HPV-Negative Cervical Cancer: A Narrative Review

Serum Proteomic Signatures in Cervical Cancer: Current Status and Future Directions

In 2020, the World Health Organization (WHO) reported 604,000 new diagnoses of cervical cancer (CC) worldwide, and over 300,000 CC-related fatalities. The vast majority of CC cases are caused by persistent human papillomavirus (HPV) infections. HPV-related CC incidence and mortality rates have declined worldwide because of increased HPV vaccination and CC screening with the Papanicolaou test (PAP test). Despite these significant improvements, developing countries face difficulty implementing these programs, while developed nations are challenged with identifying HPV-independent cases. Molecular and proteomic information obtained from blood or tumor samples have a strong potential to provide information on malignancy progression and response to therapy in CC. There is a large amount of published biomarker data related to CC available but the extensive validation required by the FDA approval for clinical use is lacking. The ability of researchers to use the big data obtained from clinical studies and to draw meaningful relationships from these data are two obstacles that must be overcome for implementation into clinical practice. We report on identified multimarker panels of serum proteomic studies in CC for the past 5 years, the potential for modern computational biology efforts, and the utilization of nationwide biobanks to bridge the gap between multivariate protein signature development and the prediction of clinically relevant CC patient outcomes.

High-risk human papillomavirus distribution according to human immunodeficiency virus status among women with cervical cancer in Abidjan, Côte d'Ivoire, 2018 to 2020

As human papillomavirus (HPV) immunisation and HPV-based cervical cancer (CC) screening programmes expand across sub-Saharan Africa, we investigated the potential impact of human immunodeficiency virus (HIV) status on high-risk (HR)-HPV distribution among women with CC in Côte d'Ivoire. From July 2018 to June 2020, paraffin-embedded CC specimens diagnosed in Abidjan, Côte d'Ivoire were systematically collected and tested for HR-HPV DNA. Type-specific HR-HPV prevalence was compared according to HIV status. Of the 170 CC specimens analysed (median age 52 years, interquartile range: [43.0-60.0]), 43 (25.3%) were from women living with HIV (WLHIV) with a median CD4 count of 526 [373-833] cells/mm3 and 86% were on antiretroviral therapy (ART). The overall HR-HPV prevalence was 89.4% [95% CI: 84.7-94.1]. All were single HR-HPV infections with no differences according to HIV status (P = .8). Among HR-HPV-positive CC specimens, the most prevalent HR-HPV types were HPV16 (57.2%), HPV18 (19.7%), HPV45 (8.6%) and HPV35 (4.6%), with no significant differences according to HIV status. Altogether, infection with HPV16/18 accounted for 71.1% [95% CI: 55.9-86.2] of CC cases in WLHIV vs 78.9% [95% CI: 71.3-86.5] in women without HIV (P = .3). The study confirms the major role of HPV16/18 in CC in Côte d'Ivoire and should support a regional scale-up of HPV16/18 vaccination programmes regardless of HIV status. However, vaccines targeting additional HR-HPV types, including HPV45 and HPV35, could further decrease future CC incidence in Côte d'Ivoire, both for WLHIV and women without HIV.

Glycolysis Induced by METTL14 Is Essential for Macrophage Phagocytosis and Phenotype in Cervical Cancer

N 6-methyladenosine (m6A) is the most abundant mRNA modification in mammals and it plays a vital role in various biological processes. However, the roles of m6A on cervical cancer tumorigenesis, especially macrophages infiltrated in the tumor microenvironment of cervical cancer, are still unclear. We analyzed the abnormal m6A methylation in cervical cancer, using CaSki and THP-1 cell lines, that might influence macrophage polarization and/or function in the tumor microenvironment. In addition, C57BL/6J and BALB/c nude mice were used for validation in vivo. In this study, m6A methylated RNA immunoprecipitation sequencing analysis revealed the m6A profiles in cervical cancer. Then, we discovered that the high expression of METTL14 (methyltransferase 14, N6-adenosine-methyltransferase subunit) in cervical cancer tissues can promote the proportion of programmed cell death protein 1 (PD-1)-positive tumor-associated macrophages, which have an obstacle to devour tumor cells. Functionally, changes of METTL14 in cervical cancer inhibit the recognition and phagocytosis of macrophages to tumor cells. Mechanistically, the abnormality of METTL14 could target the glycolysis of tumors in vivo and vitro. Moreover, lactate acid produced by tumor glycolysis has an important role in the PD-1 expression of tumor-associated macrophages as a proinflammatory and immunosuppressive mediator. In this study, we revealed the effect of glycolysis regulated by METTL14 on the expression of PD-1 and phagocytosis of macrophages, which showed that METTL14 was a potential therapeutic target for treating advanced human cancers.

Screening and identification of B cell epitope within the major capsid protein L1 of HPV 52, using monoclonal antibodies

The L1 protein of Human papillomavirus (HPV), the main capsid protein, induces the formation of neutralizing antibodies. In this study, HPV52 L1 protein was induced to be expressed. Monoclonal antibody (mAb) 6A7 against L1 protein were screened by cell fusion techniques. Western Blot and immunofluorescence assay (IFA) demonstrated the specificity of the mAb. The L1 protein was truncated for prokaryotic expression (N1∼N7) and Dot-ELISA showed that 6A7 recognized N3 (aa 200-350). The immunodominant regions were truncated again for expression, with 6A7 recognizing N6 (aa 251-305). The N6 proteins were further truncated and then were constructed an four-segment eukaryotic expression vector. IFA showed that 6A7 could recognize amino acid 262-279. Amino acid 262-279 was selected to be truncated into short peptides P1 and P2. Finally, Peptide-ELISA and Dot-ELISA showed that the epitope regions of mAb 6A7 were amino acid 262-273. The mAbs with defined epitopes can lay the foundation for the analysis of antigenic epitope characteristics and promote the development of epitope peptide vaccines.

Understanding the Dynamics of Human Papillomavirus and Diagnostic Discrepancies in Cervical Pathology: A Single Center Experience

Cervical cancer (CC) is the most prevalent gynecological malignancy and a leading cause of death among women. It is primarily caused by human papillomavirus (HPV) infection, with 99.7% of cases showing high-risk HPV genotypes. This study sheds light on HPV dynamics as well as the discrepancies of different CC screening modalities results while highlighting factors that may have contributed to such a scenario. Moreover, we underscore the importance of the non-viral etiology of CC as well. We examined the current trends of HPV infection and its effects on cervical health in women treated at a tertiary care center in Belgrade, Serbia. Patients with abnormal colposcopy findings like dysplasia and re-epithelization were more likely to test negative for HPV (p < 0.001). Interestingly, women with a positive Pap smear tested HPV negative significantly more often (p = 0.041). Finally, HPV-positive individuals were more likely to have CIN I and II histologies (p < 0.001), while CIN III occurred equally in women with and without the virus. It may be inferred that inconsistencies in detecting HPV and the presence of cervical lesions may eventually result in adjustments to screening guidelines, as is crucial to adopt a meticulous approach to promote periodical CC screening, as initial samples may test negative for HPV.

PAX1 and SEPT9 methylation analyses in cervical exfoliated cells are highly efficient for detecting cervical (pre)cancer in hrHPV-positive women

Studies have investigated PAX1 and SEPT methylation were closely associated with cervical cancer. For this study, we verified the expressions of PAX1 and SEPT9 methylation in 236 hrHPV women cervical exfoliated cells by using quantitative methylation-specific PCR and we further explored their diagnostic value in cervical (pre)cancer detection. Our results identified that the methylation rates and levels of PAX1 and SEPT9 increased with cervical lesion severity. For a diagnosis of cervical (pre)cancer, the area under the curve (AUC) of PAX1 methylation was 0.77 (95% CI 0.71-0.83) and the AUC of SEPT9 methylation was 0.86 (95% CI 0.81∼0.90). Analyses of the PAX1 and SEPT9 methylation statuses alone or combined with commonly used tests can efficiently identify cervical (pre)cancer. In particular, SEPT9 methylation might serve as an effective and powerful biomarker for the diagnosis of cervical (pre)cancer and as an alternative triage test in HPV-based cervical (pre)cancer screening programs.Impact StatementWhat is already known on this subject? This subject showed that PAX1 and SEPT9 methylation were closely associated with cervical cancer. The methylation rates and levels of PAX1 and SEPT9 increased with cervical lesion severity and reached a peak in cervical cancer exfoliated cells. We further assessed the diagnostic performances of PAX1 and SEPT9 methylation in cervical cancer screening. In detecting cervical (pre)cancer, the sensitivity values of PAX1 and SEPT9 methylation were up to 61.18% and 82.35%, respectively, and the specificity values of PAX1 and SEPT9 methylation were up to 95.36% and 86.75%, respectively. Moreover, the ROC curve analysis showed AUC values of 0.77 for PAX1 methylation and 0.86 for SEPT9 methylation tests, which were significantly superior to other commonly used tests. These findings suggest that PAX1 and SEPT9 methylation detection may have great clinical potential in cervical cancer screening.What the results of this study add? The rates and levels of PAX1 and SEPT9 methylation increased with the severity of the cervical lesions. For a diagnosis of cervical (pre)cancer, the area under the curve (AUC) of PAX1 methylation was 0.77 (95% CI 0.71-0.83), and the sensitivity and specificity values were 61.18% and 95.36%, respectively. The AUC value of the SEPT9 methylation was 0.86 (95% CI 0.81 ∼ 0.90), and the sensitivity and specificity values were 82.35% and 86.75%, respectively. Compared with the various tests we conducted, the PAX1 methylation showed the highest specificity (95.36%), and the SEPT9 methylation demonstrated the highest accuracy(86.00%).What the implications are of these findings for clinical practice and/or further research? The methylation levels of PAX1 and SEPT9 had a certain predictive effect on the severity of cervical lesions in hrHPV-positive women. In addition, SEPT9 methylation analysis performs better than PAX1 methylation analysis and commonly used tests in cervical exfoliated cells for detecting cervical (pre)cancer in hrHPV-positive women. SEPT9 methylation analysis merits consideration as an effective and objective, alternative triage test in HPV-based cervical (pre)cancer screening programs.

Altered mitochondrial DNA copy number in cervical exfoliated cells among high‑risk HPV‑positive and HPV‑negative women

The majority of cervical cancer cases are due to human papillomavirus (HPV) infection. However, certain cases of cervical cancer are not caused by HPV. Recent studies have shown a link between altered mitochondrial DNA (mtDNA) copy number, an indicative measure of mitochondrial dysfunction, and cervical cancer in women who test positive for HPV. However, the role of the mtDNA copy number in HPV-negative cervical cancer has remained elusive. In the present study, the mtDNA copy number was determined using quantitative PCR as the ratio between mtDNA and nuclear DNA in 287 ThinPrep cervical samples, including 143 cases with cervical abnormalities and 144 control subjects with high-risk (hr)-HPV positive or HPV-negative status. In an overall analysis of cases categorized based on the cytology diagnosis into squamous cervical carcinoma/high-grade squamous intraepithelial lesions (SCC/HSIL), low-grade squamous intraepithelial lesions (LSIL) and normal controls, the mtDNA copy number was significantly higher in all cases compared to the controls and a higher mtDNA copy number was observed in SCC/HSIL compared to LSIL cases. In the stratification analyses based on hr-HPV positive and HPV-negative status, an increased mtDNA copy number was observed in the cases compared with the controls regardless of their HPV status (P<0.05). When cases with cervical abnormalities were categorized based on histological diagnosis into cervical intraepithelial neoplasia (CIN)2/CIN3 and CIN1, an overall analysis indicated an increased mtDNA copy number in CIN2/CIN3 compared to CIN1 (P=0.01). Stratification analyses of these cases based on HPV status revealed a higher mtDNA copy number in CIN2/CIN3 compared to CIN1 regardless of HPV infection (P<0.05). These results showed that an elevated mtDNA copy number in subjects with cervical abnormalities was not influenced by the HPV status and suggested the possibility of its role in the progression of cervical cancer. The increased mtDNA copy number may be an adaptive response mechanism to compensate for mtDNA oxidative stress and energy deficiency, possibly induced by HPV infection and other environmental exposures.

Distribution of human papilloma virus genotypes and treatment outcomes in definitive radiotherapy for cervical cancer

Most oncogenic human papilloma virus (HPV) genotypes stratify into two species, α-7 HPV and α-9 HPV. There are several studies that evaluate the relationship between HPV species and treatment outcomes and reports that HPV species is prognostic. The HPV genotyping was conducted using biopsy specimens which had been stored in these studies. We conducted the study using the HPV test performed by cytology specimens which is less invasive and more useful in clinical settings. This study enrolled 46 patients who received HPV genotyping before the definitive radiotherapy. The results of the HPV genotyping were classified into HPVα-7, HPVα-9 and negatives. Of the 46 patients, 10 were positive for HPVα-7, 21 positive for HPVα-9 and 15 were negative. The median follow-up period was 38 months (range 4-142). The HPVα-7, HPVα-9 and negative groups showed the 3-year overall survival (OS; 59.3%, 80.4% and 72.2% [P = 0.25]); local control (LC; 67.5%, 81% and 80% [P = 0.78]); pelvic control (PC) (50%, 81% and 72.7% [P = 0.032]); pelvic lymph node (PLN) control (78.7%, 95% and 92.3% [P = 0.012]); distant metastasis free (DMF) survival (50%, 75.4% and 42.8% [P = 0.098]); and progression free survival (PFS) rate of patients (30%, 66.7% and 38.9% [P = 0.085]), respectively. Patients with HPVα-7 showed statistically significant poorer PC than the HPVα-9 group, in multivariate analysis. This result is consistent with previous studies for HPV positive patients. The HPV negativity rate was higher in this study than in other studies and further work on this may be needed for clinical use.

Machine learning applied to MRI evaluation for the detection of lymph node metastasis in patients with locally advanced cervical cancer treated with neoadjuvant chemotherapy

PURPOSE

Concurrent cisplatin-based chemotherapy and radiotherapy (CCRT) plus brachytherapy is the standard treatment for locally advanced cervical cancer (LACC). Platinum-based neoadjuvant chemotherapy (NACT) followed by radical hysterectomy is an alternative for patients with stage IB2-IIB disease. Therefore, the correct pre-treatment staging is essential to the proper management of this disease. Pelvic magnetic resonance imaging (MRI) is the gold standard examination but studies about MRI accuracy in the detection of lymph node metastasis (LNM) in LACC patients show conflicting data. Machine learning (ML) is emerging as a promising tool for unraveling complex non-linear relationships between patient attributes that cannot be solved by traditional statistical methods. Here we investigated whether ML might improve the accuracy of MRI in the detection of LNM in LACC patients.

METHODS

We analyzed retrospectively LACC patients who underwent NACT and radical hysterectomy from 2015 to 2020. Demographic, clinical and MRI characteristics before and after NACT were collected, as well as information about post-surgery histopathology. Random features elimination wrapper was used to determine an attribute core set. A ML algorithm, namely Extreme Gradient Boosting (XGBoost) was trained and validated with tenfold cross-validation. The performances of the algorithm were assessed.

RESULTS

Our analysis included n.92 patients. FIGO stage was IB2 in n.4/92 (4.3%), IB3 in n.42/92 (45%), IIA1 in n.1/92 (1.1%), IIA2 in n.16/92 (17.4%) and IIB in n.29/92 (31.5%). Despite detected neither at pre-treatment and post-treatment MRI in any patients, LNM occurred in n.16/92 (17%) patients. The attribute core set used to train ML algorithms included grading, histotypes, age, parity, largest diameter of lesion at either pre- and post-treatment MRI, presence/absence of fornix infiltration at pre-treatment MRI and FIGO stage. XGBoost showed a good performance (accuracy 89%, precision 83%, recall 78%, AUROC 0.79).

CONCLUSIONS

We developed an accurate model to predict LNM in LACC patients in NACT, based on a ML algorithm requiring few easy-to-collect attributes.

Knowledge and Perceptions about Cervical Cancer and HPV Screening in Women in Rural Areas of Ecuador: A Qualitative Research Study

BACKGROUND

Cervical cancer continues to be a major health problem in developing countries. Educational programs, as well as Pap and HPV screening and vaccination, are important tools to reduce the morbidity and mortality rates associated with this disease. The objective of this study is to explore the diverse knowledge and perceptions about cervical cancer and the different diagnostic tests for HPV of populations living in the rural parish "El Valle".

METHOD

A qualitative study was conducted through eight focus groups, which included 46 participants from mixed ethnic groups. A phenomenological analysis was performed.

RESULTS

Four topics and seven sub-topics were identified. By analyzing all the narratives, it was possible to identify that the perception of cervical cancer was focused on its severity, secondary to its infectious process and screening periodicity. However, despite the diverse knowledge, indigenous people do not relate it to the human papilloma virus; in addition, there is also certain resistance to undergo the Pap smear test, for reasons such as inaccessibility and its sampling process.

CONCLUSIONS

It is necessary to develop educational programs for the prevention of cervical cancer and to implement diagnostic alternatives to reach populations with precarious accessibility, as well as women who refuse to undergo the Pap smear test.

Untold story of human cervical cancers: HPV-negative cervical cancer

Cervical cancer is the fourth most common malignancy in women worldwide. Although infection from human papillomavirus (HPV) has been the leading cause of cervical cancer, HPV-negative cervical cancer accounts for approximately 3-8% of all cases. Previous research studies on cervical cancer have focused on HPV-positive cervical cancer due to its prevalence, resulting in HPV-negative cervical cancer receiving considerably less attention. As a result, HPV-negative cervical cancer is poorly understood. Its etiology remains elusive mainly due to limitations in research methodology such as lack of defined markers and model systems. Moreover, false HPV negativity can arise from inaccurate diagnostic methods, which also hinders the progress of research on HPV-negative cervical cancer. Since HPV-negative cervical cancer is associated with worse clinical features, greater attention is required to understand HPV-negative carcinoma. In this review, we provide a summary of knowledge gaps and current limitations of HPV-negative cervical cancer research based on current clinical statistics. We also discuss future directions for understanding the pathogenesis of HPV-independent cervical cancer. [BMB Reports 2022; 55(9): 429-438].

The Accuracy of Cytology, Colposcopy and Pathology in Evaluating Precancerous Cervical Lesions

Introduction: Cervical cancer (CC) is the third most common cancer in the world, and Romania has the highest incidence of cervical cancer in Europe. The aim of this study was to evaluate the correlation between cytology, colposcopy, and pathology for the early detection of premalignant cervical lesions in a group of Romanian patients. Methods: This observational type 2 cohort study included 128 women from our unit, “Bucur” Maternity, who were referred for cervical cancer screening. Age, clinical diagnosis, cytology results, colposcopy impression, and biopsy results were considered. Colposcopy was performed by two experienced examiners. The pathological examination was performed by an experienced pathologist. Results: The cytology found high-grade squamous intraepithelial lesions in 60.9% of patients, low-grade squamous intraepithelial lesions in 28.1%, atypical squamous cells for which a high-grade lesion could not be excluded in 9.4%, and atypical squamous cells of undetermined significance, known as repeated LSIL, in 1.6%. The first evaluator identified low-grade lesions in 56.3%, high-grade lesions in 40.6%, and invasion in 3.1% of patients. The second evaluator identified low-grade lesions in 59.4%, high-grade lesions in 32.0%, and invasion in 8.6% of patients. The pathological exam identified low-grade lesions in 64.1%, high-grade lesions in 25%, and carcinoma in 14% of patients. The colposcopic accuracy was greater than the cytologic accuracy. Conclusions: Colposcopy remains an essential tool for the identification of cervical premalignant cancer cells. Standardization of the protocol provided an insignificant interobserver variability and can serve as support for further postgraduate teaching.

Cyto-Histological Findings in HPV Negative Cases from HPV Primary Screening Programme: Quality Assurance Study

OBJECTIVE

To evaluate the risk of false HPV negative results and possible related morphological abnormalities in HPV primary cervical cancer screening.

METHODS

Out of 53 661 HPV negative cases, 5469 (10.2%) randomly selected cytology slides were evaluated as a part of the quality assurance protocol.

RESULTS

The Bethesda category Negative for Intraepithelial Lesion or Malignancy (NILM) in the HPV negative cases given was present in 95.4%. Due to cytology other than NILM, 0.4% of cases were referred to colposcopy and 4.2% to the follow up in one year. In the follow up HPV negativity and NILM cytology was present in 88.3 % of attended women. Cases other than HPV negative and NILM were referred to colposcopy. One biopsy-proven histological HSIL was found in the first round and one in follow up screening. More comprehensive genotyping of HSIL cases revealed genotypes 69 and 11.

CONCLUSIONS

Only two HPV test negative cases with histological HSIL were revealed forming 0.04% of quality control group. In both cases, HPV genotype not included in screening tests was found. According to the results, the primary HPV test with cytology triage is an efficient and specific method for cervical cancer screening despite of the fact that some non-high-risk genotypes are missed.

Clinicopathological characteristics and survival outcomes in human papillomavirus independent cervical cancer: a propensity score matched analysis

OBJECTIVE

To investigate the clinicopathological characteristics and overall survival in high-risk human papillomavirus (HPV)-independent and HPV-associated cervical cancer.

METHODS

Patients with cervical cancer hospitalized between September 2015 and December 2019 from the Affiliated Cancer Hospital of Guizhou Medical University were enrolled. First, patients with negative results by HPV primary screening were excluded. Second, the paraffin-embedded tumor tissues from patients with negative results were used for extraction of deoxyribonucleic acid (DNA). The Hybribio K-37 test (PCR and flow-through hybridization for 37 types of HPV) was used to further identify HPV-negative infection status. Finally, 1:4 propensity score matching between high-risk HPV-independent and HPV-associated groups was performed, and the clinicopathological characteristics and overall survival were compared between the two groups.

RESULTS

Forty cervical HPV primary screening negative patients were screened of 729 patients (5.5%). Among them, 13 (1.8%) patients who were identified with high-risk HPV-independent cervical cancer after the K-37 test were selected as the study group. There were significant intergroup differences in the distribution of International Federation of Gynecology and Obstetrics (FIGO, 2018) stage (χ²=5.825, p=0.016), pathological types (χ²=6.910, p=0.009), lymph node metastasis (χ²=6.168, p=0.013), and tumor size (χ²=5.319, p=0.021). After propensity score matching, 52 patients from the HPV-associated group were selected as the control group. Patients with high-risk HPV-independent cervical cancer had poorer prognosis than those with HPV-associated cervical cancer (median overall survival: 27 vs 29 months, p=0.03; median disease-free survival: 27 vs 29 months, p=0.021).

CONCLUSION

Patients with high-risk HPV-independent cervical cancer more frequently had advanced stage disease, nodal metastasis, larger tumor, and a higher proportion of adenocarcinoma. The prognosis of patients with high-risk HPV-independent cervical cancer was poorer than those with HPV-associated cervical cancer.

The Application of Sonovaginography for Implementing Ultrasound Assessment of Endometriosis and Other Gynaecological Diseases

Sonovaginography is a way of assessing gynaecological diseases that can be described as cheap yet accurate and non-invasive. It consists of distention of the vagina with ultrasound gel or saline solution while performing transvaginal sonography to clearly visualize and assess a host of local cervical, as well as any vaginal, disorders. With endometriosis being a steadily growing gynaecological pathology affecting 8-15% of women of fertile age, transvaginal sonography (TVS) can be considered as one of the most accurate and comprehensive imaging techniques in its diagnosis. Nevertheless, the accuracy may vary depending on scan sites. The purpose of this narrative review is to assess the performance of sonovaginography in detecting endometriosis in those sites where TVS has a low sensitivity.