Factors that influence the choice of seeking treatment at polyclinics.

INTRODUCTION: Patients in Singapore can choose their primary care provider on a per-episode basis and pay out-of-pocket for services rendered. The infrastructure of subsidised and private primary care sector facilities differs. Onsite ancillary services are available in subsidised facilities, allowing for convenience of routine investigations, while private clinics are usually standalone practices. This study sought to examine the factors influencing patients' choice of polyclinic. METHODS: This was a cross-sectional survey of a convenient sample of 484 random patients who sought treatment at a polyclinic located in a new housing estate from 24-27 June 2008. RESULTS: The response rate was 85.4% (n = 409). 38.1% of the patients were male. Mean age was 36.2 years. Only 13.8% had a regular private family physician, while 37.3% were followed up at polyclinics. Patients on regular polyclinic follow-up were more likely to be older (p < 0.001), unemployed, retirees or housewives (p < 0.001) and were seeking treatment for chronic diseases (p < 0.001). Geographical convenience (p = 0.002), low cost of consultation (p = 0.024), and onsite laboratory (p = 0.001) and imaging services (p = 0.018) significantly influenced those on regular polyclinic follow-up to attend the polyclinic. CONCLUSION: Affordability, convenience of travel and onsite laboratory facilities influence patients' choice of seeking treatment at polyclinics. Further research examining whether the overall convenience of onsite ancillary services influences patients' choice of primary care provider would be useful in redesigning private primary care infrastructure to enhance patient convenience and encourage more patients to have a regular private family physician.

Dysregulation of microRNA-204 mediates migration and invasion of endometrial cancer by regulating FOXC1.

MicroRNAs (miRNAs) regulate mRNA stability and protein expression, and certain miRNAs have been demonstrated to act either as oncogenes or tumor suppressors. Differential miRNA expression signatures have been documented in many human cancers but the role of miRNAs in endometrioid endometrial cancer (EEC) remains poorly understood. This study identifies significantly dysregulated miRNAs of EEC cells, and characterizes their impact on the malignant phenotype. We studied the expression of 365 human miRNAs using Taqman low density arrays in EECs and normal endometriums. Candidate differentially expressed miRNAs were validated by quantitative real-time PCR. Expression of highly dysregulated miRNAs was examined in vitro through the effect of anti-/pre-miRNA transfection on the malignant phenotype. We identified 16 significantly dysregulated miRNAs in EEC and 7 of these are novel findings with respect to EEC. Antagonizing the function of miR-7, miR-194 and miR-449b, or overexpressing miR-204, repressed migration, invasion and extracellular matrix-adhesion in HEC1A endometrial cancer cells. FOXC1 was determined as a target gene of miR-204, and two binding sites in the 3'-untranslated region were validated by dual luciferase reporter assay. FOXC1 expression was inversely related to miR-204 expression in EEC. Functional analysis revealed the involvement of FOXC1 in migration and invasion of HEC1A cells. Our results present dysfunctional miRNAs in endometrial cancer and identify a crucial role for miR-204-FOXC1 interaction in endometrial cancer progression. This miRNA signature offers a potential biomarker for predicting EEC outcomes, and targeting of these cancer progression- and metastasis-related miRNAs offers a novel potential therapeutic strategy for the disease.

Identification of molecular markers and signaling pathway in endometrial cancer in Hong Kong Chinese women by genome-wide gene expression profiling.

Endometrial cancer is the third most common gynecologic malignancy and the ninth most common malignancy for females overall in Hong Kong. Approximately 80% or more of these cancers are endometrioid endometrial adenocarcinomas. The aim of this study was to reveal genes contributing to the development of endometrioid endometrial cancer, which may impact diagnosis, prognosis and treatment of the disease. Whole-genome gene expression analysis was completed for a set of 55 microdissected sporadic endometrioid endometrial adenocarcinomas and 29 microdissected normal endometrium specimens using the Affymetrix Human U133 Plus 2.0 oligonucleotide microarray. Selected genes of interest were validated by quantitative real-time-polymerase chain reaction (qRT-PCR). Pathway analysis was performed to reveal gene interactions involved in endometrial tumorigenesis. Unsupervised hierarchical clustering displayed a distinct separation between the endometrioid adenocarcinomas and normal endometrium samples. Supervised analysis identified 117 highly differentially regulated genes (>or=4.0-fold change), which distinguished the endometrial cancer specimens from normal endometrium. Twelve novel genes including DKK4, ZIC1, KIF1A, SAA2, LOC16378, ALPP2, CCL20, CXCL5, BST2, OLFM1, KLRC1 and MBC45780 were deregulated in the endometrial cancer, and further validated in an independent set of 56 cancer and 29 normal samples using qRT-PCR. In addition, 10 genes were differentially regulated in late-stage cancer, as compared to early-stage disease, and may be involved in tumor progression. Pathway analysis of the expression data from this tumor revealed an interconnected network consisting of 21 aberrantly regulated genes involved in angiogenesis, cell proliferation and chromosomal instability. The results of this study highlight the molecular features of endometrioid endometrial cancer and provide insight into the events underlying the development and progression of endometrioid endometrial cancer.

Protein profiling of cervical cancer by protein-biochips: proteomic scoring to discriminate cervical cancer from normal cervix.

Analysis of multiple proteins is thought to be essential for establishment of signature proteomic patterns that may distinguish cancer from non-cancer. Surface-enhanced laser desorption/ionization (SELDI) is an affinity-based mass spectrometric method in which proteins of interest are selectively absorbed to a chemically modified surface on a biochip. This technology may provide protein profiling of a variety of biological specimens. In this study, we explored whether the protein biochip SELDI approach could differentiate cervical cancer from non-cancer cohorts. We screened protein profiles generated by SELDI in 62 cervical epithelial cell samples microdissected from 35 invasive cervical cancer and 27 age-matched normal cervix tissue specimens, respectively. The cell lysates of pure populations of cervical cells were applied onto Ciphergen ProteinChip WCX2 Arrays. Proteins bound to the chips were analyzed on a ProteinChip Reader Model PBS II. Derived proteomic patterns were converted to a simple proteomic scoring for distinguishing cancer from non-cancer cohorts. SELDI protein profiles of cell lysates from 20 cervical cancer and 15 normal cervix tissue specimens were used to train and develop a classification scoring system that used a seven-protein mass pattern. The training samples could be correctly discriminated. When a test set of 27 samples was used for evaluation of this scoring system to distinguish cervical cancer from non-cancer, a sensitivity of 87%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 86% for the test population were obtained. All seven proteins appeared to be down regulated in cervical cancer. The results from this study indicate that the proteomics approach of SELDI mass spectrometry, in combination with a simple scoring system, may distinguish cervical cancer from its normal counterpart. If this approach is also workable in the analysis of cervical exfoliated cell lysate, it might potentially be used in the early diagnosis of invasive cervical cancer. In addition, the identification of these specific proteins in cervical cancer may also facilitate the discovery of new cervical tumor marker(s).

Microsatellite instability, expression of hMSH2 and hMLH1 and HPV infection in cervical cancer and their clinico-pathological association.

Infection with specific genotypes of human papillomavirus (HPV) has been strongly implicated in cervical carcinogenesis. However, HPV infection alone is insufficient for malignant transformation of the cervical epithelium. An alteration of microsatellite repeats is the result of slippage owing to strand misalignment during DNA replication and is referred to as microsatellite instability (MSI). These defects in DNA repair pathways have been related to human carcinogenesis; however, the role of MSI in the tumorigenesis of cervical cancer remains unclear. The clinical and pathological features of cervical cancers which are MSI-positive have also not been fully characterized. This study investigated the prevalence of MSI in cervical cancer and its relationship to clinico-pathological characteristics and HPV infection. Polymerase chain reaction-based microsatellite assay combined with tissue microdissection was used to examine for MSI in 50 cervical squamous cell carcinomas in Hong Kong women. In addition, the immunohistochemical staining was performed to determine the expression of major DNA mismatch repair genes, hMSH2 and hMLH1. Six cases (12%) displayed a low frequency of MSI (MSL-L) showing MSI at one locus only in 5 loci examined. Seven cases (14%) showed a high frequency of MSI (MSI-H) having MSI at 2 or more loci. Grouping MSI-L and MSI-H cases together as MSI-positive, statistical analysis of HPV infection, tumor grade, clinical stage and clinical status failed to disclose differences between MSI-positive and MSI-negative cases (p > 0.05). However, MSI-H correlated with advanced stage of disease (p < 0.05). Individuals with MSI-H tumors appeared to have reduced overall survival compared to individuals with MSI-L and MSI-negative tumors, but the difference was not statistically significant (p = 0.059). An absence of either MSH2 or MLH1 expression was observed in 2 MSI-L and 4 MSI-H cases, respectively. The results suggest that MSI is present in a subgroup of cervical squamous cell carcinomas, and defects resulting in MSI may be related to tumor progression and possibly poor prognosis in cervical cancer.

Whole genome amplification and high-throughput allelotyping identified five distinct deletion regions on chromosomes 5 and 6 in microdissected early-stage ovarian tumors.

Investigation of genetic changes in tumors by loss of heterozygosity is a powerful technique for identifying chromosomal regions that may contain tumor suppressor genes. In this study, we determined allelic loss on chromosomes 5 and 6 in 29 primary early-stage epithelial ovarian carcinomas including 3 microscopically identified adenocarcinomas using a high-throughput PCR-based method combined with laser capture microdissection and whole genome amplification techniques. Twenty microsatellite markers spanning chromosomes 5 and 6 at an average distance of 20 cM were examined. High frequencies of loss on chromosome 5 were identified at loci D5S428 (48%), D5S424 (32%), and D5S630 (32%). Our study also showed that chromosome 6 exhibited high frequencies of loss of heterozygosity at loci D6S1574 (46%), D6S287 (42%), D6S441 (45%), D6S264 (60%), and D6S281 (35%). These results suggest that multiple tumor suppressor genes are located on five distinct regions on chromosomes 5 and 6, i.e., 5p15.2, 5q13-21, 6p24-25, 6q21-23, and 6q25.1-27, and may be involved in the early development of ovarian carcinomas.

Clinical and prognostic significance of human papillomavirus in a Chinese population of cervical cancers.

OBJECTIVE: To investigate the clinical and prognostic significance of human papillomavirus (HPV) in a Chinese population of cervical cancers. METHODS: We studied 121 cervical cancer tissue samples from patients treated at our hospital. Identification and typing of HPV were done by polymerase chain reaction (PCR) using consensus primers MY11 and MY09 followed by direct DNA sequencing. The results were correlated with various clinical and prognostic parameters. RESULTS: We found HPV DNA in 95 (78.5%) cases, including HPV-16 in 59 (48.8%) and HPV-18 in 14 (11.6%) cases. chi(2) analysis revealed no significant correlation between the presence of HPV DNA and age at diagnosis, clinical stage, histologic type, tumor grading, 2-year and 5-year survival rate. Of the factors evaluated, age at diagnosis and histologic type were found to have a statistically significant relationship with HPV type. The mean age of the HPV-18 group was 48.6 years compared to 57.1 years for the HPV-16 group (p = 0.045) and 58.2 years for the HPV-negative group (p = 0.04). HPV-18 was detected more often in adenocarcinomas (AC) than in squamous cell carcinomas (SCC). Conversely HPV-16 was detected significantly more often in SCC (p < 0.0001). The HPV-negative group also had a higher incidence of SCC (p = 0.007). HPV-18-positive patients seemed to have more nodal involvement than both HPV-16-positive patients (45.5 vs. 20.8%) and HPV-negative patients (45.5 vs. 18.2%); however, it did not reach statistical significance. CONCLUSIONS: These observations suggest that the presence of HPV DNA does not bear any clinical or prognostic significance in a Chinese population of cervical cancers. HPV-18 is found more often in younger patients and is associated with AC.

Microsatellite instability in cervical carcinoma.

OBJECTIVE: To investigate the incidence of microsatellite instability (MI) in cervical carcinoma and its relationship with clinicopathological characteristics. STUDY DESIGN: A retrospective study of 100 cases of cervical carcinoma. RESULTS: MI, defined as tumor-associated alterations in at least one of five dinucleotide microsatellite markers examined, was detected in 25% of the cervical carcinomas which were observed. There was a nonsignificant trend towards MI occurrence in higher grade tumors, more advanced stage and cases with poor clinical outcome. CONCLUSION: The results suggest that microsatellite instability is present in a subset of cervical carcinoma and may be an independent prognostic factor. Further research with more samples is required.

p53 polymorphism and human papillomavirus infection in Hong Kong women with cervical cancer.

In this study we investigated the involvement of p53 polymorphism at codon 72, the infection and typing of human papillomavirus (HPV) and the correlation of p53 polymorphism with HPV type and other clinicopathologic characteristics in 72 Hong Kong women with cervical cancer. We developed a simple and nonradioactive method for determining polymorphism at codon 72 of the p53 gene. The homozygous p53 arginine allele (Arg/Arg) was detected in 22 (31%), the homozygous p53 proline allele (Pro/Pro) in 14 (19%) and the heterozygous allele (Arg/Pro) in 36 (50%) cases, respectively. Using the consensus primers MY11 and MY09, HPV infection was detected in 55 of 72 (76%) cases. The prevalent types were HPV-16 (55%), HPV-18 (16%) and HPV-58 (9%). The number of HPV-positive cases with Arg/Arg, Pro/Pro and Arg/Pro were 17 (31%), 12 (22%) and 26 (47%), respectively. The p53 polymorphism at codon 72 was not significantly correlated with any of the HPV types (p > 0.05). No striking overrepresentation of homozygous arginine-72 p53 was observed in HPV-associated cervical cancer. The results in this study did not show that any p53 polymorphic form has a prognostic significance for cervical cancer.

Allelic loss on chromosome 1 is associated with tumor progression of cervical carcinoma.

BACKGROUND: Alterations in chromosome 1 are common in human malignancies. The frequency of loss of heterozygosity (LOH) on chromosome 1 in cervical carcinoma and its clinical significance are not clearly understood. METHODS: LOH on chromosome 1 was studied in 100 cervical carcinomas by the polymerase chain reaction (PCR) using 29 highly polymorphic microsatellite markers spaced approximately 10 centimorgans apart. Loci with high frequencies of LOH were identified and the findings were correlated with clinicopathologic characteristics. RESULTS: LOH on chromosome 1 at 1 or more loci was detected in 93% of tumors. The frequencies of LOH at locus D1S2829 (1p31), D1S2663 (1p36.3), and D1S2725 (1q25) exceeded 30%, and 12 other loci exhibited frequencies of LOH of 20-30%. Advanced stage tumors had a significantly higher percentage of informative microsatellite markers with LOH than early stage tumors. Of the 29 microsatellite markers studied, 4 loci had a significantly higher frequency of LOH in Stage III and IV tumors than in earlier stage tumors. CONCLUSIONS: Frequent aberrations on chromosome 1 in cervical carcinoma suggest that inactivation of tumor suppressor genes is important in cervical tumorigenesis. Higher frequencies of LOH in Stage III and IV tumors suggest that chromosome 1 changes are late events in cervical carcinoma. The findings of this study are consistent with earlier reports that suggest that tumor suppressor genes are present at 1p36.3 and 1p31. To the authors' knowledge, the high frequency of LOH mapped to 1q25 has not been reported previously. Its significance awaits further clarification.

Clinical and pathologic significance of microsatellite instability in endometrial cancer.

Microsatellite instability (MSI) is identified as electrophoretic shifts in allele sizes of microsatellite DNA sequences. It is characteristic of a subset of sporadic colorectal tumors as well as hereditary nonpolyposis colorectal cancer (HNPCC). The cells that display MSI are thought to be susceptible to increased mutability. MSI has been detected in a wide variety of human tumors, but the influence of this form of genetic instability on disease initiation and progression remains unclear. Using a polymerase chain reaction (PCR)-based method we screened 50 sporadic primary endometrial carcinomas to characterize the prevalence of MSI in these tumors and analyze the correlation of MSI with clinicopathologic parameters in this malignancy. Fifteen cases (30%) displayed low frequency of MSI (MSI-L) showing MSI at one locus in 5 loci examined. Two cases (4%) showed high frequency of MSI (MSI-H) having MSI at 2 or more loci. Taking MSI-L and MSI-H cases together as MSI-positive, statistical analysis of patient age, tumor grade, and stage failed to disclose significant differences or trends between cases with MSI-positive and MSI-negative (P > 0.05). No significant relationship was observed between patients with MSI and without MSI (P > 0.05), however, the MSI exhibited only in those cases without evidence of disease at the 24th month after treatment. The difference is statistically significant when compared with patients who are alive with disease or died of disease (P < 0.01). However, the overall survival curves were not statistically different. We conclude that MSI is present in a subgroup of endometrial cancer.