Prognostic value of HPV-mRNA in sentinel lymph nodes of cervical cancer patients with pN0-status

TRANSLACOL project: Nodal human papillomavirus tumoral DNA detection by ddPCR for survival prediction in early cervical cancer patients without pelvic lymph node invasion

INTRODUCTION

In early cervical cancer (EEC), 10 to 15% of patients without nodal metastasis (N-) will suffer from recurrences with further similar survival as N+ patients. However, no clinical, imaging or pathological risk-factor is today available to identify them. In the present study, we hypothesized that the N- histologically characterized patients who present a poor prognosis could be patients for whom metastasis are missed by classical procedure. Therefore, we propose to research HPV tumoral DNA (HPVtDNA) in pelvic Sentinel Lymph Nodes (SLN) biopsy using ultrasensitive droplet-based digital PCR (ddPCR) to detect eventual occult metastasis.

MATERIALS AND METHODS

Sixty HPV16, HPV18 or HPV33 positive EEC N- patients with available SLN were included. In SLN, HPV16 E6, HPV18 E7 and HPV33 E6 gene were respectively detected using ultrasensitive ddPCR technology. Survival data were analysed using Kaplan-Meier-curves and log-rank-test to compare progression-free survival (PFS) and disease-specific survival (DSS) in two groups according to their HPVtDNA status in SLN.

RESULTS

More than half (51.7%) of the patients finally showed HPVtDNA positivity in SLN initially diagnosed as negative by histology. Two patients with negative HPVtDNA SLN and 6 with positive HPVtDNA SLN group presented recurrence. Finally, all of the 4 deaths listed in our study occurred in the positive HPVtDNA SLN group.

CONCLUSION

These observations hint that the use of ultrasensitive ddPCR to detect HPVtDNA in SLN could allow the identification of two subgroups of histologically N- patients that may have different prognosis and outcome. To our knowledge, our study is the first one to evaluate the detection of HPVtDNA in SLN in early cervical cancer using ddPCR highlighting its interest as a complementary tool for N- specific early cervical cancer diagnosis.

RIPOR2 Expression Decreased by HPV-16 E6 and E7 Oncoproteins: An Opportunity in the Search for Prognostic Biomarkers in Cervical Cancer

High-risk human papillomavirus (HPV) infection is the main risk factor for cervical cancer (CC) development, where the continuous expression of E6 and E7 oncoproteins maintain the malignant phenotype. In Mexico, around 70% of CC cases are diagnosed in advanced stages, impacting the survival of patients. The aim of this work was to identify biomarkers affected by HPV-16 E6 and E7 oncoproteins that impact the prognosis of CC patients. Expression profiles dependent on E6 and E7 oncoproteins, as well as their relationship with biological processes and cellular signaling pathways, were analyzed in CC cells. A comparison among expression profiles of E6- and E7-expressing cells and that from a CC cohort obtained from The Cancer Genome Atlas (TCGA) demonstrated that the expression of 13 genes impacts the overall survival (OS). A multivariate analysis revealed that the downregulated expression of RIPOR2 was strongly associated with a worse OS. RIPOR2, including its transcriptional variants, were overwhelmingly depleted in E6- and E7-expressing cells. Finally, in a Mexican cohort, it was found that in premalignant cervical lesions, RIPOR2 expression decreases as the lesions progress; meanwhile, decreased RIPOR2 expression was also associated with a worse OS in CC patients.

Cervical Cancer Diagnosis: Insights into Biochemical Biomarkers and Imaging Techniques

Cervical malignancy is known as one of the important cancers which is originated from cervix. This malignancy has been observed in women infected with papillomavirus who had regular oral contraceptives, multiple pregnancies, and sexual relations. Early and fast cervical cancer diagnosis is known as two important aspects of cervical cancer therapy. Several investigations indicated that early and fast detection of cervical cancer could be associated with better treatment process and increasing survival rate of patients with this malignancy. Imaging techniques are very important diagnosis tools that could be employed for diagnosis and following responses to therapy in various cervical cancer stages. Multiple lines of evidence indicated that utilization of imaging techniques is related to some limitations (i.e. high cost, and invasive effects). Hence, it seems that along with using imaging techniques, finding and developing new biomarkers could be useful in the diagnosis and treatment of subjects with cervical cancer. Taken together, many studies showed that a variety of biomarkers including, several proteins, mRNAs, microRNAs, exosomes and polymorphisms might be introduced as prognostic, diagnostic and therapeutic biomarkers in cervical cancer therapy. In this review article, we highlighted imaging techniques as well as novel biomarkers for the diagnosis of cervical cancer.

Evidence for disseminated tumor cells in lymphatic vessels afferent to sentinel lymph nodes in patients diagnosed with cervical cancer

BACKGROUND

In patients diagnosed with cervical cancer, the purpose of lymphadenectomy is the removal of lymph nodes for diagnosis and potential treatment of metastasized tumor cells. It is unclear if afferent lymphatic vessels harbor tumor cells and, thus, may pose additional risk for recurrence or progression if not removed.

AIM

In this feasibility study, we analyzed the lymphatic vessels afferent to sentinel lymph node (SLN) using a highly sensitive and specific molecular marker for cervical cancer cells.

METHODS AND RESULTS

Twenty patients diagnosed with cervical cancer of FIGO stage IA1 to IIB2 underwent laparoscopic SLN removal. Labeling was done using patent blue and the afferent lymphatic vessels were harvested from the parametric tissue and frozen at -80°C. HPV DNA type was evaluated in the primary tumor. Lymphatic vessels afferent to the sentinel lymph nodes were analyzed for the presence of viral oncogene transcripts of the respective HPV type. In one of 18 patients, all with tumor stage ≤IBI and pN0 by conventional histopathology, HPV mRNA could be detected in two of four lymphatic vessels, whereas at least one of the lymphatic vessel biopsies of both patients with tumors ˃4 cm and pN1 status was HPV mRNA positive. No clinical correlation with recurrence after a median follow-up of 9 years was noticed.

CONCLUSION

HPV mRNA indicative of disseminated tumor cells could be detected in lymphatic vessels. The relevance of harvesting lymphatic vessels afferent to SLN in order to increase oncologic safety will have to be investigated in a future prospective study.

Diagnostic value of frozen section examination of sentinel lymph nodes in early-stage cervical cancer at the time of ultrastaging

OBJECTIVES

We aimed to assess the diagnostic value of frozen-section pathologic examination (FSE) of sentinel lymph nodes (SLN) in patients with early-stage cervical cancer.

METHODS

Two French prospective multicentric database on SLN biopsy for cervical cancer (SENTICOL I and II) were analysed. Patients with IA to IIA1 2018 FIGO stage, who underwent SLN biopsy with both FSE and ultrastaging examination were included.

RESULTS AND DISCUSSION

Between 2005 and 2012, 313 patients from 25 centers fulfilled the inclusion criteria. Metastatic involvement of SLN was diagnosed in 52 patients (16.6%). Macrometastases, micrometastases and isolated tumor cells (ITCs) were found in 27, 12 and 13 patients respectively. Among the 928 SLNs analysed, FSE identified 23 SLNs with macrometastases in 20 patients and 5 SLNs with micrometastases in 2 patients whereas no ITCs were identified. Ultrastaging of negative SLNs by FSE found macrometastases, micrometastases and ITCs in additional 7, 11 and 17 SLNs. Ultrastaging increased significantly the rate of patients with positive SLN from 7% to 16.6% (p < 0.0001). The sensitivity and the negative predictive value of FSE were 42.3% and 89.7% respectively or 56.4% and 94.1% if ITCs were excluded. False-negative cases were more frequent with tumor size ≥ 20 mm (OR = 4.46, 95%IC = [1.45-13.66], p = 0.01) and preoperative brachytherapy (OR = 4.47, 95%IC = [1.37-14.63], p = 0.01) and less frequent with patients included in higher volume center (>5 patients/year) (OR = 0.09, 95%IC = [0.02-0.51], p = 0.01).

CONCLUSIONS

FSE of SLN had a low sensitivity for detecting micrometastases and ITCs and a high negative predictive value for SLN status. Clinical impact of false-negative cases has to be assessed by further studies.

Detection of high-risk human papillomavirus DNA in sentinel lymph nodes of patients with cervical cancer

The aim of the present study was to investigate the expression of human papillomavirus (HPV) DNA in sentinel lymph nodes (SLN) in patients with early-stage cervical cancer (CC). In addition, the present study compared the positive rate of SLNs metastasis detected by routine pathological examination, and investigated the value of HPV-DNA in the detection of early CC lymph node micrometastasis. Reverse transcription-quantitative PCR (RT-qPCR) was used in order to evaluate the HPV DNA detection in all CC samples [International Federation of Gynecology and Obstetrics (FIGO) stage IA2-IIA2]. The consistency of HPV-DNA was compared between primary lesions and SLNs. The positive rates of HPV-DNA were compared with pathological diagnosis of SLN metastasis, and the association between the positive expression of HPV-DNA in SLNs and the clinical and pathological parameters of patients with cervical cancer were analyzed. A total of 345 sentinel lymph nodes were detected in 100 patients with IA2-IIA2 CC. The positive rates of RT-qPCR and conventional histopathological detection of SLNs metastasis were 31.6% (109/345) and 12.8% (44/345), respectively (P<0.001). The positive expression of HPV-DNA in SLNs was associated with the clinical stage and tumor diameter (P<0.05), but not with patients' age, depth of cervical invasion, histological grade, lymphatic and vascular space invasion (LVSI), squamous cell carcinoma antigen (SCCAg) (P>0.05). The detection of HPV-DNA expression in pelvic lymph nodes of early CC may be used to improve the detection rate of micrometastasis, guide the postoperative adjuvant therapy more accurately and improve prognosis. Patients with positive HPV-DNA would require closer surveillance than those with negative HPV-DNA.

Detection of high-risk human papillomavirus DNA in tissue from primary cervical cancer tumor, pelvic lymph nodes and recurrent disease

Objectives

The present study investigated Human Papillomavirus (HPV) DNA genotyping in primary tumor, pelvic lymph nodes (PLN) and recurrence in early-stage cervical cancer patients.

Methods

We conducted a hospital-based case-control study. From 2003 to 2015, 282 patients underwent surgery for cervical cancer in the Department of Gynecology, Aarhus University Hospital, Denmark. Twenty-nine recurrent cases were identified. HPV DNA genotyping was performed on formalin-fixed, paraffin-embedded tissue specimens from the primary tumor, PLN, and recurrent disease.

Results

In the primary tumor, HPV DNA was detectable in 18(72%) of 25 tissue specimens from recurrent cases and in 15(83%) of 18 controls. HPV DNA-positive PLN was significantly associated with recurrence, 83%(95%CI: 52–98%), compared to patients with HPV-negative PLN, 38%(95%CI: 18–62%)(p < 0.05). HPV DNA genotyping was positive in eight of 12(67%) patients with recurrent disease. The genotype was identical in all three tissues types.

The positive predictive value for recurrence was the same for detection of HPV-DNA and metastases in the PLN, with reasonable sensitivity. The negative predictive value for recurrence, however, was best for HPV-DNA, 62%(95%CI: 38–98%).

Conclusions

In conclusion, our data suggest that the presence of HPV in pelvic lymph nodes is associated with an increased risk of recurrence.

HPV16 viral characteristics in primary, recurrent and metastatic vulvar carcinoma

Vulvar carcinoma is the fourth most common gynecological malignancy. Two separate carcinogenic pathways are suggested, where one is associated with the human papillomavirus (HPV) and HPV16 the most common genotype. The aim of this study was to evaluate HPV-markers in a set of primary tumors, metastases and recurrent lesions of vulvar squamous cell carcinomas (VSCC). Ten HPV16-positive VSCC with metastatic regional lymph nodes, distant lymphoid/hematogenous metastases or local recurrent lesions were investigated for HPV genotype, HPV16 variant, HPV16 viral load, HPV16 integration and HPV16 E2BS3 and 4 methylation. In all 10 analyzed case series, the same HPV genotype (HPV16), HPV16 variant and level of viral load were detected in all lesions within a patient case. Primary tumors with a high E2/E6 ratio were found to have fewer vulvar recurrences and/or metastases after diagnosis and treatment. Also, a significantly lower viral load was evident in regional lymph nodes compared to primary tumors. The data presented strengthens the evidence for a clonal HPV-induced pathway for vulvar carcinoma.

A comparative study of digital PCR and real-time qPCR for the detection and quantification of HPV mRNA in sentinel lymph nodes of cervical cancer patients

Background

Qualitative analyses showed that the presence of HPV mRNA in sentinel lymph nodes of cervical cancer patients with pN0 status is associated with significantly decreased recurrence free survival. To further address the clinical potential of the strategy and to define prognostic threshold levels it is necessary to use a quantitative assay. Here, we compare two methods of quantification: digital PCR and standard quantitative PCR.

Methods

Serial dilutions of 5 ng–5 pg RNA (≙ 500–0.5 cells) of the cervical cancer cell line SiHa were prepared in 5 µg RNA of the HPV-negative human keratinocyte cell line HaCaT. Clinical samples consisted of 10 sentinel lymph nodes with varying HPV transcript levels. Reverse transcription of total RNA (5 µg RNA each) was performed in 100 µl and cDNA aliquots were analyzed by qPCR and dPCR. Digital PCR was run in the RainDrop^® Digital PCR system (RainDance Technologies) using a probe-based detection of HPV E6/E7 cDNA PCR products with 11 µl template. qPCR was done using a Rotor Gene Q 5plex HRM (Qiagen) amplifying HPV E6/E7 cDNA in a SYBR Green format with 1 µl template.

Results

For the analysis of both, clinical samples and serial dilution samples, dPCR and qPCR showed comparable sensitivity. With regard to reproducibility, both methods differed considerably, especially for low template samples. Here, we found with qPCR a mean variation coefficient of 126% whereas dPCR enabled a significantly lower mean variation coefficient of 40% (p = 0.01). Generally, we saw with dPCR a substantial reduction of subsampling errors, which most likely reflects the large cDNA amounts available for analysis.

Conclusions

Compared to real-time PCR, dPCR shows higher reliability. Thus, our HPV mRNA dPCR assay holds promise for the clinical evaluation of occult tumor cells in histologically tumor-free lymph nodes in future studies.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2846-8) contains supplementary material, which is available to authorized users.

Detection of human papillomavirus DNA in peri-tumor tissues and pelvic lymph nodes as potential molecular marker of micrometastasis in cervical cancer

Background

The association between high risk human papillomaviruses (HPV) and cervical cancer has been firmly established. HPV genome is present in nearly all cases of cervical cancer and detection of viral DNA could therefore be used as a surrogate marker of micrometastasis in peri-tumor tissues and lymph nodes.

Methods

We analyzed primary cervical carcinomas, peri-tumor biopsies and pelvic lymph nodes in 20 women with invasive cancer (FIGO stage I-II) who underwent radical pelvic surgery and lymphadenectomy. HPV DNA was searched by broad spectrum PCR in 142 DNA samples extracted from paraffin embedded tissues. Viral genotypes were identified by direct sequencing analysis.

Results

HPV DNA sequences were identified in all available primary cervical tumors (n = 15). The most common genotype was HPV16 (60 %), followed by HPV18 (20 %), HPV35 (7 %), HPV45 (7 %) and HPV66 (7 %). Seven out of 20 (35 %) women had metastatic spread in peri-tumor tissues and/or lymph nodes, as determined by histology. HPV DNA was detected in all histological positive samples as well as in 16 and 25 % of histological negative peri-tumor tissues and lymph nodes, respectively. Three out of 20 (15 %) women without histological evidence of metastatic spread had HPV-positive lymph nodes. HPV genotype was found always concordant between primary tumor and metastatic lesions. The remaining 10 women (50 %) were histology and HPV-negative in all peri-tumor biopsies and lymph nodes analyzed.

Conclusions

Evaluation of HPV DNA in peri-tumor tissues as well as pelvic lymph nodes could be a sensitive marker to identify micrometastasis or isolated tumor cells and to monitor the risk of disease recurrence in women with cervical cancer.

Translational progress on tumor biomarkers

There is an urgent need to apply basic research achievements to the clinic. In particular, mechanistic studies should be developed by bench researchers, depending upon clinical demands, in order to improve the survival and quality of life of cancer patients. To date, translational medicine has been addressed in cancer biology, particularly in the identification and characterization of novel tumor biomarkers. This review focuses on the recent achievements and clinical application prospects in tumor biomarkers based on translational medicine.