Akinori Oki

Tissue factor expression as a possible determinant of thromboembolism in ovarian cancer

Ovarian cancer, and clear cell carcinoma in particular, reportedly increases the risk of venous thromboembolism (VTE). However, the mechanisms remain unclear. Tissue factor (TF) supposedly represents a major factor in the procoagulant activities of cancer cells. The present study examined the involvement of TF expression in VTE for patients with ovarian cancer. Subjects comprised 32 consecutive patients (mean age 49.8 years) with histologically confirmed ovarian cancer. Presence of VTE was examined using a combination of clinical features, D-dimer levels and venous ultrasonography. Immunohistochemical analysis was used to evaluate TF expression into 4 degrees. Venous thromboembolism was identified in 10 of the 32 patients (31%), including five of the 11 patients with clear cell carcinoma. Tissue factor expression was detected in cancer tissues from 24 patients and displayed significant correlations with VTE development (P=0.0003), D-dimer concentration (P=0.003) and clear cell carcinoma (P<0.05). Multivariate analysis identified TF expression as an independent predictive factor of VTE development (P<0.05). Tissue factor (TF) expression is a possible determinant of VTE development in ovarian cancer. In particular, clear cell carcinoma may produce excessive levels of TF and is more likely to develop VTE.

Human papillomavirus infections among Japanese women: age-related prevalence and type-specific risk for cervical cancer

To obtain baseline data for human papillomavirus (HPV) screening and vaccination in Japan, we analyzed HPV DNA data from 2282 Japanese women (1517 normal cytology, 318 cervical intraepithelial neoplasia [CIN] grade 1, 307 CIN2–3, and 140 invasive cervical cancer [ICC]) that visited the University of Tsukuba Hospital or Ibaraki Seinan Medical Center Hospital for screening or treatment of cervical diseases between 1999 and 2007. An L1‐based PCR method was used for individual HPV genotyping. The most common HPV types in ICC were, in order of decreasing prevalence, HPV16 (40.5%), HPV18 (24.4%), HPV52 (8.4%), HPV58 (3.1%), and HPV33 (3.1%). Based on the comparison of HPV type distributions between normal cytology and CIN2–3 and ICC, estimated risk of disease progression varied considerably by genotype: HPV16, HPV18, HPV31, HPV33, HPV35, HPV52, and HPV58 (prevalence ratio, 1.92; 95% confidence interval 1.58–2.34); other oncogenic types (0.31, 95% confidence interval 0.19–0.50); and non‐oncogenic types (0.09, 95% confidence interval 0.03–0.43). HPV16 and/or HPV18, including coinfections with other types, contributed to 67.1% of ICC and 36.2% of CIN2–3 among Japanese women. More importantly, the overall prevalence of HPV16 and/or HPV18 varied greatly according to the womens age: highest in women aged 20–29 years (ICC, 90.0%; CIN2–3, 53.9%), decreasing with age thereafter, and lowest in women aged 60 years or older (ICC, 56.3%; CIN2–3, 25.0%). In conclusion, type‐specific HPV testing may help identify Japanese women at high risk of progression to CIN2–3 and cancer. In Japan, current HPV vaccines are estimated to provide approximately 70% protection against ICC and may be more useful in reducing the incidence of cervical cancer and precancer in young women of reproductive age. (Cancer Sci 2009; 100: 1312–1316)

High incidence of silent venous thromboembolism before treatment in ovarian cancer

Venous thromboembolism (VTE) such as deep-vein thrombosis (DVT) and pulmonary thromboembolism (PTE) often occurs after surgery and rarely occurs even before surgery in patients with ovarian cancer. It is well known that levels of plasma D-dimer (DD) before treatment in most ovarian cancer patients are increased. This study therefore examined whether increased levels of DD are associated with presence of VTE before treatment of ovarian cancer. Between November 2004 and March 2007, DD levels prior to initial treatment were measured in 72 consecutive patients with presumed epithelial ovarian cancer (final diagnosis: epithelial ovarian cancer, n=60; and epithelial ovarian borderline malignancy, n=12). Venous ultrasound imaging (VUI) of the lower extremity was conducted for all patients except for two patients in whom DVT was detected by pelvic computed tomography (CT). When DVT was found, pulmonary scintigraphy was subsequently performed to ascertain presence of PTE. D-dimer levels were above the cut-off value (0.5 μg ml−1) in 65 of 72 patients (90.2%). Venous ultrasound imaging or CT revealed DVT in 18 of 72 patients (25.0%) and pulmonary scintigraphy found PTE in 8 patients (11.1%). All patients with VTE were asymptomatic when VTE was found. D-dimer levels were associated with incidence of VTE (0–1.4 μg ml−1; 0 of 26 (0%), 1.5–7.4 μg ml−1; 9 of 30 (30%) and ⩾7.5 μg ml−1; 9 of 16 (56.3%), P for trend=0.0003). However, even if 1.5 μg ml−1 was used as a cut-off value, this had low specificity and positive predictive value (47.2, 38.3%), though it had high sensitivity and negative predictive value (100, 100%). Therefore, ovarian cancer patients with DD level ⩾1.5 μg ml−1 should be examined using VUI to detect silent DVT. Patients with VTE underwent preventive managements including anticoagulant therapy before initial treatment, chemotherapy or surgery, and after surgery. There was no clinical onset of postoperative VTE in all 72 patients. Measurement of DD levels and subsequent ultrasonography revealed that silent or subclinical VTE frequently occurs before surgery in ovarian cancer. The usefulness of preoperative assessment of VTE needs further confirmation in randomised controlled trials.

Do we need a different strategy for HPV screening and vaccination in East Asia

Dear Sir, Recently, pooled IARC studies and meta-analyses have showed that at least 13 human papillomavirus (HPV) types, including types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 68, are commonly associated with invasive cervical cancer (ICC). Based on HPV type prevalence data from these studies, current HPV vaccines against only HPV16/18 are considered to prevent a majority (>70%) of cervical cancer worldwide. However, HPV data in East Asia have not been fully evaluated in previous pooled and meta-analyses. The present study thus focused on HPV type prevalence in Japan. We performed a meta-analysis of published data to obtain the representative results, and investigated HPV type prevalence and type-specific risks for cervical carcinogenesis in Japan. Furthermore, obtained data were compared with those in China, Korea and other regions. Source articles presenting HPV prevalence data among Japanese women were identified from National Library of Medicine (PubMed). For the meta-analysis, the following inclusion criteria were considered: (i) Studies were published between 1995 and 2005. (ii) Studies had to use PCR-based assays to identify at least 16 strains of HPV6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59 and 68. (iii) Studies had to include at least 20 HPV-positive women with squamous intraepithelial lesion (SIL), cervical intraepithelial neoplasia (CIN) or ICC. When data or data subsets from an identical study had been published in more than one article, only the publication with the largest sample size was included. However, data from different studies conducted by the same study group were included. Overall, a total of 14 Japanese studies were identified for the present study. For some articles, additional typespecific data were obtained from the authors. HPV type prevalence data were collected separately for squamous cell carcinoma (SCC) and for adenoand adenosquamous carcinoma (ADC). Where histological data were not reported, ICC cases were classified as unspecified carcinoma (UC). On the basis of the pooled analysis of IARC studies, HPV types were separated into 2 groups. High-risk HPVs considered as carcinogenic or probably carcinogenic included HPV16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73 and 82; all other HPV types were classified as low-risk types. To evaluate HPV genotype-specific risks for progression from LSIL (low grade SIL) to HSIL (high grade SIL) or more, prevalence ratios [(HSIL 1 ICC):LSIL] and 95% confidence intervals were calculated after adjusting for study area, specimen used for HPV DNA testing, and PCR primers. Logistic regression model was used for statistical adjustment, and the analysis was carried out using JMP 6.0J statistics package (SAS Institute, Cary, NC, USA). The p-values obtained in all tests were considered significant at <0.05. This analysis included 7,262 Japanese women (4,941 normal cytology, 475 LSIL, 720 HSIL and 1,126 ICC) from 14 Japanese HPV studies. Consensus primers for the L1, E6/E7 or E7LCR region or GP5/GP6 primers were employed in these studies. In this meta-analysis, HPV prevalence was 10.2% in women with normal cytology, 79.4% in LSIL, 89.0% in HSIL and 87.4% in ICC. HPV positivity was significantly lower in ADC (69.8%) than in SCC (90.7%). Since overall and typespecific HPV prevalence in UC was very similar to that in SCC, UC cases were combined with SCC cases for comparison of HPV type-specific prevalence by histological type. HPV type distributions by cervical disease were summarized in Table I. In ICC, the most common HPV types were, in order of decreasing prevalence, HPV16 (44.8%), 18 (14.0%), 52 (7.0%), 58 (6.7%), 33 (6.3%), 31 (5.1%), 35 (2.3%), 51 (1.0%) and 56 (0.9%). HPV16 was the predominant type (49.2%) in SCC, although HPV18 was the most prevalent (58.2%) in ADC. On the basis of the comparison of HPV type distributions between LSIL and HSIL/ICC, the type-specific risks for progression from LSIL to HSIL/ICC were analyzed (Table I). HPV16, 18 and 33 conferred a significantly higher risk. Seven types of HPV16/18/31/33/ 35/52/58 (the prevalence ratio; 1.86, 95% CI 1.63–2.15) presented a higher risk of progression than the other high-risk types (0.24, 95% CI 0.17–0.33) and low-risk types (0.18, 95% CI 0.09–0.37). Among Japanese women with ICC, HPV16 and 18 were the most common types, which was consistent with the results from other regions. A pooled analysis demonstrated that HPV16 and 18 were associated with 73.5% of ICC in Southeast Asia, 76.9% in Northern Africa and 71.5% in Europe/ North America, and that HPV52 and 58 were detected in 6.1% of ICC cases in Southeast Asia, 1.5% in Northern Africa and 1.1% in Europe/North America. In Japan, however, HPV16 and 18 were less frequently identified (58.8%), and HPV52 and 58 were more common (13.7%). In China, although HPV16 and 18 were predominant (87.1% of all ICC cases from 5 areas), a multicenter study showed that HPV52 and 58 were locally common in Hong Kong (11.8%) and Guangzhou (southern China, 8.3%). Other small studies also reported

Predicting the progression of cervical precursor lesions by human papillomavirus genotyping: A prospective cohort study

Only a subset of cervical precursor lesions progress to cervical cancer and because of the lack of the predictive markers, it cannot be ascertained which lesions will progress or not. To estimate the risk of disease progression associated with human papillomavirus (HPV) genotypes, we followed 570 Japanese women with cytological LSIL (low‐grade squamous intraepithelial lesion) and histological CIN (cervical intraepithelial neoplasia) grade 1–2 lesions (479 CIN 1; 91 CIN 2) at 3 to 4 month intervals for a mean follow‐up period of 39.1 months. At entry, we detected HPV DNA in cervical samples by polymerase chain reaction‐based methodology. Over the period of follow‐up period, 46 lesions progressed to CIN 3 while 362 regressed to normal cytology. Women with multiple HPV infections were more likely to have persistent lesions (hazard ratio [HR] for regression, 0.65; 95% confidence interval [CI], 0.42–1.02; p = 0.07); however, multiple infections did not increase the risk of progression (HR for progression, 1.04; 95% CI, 0.37–2.94; p = 0.94). After adjusting for CIN grade and womens age, HRs for progression to CIN 3 (vs. women with low‐risk types or negative for HPV DNA) varied markedly by HPV genotype: type 16 (11.1, 95% CI: 1.39–88.3); 18 (14.1, 0.65–306); 31 (24.7, 2.51–243); 33 (20.3, 1.78–231); 35 (13.7, 0.75–251); 52 (11.6, 1.45–93.3); 58 (8.85, 1.01–77.6); other high‐risk types (4.04, 0.47–34.7). HPV 45 was not detected in our study subjects. The cumulative probability of CIN 3 within 5 years was 20.5% for HPV 16, 18, 31, 33, 35, 52 and 58; 6.0% for other high‐risk types; 1.7% for low‐risk types (p = 0.0001). In conclusion, type‐specific HPV testing for women with LSIL/CIN 1–2 lesions is useful for identifying populations at increased or decreased risk of disease progression.

Silent venous thromboembolism before treatment in endometrial cancer and the risk factors

Venous thromboembolism (VTE) often occurs after surgery and can even occur before surgery in patients with gynaecological malignancies. We investigated the incidence of VTE before treatment of endometrial cancer and associated risk factors. Plasma D-dimer (DD) levels before initial treatment were examined in 171 consecutive patients with endometrial cancer. Venous ultrasound imaging (VUI) of the lower extremities was performed in patients with DD ⩾1.5 μg ml−1, as the negative predictive value of DD for VTE is extremely high. For patients with deep vein thrombosis (DVT), pulmonary scintigraphy was performed to ascertain the presence of pulmonary thromboembolism (PTE). Risk factors for VTE were analysed using univariate and multivariate analyses for 171 patients. Of these, 37 patients (21.6%) showed DD ⩾1.5 μg ml−1, 17 (9.9%) displayed DVT by VUI and 8 (4.7%) showed PTE on pulmonary scintigraphy. All patients with VTE were asymptomatic. Univariate analysis for various risk factors revealed older age, non-endometrioid histology and several variables of advanced disease as significantly associated with VTE before treatment. Obesity, smoking and diabetes mellitus were not risk factors. Multivariate analysis confirmed extrauterine spread and non-endometrioid histology as independently and significantly associated with risk of VTE. These data suggest that silent or subclinical VTE occurs before treatment in at least around 10% of patients with endometrial cancer. Risk factors for VTE before treatment might not be identical to those after starting treatment.

PIK3CA overexpression is a possible prognostic factor for favorable survival in ovarian clear cell carcinoma

Dysregulated signaling on the PI3-kinase/Akt cascade is reportedly associated with early stage and favorable prognosis in some kinds of malignancies including breast cancer, endometrial cancer, and colorectal cancer. PIK3CA, a catalytic subunit of PI3-kinase, is known to be activated in ovarian clear cell carcinoma (CCC), which is categorized as type I ovarian cancer. The aim of this study was to investigate the clinical significance of PIK3CA overexpression in the disease. We performed immunohistochemical analyses of PIK3CA, PTEN, p-Akt, p27 and p53 expressions in primary ovarian clear cell carcinomas from 62 Japanese patients. Genetic analyses of PIK3CA mutation and amplification were further conducted. PIK3CA was overexpressed in 45 tumors (73%), PTEN expression was negative in 3 (5%), and p53 was positive in 8 (13%). Overexpressed PIK3CA was found to be associated with p-Akt overexpression (P = .007). PIK3CA overexpression tended to be observed in more of stage I disease (73% versus 47%, P = .07) and was associated with absence of residual tumor at the initial surgery (96% versus 71%, P = .01). Furthermore, survival analyses revealed that PIK3CA overexpression correlated with improved overall survival (P = .03). Subsequent genetic analyses demonstrated that PIK3CA overexpression correlated with the presence of mutation or amplification of the PIK3CA gene in tumors (P = .009). Our observations suggest that the subgroup of ovarian clear cell carcinomas harboring activated PIK3CA seems to have better prognosis possibly due to more indolent biological property compared to tumors without PIK3CA activation. PIK3CA may serve as a biomarker for good prognosis and a possible therapeutic target in this lethal subtype of ovarian cancer.

Are smoking and chlamydial infection risk factors for CIN? Different results after adjustment for HPV DNA and antibodies.

To identify the risk factors for cervical intraepithelial neoplasia (CIN), we reanalysed the data from our previous case–control study by adjusting for human papillomavirus (HPV) antibodies. Unlike our previous study based only on HPV DNA, smoking and Chlamydia trachomatis infection were revealed as significant risk factors for CIN after adjustment for HPV antibodies.

Tobacco smoking and regression of low-grade cervical abnormalities

The role of tobacco smoking in the multistage carcinogenesis at the cervix is not fully understood because of a paucity of prospective data. To assess the relationship between smoking and spontaneous regression of cervical precursor lesions, a total of 516 women with low‐grade squamous intraepithelial lesion (LSIL) were monitored by cytology and colposcopy every 4 months. Probability of LSIL regression within 2 years was analyzed in relation to smoking behaviors, with regression defined as at least two consecutive negative Pap smears and normal colposcopy. Women’s age, initial biopsy results, and human papillomavirus (HPV) genotypes were included in the multivariate models for adjustments. Our study subjects included 258 never‐smokers and 258 smokers (179 current and 79 former smokers). During a mean follow‐up time of 39.8 months, 320 lesions regressed to normal cytology. Probability of regression within 2 years was significantly lower in smokers than in never‐smokers (55.0%vs 68.8%, P = 0.004). The risk of LSIL persistence increased with smoking intensity and duration and with younger age at starting smoking (P = 0.003, P < 0.001, and P = 0.03, respectively). Smokers had twice as high a risk of persistent HPV infection compared to never‐smokers (odds ratio, 2.50; 95% confidence interval, 1.30–4.81; P = 0.006). In young women, passive smoking since childhood reduced probability of regression within 2 years (56.7%vs 85.9%, P < 0.001). Further adjustments for a wide range of cervical cancer risk factors did not change the findings. In conclusion, tobacco smoking may interfere with regression of cervical precursor lesions. Childhood exposure to second‐hand smoke may increase a risk of persistent cervical abnormalities among young women. (Cancer Sci 2010)

Interleukin-10 −1082 Gene Polymorphism and Susceptibility to Cervical Cancer Among Japanese Women

Polymorphisms in cytokine genes can influence immune responses to human papillomavirus infection, possibly modifying risks of cervical cancer. Using an amplification refractory mutation system-polymerase chain reaction method, we analyzed a single nucleotide polymorphism (A/G) at position -1082 in interleukin-10 promoter region in 440 Japanese women: 173 women with normal cytology, 163 women with cervical intraepithelial neoplasia and 104 women with invasive cervical cancer. The carrier frequency of interleukin-10 -1082 G alleles associated with higher interleukin-10 production increased with disease severity: 9.8% for normal cytology; 19.6% for cervical intraepithelial neoplasia; 29.8% for invasive cervical cancer (P for trend < 0.001). Among cytologically normal women, human papillomavirus infections were more common in those who were positive for an interleukin-10 -1082 G allele (P = 0.04). In conclusion, our data suggest that interleukin-10 -1082 gene polymorphism may serve as a marker of genetic susceptibility to cervical cancer among Japanese women.