Cervical cancer incidence in Denmark over six decades (1943-2002)

INTRODUCTION: The purpose of the study was to describe developments in the incidence of invasive cervical cancer in Denmark, focusing on histological types, over a period of 60 years. We also describe developments in the incidence of carcinoma in situ and mortality. MATERIAL AND METHODS: The study is based on the Danish Cancer Registry database of 39,623 reported cases of invasive cervical cancer diagnosed among Danish women in the period 1943-2002. The most important variables and measures are age-specific and age-standardized incidence and estimated annual percent changes in incidence. RESULTS: A significant reduction in incidence of invasive squamous cell carcinoma among women over 30 during the last 35 years and in incidence of invasive adenocarcinoma among women over 40 during the last 15 years has been seen. In both histological subgroups the relative estimated annual percent change in incidence was largest in the period 1988-2002 as compared to 1968-1987, coinciding with an increase in the number of Danish women covered by the organized screening program. Women 20-29 years old showed a relatively stable squamous cell carcinoma incidence but an increasing adenocarcinoma incidence throughout the study period. CONCLUSIONS: These results suggest that the increasing coverage of the Danish organized screening program is associated with a significant reduction in incidence of invasive squamous cell carcinoma among women over 30, and of invasive adenocarcinoma among women over 40. So far, squamous cell carcinoma incidence and adenocarcinoma incidence among women 20-29 years old seem quite unaffected by the organized screening program.     

Trends in teenage fertility,abortion, and pregnancy rates in Iceland compared with other Nordic countries, 1976-99

BACKGROUND: Iceland is often considered very similar to the other Nordic countries. The purpose of this study was to explore trends in teenage fertility, abortion, and pregnancy rates in Iceland, compare these trends with corresponding rates in Denmark, Finland, Norway, and Sweden during the period 1976-99, and to evaluate similarities and dissimilarities. METHODS: The study is based on data about fertility, abortion, and pregnancy rates obtained from the Icelandic and Nordic national population and abortion registers for the age group 15-19 years years. RESULTS: Teenage fertility and pregnancy rates in the five Nordic countries declined over the study period by 57-67% and 31-50%, respectively, and in Iceland they remained significantly higher than in the Nordic countries. In 1999 almost every other teenage pregnancy in Iceland (45.9/1000) resulted in a childbirth (24.4/1000). Regional fertility rates were highest in the countryside. While the abortion rate has been declining in the four Nordic countries by 20-41%, they have concurrently been rising in Iceland by 133% (9.4/1000 in 1976-80, 21.9/1000 in 1996-99) and are presently higher than in the other Nordic countries. Regionally, abortion rates in Iceland were highest in the Capital area. CONCLUSIONS: The teenage pregnancy rate is higher in Iceland than in the other Nordic countries. This may be explained by cultural norms in Iceland's society regarding childbearing, early initiation of sexual intercourse, more limited sex education, and less effective delivery and use of contraceptive methods. There is a need to promote sexual and reproductive health to young people in Iceland by combining diverse preventive approaches.     

Supravaginal uterine amputation in Denmark 1978-1988 and risk of cancer.

In Denmark, total rather than subtotal hysterectomy has been recommended as treatment for benign conditions of the uterine corpus, primarily due to the risk of cervical cancer in the residual stump. Due to possible benefits during and after surgery, it has recently been argued that total hysterectomy for benign conditions could be substituted by subtotal hysterectomy, particularly since cancers of the cervix are declining as a consequence of screening. Cancer risk following supravaginal uterine amputation among 1104 Danish women undergoing operations during 1978-1988 was studied using record linkage techniques with the Danish Cancer Registry. No overall cancer risk, nor an overall increased risk of cancers coded as cervical, was observed. However, a 3.3 to 5.0-fold increased risk for cervical cancer was observed among women whose operations occurred at 50 years of age or older, possibly reflecting an increased risk of cancer in the endocervical area or in remaining uterine tissue. This observation, together with the difficulties in treating a cervical cancer of the stump when it does occur, should be taken into account before a change in surgical procedures from total to subtotal hysterectomies is recommended.     

Trends in the mortality of chronic obstructive pulmonary disease in Taiwan, 1981-2002.

BACKGROUND AND PURPOSE: The reported prevalence, morbidity and mortality of chronic obstructive pulmonary disease (COPD) varies in different countries due to actual differences and to differences in classification criteria. This study analyzed the trends in COPD mortality and its rank among leading causes of death in Taiwan. METHODS: Using national mortality and population data, we identified COPD as a cause of death according to codes 490 (bronchitis, not specified as acute or chronic), 491 (chronic bronchitis), 492 (emphysema) as has been officially calculated previously in Taiwan, and by adding code 496 (chronic airway obstruction, not elsewhere classified) of the ninth revision of the International Classification of Diseases (ICD-9). We calculated crude, age-adjusted and age-specific mortality rates and analyzed the rank of COPD as a cause of death for the period from 1981 to 2002. RESULTS: Crude COPD mortality was unchanged from 1981 to 1993 at 8.26 to 8.47 deaths per 100,000 population, and steadily increased thereafter to 17.88 per 100,000 in 2002. After age standardization, mortality decreased from 8.26 to 4.91 per 100,000 population from 1981 to 1993 and then increased to a peak of 7.36 per 100,000 in 1999. This increase was due to greater increase in mortality in men. COPD mortality decreased steadily throughout the study period in those younger than 65 years while in older groups, it decreased during 1981-1991 and then increased. ICD-9 code A323 (including codes 490-493) has been previously used in official mortality data for asthma, chronic bronchitis and emphysema in Taiwan without inclusion of a specific code for chronic airway obstruction. According to our analysis, this method underestimated two-thirds of real overall mortality due to COPD and asthma. By including COPD and asthma, the obstructive airway disease category increased from 11th to sixth as a cause of death in 2002. CONCLUSIONS: In Taiwan, mortality rates for COPD decreased from 1981 to 1993 and increased thereafter, which is largely attributable to increased rates in men. COPD is increasingly important and a leading cause of death in Taiwan.     

Improved survival of patients with ovarian cancer in Northern Denmark, 1985-2004

OBJECTIVE: Ovarian cancer is a serious disease with a high mortality. Our aim was to examine changes in the survival of patients with ovarian cancer in Northern Denmark. STUDY DESIGN AND SETTING: Patients (no. = 3,719) with an incident discharge diagnosis of ovarian cancer (1985-2004) from any hospital in four Danish counties (population, 1.6 million) were included and tracked for mortality through the Danish Civil Registration System. We determined survival and mortality rates stratified by age, and used Cox proportional hazard regression analyses to assess changes over time. RESULTS: Overall survival rate improved between 1985 and 2004. One-year survival increased from 61% to 73%, and five-year survival from 30% to 38%. Compared with the period 1985-1989 the age-adjusted one-year mortality rate ratio (MRR) was 0.65 (2000-2004) and the age-adjusted five-year MRR was 0.80 (1995-1999). The improvement was most pronounced in patients older than 40 years. CONCLUSION: The survival of ovarian cancer patients has improved in Denmark in recent decades. This change may be the result of improved treatment.     

Changing incidence of anal sphincter tears in four Nordic countries through the last decades

Objectives

Anal sphincter rupture is a serious complication of a vaginal delivery. A considerable number of women suffer permanent anal incontinence after this type of injury. The incidence of sphincter tears is believed to have increased over several decades in Denmark, Norway, Sweden and Finland, but there seem to be significant differences in the incidence rates among these countries. The aim of this study is to compare frequency of anal sphincter tears among the four Nordic countries, and to discuss the possible reasons for the development.

Study design

Ecological register study. Anal sphincter ruptures are registered as third and fourth degree perineal tears in the national birth and hospital registries in the Nordic countries. Data from these registries were sampled from Denmark, Finland, Norway and Sweden. The incidences of anal sphincter ruptures were calculated as percentages of all vaginal deliveries and caesarean sections were excluded. The test of relative proportions, Chi-square and linear regression modelling were used to study the difference between countries and time trends.

Results

The frequency of anal sphincter rupture was significantly higher in three countries, Denmark 3.6%, Norway 4.1% and Sweden 4.2%, compared to Finland 0.6%. The trend was clearly increasing from the early 1970s in all countries.

Conclusions

There is a significant difference in the Nordic countries in the incidence of anal sphincter tears and a significant increment in the incidence over three decades. Our hypothesis is that change in the routines during labour may be one reason for this increment. Higher episiotomy frequency in Finland may be one contributing reason. We assume that there has been a change in the conduct of labour during the last decades, and protecting the perineum may have lost its importance in the three Nordic countries, while the classic method of protecting perineum is still in use in Finland.     

Strengthening prevention programs to eliminate cervical cancer in the Nordic countries

Disease trend studies based on birth cohort analysis and serological studies indicate that recent generations have a higher prevalence of oncogenic Human Papilloma Virus (HPV) types, and are likely to be at higher risk of cancer than previous generations. This implies that prevention strategies to protect young populations from HPV-associated cancers need to be strengthened, and hence organized implementation of vaccination and better screening programs are being considered. In this context, randomized large-scale policy evaluations will be instrumental in accelerating disease control and improve effective prevention programs. This report shares experiences from Nordic countries with examples of prevention strategies through vaccination and cervical screening. The same principles as set up for organized programs and new HPV technologies may apply for screening and vaccination as key tools to eliminate cervical cancer in the Nordic countries and globally.     

The Icelandic and Nordic cervical screening programs: trends in incidence and mortality rates through 1995.

BACKGROUND: The objective of cervical cancer screening is to lower the incidence and mortality rates of the disease. This study evaluates the effectiveness of cervical screening and the UICC and EC screening recommendations based on the Nordic screening experience. METHODS: The study analyzes the features of the Icelandic and the Nordic screening programs and the observed trends in the incidence and mortality rates in these countries through 1995. RESULTS: Organized screening started in all the Nordic countries soon after 1960 and had nation-wide coverage in all these countries, except in Denmark (45% coverage in 1991), by around 1973 but in Norway screening was only spontaneous up to late in 1994. Up to 1985 the target age group and screening interval were most intensive in Iceland, followed by Finland, Sweden and Denmark. All countries except Finland lowered the lower age limit and intensified the screening intervals after 1985. Through the period 1986-1995 the reduction in both the mortality and the incidence rates was greatest in Iceland (mortality: 76% and incidence: 67%) and Finland (73% and 75%, respectively), intermediate in Sweden (60% and 55%, respectively) and Denmark (55% and 54%, respectively), and lowest in Norway (43% and 34%, respectively). The age-specific incidence in the 20-29 age group has been increasing since 1971 in all the Nordic countries, except in Finland, where the yearly registered age-specific incidence has been increasing in the targeted 30-54 age group since 1991. In Iceland screening has greatly affected the rate of all stages of squamous cell carcinoma, but not the rate of adeno- and adenosquamous carcinomas. In fact the rate of adenocarcinoma has been increasing. CONCLUSIONS: Organized screening is more effective than spontaneous screening in reducing the risk of cervical cancer. Although differences in environmental, biological and ethnic factors may call for different screening strategies, screening should preferably start soon after age 20 with a screening interval of 2-3 years.     

Effectiveness of cervical cancer screening in Iceland, 1964-2002: a study on trends in incidence and mortality and the effect of risk factors

BACKGROUND: Data on cervical cancer screening programs that have covered a whole nation over a prolonged time are scarce. The effectiveness of a 40-year established nationwide cervical screening program has been evaluated to define optimal age limits and screening intervals. METHODS: Trends in incidence and mortality by calendar time, age, histology, stage and attendance during 1964-2002 and the predictive power of calendar year, age, stage and histology on the cause-specific mortality rate were analyzed. RESULTS: The rate of squamous cell carcinoma decreased significantly, but the rate of adenocarcinoma increased. The age-specific incidence and cause-specific mortality decreased significantly for all age groups except those women aged 20-29 years. An increased age-specific incidence rate, confined to stage I, was observed in the age group 20-39 years after 1980 and a positive correlation was observed between early attendance and the rate of microinvasive squamous (stage IA) cell carcinoma and adenocarcinoma in this age group. The cumulative incidence of invasive disease started to increase two years after the last negative smear. Stage was the strongest risk factor, followed by age and calendar time, and to a lesser degree histology. CONCLUSIONS: The results confirm the effectiveness of the screening program and support the recommendation that screening should commence below age 25 with a maximum of 3-year initial screening intervals. The interval can then be extended after age 40 and stopped after age 65.     

Trends in the incidence of ovarian cancer in a heterogenic population (1960–1976)

Data of an epidemiologic study of ovarian cancer in Israel are presented. During the 5-year period of this survey, 1001 new cases of primary cancer of the ovary were diagnosed. The findings are compared with those of two previous surveys covering the periods 1960-1965 (746 cases) and 1966-1971 (911 cases). The incidence during the 17-year period ranged between 15 and 19/100,000 women over the age of 15. The disease was three to five times more prevalent in women of European/American origin than in those of Asian/African descent. Seventy-five percent of the patients were between the ages of 45 and 74. The majority (50-71%) were already in stage III or stage IV at diagnosis. Factors affecting the prognosis are the age of the patient and clinical stage of the malignancy when first diagnosed, histology of the tumor, and type of treatment. Although the time interval between onset of the disease and its detection has remained protracted, the 5-year survival rate was improved from 15% during the period 1960-1965 to 31% between the years 1972-1976. This favorable trend is to be ascribed to new treatment modalities.     

Urban-rural differences in gynaecological cancer occurrence in a central region of Italy: 1978-1982 and 1998-2002

Differences in gynaecological cancer incidence and mortality in the urban and rural areas of the Umbria region (central Italy) were investigated. All women with primary invasive breast cancers, uterine cervix and uterine corpus, and ovarian cancers diagnosed during the periods 1978-1982 and 1998-2002 were identified and analysed according to place of residence (either urban or rural). Mortality data were supplied by the National Institute of Statistics (ISTAT) for the period 1978 to 1982, whereas for the 1994-2002 period they were supplied by the Regional Nominative Causes of Death Registry (ReNCaM). Incident cases considered were taken from an ad hoc survey for the first period and from the Umbrian Population Cancer Registry database for the second one. For each site the age-adjusted incidence (AAIR) and mortality (AADR) rates were calculated. The expected number of rural cases was obtained from indirect standardisation with urban incidence and mortality rates of several sites. The significance of the observed expected ratios (SIRs for incidence and SMRs for mortality) and the corresponding 95% confidence intervals were based on the Poisson distribution. Urbanisation levels were established following the classification of the Italian Institute of Statistics. For all sites, excluding the ovary during the most recent period, the SIR relative to rural areas was below 1, but the rates were statistically significant only for breast cancer in both periods (SIR 0.81, 95% CI 0.74-0.88 and SIR 0.82, 95% CI 0.77-0.88, respectively) and for cervix uteri in the first period (SIR 0.77, 95% CI 0.59-0.94). The lower breast cancer incidence in the rural area could also be due to lesser compliance with screening procedures which, up until 2002, were not provided in the form of mass-screenings throughout the region by the Regional Health Department. These results underscore the need for continued efforts to provide preventive health services to medically underserved women throughout Umbria, including rural communities. Underutilisation of preventive healthcare services may result in failure to identify healthcare problems that might be successfully managed with medication or lifestyle changes, as well as missed opportunities to prevent potentially life-threatening diseases.     

Gynaecological cancers in Umbria (Italy): trends of incidence, mortality and survival, 1978-1998

OBJECTIVE: For the period 1978-1998 incidence, mortality and survival from gynaecological cancers in the Umbria region (Central Italy) were examined. STUDY DESIGN: Mortality data were derived from the National Institute of Statistics while incidence and survival data were provided by an ad hoc survey carried out over the period 1978-1982 and by the Umbrian Population-Based Cancer Registry operating since 1994. Age-standardised mortality and incidence rates were calculated. Survival was assessed using the Estève method. Mortality trends were analysed by joinpoint regression model. RESULTS: In the Umbria Region, over the period 1978-1998, the incidence rate of cervical cancer decreased, while those for endometrial and ovarian cancers rose. By contrast, the mortality rates from ovarian and endometrial cancers decreased, while that for cervical cancer rose slightly. Comparing relative survival rates, at 5 years an increase in survival was reported for ovarian cancer, cervical cancer remained constant and endometrial cancer slightly decreased; at 1 year only the ovarian cancer survival improved. Nevertheless, age-standardised survival rates showed that survival improved in all examined sites. CONCLUSIONS: The improvement in diagnosis and in data coding could have determined an increase in endometrial and ovarian cancer incidence, while the dramatic decrease in cervical cancer incidence is probably due to the effectiveness of cervical screening.     

Patterns in the incidence of age-related ovarian cancer in South East England 1967-1996

Objective To study the age-related trends in the incidence rates of ovarian cancer in South East England between 1967 and 1996.
Design A retrospective review of systematically collected data on ovarian cancer in South East England.
Methods Data were obtained from the Thames Cancer Registry on the numbers and rates per 100,000 population of ovarian cancer per five-year age group (0–85+) in the 30-year period from 1967 to 1996 from the 26 health authorities in the Thames region. Linear regression was performed to determine the changes in incidence rates of ovarian cancer per age group over time.
Main outcome measures The change in overall incidence of ovarian cancer in South East England, as well as the change in incidence of ovarian cancer in each five-year age groups (20–85+) in the 30-year study period.
Results There was a strong positive correlation between ovarian cancer rates and year of diagnosis in women aged ≥ 70 years, and this was particularly marked in women > 85 years of age. There was a negative correlation between rates and year of diagnosis in women aged 45–59 years. The analysis did not demonstrate a significant correlation between ovarian cancer rates and year of diagnosis in women < 44 years of age or women aged 60–69 years.
Conclusions There have been significant changes in the pattern of ovarian cancer incidence in South East England during the 30-year period studied. The observed changes in ovarian cancer incidence in younger women may, in part, be explained by known reproductive factors. The rise in ovarian cancer rates among the older age group is difficult to explain, but has important implications for the future planning and provision of cancer services.