Yong-Zhen Zhang

Peking Union Medical College Hospital, Peping, Beijing, China

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Publications (6)8.74 Total impact

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    ABSTRACT: Hybrid Capture 2 (HC2) has been demonstrated to be a feasible screening method for cervical cancer. Based upon HC2 technology, careHPV is a simple, rapid, accurate, and inexpensive screening test for women in low-resource settings. This study aims to characterize both the careHPV test and HC2 test, and to compare careHPV results of specimens stored in careHPV test collection medium (TCM) to HC2 results from partner specimens stored in Qiagen specimen transport medium and TCM. The positive rates of high-risk HPV in careHPV, HC2, and HC2 (TCM) were 13.2% (108/818), 13.2% (108/818), and 13.6% (111/818), respectively. The agreement rates of pairwise tests were 95.8% (95% CI: 94.5-97.2%), 96.7% (95% CI: 95.5-97.9%), and 97.2% (95% CI: 96.1-98.3%), respectively. The Kappa values of the pairwise tests were 0.82 (95% CI: 0.76-0.88), 0.86 (95% CI: 0.81-0.91), and 0.88 (95% CI: 0.83-0.93), respectively. Based on these findings, although careHPV is demonstrated to be a viable alternative to the HC2 test, improvements on the careHPV test are still required prior to its implementation as a suitable screening method for women in low-resource settings. Further studies on the significance and applicability of the careHPV test must be performed.
    Journal of virological methods 03/2014; · 2.13 Impact Factor
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    ABSTRACT: Cost estimation is a central feature of health economic analyses. The aim of this study was to use a micro-costing approach and a societal perspective to estimate aggregated costs associated with cervical cancer screening, diagnosis and treatment in rural China. We assumed that future screening programs will be organized at a county level (population ~250,000), and related treatments will be performed at county or prefecture hospitals; therefore, this study was conducted in a county and a prefecture hospital in Shanxi during 2008-9. Direct medical costs were estimated by gathering information on quantities and prices of drugs, supplies, equipment and labour. Direct non-medical costs were estimated via structured patient interviews and expert opinion. Under the base case assumption of a high-volume screening initiative (11,475 women screened annually per county), the aggregated direct medical costs of visual inspection, self-sampled careHPV (Qiagen USA) screening, clinician-sampled careHPV, colposcopy and biopsy were estimated as US$2.64,$7.49,$7.95,$3.90 and $5.76, respectively. Screening costs were robust to screening volume (<5% variation if 2,000 women screened annually), but costs of colposcopy/biopsy tripled at the lower volume. Direct medical costs of Loop Excision, Cold-Knife Conization and Simple and Radical Hysterectomy varied from $61-544, depending on the procedure and whether conducted at county or prefecture level. Direct non-medical expenditure varied from $0.68-$3.09 for screening/diagnosis and $83-$494 for pre-cancer/cancer treatment. Diagnostic costs were comparable to screening costs for high-volume screening but were greatly increased in lower-volume situations, which is a key consideration for the scale-up phase of new programs. The study's findings will facilitate cost-effectiveness evaluation and budget planning for cervical cancer prevention initiatives in China.
    BMC Health Services Research 05/2012; 12:123. · 1.77 Impact Factor
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    ABSTRACT: A new lower-cost rapid-throughput human papillomavirus (HPV) test (careHPV, Qiagen, Gaithersburg, USA) has been shown to have high sensitivity for the detection of high grade cervical intraepithelial neoplasia. We assessed the outcomes and cost-effectiveness of careHPV screening in rural China, compared to visual inspection with acetic acid, when used alone (VIA) or in combination with Lugol's iodine (VIA/VILI). Using data on sexual behaviour, test accuracy, diagnostic practices and costs from studies performed in rural China, we estimated the cost-effectiveness ratio (CER) and associated lifetime outcomes for once-lifetime and twice-lifetime screening strategies, and for routine screening at 5-yearly, 10-yearly and IARC-recommended intervals. The optimal age range for once-lifetime screening was also assessed. For all strategies, the relative ordering of test technologies in reducing cervical cancer incidence and mortality was VIA (least effective); VIA/VILI; careHPV@1.0 pg/ml and careHPV@0.5 pg/ml (most effective). For once-lifetime strategies, maximum effectiveness was achieved if screening occurred between 35-50 years. Assuming a participation rate of ~70%, once-lifetime screening at age 35 years would reduce cancer mortality by 8% (for VIA) to 12% (for careHPV@0.5) over the long term, with a CER of US$557 (for VIA) to $959 (for careHPV@1.0) per life year saved (LYS) compared to no intervention; referenced to a 2008 GDP per capita in Shanxi Province of $2,975. Correspondingly, regular screening with an age-standardised participation rate of 62% (which has been shown to be achievable in this setting) would reduce cervical cancer mortality by 19-28% (for 10-yearly screening) to 43-54% (using IARC-recommended intervals), with corresponding CERs ranging from $665 (for 10-yearly VIA) to $2,269 (for IARC-recommended intervals using careHPV@1.0) per LYS. This modelled analysis suggests that primary careHPV screening compares favourably to visual inspection screening methodologies in rural China, particularly if used as part of a regular screening program.
    BMC Cancer 06/2011; 11:239. · 3.33 Impact Factor
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    ABSTRACT: To determine the age-stratified HPV prevalence rate and the risk factors of life-style associated with HPV infection among women in rural China. An age-stratified, cross-sectional survey of 941 women between 16-59 years old was conducted in rural China. Carcinogenic HPV infection was determined using Digene's Hybrid Capture II HPV DNA test and interviews of life-style were conducted. Odds ratios (OR) and 95% confidence interval (CI) from the logistic regression models were used to determine the risk factors associated with HPV. Among 941 women, 745 who had sexual intercourse underwent a cervical examination. The prevalence rate of 13 carcinogenic HPV infections among women 20-59 years old was 15.97%. the rate of HPV prevalence in the 25-34 age group was statistically lower than that in 20-24 and 35-59 age groups (X²=13.3, P=0.0013). The OR of bathing every 7-19 days, 20-180 days, less than once every 180 days vs. bathing at least once a week were 1.19, 1.83 and 2.29 respectively and they had a dose-response relationship (Trend Test: P=0.003). The OR of women aged 25-34 age group vs. 20-24 age group was 0.40 (0.16 - 0.97) and the OR of bathing once every 180 days or less vs. at least once weekly was 2.22 (1.14 - 4.33) adjusted for the other confounding factors,. The HPV prevalence rate was lowest among child bearing women aged 25-34 year. Also, personal hygiene is significantly associated with the HPV infection in this area, regardless of age.
    Asian Pacific journal of cancer prevention: APJCP 01/2011; 12(3):781-6. · 1.50 Impact Factor
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    ABSTRACT: In China, there has been no established national program for cervical cancer prevention, the screening methods and experiences are especially deficient in the rural areas. The aim of this paper is to evaluate the effects of acetic acid/Lugol's iodine (VIA/VILI) used for screening of cervical cancer and pre-cancerous lesions in a rural area of China by analyzing the large-scale population-based screening data from the demonstration site. Women aged 30-59 years from Xiangyuan County in Shanxi Province were recruited for cervical cancer screening from 2005 to 2007. VIA/VILI was the primary screening method followed by colposcopy if the VIA/VILI was positive. Cervical lesions were diagnosed by directed biopsy under the colposcopy. The VIA/VILI negative women or cervical intraepithelial neoplasia 1 (CIN1) were re-screened using the same procedure in the next year. In total, 7145 women received the cervical cancer screening, with a participation rate of 74.75%. Their average age was 42.16 years. A total of 1287 women were consecutively screened for three times from 2005 to 2007. The detection rates of CIN2, CIN3 and cervical cancer were 0.70% (9/1287), 1.01% (13/1287) and 0.23% (3/1287) for the first round screening, and were 0.22% (2/976), 0.11% (1/976) and 0% (0/976) for the second round screening, respectively. Only one CIN2 was found in the third round screening. In the years of 2006-2007, 3490 women were screened consecutively twice. The detection rates of CIN2, CIN3 and cervical cancer were 0.26% (9/3490), 0.52% (18/3490) and 0.15% (5/3490) for the first round screening, and 0.40% (14/2943), 0.40% (14/2943) and 0.03% (1/2943) for the second round screening. Likewise, 2 368 women were screened consecutively twice in the years of 2007-2008. The detection rates of CIN2, CIN3 and cervical cancer were 0.55% (13/2368), 0.25% (6/2368) and 0.12% (3/2368) for the first round screening, and 0.42 (10/2040), 0.04% (1/2040) and 0% for the second round screening. The cumulative detection rates for CIN2, CIN3 and cervical cancer were 0.81% (58/7145), 0.74% (53/7145) and 0.17% (12/7145), respectively. And 53.45% (31/58) of CIN2, 68.81% (37/53) of CIN3 and almost all cervical cancers (11/12) were found during the first round screening, except for an early stage cervical cancer (Ia). Only one CIN2 was detected in the third round screening in the same population. The average age of CIN1, CIN2, CIN3 and cervical cancer were 38.65, 40.61, 44.10 and 46.73 years, respectively. VIA/VILI can be used as an alternative screening method for cervical cancer and high-grade pre-cancerous lesions among the women aged 30-59 years in China's rural areas because of its low cost, easy training for the local health providers, and less depending on facilities. One round screening by VIA/VILI can detect more than a half of CIN2, two-thirds of CIN3 and almost all the cervical cancer in the population, and the detection rates of CIN2/3 can be increased by two consecutive rounds of screening.
    Chinese journal of cancer 01/2010; 29(1):4-8.
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    ABSTRACT: To evaluate visual inspection with Lugol's iodine (VILI) in cervical cancer screening program and to provide evidence for designing a cervical cancer screening algorithm in high risk areas of existing low-resource settings to reduce the incidence and mortality of cervical cancer. Women in Yangcheng county, Shanxi province were screened with VILI, colposcopy, liquid-based cytology test and human papilloma virus (HPV) DNA test. The efficacy of different screening tests was compared by Youden's index based on the pathology as the gold standard. In the population being screened, the mean age was 40.80 +/- 10.75 years old. Based on pathological findings, 4.35% (32/735) of the subjects had >or= CIN (cervical intraepithelial neoplasia) II. The sensitivity and specificity for the VILI test (>or= positive) were 53.13 and 82.19, while 56.25 and 79.09 were for colposcopy (>or= low grade dysplasia) respectively. Comparing by the Youden's indexs, there was no statistically significant difference (P > 0.05) between VILI and colposcopy. However, statistical significant difference (P < 0.05) was found between VILI and liquid-based cytology test and HPV DNA test. In addition, there was no statistically significant difference (P > 0.05) found between the experienced doctors and the newly-trained doctors working in the field station. With low sensitivity when using microscope but low cost of equipments, VILI can be one of the primary screening tests in China's rural area with low-resource settings if the screening frequency is to be increased.
    Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi 01/2006; 27(1):15-8.