Laboratory implementation of human papillomavirus testing

Single cell transcriptomic analysis of HPV16-infected epithelium identifies a keratinocyte subpopulation implicated in cancer

Persistent HPV16 infection is a major cause of the global cancer burden. The viral life cycle is dependent on the differentiation program of stratified squamous epithelium, but the landscape of keratinocyte subpopulations which support distinct phases of the viral life cycle has yet to be elucidated. Here, single cell RNA sequencing of HPV16 infected compared to uninfected organoids identifies twelve distinct keratinocyte populations, with a subset mapped to reconstruct their respective 3D geography in stratified squamous epithelium. Instead of conventional terminally differentiated cells, an HPV-reprogrammed keratinocyte subpopulation (HIDDEN cells) forms the surface compartment and requires overexpression of the ELF3/ESE-1 transcription factor. HIDDEN cells are detected throughout stages of human carcinogenesis including primary human cervical intraepithelial neoplasias and HPV positive head and neck cancers, and a possible role in promoting viral carcinogenesis is supported by TCGA analyses. Single cell transcriptome information on HPV-infected versus uninfected epithelium will enable broader studies of the role of individual keratinocyte subpopulations in tumor virus infection and cancer evolution.

Low initial human papillomavirus viral load may indicate worse prognosis in patients with cervical carcinoma treated with surgery

Objective

To evaluate the prognostic implication of human papillomavirus (HPV) viral load in cervical cancer patients who underwent radical hysterectomy.

Methods

We conducted a retrospective review of patients with stage IA2 through stage IIIA cervical carcinoma who underwent radical hysterectomy at Sun Yat-sen University Cancer Center between January 2005 and December 2009. Patients who had undergone preoperative hybrid capture 2 testing to detect HPV DNA were included. A total of 346 patients positive for HPV DNA were enrolled and stratified into two groups according to the median HPV viral load.

Results

HPV viral load was significantly correlated with lymphovascular space invasion (p=0.026) and deep stromal invasion (p=0.024). However, other factors, such as age, stage, histologic grade, histologic type, lymph node metastasis, and tumor size, were not significantly associated with viral load. Low HPV viral load was correlated with poor disease-free survival in univariate analysis (p=0.037) and multivariate analysis (p=0.027). There was no significant difference in overall survival with regard to initial HPV viral load.

Conclusion

Low initial HPV viral load may be a poor prognostic factor for cervical cancer patients who have undergone radical hysterectomy.

Screening for Cervical Cancer in Low-Resource Settings in 2011

Context.—Cervical cancer remains the most common malignancy in women living in low- and middle-income countries, despite the decline of the disease in countries where cervical cytology screening programs have been implemented.

Objectives.—To review the current incidence of cervical cancer in low-resource countries, the availability and types of screening programs, and the treatment options.

Data Sources.—Literature review through PubMed, Internet search, and personal communication.

Conclusions.—Although data are incomplete, available figures confirm that the rate of cervical cancer deaths and the availability of cervical cancer screening programs are inversely proportional and vary, in general, by the wealth of the nation. Despite the success of cervical cytology screening, many major health care organizations have abandoned screening by cytology in favor of direct visualization methods with immediate treatment of lesions by cryotherapy provided by trained, nonmedical personnel.

The fanconi anemia pathway limits human papillomavirus replication

High-risk human papillomaviruses (HPVs) deregulate epidermal differentiation and cause anogenital and head and neck squamous cell carcinomas (SCCs). The E7 gene is considered the predominant viral oncogene and drives proliferation and genome instability. While the implementation of routine screens has greatly reduced the incidence of cervical cancers which are almost exclusively HPV positive, the proportion of HPV-positive head and neck SCCs is on the rise. High levels of HPV oncogene expression and genome load are linked to disease progression, but genetic risk factors that regulate oncogene abundance and/or genome amplification remain poorly understood. Fanconi anemia (FA) is a genome instability syndrome characterized at least in part by extreme susceptibility to SCCs. FA results from mutations in one of 15 genes in the FA pathway, whose protein products assemble in the nucleus and play important roles in DNA damage repair. We report here that loss of FA pathway components FANCA and FANCD2 stimulates E7 protein accumulation in human keratinocytes and causes increased epithelial proliferation and basal cell layer expansion in the HPV-positive epidermis. Additionally, FANCD2 loss stimulates HPV genome amplification in differentiating cells, demonstrating that the intact FA pathway functions to restrict the HPV life cycle. These findings raise the possibility that FA genes suppress HPV infection and disease and suggest possible mechanism(s) for reported associations of HPV with an FA cohort in Brazil and for allelic variation of FA genes with HPV persistence in the general population.

Human Papillomavirus and Pap Smear

High-risk human papillomavirus (HPV) infection and viral persistence is a major risk factor in the development of squamous intraepithelial lesions and invasive carcinoma of the cervix. In the United States, deaths due to squamous cell carcinoma of the cervix have fallen by 75% since the 1960s because of Papanicolaou (Pap) smear screening. However, the traditional Pap had a sensitivity of about 70% for detecting clinically significant precancerous lesions and cancer because of sampling and interpretive errors. The introduction of 2 liquid-based Pap smear collection systems in the 1990s, the use of HPV testing as a triage and co-testing with Pap smear, and the introduction of 2 automated screening devices have had a significant impact on improving the detection of such precancerous lesions. This review provides an analysis of the changes in Pap smear collection, improvements in screening, the evolutionary changes of high-risk HPV testing, reporting terminology of Pap smears, and clinical management guidelines. The future impact of 2 prophylactic HPV vaccines on the incidence of cervical carcinoma is also discussed. This article also discusses alternatives such as primary screening for high-risk HPV testing with visual inspection for cervical cancer detection used in resource-poor settings with a high incidence of cervical cancer.

Detection of HPV by in situ hybridization in thin-layer (ThinPrep) cervicovaginal samples

We have studied an automated in situ hybridization (ISH) method as a possible alternative approach for detecting high-risk human papillomavirus (HPV) in monolayer (ThinPrep) cervico-vaginal samples, comparing the results with those obtained by polymerase chain reaction (PCR) using consensus primers and studying the relationship between the ISH staining pattern and the viral integration in HPV 16-positive cases. Eighty atypical squamous cells of undetermined significance (ASCUS) and low-grade squamous intraepithelial lesion (LSIL) cases were used for our purposes. The patients were monitored through periodic cytologies. ISH with was performed with an automated Ventana System, analysis by PCR was performed with consensus primers and integration of HPV16 was performed by realtime PCR analyzing E2 and E6 genes. Additionally, 27 HSIL cases were also studied to observe the ISH staining patterns. HPV infection was detected by ISH in 21.7% of the ASCUS cases and 55.8% of the LSIL cases. Two distinct staining patterns were observed: multipunctated (MP) and diffuse (DI). In some cases, a mixed pattern (MP + DI) was observed and these cases were considered as MP. The MP pattern increased with the degree of lesion and seemed to have a prognostic value in ASCUS/LSIL cases. The lesion in MP pattern cases persisted throughout the entire study in 77% of cases, whereas in cases with a DI staining pattern, only 41% of them showed persistence of the lesion (p <0.001). No correlation was found between HPV integration and the ISH staining pattern. Given the lower sensitivity and negative predictive value of ISH and its incapacity to demonstrate the integration of high-risk HPV in ASCUS and LSIL cases using liquid-based cytology, we do not recommend this technique for the triage of ASCUS and LSIL cases.

Does pretreatment HPV viral load correlate with prognosis in patients with early stage cervical carcinoma?

OBJECTIVE

Recent data suggest that pretreatment HPV (Human papillomavirus) viral load is useful to predict the severity of intraepithelial lesions of the uterine cervix and formulate a treatment plan. However, the relationship between initial HPV viral load and prognosis of cervical cancer patients has not yet been clearly defined. The objective of this study was to determine whether HPV viral load has prognostic significance in patients with early stage cervical carcinoma treated by surgery.

METHODS

A retrospective review of all patients with early stage cervical carcinoma who underwent radical hysterectomy and pelvic lymphadenectomy at our institution from August 2003 to December 2007 was conducted. Patients were included only if they had pretreatment Hybrid Capture II test for HPV DNA detection.

RESULTS

We identified 34 patients who met the inclusion criteria. Two groups were identified: patients who had low HPV viral load (</=100 RLU) versus those who had high viral load (>100 RLU). There were no differences in age, FIGO stage, histology, pathologic risk factors - tumor size, deep stromal invasion, lymph-vascular space invasion, parametrial extensions, vaginal margin involvement, and lymph node metastasis - and adjuvant CCRT. There was no significant difference of disease-free survival regard to pretreatment HPV viral load (p=0.7756).

CONCLUSION

In our study, survival was not significantly different between early stage cervical cancer patients who had low and high pretreatment HPV viral load. It seems that pretreatment HPV viral load may not be of help to predict disease prognosis.

Does pretreatment human papillomavirus (HPV) titers predict radiation response and survival outcomes in cancer cervix?—A pilot study

OBJECTIVE

To evaluate if pretreatment HPV titers in cancer cervix could predict radiation response and survival outcomes.

METHODS

Twenty-one patients of cancer cervix were treated by radiotherapy (RT) alone. HPV titers were estimated using DNA Hybrid Capture II test. Loco-regional response at 1 month of RT--complete or partial response (CR and PR respectively) and survival outcomes--local disease-free (LDFS), disease-free (DFS) and overall (OS) survivals were evaluated against pre- and posttreatment HPV titers.

RESULTS

Pretreatment HPV titers ranged from 0.81 to 3966.10 RLU/cut off (mean +/- SD: 1264.39 +/- 1148.22, median: 1129.98). Of the demographic features evaluated, mean HPV titers were significantly different only for patients achieving CR or PR at completion of RT (mean +/- SD for CR vs. PR: 1616.31 +/- 1146.86 vs. 384.57 +/- 538.80, P = 0.022). HPV titers at end of RT ranged from 0.12 to 487.42 RLU/cut off (mean +/- SD: 37.31 +/- 108.60, median: 2.33). Patients with higher pretreatment HPV titers (>1000 RLU/cutoff) had a higher CR (P = 0.022) and better survival compared to those with < or =1000 RLU/cutoff (LDFS, P = 0.004; DFS, P = 0.005; OS, P = 0.012). At completion of RT, those having > or =99.5% fall in HPV had superior survival outcomes than those with <99.5% reduction (LDFS, P = 0.002; DFS, P = 0.002; OS, P = 0.004).

CONCLUSIONS

Higher pretreatment HPV titers (>1000 RLU/cutoff) could be considered as a predictor of radiotherapy response and survival in cancer cervix. A reduction in these titers to 99.5% of their baseline values at end of radiotherapy is also associated with better survival outcomes.

The PapSpin: a reasonable alternative to other, more expensive liquid-based Papanicolaou tests

BACKGROUND

This study was designed to optimize a liquid-based Papanicolaou (Pap) test by using common cytopathology laboratory equipment and resulted in an inexpensive test that was equivalent at least diagnostically to the conventional Papanicolaou (Pap) smear.

METHODS

Adult women (n = 482) were consented, enrolled, and included in this Institutional Review Board-approved study. After conventional Pap smear slides were obtained, clinicians placed the collection device with residual cells from the uterine cervix in a preservative fluid. In the cytopathology laboratory, a conventional centrifuge device was used to deposit the cells from the liquid onto a glass slide.

RESULTS

Among the conventional Pap smears, 43 were categorized as low-grade squamous intraepithelial lesions (LSIL), and 30 were categorized as high-grade squamous intraepithelial lesions or greater (HSIL+). Among the PapSpin samples, 49 were categorized as LSIL and 24 were categorized as HSIL+. Biopsy confirmation was obtained in 124 patients. There were 23 women diagnosed with LSIL and 27 women diagnosed with HSIL+. Diagnostic agreement between cytologic samples and biopsies is as follows: for conventional Pap smears, there was agreement on 11 of 23 LSIL diagnoses and on 15 of 27 HSIL+ diagnoses; for PapSpin samples, there was agreement on 11 of 23 LSIL diagnoses and on 14 of 27 HSIL+ diagnoses. Exact agreement was achieved between PapSpin and conventional smears in 404 patients (84%). Quality indictors were better in the PapSpin group, except for inadequate endocervical component, which was greater in the PapSpin samples, a difference that was explained by the split-sample study design, which favored the conventional smear.

CONCLUSIONS

The current results indicated that PapSpin is a legitimate, inexpensive alternative to the conventional Pap smear for the detection of cervical intraepithelial neoplasia, resulting in better preservation and improved cell visualization. In addition, the liquid residual allows for reflex human papillomavirus-DNA or polymerase chain reaction testing.

HPV DNA testing in the triage of atypical squamous cells of undetermined significance (ASCUS): cost comparison of two methods

Human papillomavirus (HPV) DNA testing for triage of cervical cytologies showing atypical squamous cells of undetermined significance (ASCUS) has become the standard of practice. Currently, Hybrid Capture II (HCII) is the preferred method for ASCUS triage. In situ hybridization for HPV represents an alternative to HCII and appears to have a superior specificity but is more expensive. We compare the reimbursement rates of ASCUS triage (HPV high risk) using the methods of HCII and INFORM (in situ hybridization for HPV) in a series of 431 ASCUS patients. The patients were followed for 1 yr, during which each patient had either colposcopic biopsy or follow-up cervical cytology after ASCUS HPV DNA triage. Eighty-nine patients were excluded from the analysis because of incomplete follow-up. The HPV triage percentages, colposcopic biopsy positivity rates and cervical cytology positivity percentages were calculated for each method. The reimbursement rates of the tests/procedures used in the analysis were those in effect at the University of Utah in 2003. The total triage and follow-up reimbursement costs were calculated for HCII and INFORM and compared.HCII referred 19.9% of patients to colposcopy, with a biopsy positivity rate of 25.6% for dysplasia. INFORM referred 11.8% of patients to colposcopy, of whom 34% had a biopsy diagnosis of dysplasia. HCII negative cases revealed 19% to have ASCUS or higher on the follow-up cervical cytology, while 19.9% of INFORM negative cases had a reading of ASCUS or higher at follow-up cytologic examination. The 1-yr HPV DNA triage and follow-up reimbursements for HCII were 316,942.00 US dollars per 1,000 women, and for the INFORM methodology, the reimbursements were 369,484.00 US dollars per 1,000 women. The INFORM method was associated with higher specificity and sent fewer (41%) patients to colposcopy than did HCII. Although this smaller referral rate reduced reimbursement costs associated with colposcopy, the increased reimbursement paid for follow-up cytologies and office visits of HPV DNA negative patient and the greater cost of the INFORM test results in higher overall reimbursement for INFORM. Based on these costs and diagnostic accuracies, it appears that the INFORM HPV technology represents a viable option to HCII ASCUS triage. INFORM HPV appears to be 16% more expensive than HCII but has the advantage of sending 41% fewer women to colposcopy.