The impact and cost-effectiveness of 9-valent human papillomavirus vaccine in adolescent females in Hong Kong.

INTRODUCTION: In Hong Kong (HK), a single-cohort vaccination program for 10-12-year-old girls with the 9-valent human papillomavirus (HPV) vaccine (9vHPV; types 6/11/16/18/31/33/45/52/58) has been launched. This study assessed the public health impact and cost-effectiveness of implementing routine 9vHPV vaccination (12-year-olds) with or without catch-up 9vHPV vaccination (13-18-year-olds) in HK. METHODS: The health impact and costs of implementing routine 9vHPV vaccination with or without catch-up vaccination over a 100-year time horizon were evaluated using a validated HPV-type transmission dynamic model adapted to the HK population; analyses were performed from a healthcare payer perspective. Routine vaccination (12-year-old girls) and catch-up vaccination (13-18 years) assumed vaccine coverage rates of 70% (base case) and 30%, respectively. The model also assumed herd immunity, lifelong vaccine protection, a discount rate of 3%, and a cost per dose of HK dollars (HKD) 858 [United States dollars (USD) 110] and HKD 1390 (USD 179) for the 2-valent HPV (2vHPV) and 9vHPV vaccines, respectively. HPV disease-related incidence and the incremental cost-effectiveness ratio (ICER) per quality-adjusted-life-year (QALY) were estimated. Cost-effectiveness was determined at a ceiling threshold of HK dollars (HKD) 382,046 (USD 49,142) or 1.0 times the gross domestic product per capita of HK. RESULTS: Compared with routine 9vHPV alone, routine plus catch-up 9vHPV is projected to reduce cervical cancer incidence by 3.4%. Routine plus catch-up 9vHPV will also reduce genital warts incident cases for males/females by 2.6%/5.4%. The incremental cost-effectiveness ratios were HKD 29,911 (USD 3847)/quality-adjusted life-year (QALY) for routine plus catch-up 9vHPV versus routine 9vHPV alone and HKD 25,524 (USD 3283)/QALY for routine 9vHPV alone versus screening only. Sensitivity analyses indicated that routine plus catch-up 9vHPV compared with routine 9vHPV alone remained cost-effective at coverage rates of 30% and 90%. CONCLUSIONS: This analysis predicts that the current HK vaccination strategy can be considered cost-effective and will provide maximum health benefit. These results support addition of the routine 9vHPV vaccine with or without catch-up 9vHPV vaccination to the regional vaccination program in HK.

Prevalence and impact of hepatitis B virus infection in ovarian cancer patients in an endemic area-A retrospective cohort study.

Hepatitis B virus (HBV) infection is associated with many extrahepatic malignancies, but its association with and impact on ovarian cancer has not been examined. We therefore examined the prevalence of HBV infection among women with primary ovarian carcinoma in an endemic area, and whether this impacts the presentation and survival of these patients. In a retrospective study, we reviewed 523 patients presenting with primary ovarian cancer and known HBV status between 1 January 2006 and 31 December 2017. Patients were divided into HBV-positive and negative groups for the comparison of the patient characteristics and presentation, including staging and histological types, and short term (2 years) mortality from ovarian cancer. Among the 10.1% (53/523) patients screened positive for HBV, more of them presented with advanced staging at FIGO stage 3 or above (OR 1.378, 95% CI 1.063-1.787), although there were no significant differences in patient characteristics. Within 24 months from presentation, there were more deaths due to malignancy in the HBV-positive group (73.3% vs 44.2%, OR 1.659, 95% CI 1.135-2.425). On multivariate analysis after adjusting for nulliparity status, previous use of oestrogens, presence of metastases, histological type (epithelial or others) and grading (high grade or not), whether optimal debulking was performed, and chemotherapy, HBV infection was independently associated with increased death within 24 months of presentation (aOR 2.683, 95% CI 1.015-7.091). In conclusion, the findings of this study suggested an adverse effect of chronic HBV infection on survival within two years of presentation in patients with primary ovarian cancer.

Liquid biopsy of PIK3CA mutations in cervical cancer in Hong Kong Chinese women.

INTRODUCTION: Cervical cancer is the fourth most common female cancer worldwide. The prognosis for women with advanced-stage or recurrent cervical cancer remains poor and response to treatment is variable. Standardized management protocols leave little room for individualization. We report on a novel blood-based liquid biopsy for specific PIK3CA mutations as a clinically useful biomarker in patients with invasive cervical cancer. METHODS: One hundred seventeen Hong Kong Chinese women with primary invasive cervical cancer and their pre-treatment plasma samples were investigated. Two PIK3CA mutations, p.E542K and p.E545K were measured in cell free DNA (cfDNA) extracted from plasma using droplet digital PCR. This liquid biopsy of PIK3CA in cervical cancer was correlated to clinico-pathological features to verify the potential of PIK3CA as a clinically useful molecular biomarker for predicting disease prognosis and monitoring for progression. RESULTS: PIK3CA mutations, either p.E542K or p.E545K, were detected in plasma cfDNA from 22.2% of the patients. PIK3CA mutation status was significantly correlated to median tumor size (p<0.01). PIK3CA mutations detected in the plasma were significantly associated with decreased disease-free survival and overall survival (p<0.05). CONCLUSIONS: As a liquid molecular biopsy, analysis of circulating PIK3CA mutations shows promise as a way to refine risk stratification of individual patients with cervical cancer, and provides a platform for further research to offer individualized therapy with the purpose of improving outcomes.

Genomic aberrations in cervical adenocarcinomas in Hong Kong Chinese women.

Although the rates of cervical squamous cell carcinoma have been declining, the rates of cervical adenocarcinoma are increasing in some countries. Outcomes for advanced cervical adenocarcinoma remain poor. Precision mapping of genetic alterations in cervical adenocarcinoma may enable better selection of therapies and deliver improved outcomes when combined with new sequencing diagnostics. We present whole-exome sequencing results from 15 cervical adenocarcinomas and paired normal samples from Hong Kong Chinese women. These data revealed a heterogeneous mutation spectrum and identified several frequently altered genes including FAT1, ARID1A, ERBB2 and PIK3CA. Exome sequencing identified human papillomavirus (HPV) sequences in 13 tumors in which the HPV genome might have integrated into and hence disrupted the functions of certain exons, raising the possibility that HPV integration can alter pathways other than p53 and pRb. Together, these provisionary data suggest the potential for individualized therapies for cervical adenocarcinoma based on genomic information.

Cancer cell-derived lymphotoxin mediates reciprocal tumour-stromal interactions in human ovarian cancer by inducing CXCL11 in fibroblasts.

We have investigated the role of cytokine lymphotoxin in tumour-stromal interactions in human ovarian cancer. We found that lymphotoxin overexpression is commonly shared by the cancer cells of various ovarian cancer subtypes, and lymphotoxin-beta receptor (LTBR) is expressed ubiquitously in both the cancer cells and cancer-associated fibroblasts (CAFs). In monoculture, we showed that ovarian cancer cells are not the major lymphotoxin-responsive cells. On the other hand, our co-culture studies demonstrated that the cancer cell-derived lymphotoxin induces chemokine expression in stromal fibroblasts through LTBR-NF-κB signalling. Amongst the chemokines being produced, we found that fibroblast-secreted CXCL11 promotes proliferation and migration of ovarian cancer cells via the chemokine receptor CXCR3. CXCL11 is highly expressed in CAFs in ovarian cancer biopsies, while CXCR3 is found in malignant cells in primary ovarian tumours. Additionally, the overexpression of CXCR3 is significantly associated with the tumour grade and lymph node metastasis of ovarian cancer, further supporting the role of CXCR3, which interacts with CXCL11, in promoting growth and metastasis of human ovarian cancer. Taken together, these results demonstrated that cancer-cell-derived lymphotoxin mediates reciprocal tumour-stromal interactions in human ovarian cancer by inducing CXCL11 in fibroblasts. Our findings suggest that lymphotoxin-LTBR and CXCL11-CXCR3 signalling represent therapeutic targets in ovarian cancer.

Geographical distribution and risk association of human papillomavirus genotype 52-variant lineages.

Human papillomavirus (HPV) genotype 52 is commonly found in Asian cases of cervical cancer but is rare elsewhere. Analysis of 611 isolates collected worldwide revealed a remarkable geographical distribution, with lineage B predominating in Asia (89.0% vs 0%-5.5%; P(corrected) < .001), whereas lineage A predominated in Africa, the Americas, and Europe. We propose that the name "Asian lineage" be used to denote lineage B, to signify this feature. Preliminary analysis suggested a higher disease risk for lineage B, although ethnogeographical confounders could not be excluded. Further studies are warranted to verify whether the reported high attribution of disease to HPV52 in Asia is due to the high prevalence of lineage B.

Geographical distribution and oncogenic risk association of human papillomavirus type 58 E6 and E7 sequence variations.

Human papillomavirus (HPV) 58 accounts for a notable proportion of cervical cancers in East Asia and parts of Latin America, but it is uncommon elsewhere. The reason for such ethnogeographical predilection is unknown. In our study, nucleotide sequences of E6 and E7 genes of 401 HPV58 isolates collected from 15 countries/cities across four continents were examined. Phylogenetic relationship, geographical distribution and risk association of nucleotide sequence variations were analyzed. We found that the E6 genes of HPV58 variants were more conserved than E7. Thus, E6 is a more appropriate target for type-specific detection, whereas E7 is more appropriate for strain differentiation. The frequency of sequence variation varied geographically. Africa had significantly more isolates with E6-367A (D86E) but significantly less isolates with E6-203G, -245G, -367C (prototype-like) than other regions (p ≤ 0.003). E7-632T, -760A (T20I, G63S) was more frequently found in Asia, and E7-793G (T74A) was more frequent in Africa (p < 0.001). Variants with T20I and G63S substitutions at E7 conferred a significantly higher risk for cervical intraepithelial neoplasia grade III and invasive cervical cancer compared to other HPV58 variants (odds ratio = 4.44, p = 0.007). In conclusion, T20I and/or G63S substitution(s) at E7 of HPV58 is/are associated with a higher risk for cervical neoplasia. These substitutions are more commonly found in Asia and the Americas, which may account for the higher disease attribution of HPV58 in these areas.

Virological characteristics of cervical cancers carrying pure episomal form of HPV16 genome.

OBJECTIVE: Many studies on integration have reported conflicting results regarding the role of HPV integration in cervical cancer. We hypothesized that high viral load and disruption of E2 gene associated with integration of HPV were not the only pathway leading to cancer development. METHODS: This study analysed the viral load and integration status of HPV16, measured the HPV16 E6/E7 mRNA transcript levels, delineated the E2 and LCR sequence variation, and determined the methylation status of two E2 binding sites. RESULTS: The results showed that viral load was not associated with the physical status of HPV genome. Levels of the three E6/E7 mRNA transcripts in invasive cervical cancers containing purely episomal viral genome were found to be similar to those containing integrated viral genome, suggesting that cancers containing episomal viral genome were also mediated by an up-regulated E6/E7 mRNA expression, and more importantly, did not depend on integration and disruption of the E2 gene. CONCLUSIONS: The alternative mechanism that up-regulated the expression of E6 and E7 in invasive cancers harbouring episomal viral genome was likely to be a consequence of methylation of the two E2 binding sites located at the promoter region of HPV16. These observations are in line with the hypothesis that HPV integration was not the only mechanism leading to the development of cervical cancer.

MicroRNA-182 plays an onco-miRNA role in cervical cancer.

OBJECTIVES: The purposes of this study were to identify aberrantly expressed miRNAs and investigate their pathogenic roles in cervical cancer. METHODS: miRNA expression was assessed in cervical cancer cell lines, micro-dissected normal cervical epithelium cells and primary cervical carcinoma by TaqMan RT-PCR. Spatial expression of miR-182 in cervical carcinoma and normal cervix was explored by in situ hybridization. HeLa xenograft mice model was used for evaluation of the effect on tumor growth of miR-182 inhibitor. Western blot, flow cytometry and gene expression analysis were used for identification of the functional role of miR-182 in HeLa cells. RESULTS: Two up-regulated (miR-182 and -183) and nine down-regulated (miR-211, 145, 223, 150, 142-5p, 328, 195, 199b, 142-3p) microRNAs were consistently identified in cervical cancer cell lines. Further investigation confirmed the most up-regulated miRNA (miR-182) was significantly elevated in primary cervical carcinoma and discovered a significant correlation between the increased expression of miR-182 and advanced stages of cervical cancer. In HeLa xenograft mouse model, we demonstrated that inhibition of the miR-182 could exert the effect of tumor growth regression. Western blot, flow cytometry and pathway analysis for the HeLa cells with miR-182 over/down-expression in vitro showed that miR-182 was involved in apoptosis and cell cycle pathways, it also associated with the regulation of FOXO1. CONCLUSIONS: Our findings indicated that miR-182 plays an onco-miRNA role in cervical cancer and its alteration is associated with cervical cancer pathogenesis by disrupting cell proliferation.

Health impact and cost-effectiveness of implementing gender-neutral vaccination with the 9-valent HPV vaccine in Hong Kong.

Human papillomavirus (HPV) can cause several diseases, including cancers, in both sexes. In January 2020, the Hong Kong government launched a school-based vaccination program for girls 10-12 years of age with the 9-valent HPV (9vHPV) vaccine for the prevention of HPV-related diseases; however, boys were not included. The current study estimated the potential health and economic impact of a routine gender-neutral vaccination (GNV) approach compared with the current female-only vaccination (FOV) strategy. We used a dynamic transmission model, adapted to Hong Kong. The model estimates changes in HPV-related disease incidence and mortality, treatment costs (in 2019 Hong Kong dollars), quality-adjusted life years (QALY), and incremental cost-effectiveness ratios (ICERs) over a 100-year time horizon. The base case analysis compared FOV with the 9vHPV vaccine with routine GNV (coverage rate 70%) for the prevention of HPV-related diseases. Compared with a FOV approach, routine GNV with the 9vHPV vaccine is predicted to provide greater reductions in cumulative HPV-related disease incidence and mortality, as well as lower HPV-related treatment costs. In the base case analysis, the ICER was $248,354 per QALY for routine GNV. As compared with FOV, routine GNV fell below the cost-effectiveness ceiling of $382,046/year for Hong Kong. These results highlight the potential value of a routine GNV program with the 9vHPV vaccine among 12-year-olds in Hong Kong to reduce the public health and economic burden of HPV-related diseases.

Design, Control, and Experiments of a Novel Robotic Uterine Manipulator With the Motorized 3-DoF Manipulation Rod.

To address the issue of declining performance over time with manual uterine manipulation during minimally invasive gynecologic surgery, we propose a novel uterine manipulation robot that consists of a 3-DoF remote center of motion (RCM) mechanism and a 3-DoF manipulation rod. This allows for tireless, stable, and safer manipulation in place of a human assistant. For the RCM mechanism, we propose a single-motor bilinear-guided mechanism that can achieve a wide range of pitch motion (-50  âˆ¼  34 degrees) while maintaining a compact structure. This novel uterine manipulation robot is equipped with a manipulation rod that has a tip diameter of only 6 mm, allowing it to accommodate almost any patient's cervix. The 30-degree distal pitch motion and ±45-degree distal roll motion of the instrument further improve uterine visualization. Additionally, the tip of the rod can be opened into a T-shape to minimize damage to the uterus. Laboratory experiments have shown the mechanical RCM accuracy of 0.373 mm and the maximum load of the distal pitch joint of 500 g. Feasibility has been demonstrated through ex-vivo and cadaver tests, as well as clinical trials.

Laboratory and clinical aspects of human papillomavirus testing.

Human papillomavirus (HPV) infection is associated with a wide spectrum of disease that ranges from self-limited skin warts to life-threatening cancers. Since HPV plays a necessary etiological role in cervical cancer, it is logical to use HPV as a marker for early detection of cervical cancer and precancer. Recent advances in technology enable the development of high-throughput HPV assays of different formats, including DNA-based, mRNA-based, high-risk group-specific and type-specific methods. The ultimate goal of these assays is to improve the accuracy and cost-effectiveness of cervical screening programs. HPV testing has several potential advantages compared to cytology-based screening. However, since the cancer to transient infection ratio is always low in the general population, HPV test results are bound to have a low positive predictive value that may subject women to unnecessary follow-up investigations. The wide-spread administration of prophylactic HPV vaccine will substantially decrease the incidence of cancer and precancer. This poses a number of challenges to cytology-based screening, and the role of HPV testing is expected to increase. Finally, apart from technical and cost-effectiveness considerations, one should also keep in mind the psycho-social impact of using sexually-transmitted agents as a marker for cancer screening.

Attribution of human papillomavirus types to cervical intraepithelial neoplasia and invasive cancers in Southern China.

The attribution of individual human papillomavirus (HPV) types to cervical neoplasia, especially intraepithelial lesions, varies ethnogeographically. Population-specific data are required for vaccine cost-effectiveness assessment and type replacement monitoring. HPV was detected from 2,790 Chinese women (444 invasive cervical cancers [ICC], 772 cervical intraepithelial neoplasia [CIN] grade 3, 805 CIN2 and 769 CIN1. The attribution of each HPV type found in multiple-type infections was approximated by the fractional contribution approach. Multiple-type infection was common and correlated inversely with lesion severity (54.7% for CIN1, 48.7% for CIN2, 46.2% for CIN3, 27.5% for ICC). Vaccine-covered high-risk types (HPV16/18) attributed to 59.5% of squamous cell carcinoma, 78.6% of adenocarcinoma, 35.9% of CIN3, 18.4% of CIN2 and 7.4% of CIN1. Distinct features compared to worldwide were a higher attribution of HPV52 and HPV58, and a much lower attribution of HPV45. Inclusion of HPV52 and HPV58 in future vaccines would provide the highest marginal increase in coverage with 11.7% for squamous cell carcinoma, 14.4% for CIN3, 22.6% for CIN2 and 17.7% for CIN1. The attribution of HPV types in southern China is different from elsewhere, which should be considered in prioritizing HPV types for vaccine and screening assay development.

Identification of human papillomavirus type 58 lineages and the distribution worldwide.

BACKGROUND: Human papillomavirus type 58 (HPV-58) accounts for a much higher proportion of cervical cancers in East Asia than other types. A classification system of HPV-58, which is essential for molecular epidemiological study, is lacking. METHODS AND RESULTS: This study analyzed the sequences of 401 isolates collected from 15 countries and cities. The 268 unique concatenated E6-E7-E2-E5-L1-LCR sequences that comprised 57% of the whole HPV-58 genome showed 4 distinct clusters. L1 and LCR produced tree topologies that best resembled the concatenated sequences and thus are the most appropriate surrogate regions for lineage classification. Moreover, short fragments from L1 (nucleotides 6014-6539) and LCR (nucleotides 7257-7429 and 7540-52) were found to contain sequence signatures informative for lineage identification. Lineage A was the most prevalent lineage across all regions. Lineage C was more frequent in Africa than elsewhere, whereas lineage D was more prevalent in Africa than in Asia. Among lineage A variants, sublineage A2 dominated in Africa, the Americas, and Europe, but not in Asia. Sublineage A1, which represents the prototype that originated from a patient with cancer, was rare worldwide except in Asia. CONCLUSIONS: HPV-58 can be classified into 4 lineages that show some degree of ethnogeographic predilection in distribution. The evolutionary, epidemiological, and pathological characteristics of these lineages warrant further study.

Unsupervised feature disentanglement for video retrieval in minimally invasive surgery.

In this paper, we propose a novel method of Unsupervised Disentanglement of Scene and Motion (UDSM) representations for minimally invasive surgery video retrieval within large databases, which has the potential to advance intelligent and efficient surgical teaching systems. To extract more discriminative video representations, two designed encoders with a triplet ranking loss and an adversarial learning mechanism are established to respectively capture the spatial and temporal information for achieving disentangled features from each frame with promising interpretability. In addition, the long-range temporal dependencies are improved in an integrated video level using a temporal aggregation module and then a set of compact binary codes that carries representative features is yielded to realize fast retrieval. The entire framework is trained in an unsupervised scheme, i.e., purely learning from raw surgical videos without using any annotation. We construct two large-scale minimally invasive surgery video datasets based on the public dataset Cholec80 and our in-house dataset of laparoscopic hysterectomy, to establish the learning process and validate the effectiveness of our proposed method qualitatively and quantitatively on the surgical video retrieval task. Extensive experiments show that our approach significantly outperforms the state-of-the-art video retrieval methods on both datasets, revealing a promising future for injecting intelligence in the next generation of surgical teaching systems.

Debulking metastatic pelvic nodes before radiotherapy in cervical cancer patients: a long-term follow-up result.

BACKGROUND: Enlarged pelvic nodes are commonly found during preoperative imaging studies in cervical cancer patients and may represent tumor metastasis. It remains controversial whether debulking of these enlarged nodes prior to definitive radiotherapy offers any survival benefit to the patient. METHODS: Enlarged suspicious pelvic nodes identified by imaging studies in stage 1B to stage IIA (early-stage) cervical cancer patients prior to scheduled radical hysterectomy and in stage 1B2 or above (advanced-stage) cervical cancer patients destined for radiotherapy were debulked. Patients with confirmed nodal metastasis (node-positive) were primarily treated by radiotherapy and patients with no evidence of nodal metastasis (node-negative) were treated as planned. Clinical outcomes of these two groups of patients are reported after a long-term follow-up. RESULTS: Sixteen of 110 early-stage and 37 of 97 advanced-stage cervical cancer patients had their enlarged metastatic nodes removed before they were treated by radiotherapy. Microscopic metastatic pelvic nodes were found in six additional patients after the radical hysterectomy and four of them received postoperative adjuvant radiotherapy. After a median follow-up of 62 months, the rates of recurrence inside the pelvis are not significantly different between node-positive and node-negative patients with both early-stage and advanced-stage disease. Recurrences outside the pelvis occurred in 59.1% early-stage and 44.8% advanced-stage node-positive patients, and were the primary cause of poor survival. CONCLUSIONS: Debulking enlarged metastatic pelvic nodes may help reducing pelvic recurrence but does not seem to benefit survival.

Short-Form Thymic Stromal Lymphopoietin (sfTSLP) Is the Predominant Isoform Expressed by Gynaecologic Cancers and Promotes Tumour Growth.

Thymic stromal lymphopoietin (TSLP) is an epithelial cell derived cytokine belonging to the IL-7 family and a key initiator of allergic inflammation. Two main isoforms of TSLP, classified as long- (lfTSLP) and short-form (sfTSLP), have been reported in human, but their expression patterns and role(s) in cancers are not yet clear. mRNA expression was examined by isoform-specific RT-PCR and RNA in situ hybridisation. Epigenetic regulation was investigated by chromatin immunoprecipitation-PCR and bisulfite sequencing. Tumour progression was investigated by gene overexpression, cell viability assay, cancer organoid culture and transwell invasion. Signals were investigated by proteome profiler protein array and RNA-sequencing. With the use of isoform-specific primers and probes, we uncovered that only sfTSLP was expressed in the cell lines and tumour tissues of human ovarian and endometrial cancers. We also showed the epigenetic regulation of sfTSLP: sfTSLP transcription was regulated by histone acetylation at promoters in ovarian cancer cells, whereas silencing of the sfTSLP transcripts was regulated by promoter DNA methylation in endometrial cancer cells. In vitro study showed that ectopically overexpressing sfTSLP promoted tumour growth but not invasion. Human phosphokinase array application demonstrated that the sfTSLP overexpression activated phosphorylation of multiple intracellular kinases (including GSK3α/ß, AMPKα1, p53, AKT1/2, ERK1/2 and Src) in ovarian cancer cells in a context-dependent manner. We further investigated the impact of sfTSLP overexpression on transcriptome by RNA-sequencing and found that EFNB2 and PBX1 were downregulated in ovarian and endometrial cancer cells, suggesting their role in sfTSLP-mediated tumour growth. In conclusion, sfTSLP is predominantly expressed in ovarian and endometrial cancers and promotes tumour growth.

Dissection of PIK3CA Aberration for Cervical Adenocarcinoma Outcomes.

Personalized treatment of genetically stratified subgroups has the potential to improve outcomes in many malignant tumors. This study distills clinically meaningful prognostic/predictive genomic marker for cervical adenocarcinoma using signature genomic aberrations and single-point nonsynonymous mutation-specific droplet digital PCR (ddPCR). Mutations in PIK3CA E542K, E545K, or H1047R were detected in 41.7% of tumors. PIK3CA mutation detected in the patient's circulating DNA collected before treatment or during follow-up was significantly associated with decreased progression-free survival or overall survival. PIK3CA mutation in the circulating DNA during follow-up after treatment predicted recurrence with 100% sensitivity and 64.29% specificity. It is the first indication of the predictive power of PIK3CA mutations in cervical adenocarcinoma. The work contributes to the development of liquid biopsies for follow up surveillance and a possibility of tailoring management of this particular women's cancer.

Age distribution of human papillomavirus infection and cervical neoplasia reflects caveats of cervical screening policies.

Although a second age-related peak of human papillomavirus (HPV) infection is observed in many populations, it does not seem to have any impact on cervical screening policies. We examined the age-specific prevalence of HPV infection among 2,604 women enrolled for cervical screening and correlated the age at diagnosis of 2,491 cervical intraepithelial neoplasia Grade 2/3 (CIN2/3) lesions and 801 invasive cervical cancers (ICC). Two peaks of HPV infection were detected at 26-30 and 46-50 years, respectively. The first infection peak was followed by a CIN2/3 peak and an ICC peak at 5-15 and 15 years later, respectively. The second infection peak was followed by an ICC peak 20 years later, but strikingly no CIN2/3 peak was detected in between and thus eliminated an opportunity of treating the lesions at preinvasive stages. The most plausible explanation is that women at the expected second CIN2/3 peak (50-65 years) are not having Pap smears under the current opportunistic screening program. Furthermore, women of this age may have physiological retraction of the transformation zone, and CIN lesions may remain undetected if an adequate Pap smear sample is not obtained. To combat this problem, the screening program in Hong Kong needs to focus on women aged 50 years and older and a mop-up screening up to 75 years is necessary. Bimodal peaks of HPV infection and cervical cancer are seen in many countries and the analysis of population-specific age distribution of CIN2/3 should be an integral exercise in evaluating the effectiveness of a screening program.

A collaborative robotic uterine positioning system for laparoscopic hysterectomy: Design and experiments.

BACKGROUND: Uterus manipulation is a lengthy and tedious task that is usually performed by a human assistant during laparoscopic hysterectomy. Note that the performance of the assistant may decrease with time. Moreover, under this approach, the primary surgeon does not have direct control over the uterus position. He/she can only verbally request the assistant to place it on a particular configuration. METHODS: A robotic system composed of a 3 degrees-of-freedom uterine positioner is developed to assist in changing configuration of the uterus during laparoscopic hysterectomy. The developed system has a remote centre of motion structure; independently controlling the uterus motion with one joint at the time is allowed. RESULTS: From the lab experiments, it is found that the robot shows better performance in retaining the uterus position and shows quicker response to the surgeon's instruction. Cadaver studies have been conducted to evaluate the feasibility of the robot. The robot was also applied to real patients in a clinical study. CONCLUSIONS: The robot is capable of assisting in uterus manipulation during laparoscopic hysterectomy. However, its user friendliness can be improved by simplifying the docking procedure. Furthermore, a more ergonomic user interface is desired.