Early Experience of Sexual Intercourse - A Risk Factor for Cervical Cancer Requiring Specific Intervention for Teenagers

There is consensus that the main risk factor for cervical cancer development is persistent infection with high-risk ‍group human papilloma viruses (HPVs), together with smoking, and reproductive history. Since sexual behaviour ‍determines exposure to HPVs and the adolescent period may be particularly important in this regard it is of interest ‍to consider behavioural determinants of teenagers. In one survey conducted in Khon Kaen, Thailand, some 62% ‍percent of male and 19.3 % of female respondents aged 13-15 years reported having experienced sexual desire, and ‍19.1% of male and 4.7 % of female respondents admitted to sexual intercourse. The possibility that this might ‍impact on HPV infection rates, with added risk due to the physical trauma associated with pregancy and illegal ‍abortions, indicates that more attention needs to education of early teens, not only for avoidance of HIV and AIDS, ‍but also for prevention of cervical cancer.     

Risk Factors for Cervical Cancer in Northeastern Thailand: Detailed Analyses of Sexual and Smoking Behavior

Cervical cancer is a serious public health problem in Thailand. We investigated possible risk factors forcervical cancer including HPV infection, p53 polymorphism, smoking and reproductive history among womenin Northeast Thailand using a case control study with 177 cases and age-matched controls. Among the HPVcarriers, a significantly increased risk for cervical cancer with an OR of 36.97 (p<0.001) and an adjusted OR of38.07 (p<0.001) were observed. Early age at first sexual exposure, and multiple sexual partners increased therisk of cervical cancer with ORs ranging between 1.73-2.78 (p<0.05). The interval between menarche and firstsexual intercourse <6 years resulted in a significant increase in the risk for cervical cancer with ORs rangingbetween 3.32-4.09 and the respective adjusted OR range for the 4-5 and 2-3 year-old groups were 4.09 and 2.92.A higher risk was observed among subjects whose partner had smoking habits, whether currently or formerly;with respective ORs of 3.36 (p<0.001) and 2.17 (p<0.05); and respective adjusted ORs of 2.90 (p<0.05) and 3.55(p<0.05). Other smoking characteristics of the partners including smoking duration ≥ 20 years, number ofcigarettes smokes ≥ 20 pack-years and exposure time of the subject to passive smoking ≥ 5 hrs per day were foundto be statistically significant risks for cervical cancer with adjusted ORs of 3.75, 4.04 and 11.8, respectively. Ourdata suggest that the risk of cervical cancer in Thai women is substantially associated with smoking characteristicsof the partner(s), the interval between menarche and first sexual intercourse as well as some other aspects ofsexual behavior.     

Association between RASSF1A Promoter Hypermethylation and Oncogenic HPV Infection Status in Invasive Cervical Cancer: a Meta-analysis

Cervical carcinoma is the main cause of cancer-related mortality in women and is correlated with more than15 risk cofactors, including infection of cervical cells with high-risk types of HPV (hrHPV). Indeed, both aberrantmethylation of the RASSF1A promoter and hrHPV infection are often observed in cervical carcinomas. Thepurpose of our meta-analysis was to evaluate the role of RASSF1A promoter methylation and hrHPV infectionin cervical cancer. Our meta-analysis involved 895 cervical cancer patients and 454 control patients from 15studies. Our results suggested that RASSF1A promoter hypermethylation increased the risk of cervical cancer(OR=9.77, 95%CI=[3.06, 31.26], P=0.0001, I2=78%). By grouping cases according to cancer subtypes, we foundthat HPV infection was higher in cervical squamous cell carcinomas (SCCs) than in cervical adenocarcinomas/adenosquamous cancers (ACs/ASCs) (OR=4.00, 95%CI=[1.41, 11.30], P=0.009, I2=55%). Interestingly, HPVinfection tended to occur in cervical cancers with relatively low levels of RASSF1A promoter methylation(OR=0.59, 95%CI=[0.36, 0.99], P=0.05, I2=0%). Our study provides evidence of a possible interaction betweenHPV infection and RASSF1A promoter methylation in the development of cervical cancers.     

Association Between the XRCC3 Thr241Met Polymorphism and Cervical Cancer Risk: a Meta-analysis

Background: Numerous epidemiological studies have been conducted to evaluate the association betweenvariants of the DNA repair gene XRCC3 and cancer risk. Here we focused on one XRCC3 polymorphism anddevelopment of cervical cancer, performing a meta-analysis. Methods: The pooled association between theXRCC3 Thr241Met polymorphism and cervical cancer risk was assessed by odds ratios (ORs) and their 95%confidence intervals (95%CIs). Results: A total of 5 case-control studies met the inclusion criteria. The pooledORs for the total included studies showed no association among homozygotes TT vs. CC: OR=1.93, 95%CI=0.68-5.49, P=0.22; dominant model TT+TC vs. CC: OR=1.37, 95%CI=0.90-2.06, P=0.14; and recessive model TT vs.TC+CC: OR=1.76, 95%CI=0.68-4.55, P=0.25, but might be a slight risk factor for cervical cancer in heterozygotecontrast TT vs. CT: OR= 1.33, 95%CI=1.04-1.71, P=0.02. In subgroup analysis, significant associations werefound for Asians under all genetic models. Conclusions: Our meta-analysis suggested the XRCC3 Thr241Metpolymorphism might not act as a cervical cancer risk factor overall. However, in subgroup analysis, a significantassociation was found in Asians under all genetic models. The association should be studied with a larger, stratifiedpopulation, especially for Asians.     

Association Between p53 codon 72 Polymorphism and Cervical Cancer Risk Among Asians: a Huge Review and Meta-analysis

Objective: The aim of this Human Genome Epidemiology (HuGE) review and meta-analysis was to derive amore precise estimation of the association between p53 codon 72 polymorphism (Arg72Pro, rs1042522 G>C) andcervical cancer risk among Asians. Methods: A literature search of Pubmed, Embase, Web of Science and CBMdatabases from inception through June 2012 was conducted. The meta-analysis was performed using STATA12.0 software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength ofany association. Twenty-eight case-control studies were included with a total of 3,580 cervical cancer cases and3,827 healthy controls. When all the eligible studies were pooled into the meta-analysis, the results showed thatthe Pro/Pro genotype was associated with increased risk of cervical cancer under the heterozygous model (Pro/Pro vs. Arg/Pro: OR = 1.25, 95%CI: 1.02-1.53, P= 0.005). However, no statistically significant associations werefound under four other genetic models (Pro vs. Arg: OR = 0.97, 95%CI: 0.85-1.10, P= 0.624; Pro/Pro + Arg/Pro vs. Arg/Arg: OR = 0.84, 95%CI: 0.70-1.01, P= 0.058; Pro/Pro vs. Arg/Arg + Arg/Pro: OR = 1.13, 95%CI:0.92-1.39, P= 0.242; Pro/Pro vs. Arg/Arg: OR = 0.97, 95%CI: 0.76-1.22, P= 0.765; respectively). In the subgroupanalysis based on country, the Pro/Pro genotype and Pro carrier showed significant associations with increasedrisk of cervical cancer among Indian populations, but not among Chinese, Japanese and Korean populations.Conclusion: Results from the current meta-analysis suggests that p53 codon 72 polymorphism might be associatedwith increased risk of cervical cancer, especially among Indians.     

Breastfeeding and Ovarian Cancer Risk: a Systematic Review and Meta-analysis of 40 Epidemiological Studies

The present systematic review and meta-analysis was conducted to assess any association between breastfeeding and the risk of ovarian cancer. A systematic search of published studies was performed in PUBMED and EMBASE and by reviewing reference lists from retrieved articles through March 2013. Data extraction was conducted independently by two authors. Pooled relative risk ratios were calculated using random-effect models. Totals of 5 cohort studies and 35 case-control studies including 17,139 women with ovarian cancer showed a30% reduced risk of ovarian cancer when comparing the women who had breastfed with those who had never breastfed (pooled RR = 0.70, 95% CI: 0.64-0.76; p = 0.00), with significant heterogeneity in the studies (p = 0.00;I2 = 76.29%). A significant decreasd in risk of epithelial ovarian cancer was also observed (pooled RR = 0.68, 95% CI: 0.61-0.76). When the participants were restricted to only parous women, there was a slightly attenuated but still significant risk reduction of ovarian cancer (pooled RR = 0.76, 95% CI: 0.69-0.83). For total breastfeeding duration, the pooled RRs in the < 6 months, 6-12 months and > 12 months of breastfeeding subgroups were 0.85 (95% CI: 0.77-0.93), 0.73 (95% CI: 0.65-0.82) and 0.64 (95%CI: 0.56-0.73), respectively. Meta-regressionof total breastfeeding duration indicated an increasing linear trend of risk reduction of ovarian cancer with the increasing total breastfeeding duration (p = 0.00). Breastfeeding was inversely associated with the risk of ovarian cancer, especially long-term breastfeeding duration that demonstrated a stronger protective effect.     

Detection of MicroRNA-21 Expression as a Potential Screening Biomarker for Colorectal Cancer: a Meta-analysis

Background: Colorectal cancer (CRC) is a major cause of cancer-related death and cancer-related incidenceworldwide. The potential of microRNA-21 (miR-21) as a biomarker for CRC detection has been studied inseveral studies. However, the results were inconsistent. Therefore, we conducted the present meta-analysis tosystematically assess the diagnostic value of miR-21 for CRC. Materials and Methods: Using a random-effectmodel, the pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio(NLR), and diagnostic odds ratio (DOR) were calculated to evaluate the diagnostic performance of miR-21 forCRC. A summary receiver operating characteristic (SROC) curve and an area under the curve (AUC) were alsogenerated to assess the diagnosis accuracy of miR-21 for CRC. Q test and I2 statistics were used to assess betweenstudyheterogeneity. Publication bias was evaluated by the Deeks’ funnel plot asymmetry test. Results: A totalof 986 CRC patients and 702 matched healthy controls from 8 studies were involved in the meta-analysis. Thepooled results for SEN, SPE, PLR, NLR, DOR, and AUC were 57% (95%CI: 39%-74%), 87% (95%CI: 78%-93%), 4.4 (95%CI: 2.4-8.0), 0.49 (95%CI: 0.32-0.74), 9 (95%CI: 4-22), and 0.83 (95%CI: 0.79-0.86), respectively.Subgroup analyses further suggested that blood-based studies showed a better diagnostic accuracy comparedwith feces-based studies, indicating that blood may be a better matrix for miR-21 assay and CRC detection.Conclusions: Our findings suggest that miR-21 has a potential diagnostic value for CRC with a moderate levelof overall diagnostic accuracy. Hence, it could be used as auxiliary means for the initial screening of CRC andavoid unnecessary colonoscopy, which is an invasive and expensive procedure.     

绿茶与消化系统恶性肿瘤流行病学研究的Meta分析

[目的]探讨绿茶与消化系统恶性肿瘤发生的关系。[方法]利用MEDLINE、EM-BASE、中国生物医学文献数据库、万方数据库,检索1979年1月～2010年1月国内外公开发表的关于绿茶与消化系统恶性肿瘤关系的病例对照研究和队列研究文献,利用R软件及其Meta程序包对检索结果进行综合分析。[结果]纳入本次Meta分析的文献共83篇。经Meta分析综合后,与不饮绿茶或饮绿茶较少者相比,饮绿茶较多者的相对危险度值及其95%可信区间为0.88(95%CI:0.81～0.95)。其中绿茶可以降低胃癌的发病风险,合并RR为0.73(95%CI:0.57～0.93),有统计学意义;绿茶对食管癌、结肠癌、胰腺癌的保护作用没有统计学意义,其合并RR分别为0.89(95%CI:0.71～1.13),0.96(95%CI:0.84～1.10),0.73(95%CI:0.45～1.19);而肝癌的结果0.77(95%CI:0.57～1.03)处于临界统计学意义的水平。此外,亚组分析提示绿茶对女性食管癌有保护作用,合并RR为0.32(95%CI:0.17～0.59)。绿茶与直肠癌合并的RR为1.10(95%CI:0.97～1.24),结果没有统计学意义。[结论]绿茶与消化系统恶性肿瘤之间有比较密切的关系,可能是胃癌、肝癌、食管癌(女性)等消化系统恶性肿瘤的保护因素之一。     

Review of the Cervical Cancer Disease Burden in Mainland China

Human papillomavirus (HPV) infection is a common sexually transmitted infection (STI) worldwide. HPVmay cause several reproductive tract diseases and cervical cancer is the most serious health problem due topersistent high risk HPV infection. Although cervical cancer showed a declining trend over the past three decadesin China, it remains a major health problem in Chinese women especially women living in rural China. Thedisease burden is believed to be underestimated given the relatively high HPV prevalence shown in recent studies.To date, prophylactic vaccination as a primary prevention of cervical cancer are available in many countries andregions of the world; yet, they are not yet accessible in mainland China. Before introduction of HPV vaccines,screening remains the predominant method of prevention. Selected population based screening sites are availablein every province of China, yet, an organized screening program operating nationwide still does not exist. Abetter understanding of the disease burden is likely to help develop a comprehensive intervention policy forfuture management of cervical cancer in China. It is important to review the disease burden of cervical cancerand the current status of cervical cancer screening in mainland China.     

Cervical Cancer Screening and Analysis of Potential Risk Factors in 43,567 Women in Zhongshan,China

Objective: The objective of this study was to establish a program model for use in wide-spread cervical cancerscreening. Methods: Cervical cancer screening was conducted in Zhongshan city in Guangdong province, Chinathrough a coordinated network of multiple institutes and hospitals. A total of 43,567 women, 35 to 59 years ofage, were screened during regular gynecological examinations using the liquid-based ThinPrep cytology test(TCT). Patients who tested positive were recalled for further treatment. Results: The TCT-positive rate was3.17%, and 63.4% of these patients returned for follow-up. Pathology results were positive for 30.5% of therecalled women. Women who were younger than 50 years of age, urban dwelling, low-income, had a history ofcervical disease, began having sex before 20 years of age, or had sex during menstruation, were at elevated riskfor a positive TCT test. The recall rate was lower in women older than 50 years of age, urban dwelling, poorlyeducated, and who began having sex early. A higher recall rate was found in women 35 years of age and younger,urban dwelling, women who first had sex after 24 years of age, and women who had sex during menstruation.The positive pathology rate was higher in urban women 50 years of age and younger and women who testedpositive for human papillomavirus. Conclusion: An effective model for large-scale cervical cancer screening wassuccessfully established. These results suggest that improvements are needed in basic education regarding cervicalcancer screening for young and poorly educated women. Improved outreach for follow-up is also necessary toeffectively control cervical cancer.     

Electromagnetic Field Exposure and Male Breast Cancer Risk: A Meta-analysis of 18 Studies

Background: The possibility that electromagnetic fields (EMF) exposure may increase male breast cancer riskhas been discussed for a long time. However, arguments have been presented that studies limited by poor qualitycould have led to statistically significant results by chance or bias. Moreover, data fo the last 10 years have notbeen systematically summarized. Methods and Results: To confirm any possible association, a meta-analysis wasperformed by a systematic search strategy. Totals of 7 case-control and 11 cohort studies was identified and pooledORs with 95% CIs were used as the principal outcome measures. Data from these studies were extracted witha standard meta-analysis procedure and grouped in relation to study design, cut-off point, exposure assessmentmethod, adjustment and exposure model. A statistical significant increased risk of male breast cancer with EMFexposure was defined (pooled ORs = 1.32, 95% CI = 1.14 -1.52, P < 0.001), and subgroup analyses also showedsimilar results. Conclusions: This meta-analysis suggests that EMF exposure may be associated with the increaserisk of male breast cancer despite the arguments raised.     

Obesity and Risk of Bladder Cancer: A Meta-analysis of Cohort Studies

Objective: Previous epidemiologic studies demonstrated that obesity might associated with the risk ofbladder cancer. However, many of the actual association findings remained conflicting. To better clarify andprovide a comprehensive summary of the correlation between obesity and bladder cancer risk, we conducted ameta-analysis to summarize results of studies on the issue. Stratified analyses were also performed on potentialvariables and characteristics. Methods: Studies were identified by searching in PubMed and Wanfang databases,covering all the papers published from their inception to March 10, 2013. Summary relative risks (SRRs) withtheir corresponding 95% confidence intervals (CIs) were calculated by either random-effect or fixed-effectmodels. Results: A total of 11 cohort studies were included in our meta-analysis, which showed that obesity wasassociated with an increased risk for bladder cancer in all subjects (RR=1.10, 95% CI=1.06–1.16; p=0.215 forheterogeneity; I2=24.0%). Among the 9 studies that controlled for cigarette smoking, the pooled RR was 1.09(95% CI 1.01-1.17; p=0.131 for heterogeneity; I2=35.9%). No significant publication bias was detected (p = 0.244for Egger’s regression asymmetry test). Conclusions: Our results support the conclusion that obesity is associatedwith the increased risk of bladder cancer. Further research is needed to generate a better understanding of thecorrelation and to provide more convincing evidence for clinical intervention in the prevention of bladder cancer.     

Association Between Green Tea and Colorectal Cancer Risk: A Meta-analysis of 13 Case-control Studies

Objective: Experimental studies have suggested green tea to be a chemopreventive agent for colorectalcancer, and many studies have examined possible associations. However, the conclusions were inconsistent oreven contradictory, so we performed a meta-analysis based on published case-control studies to explore if greentea is indeed a protective factor. Methods: PubMed was searched up to May 10th, 2012 for relevant studies, andreferences of included studies were manually searched. Finally 13 eligible studies, involving 12,636 cases and38,419 controls were identified. After data extraction, a meta-analysis was performed using CMA v2 software.Results: The results indicated there may be a weak but not statistically significant reduced risk of colorectalcancer with high dose of green tea intake (OR=0.95, 95% CI:0.81-1.11, p=0.490.69–0.98). This protective effectwas also found in all subgroups, except in American and European populations. Sensitivity analysis indicatedthe result to be robust. Publication bias was not detected by either funnel plot or Egger tests. Conclusion: Theresults of this meta-analysis indicate a weak lower tendency for colorectal cancer development with green teaconsumption, but available epidemiologic data are insufficient to conclude that green tea may protect againstcolorectal cancer in humans.     

Association Between C-reactive Protein and Risk of Cancer: A Meta-analysis of Prospective Cohort Studies

Background: Associations between elevated C-reactive protein (CRP) and cancer risk have been reported formany years, but the results from prospective cohort studies remains controversial. A meta-analysis of prospectivecohort studies was therefore conducted to address this issue. Methods: Eligible studies were identified bysearching the PubMed and EMBASE up to October 2012. Pooled hazard ratios (HR) was calculated by usingrandom effects model. Results: Eleven prospective cohort studies involving a total of 194,796 participants and11,459 cancer cases were included in this meta-analysis. The pooled HR per natural log unit change in CRP was1.105 (95% confidence interval (CI): 1.033-1.178) for all-cancer, 1.308 (95% CI: 1.097-1.519) for lung cancer,1.040 (95% CI: 0.910-1.170) for breast cancer, 1.063 (95% CI: 0.965-1.161) for prostate cancer, and 1.055 (95%CI: 0.925-1.184) for colorectal cancer. Dose-response analysis showed that the exponentiated linear trend for achange of one natural log unit in CRP was 1.012 (95% CI: 1.006-1.018) for all-cancer. No evidence of publicationbias was observed. Conclusions: The results of this meta-analysis showed that the elevated levels of CRP areassociated with an increased risk of all-cancer, lung cancer, and possibly breast, prostate and colorectal cancer.The result supports a role of chronic inflammation in carcinogenesis. Further research effort should be performedto identify whether CRP, as a marker of inflammation, has a direct role in carcinogenesis.     

Meta-Analysis of Polymorphic Variants Conferring Genetic Risk to Cervical Cancer in Indian Women Supports CYP1A1 as an Important Associated Locus

Objective: Association of multiple polymorphic variants with cervical cancer has been elucidated by severalcandidate gene based as well as genome-wide association studies. However, contradictory outcomes of those studieshave failed to estimate the true effect of the polymorphic variants on cervical cancer. Methods: Literature mining ofthe PubMed database was done to gather all the publications related to genetic association with cervical cancer in India.Out of 98 PubMed hits only 29 genetic association studies were selected for meta-analysis based on specific inclusioncriteria. A fixed-effect meta-analysis was performed to evaluate the overall association of the genetic polymorphismswith cervical cancer. Cochran’s Q test was performed to assess between study heterogeneity. Publication bias wasalso estimated by funnel plots and Egger’s regression test. Further, sub-group analysis was conducted by fixed-effectmeta-regression to assess the impact of polymorphisms on cervical cancer in the presence of Human Papilloma Virus(HPV). Result: Following a fixed-effect model, meta-analysis was conducted that revealed 2 polymorphic variantsviz. ‘deletion polymorphism (Del2) (OR=1.79, 95% CI= 1.08-2.95, P=0.023) in GSTM1’ and ‘rs1048943 (OR = 2.34,95% CI=1.37-3.99, P=0.0018) in CYP1A1’ to be associated with cervical cancer. However, multiple testing correctionshowed only rs1048943 of CYP1A1 to be significantly associated (P-value=0.029) with cervical cancer with significantpublication bias (P-value=0.0113) as estimated by Egger’s regression test. The polymorphic variants ‘rs1801131’,‘rs1801133’, ‘rs2430561’, ‘rs1799782’, ‘rs25486’ and ‘rs25487’ showed significant (p<0.05) evidence of heterogeneitybetween studies by Cochran’s Q test and also by heterogeneity index (I2) calculation. Conclusion: Therefore, our studyrevealed significant association of rs1048943 in CYP1A1, but a nominal association of deletion polymorphism (Del2)in GSTM1 with cervical cancer, which provides a comprehensive insight on the true effect of the polymorphisms,reported in various case-control studies, on the risk of the development of cervical cancer in Indian women.     

Association of TERT rs2736098 Polymorphism with Cancer Risk: a Meta-analysis

Studies have reported an association between the TERT rs2736098 single nucleotide polymorphism (SNP) andcancer susceptibility, but the results remain inconclusive. Toprovide a more precise estimation of the relationship,a meta-analysis of 8 published studies including 8,070 cases and 10,239 controls was performed. Stratification bysample size, genotyping method, source of controls and ethnicity were used to explore the source of heterogeneity.In the overall analysis, no significant association was found between the TERT rs2736098 polymorphism andcancer risk. However, the result showed the rs2736098 was significantly associated with an increased cancerrisk and the heterogeneity was effectively decreased for homozygote comparison by removal of two studies: OR= 1.337 (95% CI = 1.183-1.511; Pheterogeneity = 0.087). In the subgroup analysis by ethnicity, a significantlyincreased risk of cancers was found among Asians (OR = 1.413, 95% CI = 1.187–1.683 for AA versus GG). Ourmeta-analysis did not show that the TERT rs2736098 plays an important role in cancer risk. More studies withlarger sample size and well-matched controls are needed to confirm the findings.     

宫颈癌根治术后并发肠梗阻的危险因素分析

目的 探讨宫颈癌根治术后发生肠梗阻的危险因素。方法 回顾性分析2012年6月—2017年6月149例宫颈癌根治术后并发肠梗阻患者的临床资料,与同期行该手术但未发生肠梗阻的2 436例患者资料进行对比,分析并发肠梗阻的危险因素。 结果 肠梗阻的发生与患者的年龄、手术时间、术后血钾水平、术后禁食时间、术前盆腹腔手术史、BMI、手术入径、术后感染、术后伴发腹腔积液有关（P<0.05）。其中盆腹腔手术史、术后禁食时间长、术后血钾水平低、手术消耗时间长是独立危险因素。而在手术出血量、术后患者血红蛋白水平、术中是否输血方面两组差异无统计学意义（P>0.05）。结论 缩短手术时间、鼓励患者术后尽早进食,维持术后血钾水平是预防宫颈癌术后发生肠梗阻的有效措施。     

Effectiveness of human papillomavirus vaccine against cervical precancer in Japan: Multivariate analyses adjusted for sexual activity

Japanese girls aged 12–16 years are offered free human papillomavirus (HPV) vaccination and cervical cancer screening is conducted with cytology and not HPV testing from the age of 20 years. So far, no study has analyzed the effect of HPV vaccination against cervical precancers considering HPV infection status and sexual activity. We aimed to analyze the vaccine effectiveness (VE) against HPV infection and cytological abnormalities, adjusted for sexual activity. This study comprised women aged 20–26 years who underwent cervical screening in Niigata. We obtained HPV vaccination status from municipal records and a questionnaire along with information concerning sexual activity. Of 5194 women registered for this study, final analyses included 3167 women in the vaccinated group (2821 vaccinated women prior to sexual debut) and 1386 women in the unvaccinated group. HPV 16/18 (0.2% vs 3.5%), 31/45/52 (3.4% vs 6.6%), and 31/33/45/52/58 (5.0% vs 9.3%) positive rates were significantly lower in the vaccinated group (P < 0.001). No women vaccinated before sexual debut had HPV 16/18‐related cytological abnormalities. VE for HPV 16/18 infection and high‐grade cytological abnormalities in women vaccinated prior to sexual debut were 95.8% (95% CI 81.9–99.0%; P < 0.001) and 78.3% (95% CI 11.3–94.7%; P = 0.033), respectively, in multivariate analyses adjusted for age and number of sexual partners. However, analyses of all vaccinated women did not show significant effectiveness against cytological abnormalities. Our results showed the effectiveness of HPV vaccine against high‐grade cervical cytological abnormalities and the importance of the vaccination before sexual debut.     

Cost-effectiveness Analysis of Cervical Cancer Screening Strategies Based on the Papanicolaou Smear Test in Korea

Background: Despite the increasing number of screening examinations performed for cervical cancer utilizingthe Papanicolaou smear test (Pap test), few studies have examined whether this strategy is cost-effective in Korea.Objective: This study was conducted to evaluate the cost-effectiveness of cervical cancer screening strategiesincorporating the Pap test based on age at the start and end of screening as well as screening interval. Materialsand Methods: We designed four alternative screening strategies based on patient age when screening was started(20 or 30 years) and discontinued (lifetime, 79 years). Each strategy was assessed at screening intervals of 1,2, 3, or 5 years. A Markov model was developed to determine the cost-effectiveness of the 16 possible cervicalcancer screening strategies, and this was evaluated from a societal perspective. The main outcome measures wereaverage lifetime cost, incremental quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio(ICER). Results: Compared with various strategies comprising younger starting age, discontinuation age, andlonger screening intervals, strategies employing annual screening for cervical cancer starting at a target age of30 years and above were the most cost-effective, with an ICER of 21,012.98 dollars per QALY gained (with aKorean threshold of 30,000,000 KRW or US$27,272). Conclusions: We found that annual screening for cervicalcancer beginning at a target age of 30 years and above is most cost-effective screening strategy. Considering thepotential economic advantages, more intense screening policies for cervical cancer might be favorable amongcountries with high rates of cervical cancer and relatively low screening costs.