Trends in cervical cancer mortality in korea 1993-2002: Corrected mortality using national death certification data and national cancer incidence data

Incidence and mortality of cervical cancer in Vietnam and Korea (1999-2017)

OBJECTIVES

Cervical cancer is a major disease burden in Vietnam. This study aimed to estimate the incidence and mortality rates of cervical cancer in Vietnam (1999-2017) in comparison to those in Korea, where a population-based cancer registry and national cervical cancer screening program have been implemented.

METHODS

The estimated incidence and mortality of cervical cancer in Vietnam and Korea (1999-2017) were collected from Global Burden of Disease 2017 study. Estimated age-standardized rates (ASRs) in both countries were calculated utilizing the 1999-2017 population of each country and the World Health Organization standard population. The reported ASRs in Korea were also computed using data on incidence and mortality (1999-2017) and the Korean population from the Korea Statistical Information Service.

RESULTS

In Vietnam, the estimated incidence and mortality of cervical cancer decreased annually by 0.84% and 1.01%. In Korea, the trend of reported incidence showed a dramatic drop (1999-2007 annual percent change [APC], -4.53%) before stably declining (2007-2017 APC, -2.71%). Reported mortality also significantly decreased (2003-2008 APC, -6.63%), and then maintained a stable decline (2008-2017 APC, -3.78%). The incidence and mortality rates were higher in Vietnam than in Korea. The declining trend of incidence and mortality in Vietnam was slower than the corresponding trends in Korea.

CONCLUSIONS

A national screening program should be implemented for Vietnamese women aged over 30 to maintain, or even hasten, the decline in cervical cancer incidence and mortality. A population-based cancer registry may help monitor the effectiveness of a cervical cancer screening program.

Temporal Trends of Common Female Malignances on Breast, Cervical, and Ovarian Cancer Mortality in Japan, Republic of Korea, and Singapore: Application of the Age-Period-Cohort Model

Background

Reproductive system cancer is an important cause of morbidity and mortality worldwide which threatens women's health and lives. Breast, cervical, and ovarian cancer have the higher incidence and mortality among a series of gynecology malignant tumor. We aimed to compare and assess the temporal trends of common female malignances on breast, cervical, and ovarian cancer mortality in developed regions of Asia including Japan, Republic of Korea, and Singapore and analyze the detached effects of chronological age, time period, and birth cohort by age-period-cohort (APC) analysis.

Methods

The mortality data for these three cancers were collected from the WHO Mortality Database in Japan, Republic of Korea, and Singapore from 1954 to 2013, from 1989 to 2013, and from 1964 to 2013, respectively. We fitted an age-period-cohort model and intrinsic estimator method to estimate the independent effect of each age, time period, and birth cohort on cancer mortality and describe the secular changes in three Asian countries.

Results

For the overall trends of breast cancer, the ASMRs of breast cancer showed a general increasing trend among three countries during the study periods while the change pattern in Singapore was different from the rest of the two countries for cervical and ovarian cancer. By APC analysis, the three cancer mortality risks generally increased with age and decreased with birth cohort. For period effects of breast and ovarian cancer, increasing effects with time were observed; however, for period effects of cervical cancer, converse change pattern was presented among three countries.

Conclusions

Our study shows that the ASMRs of breast, cervical, and ovarian cancer remain high in Singapore compared to Japan and Korea. Generally speaking, the mortality risk of three cancers increased with age, and period and cohort effects may collectively affect the common female malignances mortality for East Asian women.

Strategic Distributional Cost-Effectiveness Analysis for Improving National Cancer Screening Uptake in Cervical Cancer: A Focus on Regional Inequality in South Korea

PURPOSE

The purpose of this study was to conduct a cost effectiveness analysis of strategies designed to improve national cervical cancer screening rates, along with a distributional cost effectiveness analysis that considers regional disparities.

MATERIALS AND METHODS

Cost effectiveness analysis was conducted using a Markov cohort simulation model, with quality adjusted life years as the unit of effectiveness. The strategies considered were current (biennial Papanicolaou smear cytology of females aged 20 or above), strong screening recommendation by mail to target regions (effect, 12% increase in screening uptake; cost, 1,000 Korean won per person), regular universal screening recommendation by mail (effect, 6% increase in screening uptake; cost, 500 Korean won per person), and strong universal screening recommendation by mail (effect, 12% increase in screening uptake; cost, 1,000 Korean won per person). Distributional cost effectiveness analysis was conducted by calculating the cost effectiveness of strategies using the Atkinson incremental cost effectiveness ratio.

RESULTS

All strategies were under the threshold value, which was set as the Korean gross domestic product of $25,990. In particular, the 'strong screening recommendation to target regions' strategy was found to be the most cost effective (incremental cost effectiveness ratio, 7,361,145 Korean won). This was also true when societal inequality aversion increased in the distributional cost effectiveness analysis.

CONCLUSION

The 'strong screening recommendation to target regions' strategy was the most cost effective approach, even when adjusting for inequality. As efficiency and equity are objectives concurrently sought in healthcare, these findings imply a need to develop appropriate economic evaluation methodologies to assess healthcare policies.

Validity of self-reported cancer history in the health examinees (HEXA) study: A comparison of self-report and cancer registry records

PURPOSE

To assess the validity of the cohort study participants' self-reported cancer history via data linkage to a cancer registry database.

METHODS

We included 143,965 participants from the Health Examinees (HEXA) study recruited between 2004 and 2013 who gave informed consent for record linkage to the Korean Central Cancer Registry (KCCR). The sensitivity and the positive predictive value of self-reported histories of cancer were calculated and 95% confidence intervals were estimated.

RESULTS

A total of 4,860 participants who had at least one record in the KCCR were included in the calculation of sensitivity. In addition, 3,671 participants who reported a cancer history at enrollment were included in the calculation of positive predictive value. The overall sensitivity of self-reported cancer history was 72.0%. Breast cancer history among women showed the highest sensitivity (81.2%), whereas the lowest sensitivity was observed for liver cancer (53.7%) and cervical cancer (52.1%). The overall positive predictive value was 81.9%. The highest positive predictive value was observed for thyroid cancer (96.1%) and prostate cancer (96.1%), and the lowest was observed for cervical cancer (43.7%).

CONCLUSION

The accuracy of self-reported cancer history varied by cancer site and may not be sufficient to ascertain cancer incidence, especially for cervical and bladder cancers.

Trends and Age-Period-Cohort Effects on the Incidence and Mortality Rate of Cervical Cancer in Korea

PURPOSE

This study was conducted to describe the trends and age-period-cohort effects on the incidence and mortality rate of cervical cancer in Korea.

MATERIALS AND METHODS

The incidence and mortality rate of cervical cancer among ≥ 20-year-old women from 1993 to 2012 were obtained from the Korea Central Cancer Registry and the Korean Statistical Information Service. Age-standardized rates were calculated and Joinpoint regression was used to evaluate the trends in the incidence and mortality rate. Age-period-cohort analysis was performed to investigate the independent effects of age, period and cohort.

RESULTS

The incidence of cervical cancer decreased from 32.8 per 100,000 in 1993 to 15.9 per 100,000 in 2012 (annual percent change [APC], -3.9%; 95% confidence interval [CI], -4.2% to -3.6%). The mortality rate decreased from 5.2 per 100,000 in 1993 to 2.1 per 100,000 in 2012 (APC, -4.8%; 95% CI, -5.1% to -4.4%); however, the incidence and mortality rates among young women (< 30 years old) increased. An age-period-cohort model of the incidence and mortality rate showed decreasing period effects between 1993 and 2008 and decreasing cohort effects between 1928 and 1973, while birth cohorts after 1973 exhibited slight increases in the incidence and mortality rate of cervical cancer.

CONCLUSION

Recent decreases in the incidence and mortality rate of cervical cancer were due to decreases in the period and cohort effects, which reflect the implementation of a cancer screening program and changes in lifestyle. However, our findings also highlighted an increase in cohort effects on the incidence and mortality rate among young women born after 1973.

Changing trends in the incidence (1999-2011) and mortality (1983-2013) of cervical cancer in the Republic of Korea

Cervical cancer is a well-known preventable cancer worldwide. Many countries including Korea have pursued the positive endpoint of a reduction in mortality from cervical cancer. Our aim is to examine changing trends in cervical cancer incidence and mortality after the implementation of a national preventive effort in Korea. Cervical cancer incidence data from 1999 to 2011 and mortality data from 1983 to 2013 were collected from the Korean Statistical Information Service. Yearly age-standardized rates (ASR) per 100,000 were compared using two standards: the 2005 Korean population and the world standard population, based on Segi’s world standard for incidence and the World Health Organization for mortality. In Korea, the age-standardized incidence of cervical cancer per 100,000 persons declined from 17.2 in 2000 to 11.8 in 2011. However, the group aged 25 to 29 showed a higher rate in 2011 (ASR, 6.5) than in 2000 (ASR, 3.6). The age-standardized mortality rate per 100,000 persons dropped from 2.81 in 2000 to 1.95 in 2013. In the worldwide comparison, the incidence rates remained close to the average incidence estimate of more developed regions (ASR, 9.9). The decreasing mortality trend in Korea approached the lower rate observed in Australia (ASR, 1.4) in 2010. Although the incidence rate of cervical cancer is continuously declining in Korea, it is still high relative to other countries. Moreover, incidence and mortality rates in females aged 30 years or under have recently increased. It is necessary to develop effective policy to reduce both incidence and mortality, particularly in younger age groups.

Upregulation of Periostin and Reactive Stroma Is Associated with Primary Chemoresistance and Predicts Clinical Outcomes in Epithelial Ovarian Cancer

PURPOSE

Up to one third of ovarian cancer patients are intrinsically resistant to platinum-based treatment. However, predictive and therapeutic strategies are lacking due to a poor understanding of the underlying molecular mechanisms. This study aimed to identify key molecular characteristics that are associated with primary chemoresistance in epithelial ovarian cancers.

EXPERIMENTAL DESIGN

Gene expression profiling was performed on a discovery set of 85 ovarian tumors with clinically well-defined response to chemotherapies as well as on an independent validation dataset containing 138 ovarian patients from the chemotreatment arm of the ICON7 trial.

RESULTS

We identified a distinct "reactive stroma" gene signature that is specifically associated with primary chemoresistant tumors and was further upregulated in posttreatment recurrent tumors. Immunohistochemistry (IHC) and RNA in situ hybridization (RNA ISH) analyses on three of the highest-ranked signature genes (POSTN, LOX, and FAP) confirmed that modulation of the reactive stroma signature genes within the peritumoral stromal compartments was specifically associated with the clinical chemoresistance. Consistent with these findings, chemosensitive ovarian cells grown in the presence of recombinant POSTN promoted resistance to carboplatin and paclitaxel treatment in vitro. Finally, we validated the reactive stroma signature in an independent dataset and demonstrated that a high POSTN expression level predicts shorter progression-free survival following first-line chemotherapy.

CONCLUSIONS

Our findings highlight the important interplay between cancer and the tumor microenvironment in ovarian cancer biology and treatment. The identified reactive stromal components in this study provide a molecular basis to the further development of novel diagnostic and therapeutic strategies for overcoming chemoresistance in ovarian cancer.

Trends in gynecologic cancer mortality in East Asian regions

OBJECTIVE

To evaluate uterine and ovarian cancer mortality trends in East Asian countries.

METHODS

For three Asian countries and one region (Japan, Korea, Singapore, and Hong Kong), we extracted number of deaths for each year from the World Health Organization (WHO) mortality database, focusing on women ≥20 years old. The WHO population data were used to estimate person-years at risk for women. The annual age-standardized, truncated rates were evaluated for four age groups. We also compared age-specific mortality rates during three calendar periods (1979 to 1988, 1989 to 1998, and 1999 to 2010). Joinpoint regression was used to determine secular trends in mortality. To obtain cervical and uterine corpus cancer mortality rates in Korea, we re-allocated the cases with uterine cancer of unspecified subsite according to the proportion in the National Cancer Incidence Databases.

RESULTS

Overall, uterine cancer mortality has decreased in each of the Asian regions. In Korea, corrected cervical cancer mortality has declined since 1993, at an annual percentage change (APC) of -4.8% (95% confidence interval [CI], -5.3 to -4.4). On the other hand, corrected uterine corpus cancer mortality has abruptly increased since 1995 (APC, 6.7; 95% CI, 5.4 to 8.0). Ovarian cancer mortality was stable, except in Korea, where mortality rates steadily increased at an APC of 6.2% (95% CI, 3.4 to 9.0) during 1995 to 2000, and subsequently stabilized.

CONCLUSION

Although uterine cancer mortality rates are declining in East Asia, additional effort is warranted to reduce the burden of gynecologic cancer in the future, through the implementation of early detection programs and the use of optimal therapeutic strategies.

Risk factors associated with human papillomavirus infection status in a Korean cohort

By surveying extensive epidemiological behavioural and sexual risk factors in a Korean twin cohort, risk factors for human papillomavirus (HPV) infection were investigated in South Korea. A total of 912 vaginal specimens were collected from the Healthy Twin Study, consisting of twins and their families. A range of epidemiological, behavioural, and sexual activity characteristics were evaluated using multivariate logistic regression analyses of family and twin relationships, adjusted to elucidate the risk factors for HPV infection. Of the various epidemiological characteristics, the possibility of extramarital affairs [odds ratio (OR) 2·48, 95% confidence interval (CI) 1·02-6·02] significantly increased the prevalence of HPV infection. Our multivariate regression analysis indicated that oral contraceptive use (OR 40·64, 95% CI 0·99-1670·7) and history of sexually transmitted disease (OR 2·56, 95% CI 0·93-7·10) were strongly associated with an increase in HPV infection. On the other hand, more frequent vaginal douching (OR 0·32, 95% CI 0·13-0·77) significantly decreased the prevalence of HPV infection. Our results suggested that HPV infection is associated with both biological and behavioural factors.

Prevalence of human papillomavirus infection and genotype distribution determined by the cyclic-catcher melting temperature analysis in Korean medical checkup population

Although cytology screening has reduced the incidence and mortality rate of cervical cancer significantly, its usefulness is limited to samples from the site of the lesion, resulting in its low sensitivity and unsuitability for use in medical checkups. The purpose of the present study was to evaluate the prevalence of HPV infection using genotype distribution and to analyze the correlation of the HPV DNA test results with cytological results. We also evaluated the benefits of quantitative information obtained from cyclic-catcher melting temperature analysis (CMTA) in screening for cervical cancer. We performed cyclic-CMTA using Anyplex™ II HPV28 Detection in combination with cervical cytology for 2,181 subjects. The following HPV positivity types were detected using cyclic-CMTA and HPV positivity was found to increase together with the severity of the cytology results: (1) For 419 HPV positive specimens, HPV DNA was detected in 18.1% of normal specimens, 78.3% of ASCUS, and all of LSIL and HSIL; (2) high-risk HPV DNAs were detected in 63.3% of normal (N=547), 65.9% of ASCUS (N=41), 76.9% of LSIL (N=13), and 88.9% of HSIL (N=9) among total detected HPV DNA regardless multiple detection; (3) multiple HPV genotypes were detected in 4.8% of normal specimens (N=2,146), 52.2% of ASCUS (N=23), 57.1% of LSIL (N=7), and 40.0% of HSIL (N=5). In addition, a high level of viral DNA was observed using cyclic-CMTA in all specimens beyond the LSIL stage according to cytology, while only 6% of specimens with normal cytology showed a correlation with viral quantitation by cyclic-CMTA. The combination of HPV genotyping with a quantitative assay and cytology will allow for a more accurate diagnosis of cervical cancer.

Trends in Cervical Cancer Mortality by Socioeconomic Status in Korean Women between 1998 and 2009

Background

Death from uterine cervical cancer could be preventable by an active participation of women at risk in a screening program such as the Papanicolaou test. In order to examine the presence of socioeconomic disparity in preventable deaths, we evaluated the time trends of cervical cancer mortality by socioeconomic status in Korean women.

Methods

We selected level of educational attainment and marital status as surrogate indices of socioeconomic status. Using death certificate data and Korean Population and Housing Census data from Korea National Statistical office, we calculated age-standardized yearly mortality rates from cervical cancer between 1998 and 2009 according to the level of education as well as marital status.

Results

Cervical cancer mortality peaked in 2003 and then decreased gradually over time. Cervical cancer mortality was the highest in the group with the lowest level of educational attainment in all age groups and the gap between the lowest and the highest educational level has increased over time. Cervical cancer mortality was lower in married women than unmarried women in all age groups, and the degree of difference did not change over time.

Conclusion

In the Korean population, socioeconomic differential in cervical cancer mortality has persisted over time.

Methylenetetrahydrofolate reductase C677T polymorphism and susceptibility to cervical cancer and cervical intraepithelial neoplasia: a meta-analysis

Background

A number of studies have explored the association between methyl enetetrahydrofolate reductase (MTHFR) C677T polymorphism and susceptibility to cervical cancer and cervical intraepithelial neoplasia (CIN). However, results remained controversial. To address this gap, we decided to conduct a meta-analysis of all available published studies.

Methods

Electronic literature searches of the PubMed, EmBase and Medline databases were performed up to April 30, 2012. Fixed-effects or random-effects model was used to calculate the pooled ORs for different genetic models.

Results

A total of 12 case-control studies were ultimately identified. No statistical correlation was found between C677T variants and cervical cancer for the overall population. However, subgroup analyses on the White women pointed to a significant protective effect for individuals heterozygous or homozygous for the T-allele (for CT vs. CC: OR = 0.72, 95% CI 0.59–0.88; for TT vs. CC: OR = 0.69, 95% CI = 0.49–0.97; for CT+TT vs. CC: OR = 0.71, 95% CI 0.59–0.86). C677T variants were associated with neither combined nor stratified CIN among the overall population.

Conclusions

This meta-analysis suggests that White women with mutant C677T genotypes might have a lower risk of cervical cancer, yet lacking enough statistical robustness. Further investigations are needed to get more insight into the role of this polymorphism in cervical carcinogenesis.

Performance of papanicolaou testing and detection of cervical carcinoma in situ in participants of organized cervical cancer screening in South Korea

Background

The present study measured the performance of the Papanicolaou (Pap) test and detection of cervical carcinoma in situ (CIS) and cancer in participants of organized cervical cancer screening in South Korea, and examined differences in the proportion of CIS according to socio-demographic factors.

Methods

Data were obtained from the National Cancer Screening Program and National Health Insurance Cancer Screening Program databases. We analyzed data from 4,072,997 screenings of women aged 30 years or older who underwent cervical cancer screening by Pap test between January 1, 2005 and December 31, 2006. We calculated the performances of the Pap test and compared that according to socio-demographic factors.

Results

The positivity rate for all screenings was 6.6%. The cancer detection rate (CDR) and interval cancer rate (ICR) were 0.32 per 1,000 screenings, and 0.13 per 1,000 negative screenings, respectively. About 63.4% of screen-detected CIS+ cases (CIS or invasive cervical cancer) were CIS. The CDR and ICR, and percentage of CIS among all CIS+ were significantly different by age group and health insurance status. The odds ratios of CDR and ICR were higher for Medical Aid Program (MAP) recipients compared with National Health Insurance (NHI) beneficiaries. The likelihood of a detected CIS+ case to be CIS was significantly lower among MAP recipients than among NHI beneficiaries.

Conclusions

The difference in performance of cervical cancer screening among different socio-demographic groups may indicate an important influence of socio-demographic factors on preventive behavior. The findings of the study support the critical need for increasing efforts to raise awareness and provide more screening in at-risk populations, specifically low-income groups.

Current status of the National Cancer Screening Program for cervical cancer in Korea, 2009

Objective

The National Cancer Screening Program (NCSP) began in 1999. In this report, we evaluate the results of the NCSP for cervical cancer in 2009 and provide participation rates in an organized cervical cancer screening program in Korea.

Methods

Using data obtained from the National Cancer Screening Information System, cervical cancer screening participation rates were calculated. Recall rates, defined as the proportion of abnormal cases among women screened, were also estimated with 95% confidence intervals.

Results

The target population of cervical cancer screening in 2009 included 4,577,200 Korean women aged 30 and over, 1,349,668 of whom underwent the Papanicolaou smear test (29.5% participation rate). Compared with the participation rate of women covered by the National Health Insurance Program (31.3%), the participation rate of women covered by the Medical Aid Program was lower (18.4%). Participation rates also varied in different age groups (the highest of 39.3% in women aged 50 to 59 and the lowest of 14.4% in those aged 70 and older), and different areas (the highest of 34.1% in Busan and the lowest of 21.5% in Chungnam). The overall recall rate for cervical cancer screening was 0.41% (95% confidence interval, 0.40 to 0.42).

Conclusion

According to our study, efforts to facilitate participation and reduce disparities in cervical cancer screening among Korean women are needed.

Human papillomavirus 16/18 AS04-adjuvanted cervical cancer vaccine: immunogenicity and safety in 15-25 years old healthy Korean women

Objective

The study assessed the immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine in healthy Korean women aged 15-25 years.

Methods

Phase IIIB, double-blind, randomised (2:1), multi-centre trial was conducted in Korea from June 2007 to March 2008. The study enrolled 225 women in the HPV (N=149) and placebo (N=76) groups who received three doses of HPV-16/18 AS04-adjuvanted vaccine or placebo (aluminium hydroxide) administered intramuscularly at 0, 1, and 6 months and were followed until one month post-dose 3. Serum samples were collected pre-vaccination and one month post-dose 3. Safety and reactogenicity data were collected throughout.

Results

In this trial, 208 women completed the study (141 in HPV group; 67 in placebo group). At month 7, all initially seronegative women had seroconverted for HPV-16 and HPV-18 antibodies with anti-HPV-16 and anti-HPV-18 geometric mean titres of 9,351.4 El.U/mL (95% CI, 8,145.5 to 10,735.8) and 4204.1 El.U/mL (95% CI, 3,626.5 to 4,873.6), respectively. Initially seropositive women showed similar increase in geometric mean titre levels. Compliance to the three dose vaccination course was 95.3% in HPV and 89.5% in placebo group. Solicited local (pain) and general (fatigue, myalgia or headache) symptoms were commonly reported in both groups. Three serious adverse events were reported (two in HPV group; one in placebo group), all unrelated to vaccination by the investigator; all recovered.

Conclusion

The HPV-16/18 AS04-adjuvanted vaccine was highly immunogenic with a clinically acceptable safety profile in Korean women. This study was in line with previous global studies in Europe, North America, and Brazil. (ClinicalTrials.gov number, NCT 00485732.)

Vaccination with a human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine in Korean girls aged 10-14 years

The human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine has been demonstrated to be highly efficacious and immunogenic with a favorable safety profile. This study assessed the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Korean girls aged 10-14 yr. This multi-center, observer-blind trial randomly assigned 321 healthy girls to receive three doses (0, 1, 6-month schedule) of HPV-16/18 AS04-adjuvanted vaccine or hepatitis A vaccine. Immunogenicity against vaccine antigens was assessed one month post-Dose 3. Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. In the according-to-protocol analysis, all initially seronegative subjects vaccinated with the HPV-16/18 AS04-adjuvanted vaccine had seroconverted at Month 7, with a peak geometric mean titer (GMT) that was 600-fold higher than the natural infection titer of 29.8 EU/mL for HPV-16 and a peak GMT that was 400-fold higher than the natural infection titer of 22.6 EU/mL for HPV-18. The vaccine was well tolerated with no increase in reactogenicity with subsequent doses and no reports of vaccine-related SAEs. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine is shown to be highly immunogenic and generally well-tolerated in Korean girls aged 10-14 yr.

Low initial human papilloma viral load implicates worse prognosis in patients with uterine cervical cancer treated with radiotherapy

PURPOSE

To evaluate whether human papillomavirus (HPV) viral load measured in cervical smear and HPV type 18 are associated with radiotherapy outcomes in uterine cervical cancer. PATIENTS AND METHODS HPV DNA: was semiquantitatively measured in the cervical smears of 169 radiotherapy patients. HPV viral load was classified as low or high according to median HPV DNA titer and examined for its prognostic value. The multivariable Cox proportional hazards model was used to adjust for covariates. A relapse-predicting model was constructed to classify three risk groups for disease-free survival (DFS), which were used for internal validation.

RESULTS

Patients with lower HPV viral load showed worse DFS in univariate analysis. HPV type 18, younger patient age, stage group, nodal status, histologic grade, and histologic type were other prognostic factors for poor DFS. Among these factors, all except stage group were associated with HPV viral load. Multivariate analysis showed the strong influence of HPV viral load for poor DFS. The prognostic model developed using our outcome data performed well in predicting the risk of relapse.

CONCLUSION

Our data suggest that HPV viral load is a strong independent prognostic factor for DFS. HPV type 18 showed a significant relationship with poor radiotherapy outcome in univariate analysis, but not in multivariate analysis.

Current status of cervical cancer and HPV infection in Korea

Cervical cancer is an important cause of cancer-related deaths in women in developing countries. In Korea, cervical cancer is the third leading cancer among females and is fifth highest in mortality. The persistent oncogenic human papillomavirus (HPV) infections are the greatest risk of developing cervical intraepithelial neoplasia and invasive cancer. The overall prevalence of HPV was 10.4% in Korea and strong risk factors for HPV infection included a young age at sexual debut. The National Cancer Screening Program, which includes cervical cancer screening, has the following principles: the main screening tool is the Papanicolaou test conducted by gynecologists, which targets all women age 30 and over, and which is done every 2 years. HPV DNA tests have not yet been permitted as a screening test for cervical cancer in Korea; however, these are conducted along with a Pap test for screening cervical cancer in the clinic. The use of prophylactic HPV vaccine has been accepted in Korea; The Korean Society of Gynecologic Oncology and Colposcopy's recommendation for routine vaccination is for females aged 15-17 years with a catch-up vaccination recommended for females aged 18-26 years who have not been previously vaccinated. However, many people in Korea are not familiar with the HPV vaccine. Therefore, it is necessary to improve awareness for the disease and HPV vaccination and to establish the effective strategies to obtain funding for HPV vaccination. In the future, cervical cancer is expected to disappear throughout the world, including the Asia Pacific region, through a combination of vaccination and qualified screening programs for cervical cancer.

Effectiveness of an organized cervical cancer screening program in Korea: results from a cohort study

Although the value of cervical cancer screening is widely acknowledged, the effectiveness of an organized cervical cancer screening program in Korea has never been evaluated. We investigated the associations of the frequency of cervical cancer screening with cervical cancer incidence using data from a large prospective cohort study. In this analysis, 253,472 women without a hysterectomy or previous cancer diagnosis were included. Follow-up was between 1995 and 2002. Frequency of Pap smear testing was determined by searching the National Health Examination Database. Using the Korean Central Cancer Registry, 248 cases of invasive cervical cancer and 346 cases of carcinoma in situ (CIS) of the cervix were identified. Subjects screened 2 or more times showed a 71% (corrected reduction 60%) and a 66% (corrected reduction 53%) reduced risk of invasive cervical cancer and CIS of the cervix, respectively, as compared with unscreened subjects [relative risk (RR) = 0.29; 95% confidence interval (CI) = 0.20-0.45; RR = 0.34; 95% CI = 0.25-0.46, respectively]. Women with a normal or benign pap smear had a statistically significantly lower risk of invasive cervical cancer and CIS of cervix compared with those never screened. In age-stratified analyses, there was a significant reduction in cervical cancer incidence among women aged 30 and over who were screened 2 or more times compared with women never screened. The results of this prospective cohort study show that regular screening of cervical cancer reduces invasive cervical cancer incidence and CIS of the cervix among Korean women.

Trends in avoidable death over 20 years in Korea

To evaluate the achievement of health care services in Korea independent of other socioeconomic factors, we observed the time trend of avoidable death between 1983 and 2004. A list of avoidable causes of death was constructed based on the European Community Atlas of "Avoidable Death". We calculated sex- and age-standardized mortality rates of Korean aged 1-64 yr using data of the Korea National Statistical Office. The avoidable mortality rate (per 100,000 persons) decreased from 225 to 84 in men and from 122 to 41 in women. Accordingly, the proportion of avoidable deaths among all classifiable deaths was reduced by 8.1% in men and 6.4% in women. However, mortality rates from some preventable causes such as ischemic heart disease and malignant neoplasms of lung, breast, cervix, and colorectum have been on the rise. Mortality preventable by appropriate medical care showed the greatest reduction (by 77.8%), while the mortality preventable by primary prevention showed the least reduction (by 50.0%). These findings suggest that health care service has significantly contributed to the improvement of health in Korea. However, more effective intervention programs would be needed given the less reduction in mortality avoidable by primary or secondary prevention than expected and unexpectedly increasing mortality from several preventable causes.