HPV genotyping in adenocarcinoma of the uterine cervix in Thailand.

OBJECTIVE: To determine the distribution of human papillomavirus (HPV) genotypes in cervical adenocarcinoma in Thailand and to evaluate the clinicopathologic characteristics associated with common HPV genotypes. METHODS: Formalin-fixed, paraffin-embedded tissues from 150 patients with adenocarcinoma were collected from 4 areas of Thailand. Infection with HPV was detected by nested polymerase chain reaction (PCR) with primers MY09/11 and GP5+/6+. Genotyping was performed using a linear array assay, followed by type-specific PCR targeting the E6/E7 regions of HPV-16, HPV-18, and HPV-52 if the linear array test was negative. RESULTS: Human papillomavirus DNA was detected in 145 (97%) adenocarcinomas (132 single infections; 11 multiple infections; 2 tumors with undetermined HPV type). Genotype 18 was most common (66%), followed by HPV-16 (30%) and HPV-45 (3%). Infection with only HPV-16 and/or HPV-18 accounted for 88% of the HPV-positive tumors. Patients with HPV-18 infection had a younger age (P=0.009) and higher tumor grade (P<0.001) than patients with HPV-16 infection. CONCLUSION: The HPV detection rate in cervical adenocarcinomas in Thailand is high. The predominant genotype is HPV-18, being twice as common as HPV-16. Genotype variations are associated with patient age and tumor grade. Vaccination against HPV-16/HPV-18 might prevent almost 90% of adenocarcinomas.

Association of human papillomavirus type 16 long control region mutation and cervical cancer.

BACKGROUND: The variation of human papillomavirus (HPV) genes or HPV variants demonstrates different risks of cervical cancer. Mutation in the long control region (LCR) at YY1-motifs is one of the mechanisms for enhancing viral oncogene expression during the course of cancer cell progression. In Thai women, cervical cancers are almost always associated with HPV16 variant sub-lineage Asian (HPV16As); however, the mechanism involved remains elusive. The aim of this study was to understand further the oncogenic potential of HPV16As. METHODS: A total of 82 HPV16-positive specimens from Thai women were selected from formalin-fixed paraffin-embedded cervical tissues, and the full length E6 gene of each specimen was amplified and sequenced. LCRs of the HPV16As-positive cases were amplified and sequenced to analyze their polymorphisms. Transcriptional activities of the HPV16As LCRs were then compared with sub-lineage European (EUR), sub-lineage Asian-American 1 (AA1) and HPV16 prototype by insertion of the LCRs into the pGL3-Basic vector. RESULTS: The HPV16 DNA sequences were classified as HPV16 prototype (18.3%), Asian (As, 61%), Asian American-1 (AA1, 8.5%), European (EUR, 7.3%), Asian African-2 (AFR2, 3.7%) and Java-135C (J135C, 1.2%). The prevalence of HPV16As was 30% in low-grade squamous intraepithelial lesion (LSIL), while that in high-grade squamous intraepithelial lesion (HSIL) and squamous cell cervical carcinoma (SCC) were 63.9% and 66.7%, respectively, which demonstrates a significant association of HPV16As with the disease severity. LCR polymorphisms from 43 HPV16As positive cases were analyzed by PCR-sequencing. Thirty-eight nucleotide variation positions spanned nucleotide positions 7157-82. Ten new mutations found in the HPV16As LCRs were located predominantly at the enhancer and proximal to the 3'-end of the early promoter. The LCRs of the common HPV16As, EUR and AA1 showed 5, 13 and 23-fold higher activity than the HPV16 prototype LCR, while those of the new nucleotide variations of As showed 19 (As-sv1) and 30 (As-sv14) -fold higher activity than the HPV16 prototype. CONCLUSIONS: HPV16As DNA sequence variation, especially at the proximal to early promoter in the LCR, enhances transcriptional activity. This could be one of the possible mechanisms for HPV16As-associated cervical cancer development.

Human papilloma virus prevalence, genotype distribution, and pattern of infection in Thai women.

BACKGROUND: The pattern of infection in cervical lesions with respect to HPV subtype has not been systematically studied in Thai women. The aim here was to determine HPV prevalence, genotype, and infection pattern in cervical lesions and to estimate the potential efficacy of an HPV prophylactic vaccine. DESIGN: Formalin-fixed paraffin-embedded cervical tissue blocks of 410 Thai patients from 8 institutes in 4 regions of Thailand (northern, southern, north-eastern, and central) were studied. The samples included 169 low grade squamous intraepithelial lesions (LSILs), 121 high grade squamous intraepithelial lesions (HSILs), and 120 squamous cell carcinomas (SCCs). HPV-DNA was amplified by PCR using consensus primers GP5+ and GP6+. The HPV genotype was then determined by reverse linear blot assay that included 37 HPV-specific 5'-amino-linked oligonucleotide probes. Patterns of infection were classified as single infection (one HPV type), double infection (two HPV types), and multiple infection (three or more HPV types). RESULTS: The mean age of the subjects was 42 years. The prevalence of HPV infection was 88.8%. The highest HPV prevalence was found in the southern region (97.1%) and the lowest in the central region (78.6%). HPV-DNA was detected in 84.6% of LSILs, 90.1% of HSILs, and 93.3% of SCCs. A total of 20 HPV genotypes were identified. The five most common high risk HPV were HPV16 (83.2%), HPV18 (59.3%), HPV58 (9.3%), HPV52 (4.1%), and HPV45 (3.8%). In double and multiple infection patterns, the most common genotypes were HPV16/18 (27.8%) and HPV11/16/18 (54.9%). HPV6 was found only in LSIL and never in combination with other subtypes. HPV11 was most common in LSIL. CONCLUSION: There is no difference of HPV type distribution in women from 4 regions of Thailand with prominent HPV16 and HPV18 in all cases. The bivalent and quadrivalent vaccines have the potential to prevent 48.6 % and 74.5% of cervical cancers in Thai women. The potential of cancer prevention would rise to 87.6% if other frequent HR-HPV types (HPV58, 52, and 45) were also targeted by an HPV vaccine.

Prognostic significance of ER, PR, Ki67, c-erbB-2, and p53 in endometrial carcinoma.

OBJECTIVE: To better discern the prognostic significance of estrogen-progesterone (ER-PR) receptor proliferative index, tumor suppressor gene, and over expression of oncogene c-erbB-2 in correlation with survival time and recurrence of tumor. MATERIAL AND METHOD: Paraffin blocks from 65 cases of endometrial carcinoma diagnosed and treatment at Rajavithi Hospital, Bangkok, Thailand with a follow-up time of at least 60 months were immunohistochemical studiedfor ER and PR status, tumor proliferative index (Ki-67), tumor suppressor gene (p53), and overexpression of oncogene c-erbB-2. Survival analysis was performed with the Cox proportional hazards. RESULTS: The mean age of the patients was 54.94 years with a range of 24 to 80 years. The mean follow-up time was 50.35 months. Nine patients (13.8%) had recurrent tumors, 5 years after treatment. Ten patients (15.4%) died of the primary disease during the follow-up period. ER was positive in 50 cases (76.9%) and negative in 15 cases (23.1%). PR was positive in 47 cases (72.3%) and negative in 18 cases (27.7%). Both ER and PR showed significant correlation (p<0.01). Ki-67 showed 27 cases (41.5%) having >35% positive nuclear staining and 38 cases (58.5%) had < or =35% positive nuclear staining. p53 was positive in 31 cases (47.7%) and negative in 34 cases (52.3%). c-erbB-2 was positive in one case (1.5%), equivocal in six cases (9.2%), and negative in 58 cases (89.3%). CONCLUSION: Survival analysis showed that cases with low-stage, low-grade, no recurrent tumor, ER and PR positive, and Ki-67 < or =35% had good survival compared to cases with high-stage, high-grade, presence of recurrent tumor, ER-PR-negative, and Ki-67 > 35% (p<0.05). Cox regression analysis showed ER-PR status and Ki-67 were significant independent prognostic indicators for survival time. Ki-67 expression was also a significant independent prognostic indicator for recurrent tumor p53 and c-erbB-2 displayed no statistical significance related to survival time.

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.

No expression of human leukocyte antigen G (HLA-G) in colorectal cancer cells.

Although there is a specific antitumor immune response in the body, colorectal cancer cells progressively develop. This fact indicated that the cancer cells could have a variety of mechanisms to evade or escape the immune system. HLA-G is identified to inhibit the recognition of NK-cell in various kinds of cancers. This study investigated the expression of HLA-G in colorectal cancer. Eighty five specimens of colorectal cancer, carcinoma in situ and adenomatous polyp were examined by immunohistochemistry and RT-PCR for the detection of human leukocyte antigen (HLA)-G The expression of HLA-G was not found in all colorectal specimens (85/85) both protein level and transcription level, suggesting that the expression of HLA-G is not a possible immune evasion mechanism of colorectal cancer cell.