cancers is under investigation globally. In this study, we aim to investigate HPV infection in different cytological and pathological stages by different molecular methods, and then the viral genome integration of HPV-16 and -18 is determined by a specific real-time PCR method. The study included women who underwent liquid-based cytology. HPV PCR was conducted by MY09/11 universal primers, HPV genotyping was performed by INNO-LiPA HPV genotyping assay, and the viral genome status was defined by two real-time PCR assays. The statistics were calculated by SPSS v.22 software. In 1668 women included in the study with mean age±std. deviation of 35.6±0.7, HPV was detected in 632 (38%) participants. Following genotyping analyses, 16 HPV types and 713 strains were detected. HPV-16 and HPV-18 from high-risk types and HPV-6 and HPV-11 from low-risk types were the dominant types. We found HPV-16 strains in mixed form (58.8%), and of the HPV-18 strains, the episomal form was prevalent (92.9%). The statistics revealed significant presence of HPV-6 and within normal limits cases; HPV-16 and atypical squamous cells of undetermined significance; HPV-33 as well as HPV-39 and low-grade squamous intraepithelial lesion; HPV-6 and atypical squamous cells of undetermined significance; and HPV-35 as well as HPV-56 and squamous cell carcinoma. Our study showed high prevalence of HPV in low-grade cervical lesions, although it is associated with higher grades. The HPV molecular testing extra to cytology is recommended. HPV-16 and HPV-18 have different programs in genome integration in infected cells.

Association of Metformin Use and Survival Outcome in Women With Cervical Cancer

OBJECTIVE

Although preclinical studies suggest possible antitumor effects of metformin against cervical cancer, there is currently a lack of clinical data examining the association of metformin use and survival in women with cervical cancer. The aim of this study was to examine survival of women with cervical cancer who were receiving metformin.

METHODS

This is a retrospective study examining consecutive cases of stages I to IV cervical cancer between 2000 and 2014. Patient demographics, medication use, tumor characteristics, treatment patterns, and survival outcomes were correlated to metformin use.

RESULTS

There were 70 (8.9%; 95% confidence interval [CI], 6.9-10.9) metformin users and 715 nonusers identified for the analysis. Median follow-up time was 22.6 months. Recurrence/progression of disease and death due to cervical cancer were observed in 236 and 163 cases, respectively. Metformin users were more likely to be older, hypertensive, diabetic, and dyslipidemic compared with nonusers (all, P < 0.05). On univariate analysis, metformin users and nonusers had similar progression-free survival (PFS) (5-year rates; 57.3% vs 61.8%; P = 0.82) and cervical cancer-specific overall survival (71.7% vs 70.7%; P = 0.86). After adjusting for patient demographics and tumor characteristics, metformin use was not associated with PFS (adjusted hazards ratio, 1.11; 95% CI, 0.70-1.74; P = 0.67) or cervical cancer-specific overall survival (adjusted hazards ratio, 0.91; 95% CI, 0.52-1.60; P = 0.75). Among 478 women who received whole pelvic radiotherapy, metformin use was not associated with PFS (P = 0.93) or cervical cancer-specific overall survival (P = 0.32).

CONCLUSIONS

In this study population, metformin use was not associated with survival of women with cervical cancer.

Human Papillomavirus Type 16 Integration Analysis by Real-time PCR Assay in Associated Cancers

Human papillomavirus (HPV) is a common viral infection worldwide associated with a variety of cancers. The integration of the HPV genome in these patients causes chromosomal instability and triggers carcinogenesis. The aim of this study was to investigate the HPV-16 genome physical status in four major cancers related to HPV infection. Formalin-fixed paraffin-embedded blocks from our previous projects on head and neck, colorectal, penile, and cervical cancers were collected, and HPV-16–positive specimens were used for further analysis. The DNA extraction copy number of E2 and E7 genes was calculated by qualitative real-time PCR method. Serially diluted standards that were cloned in PUC57 plasmid were used. Standard curve and melting curve analysis was used for quantification. Of the 672 specimens studied, 76 (11.3%) were HPV-16 positive. We found that 35.6% (16/45) were integrated. Statistical analysis showed that there were significant correlations between integration of HPV-16 and cervical cancer end-stage carcinogenesis (P < .0001), episomal form, and ASCUS lesions (P = .045). Significant correlation in penile cancer patients was seen between the episomal form and high-grade cancer stage (P = .037). Integration is a major factor in the carcinogenesis mechanism of HPV and has different prevalence in various cancers with a higher rate in progression except in penile cancer.

Usefulness, methods and rationale of lymph nodes HPV-DNA investigation in estimating risk of early stage cervical cancer recurrence: a systematic literature review

Metastatic involvement of pelvic lymph-nodes (LNs), generally found in 0-29.3 % of early stages, is the most important prognostic factor in cervical cancer (CC). However, even in non-metastatic LNs, recurrence rate reaches 10-15 %. The role of HPV-DNA presence in pelvic LNs has been a point of debate in the last two decades. The aim of this systematic review is to collect all available data about LNs HPV-DNA detection in patients affected by early-stage CC in order to elucidate its clinical and surgical usefulness to choose the best surgical treatment, the necessity of adjuvant therapy and to estimate the overall oncological prognosis. The available data in this field results very patchy and often conflicting in the results. The high correlation between HPV-DNA genome detected in primary lesion and the one detected in LNs, as well as the high correlation between LNs metastatic involvement and HPV-DNA presence, lead to hypothesize that LNs HPV presence represents a potential risk-factor for recurrence and poor oncological prognosis. The large disparities in recurrence-rate of cases with LNs positive for HPV-DNA test and negative for metastases could be explained by the relative "inappropriateness" of PCR test to discriminate the presence of HPV-genome alone (condition necessary but not sufficient) or in association with squamous cells (condition necessary and sufficient). The use of ISH test for HPV-DNA detection in LNs, particularly if associated to CK19-assay, improve the accuracy of micro-metastasis detection, and the identification of patients with negative histology but potentially at high-risk of recurrence and poor oncological prognosis.

Oropharyngeal cancers: significance of HPV16 detection in neck lymph nodes

BACKGROUND

An increasing proportion of oropharyngeal squamous cell carcinomas (OPSCCs) is associated with human papillomavirus (HPV) type 16 infection. Several authors have suggested that HR-HPV DNA could be used as a marker of metastases in cervical cancers. Although HPV16 DNA has been detected in neck lymph node (LN) metastases of HPV16-positive OPSCC, its significance remains controversial. Does this presence correlate to metastatic involvement or is it just the consequence of LN filter function?

OBJECTIVES

This study aims to analyse the relationship between HPV16 detection in neck LNs of HPV16-positive OPSCC and their pathological status.

STUDY DESIGN

HP16-viral load (VL) was quantified by real-time-polymerase-chain reaction in primary tumours and neck LNs, in 11 patients with HPV16-positive OPSCC and in three patients with HPV16-negative OPSCC. HPV16 in situ hybridisation and p16 immunohistochemistry were performed in all LNs.

RESULTS

A total of 45 LN levels were assessed. HPV16 DNA was not identified in HPV16-negative OPSCC LNs. All metastatic LNs from HPV16-positive OPSCC had a high VL and the viral DNA was located within tumoural cells. Among 27 pathologically tumour-free LN (PTFLN) levels 16/27 had no detectable VL, whereas the VL was low or medium (<10(5)copies/million cells) in 8/27 and high (>10(5)copies/million cells) in 3/27 PTFLN. In the latter group, no metastatic cell was identified and the viral DNA was located in immune cells.

CONCLUSION

HPV16 detection in LN is explained by its presence within either metastatic cells or immune cells. HPV16 detection in PTFLN is not necessarily correlated to occult LN metastases.

Human papillomavirus DNA presence in pelvic lymph nodes in cervical cancer

INTRODUCTION

This work intends to present a systematic overview of data that have been published so far with regard to methods used for tissue sampling and DNA testing and with regard to the prevalence of human papillomavirus (HPV) DNA in pelvic lymph nodes (LNs) and its prognostic significance.

METHODS

The HPV DNA status of LN in women with cervical cancer is being explored as a potential marker of "occult" metastases. Although the presence of HPV DNA in LN usually correlates with its metastatic involvement, there is always a subgroup of HPV-positive but histologically negative LNs.

RESULTS

The significance of HPV in negative LNs remains uncertain, although several studies have concluded that HPV is a risk factor of recurrence.

CONCLUSIONS

A small group size and a short follow-up are the main limitations for drawing any conclusion concerning prognostic significance of the presence of HPV DNA in LNs.

High-risk human papillomavirus DNA in the primary tumor, sentinel, and nonsentinel pelvic lymph nodes in patients with early-stage cervical cancer: a correlation with histopathology

INTRODUCTION

Metastatic involvement of pelvic lymph nodes is the most important prognostic parameter in early-stage cervical cancer. Still, approximately 15% of patients with negative pelvic nodes experience recurrence, most of them in the pelvis. The presence of human papillomavirus (HPV) DNA in histologically negative pelvic nodes is considered a subclinical metastatic spread.

METHODS

Patients with early-stage cervical cancer referred for surgical treatment were enrolled in the study. Cytobrush technique was used for sample collection from the fresh tissue to avoid any loss of material for histology.

RESULTS

Altogether, 49 patients were enrolled in the study. High-risk (HR) HPV DNA was identified in the tumor in 91.8% patients and in the sentinel node or other pelvic nodes in 49.9% patients. Among the 10 HR HPV genotypes detected, HPV 16 was the most frequently represented in both the tumor and the lymph nodes (66.7% and 71.4%, respectively). All metastatic lymph nodes were HR HPV positive.

CONCLUSIONS

The presence of HR HPV DNA in a sentinel node had a 100% positive predictive value for metastatic involvement of pelvic lymph nodes in our study. This could be considered a sign of an early subclinical metastatic spread; however, the prognostic value has to be evaluated through a longer follow-up.

Frequency and prognostic significance of HPV DNA in sentinel lymph nodes of patients with cervical cancer

BACKGROUND

It has been suggested that histologically undetectable or 'occult' metastases in the lymphatic system could explain some recurrences. HPV DNA screening by means of the polymerase chain reaction (PCR) has been proposed as a method to detect occult metastases. This study was designed to determine the frequency of HPV DNA detection by PCR in sentinel lymph node (SN), and its relation to the clinical characteristics and outcome of women with cervical cancer.

PATIENTS AND METHODS

The primary cervical tumor and SN were tested for HPV DNA by means of PCR in 59 patients.

RESULTS

Fifteen (25.4%) of the 59 women undergoing the SN procedure had an involved SN. HPV DNA was more frequent in positive SN than in negative SN (P < 0.0001). Seven patients had a recurrence, after a mean delay of 17 months (range: 10-26). One of seven patients with a recurrence had an involved SN. HPV DNA was detected in an SN of one of seven patients with recurrence and nine (19.5%) of 46 patients without recurrence (not significant).

CONCLUSION

In women with cervical cancer, HPV DNA screening of sentinel nodes might help to identify patients at risk of lymph node metastases and recurrence.

HPV status in sentinel nodes might be a prognostic factor in cervical cancer

OBJECTIVE

Although there have been studies that focused on the correlation between the HPV presence of pelvic lymph nodes and pathological metastasis in patients with cervical cancer, the biologic role of HPV DNA in lymph nodes still remains uncertain. We performed this study to investigate the correlation between the sentinel-node HPV status and pelvic lymph node metastasis in patients with cervical cancer. The patients were followed up for 3 years to evaluate the clinical role of HPV in sentinel nodes as a prognostic factor.

METHODS

From August 2001 to July 2003, 57 patients affected by stages IB-IIA cervical cancer had sentinel-node biopsies performed during radical hysterectomy and pelvic and paraaortic lymphadenectomy. Each detected sentinel node was divided into two parts. One part of them was submitted for frozen section examination and the other was submitted for HPV typing by oligonucleotide microarray. After follow-up, we analyzed the outcome of the patients with respect to the influence of sentinel-node HPV.

RESULTS

Sentinel nodes were identified in all patients. A total of 79 nodes from 57 patients were detected as sentinel nodes. Metastasis in the sentinel nodes were found in 10 patients (17.6%) by frozen section and 11 patients by pathologic examination. The results of sentinel lymph node frozen biopsy were statistically significant for predicting the metastasis of the pelvic lymph nodes (P<0.05), but showed one false-negative case. HPV DNA was detected in the cervical cancer lesions of 55 patients (96.5%) and 80.0% (44/55) of them were found to have HPV DNA in the sentinel nodes as well. HPV DNA was detected in sentinel nodes of 10 patients among 11 patients with lymph node metastasis. Disease recurred in five patients and one of them did not show pelvic lymph node metastasis at surgery. But, all of these patients had HPV in sentinel nodes. The combination of sentinel-node frozen biopsy and HPV typing showed a negative predictive value of 100% in predicting non-metastasis of lymph node and no recurrence of disease.

CONCLUSION

Our results suggested the possibility that sentinel-node HPV typing could play a supportive role to reduce the false-negative rate of the sentinel-node biopsy. All of five patients with recurrence had HPV infection in the sentinel nodes. Absence of HPV in sentinel nodes showed reliable negative predictive value for lymph node metastasis and recurrence. Additional study will be needed to confirm the clinical application of the sentinel-node procedure and to determine whether there is a correlation of HPV status of sentinel nodes to lymph node metastasis and recurrence in cervical cancer patients.

Phenotypic features with p53 alterations related to human papillomavirus and prognostic evaluation in cervical cancer

Cervical cancer is one of the most common tumor affecting women worldwide. Human papillomavirus (HPV) was found to have a causal relationship with cervical cancer and its precursors. The interaction between HPV E6 protein and p53 was identified in in vitro studies. The aim of the study was to evaluate the prevalence of p53 alterations related to HPV infection and the prognostic significance of p53 alterations in cervical cancer. Studies were identified by a MEDLINE search, and all relevant articles were retrieved from 1991 to March 2004. The prevalence of p53 mutations is a rare event in cervical cancer. The correlation between p53 mutations and HPV or prognosis is controversial. Loss of heterozygosity (LOH) of p53 is more commonly found in cervical cancer and is related with the prognosis of this disease. There is no significant correlation between p53 polymorphism and development of cervical cancer. The p53 mutations were not commonly found in cervical cancer. LOH of p53 may contribute to the progression of this malignancy. p53 polymorphism failed to be an independent prognostic factor in predicting the outcome of patients with cervical cancer. Further, epidemiologic surveys should be undertaken in larger populations and in different geographical regions.

p14ARF, a prognostic predictor in HPV-negative vulvar carcinoma

The present study addressed the impact of human papillomavirus (HPV), p14, and the product of the retinoblastoma gene (pRb) in vulvar carcinoma in relation to other clinicopathologic variables and prognosis. We immunohistochemically studied 217 primary tumors from patients with vulvar carcinoma for the expression of pRb and p14. By the use of in situ hybridization, the primary tumors and 7 lymph node metastases were studied for the presence of HPV-16, HPV-18, HPV-31, and HPV-33 DNA. HPV-infected cases significantly correlated with high expression of p14 (P < .01) and p16 (P < .01). In HPV- cases with high expression of p53, no p14 expression predicted the poorest disease-specific survival (P < .01). For the first time, we have shown that p14 expression indicates longer disease-specific survival in patients with vulvar carcinoma. In patients with HPV- tumors expressing high levels of p53, low p14 indicated the poorest 5-year disease-specific survival.

Prognostic significance of high-risk HPV status in advanced cervical cancers and pelvic lymph nodes

OBJECTIVE

In this study, we investigated the presence of high-risk (HR) HPV types most prevalent in the Hungarian population in surgically removed cervical cancers and pelvic lymph nodes. The aim of our work was to determine the prognostic significance of HPV status in the lymph nodes draining the tumor.

METHODS

Primary tumor specimens from 150 patients and 900 lymph node samples (six per case) were studied. Fifty-six/150 were early (FIGO IA-IB) stage, while 94/150 were advanced (FIGO IIA-IIIB) stage cancers. Beside histopathological evaluation, DNA extracted from the tissue samples was subjected to nested PCR to detect characteristic type-specific sequences of HPVs 16, 18 and 33. Moreover, clinicopathological data were collected for an average 48-month postoperative follow-up period for the purposes of statistical analysis.

RESULTS

The presence of HR-HPV types in the lymph nodes shows no correlation with disease-free survival, whereas the presence of lymph node metastases significantly decreases life expectancy (P = 0.002). Lymph nodes with metastases more frequently carry HR-HPV than nodes with no evidence of tumorous infiltration (65% versus 36%, P < 0.001); however, a high number of metastases surrounding HR-HPV-positive tumors were found negative for the viruses (42/120).

CONCLUSIONS

HR-HPV status of pelvic lymph nodes draining cervical cancers has no noticeable influence on the life expectancy of the patients. HR-HPV-positive tumor cells do not necessarily have a selective advantage in forming metastases. Presumably, a number of alterations in cellular genes rather than the presence of papillomavirus DNA may have a decisive role in the progression of cervical cancers.