Whole-genome sequence analysis of human papillomavirus type 18 from infected Thai women.

OBJECTIVE: The aim of this study was to attain molecular knowledge of human papillomavirus type 18 (HPV18) by sequencing the whole genome of HPV18 isolated from Thai women at various clinical stages of disease progression. METHOD: Our group analyzed 9 samples of whole-genome HPV18 in infected women ranging from normal to cervical cancer by PCR, a sequencing method and bioinformatics programs. RESULTS: Phylogenetic analysis based on the whole genome showed that HPV18 samples were more closely related to the European and Asian-American type than the African type. The vaccine strain's L1 nucleotide (US patent 5820870) showed a close relationship to the African type. However, our data cannot indicate the correlation between cytological data and nucleotide or amino acid variation. CONCLUSION: Our group cannot draw any inference between the clinical stage of disease progression and amino acid alterations as there were only 1 or 2 samples available for each clinical trial. However, we hope that these new data on the HPV genome, which are representative of the entire genome of HPV in Southeast Asia, can serve as basis data for future research on the pathogenesis of cervical cancer. Additionally, the second-generation HPV18 vaccines should be tested on both HPV18-L1 and HPV18-L2 for increasing potential protection.

Human telomerase reverse transcriptase (hTERT) expression in borderline ovarian tumors: an immunohistochemical study.

OBJECTIVE: To investigate the expression of human telomerase reverse transcriptase (hTERT) in epithelial borderline ovarian tumor (BOT) by immunohistochemistry with correlation to clinicopathologic variables. MATERIAL AND METHOD: Paraffin-embedded tissue sections of 62 borderline ovarian tumors (47 mucinous, 14 serous, and 1 clear cell) and 12 epthelial ovarian carcinomas were immunostained with antibodies to hTERT. The intensity and quantity of the immunostaining was determined and analyzed with clinicopathological characteristics. RESULTS: hTERT expression was detected in 48.4% of BOT and all cases of epithelial ovarian carcinoma. In immunoreactive BOT 50% of cases were scored as high expression. Serous BOT had the highest rate of hTERT expression. There was no significant statistical difference of hTERT immunoreactivity between histologic types of BOT. No hTERT immunoreactivity was observed in the benign parts of the same slides of each immunoreactive case. hTERT immunoreactivity was positively correlated with FIGO stage (p = 0.04), but not with other variables. The mean follow-up time of BOT cases was 81.63 months and no recurrence or death was noted. CONCLUSION: hTERT expression was found in half of BOT and all of epithelial ovarian carcinoma. High hTERT expression was associated with FIGO stage.

Comparison between adenocarcinoma in both endocervical and endometrial specimens from fractional curettage and pathologic findings in subsequent hysterectomy specimens.

OBJECTIVE: To evaluate the hysterectomy specimen findings in the patients who underwent fractional curettage (F&C) with presence of adenocarcinoma in both endocervical and endometrial specimens. MATERIAL AND METHOD: Forty-one patients who had adenocarcinoma in both endocervical and endometrial specimens from F&C and underwent subsequent hysterectomy for surgical staging without pre-operative radiotherapy or chemotherapy at King Chulalongkorn Memorial Hospital between 1999 and 2007 were evaluated Histologic slides from both F&C and hysterectomy specimens were reviewed and assessed All cases of endometrial adenocarcinoma with cervical involvement (stage 2) in hysterectomy specimens were also assessed and compared to the results in F&C specimens. RESULTS: Fifteen patients (36.6%) with both positive endocervical and endometrial specimens from F&C were diagnosed as endometrial adenocarcinoma within uterine cavity with lower uterine segment involvement. Only 34.1% of cases were endometrial carcinomas with cervical involvement. In the 35 cases with endometrial carcinoma stage 2, 60% had adenocarcinoma in both endocervical and endometrial specimens from F&C. CONCLUSION: In the patients who had adenocarcinoma in both endocervical and endometrial specimens from fractional curettage, the most common final pathological diagnosis from hysterectomy specimens was endometrial adenocarcinoma within uterine cavity with lower uterine segment involvement. Therefore, only 60% of endometrial carcinoma stage 2 revealed positive adenocarcinoma in both endocervical and endometrial specimens from fractional curettage.

Detection of PTEN immunoreactivity in endometrial hyperplasia and adenocarcinoma.

OBJECTIVE: To investigate PTEN (phosphatase and tensin homolog deleted on chromosome 10) expression in endometrial hyperplasia and adenocarcinoma as analyzed by immunohistochemistry. MATERIAL AND METHOD: PTEN protein expression was evaluated by immunohistrochemical study of 70 paraffin-embedded curettage endometrial tissue samples (10 normal endometrium, 55 endometrial hyperplasia, and 15 endometrial adenocarcinomas) selected from surgical pathology files of the Division of Gynecologic Pathology, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University, from 2001 to 2004. Intensity of epithelial staining of PTEN immunoreactivity in different histologic types was determined. RESULTS: Absence of PTEN protein expression was detected in 60% of endometrial carcinoma, 60% of atypical endometrial hyperplasia, and 24% of typical endometrial hyperplasia. In endometrial hyperplasia without atypia group, the majority of cases revealed moderate to strong PTEN expression, with 70% in simple hyperplasia and 47% in complex hyperplasia. There is a significant statistical difference of PTEN immunoreactivity among proliferative endometrium, endometrial hyperplasia and endometrial carcinoma group (p = 0.004). CONCLUSION: Complete loss of PTEN protein expression was most commonly found in endometrial carcinoma and hyperplasia with cytologic atypia.

Cyclin A1 promoter hypermethylation in human papillomavirus-associated cervical cancer.

BACKGROUND: The aim of this study was to evaluate epigenetic status of cyclin A1 in human papillomavirus-associated cervical cancer. Y. Tokumaru et al., Cancer Res 64, 5982-7 (Sep 1, 2004)demonstrated in head and neck squamous-cell cancer an inverse correlation between cyclin A1 promoter hypermethylation and TP53 mutation. Human papillomavirus-associated cervical cancer, however, is deprived of TP53 function by a different mechanism. Therefore, it was of interest to investigate the epigenetic alterations during multistep cervical cancer development. METHODS: In this study, we performed duplex methylation-specific PCR and reverse transcriptase PCR on several cervical cancer cell lines and microdissected cervical cancers. Furthermore, the incidence of cyclin A1 methylation was studied in 43 samples of white blood cells, 25 normal cervices, and 24, 5 and 30 human papillomavirus-associated premalignant, microinvasive and invasive cervical lesions, respectively. RESULTS: We demonstrated cyclin A1 methylation to be commonly found in cervical cancer, both in vitro and in vivo, with its physiological role being to decrease gene expression. More important, this study demonstrated that not only is cyclin A1 promoter hypermethylation strikingly common in cervical cancer, but is also specific to the invasive phenotype in comparison with other histopathological stages during multistep carcinogenesis. None of the normal cells and low-grade squamous intraepithelial lesions exhibited methylation. In contrast, 36.6%, 60% and 93.3% of high-grade squamous intraepithelial lesions, microinvasive and invasive cancers, respectively, showed methylation. CONCLUSION: This methylation study indicated that cyclin A1 is a potential tumor marker for early diagnosis of invasive cervical cancer.

Prevalence and genotypes of human papillomavirus among Thai women.

One of the most common cancers in women worldwide is cervical cancer, with death rates highest in less developed countries, including Thailand. This study was conducted to explore the prevalence of human papillomavirus (HPV) and its related cytological abnormalities among women attending cervical screening clinics in Thailand using the polymerase chain reaction (PCR). LBC specimens (ThinPrep, Hologic, West Sussex, UK) were subjected to PCR of the E1 region to identify the most prevalent HPV types. Information on age and cytology grade was also collected. Among a total of 1,662 women, 29 different HPV types were found and the overall HPV prevalence was 8.7%. HPV prevalence among the general population amounted to 7.8%. The following HPV types were identified: HPV16 (17.9%), HPV90 (16.6%) and HPV71 (10.3%). The rates of other types were as follows; HPV66 (6.9%), HPV52 (6.2%), HPV34 (5.5%), HPV31 (5.3%), HPV42 (4.8%) and HPV39 (3.4%). HPV infection peaked in women aged around 20-39 years and thereafter gradually declined. As expected, HPV DNA can be found in normal cytology specimens. These results which elucidate HPV distribution in Thailand could be useful for vaccine development and the national cervical cancer prevention program.

Interobserver reproducibility in determining p16 overexpression in cervical lesions : use of a combined scoring method.

OBJECTIVES: To evaluate interobserver reproducibility of a combined scoring method for immunohistochemical interpretation of p16 overexpression in cervical lesions. MATERIALS AND METHODS: p16 immunostaining was performed in cervical samples from 183 patients, including 69 normal, 42 low grade squamous intraepithelial lesions(LSIL), 36 high grade SIL (HSIL), and 36 squamous cell carcinomas(SCCAs). Each case was evaluated by a combined scoring method based on the percentage of positive cells (score 0-3), the intensity of staining (score 0-3), and the distribution pattern (score 0-2). Immunoexpression for p16 was considered as positive when the combined score was 4-8 and negative with a score of 0-3. Ten pathologists with varied experience in interpretating p16 immunostains evaluated each slide independently. RESULTS: All normal cervical squamous epithelia (69/69) were uniformly negative for p16. All HSILs (36/36), all SCCAs (100/100), and all but one of the LSILs (40/41, 97.6%) showed positive expression. In 172 of 183 cases (93.9%), p16 interpretation was concordant with all pathologists. Eleven cases with discordant results included 10 LSILs and 1 normal mucosa sample. Percentage of agreement of each pathologist pair ranged from 96.7-100% (mean 98.1%) with mean kappa value of 0.96 (range 0.93-1.000). CONCLUSION: The proposed combined scoring method shows good reproducibility among the participating pathologists and good correlation with the histologic diagnosis. This method may be a useful guide in the interpretation of p16 expression in cervical epithelial lesions.