Total and partial cancer prevalence in the adult French population in 2008.

BACKGROUND: To provide estimations of partial and total prevalence of 24 cancer sites in France in 2008. The estimations of partial prevalence were compared with the previous estimations for 2002. METHODS: Nationwide estimations of incidence and survival data from cancer registries were used for partial prevalence. Nationwide incidence and mortality data were used to estimate total prevalence. RESULTS: At the end of 2008, in France, nearly 3 million people still alive had received a diagnosis of cancer. Of all prevalent cases, 36% were diagnosed 0 to 5 years earlier and 43% diagnosed 6 to 10 years earlier. The cancer sites with the highest prevalence were the prostate, the breast, and the colon-rectum. The changes in partial prevalence over 5 years (2002 to 2008) were considerable (+244,000 cases) and deemed to be highly related to changes in incidence. CONCLUSION: The present estimations update the French prevalence data and highlight the burden of cancer in the population, especially in the elderly. The methods of this study had the advantage of using recent incidence and survival data, which is necessary to show sudden changes in incidence trends and changes in survival that impact prevalence.

Cancer incidence in a chlorochemical plant in Isère, France: an occupational cohort study, 1979-2002.

BACKGROUND: A major French chlorine chemical plant (chlor-alkali process with diaphragm cell and manufacturing of organochlorine chemicals) has used or produced known or suspected carcinogenic compounds. METHODS: A cohort study, based on the plant occupational health service and the regional cancer registry, analyzed the standardized incidence ratios of malignant tumors for the period 1979-2002. Individual exposures were estimated from workers' occupational histories in a dual division of jobs into 9 sectors and 115 workshops with known exposures. RESULTS: Men (2,742) were followed, corresponding to 52,794 person-years. Primary tumors (304) were observed for 290 expected cases, a non-significant 5% excess. A significant excess was found of pleural mesothelioma and bladder cancer in employees hired before 1964. CONCLUSION: Excesses of mesothelioma and bladder cancer were found, whereas there was no excess of hematopoietic cancers despite high benzene and dioxin exposures. Surprisingly, mesothelioma cases did not include workers who were the most exposed to asbestos.

Risk factors for breast cancer among Filipino women in Manila.

Age-adjusted incidence rates of breast cancer vary greatly worldwide with highest rates found in the typically 'westernised' countries of North America and Europe. Much lower rates are observed in Asian and African populations but an exception to this has been reported for the Manila Cancer Registry in the Philippines. The reason for this high rate is unknown but may be associated with the change in lifestyle that has occurred in urban Manila since the 1960s. In 1995, a randomised controlled trial was set up in Manila to evaluate the feasibility of a screening intervention by clinical breast examination as an alternative to mammography. The cohort of 151,168 women was followed-up to 2001 for cancer incidence and a nested case-control study carried out. This aimed to evaluate the increase in breast cancer risk associated with known risk factors. Increased risks were seen for a high level of education (OR = 1.9 95%CI 1.1-3.3 for education stopped at > or =13 versus <13 years), nulliparity (OR = 5.0 95% CI 2.5-10.0 for nulliparity versus five or more children), and late age at first birth (OR = 3.3 95% CI 1.3-8.3 for age > or =30 versus <20 years). We found no association with excess body weight, height, use of exogenous hormones or alcohol consumption. From this study, the recognised "classical" risk factors do not fully explain the high breast cancer incidence in Metro Manila, especially when compared to other urban Asian populations. We conclude that it is too simplistic to ascribe the high risk to 'westernisation'.

Cancer prevalence in France: time trend, situation in 2002 and extrapolation to 2012.

BACKGROUND: Cancer prevalence is a basic indicator of the cancer burden in a population and essential to estimate the resources needed for care of cancer patients. This paper provides a prevalence estimate for 2002 and 2012 in France and an assessment of the trend in prevalence over the period 1993-2002. METHOD: Incidence and survival data from French cancer registries were used to estimate specific 5-year partial prevalence rates that were then applied to the whole French population. RESULTS: In 2002, the 5-year partial prevalence was over 427,000 in men and 409,000 in women. The most frequent cancer site among men was prostate (35% of the cases) and breast in women (45% of the cases). In 2002, in France, more than 3.5% of men over 74 years old are alive with a prostatic cancer diagnosed within 5 years. The increase in the number of cases between 1993 and 2002 was about 40% and was mainly due to prostate and breast cancers. The demographic variations alone induce an increase of the number of prevalent cases of 75,000 among men and 54,500 among women if both incidence and survival are considered as stable during the period 2002-2012. CONCLUSION: This study uses a large amount of information from cancer registries which makes it possible to assess the cancer burden. Five-year prevalence is very sensitive to changes in incidence and demographic changes. Prevalence has to be estimated regularly in order to ensure accurate medical care meets demand.

Lung cancer in French and Czech uranium miners: Radon-associated risk at low exposure rates and modifying effects of time since exposure and age at exposure.

Radon is recognized as a public health concern for indoor exposure. Precise quantification derived from occupational exposure in miners is still needed for estimating the risk and the factors that modify the dependence on cumulated exposure. The present paper reports on relationship between radon exposure and lung cancer risk in French and Czech cohorts of uranium miners (n = 10,100). Miners from these two cohorts are characterized by low levels of exposure (average cumulated exposure of less than 60 WLM) protracted over a long period (mean duration of exposure of 10 years) and by a good quality of individual exposure estimates (95% of annual exposures based on radon measurements). The modifying effect of the quality of exposure on the risk is analyzed. A total of 574 lung cancer deaths were observed, which is 187% higher than expected from the national statistics. This significantly elevated risk is strongly associated with cumulated radon exposure. The estimated overall excess relative risk per WLM is 0.027 (95% CI: 0.017-0.043, related to measured exposures). For age at exposure of 30 and 20 years since exposure, the ERR/WLM is 0.042, and this value decreases by approximately 50% for each 10-year increase in age at exposure and time since exposure. The present study emphasizes that the quality of exposure estimates is an important factor that may substantially influence results. Time since exposure and simultaneously age at exposure were the most important effect modifiers. No inverse exposure-rate effect below 4 WL was observed. The results are consistent with estimates of the BEIR VI report using the concentration model at an exposure rate below 0.5 WL.

Cancer incidence estimation at a district level without a national registry: a validation study for 24 cancer sites using French health insurance and registry data.

BACKGROUND: District-level cancer incidence estimation is an important issue in countries without a national cancer registry. This study aims to both evaluate the validity of district-level estimations in France for 24 cancer sites, using health insurance data (ALD demands--Affection de Longue Durée) and to provide estimations when considered valid. Incidence is estimated at a district-level by applying the ratio between the number of first ALD demands and incident cases (ALD/I ratio), observed in those districts with cancer registries, to the number of first ALD demands available in all districts. These district-level estimations are valid if the ratio does not vary greatly across the districts or if variations remain moderate compared with variations in incidence rates. METHODS: Validation was performed in the districts covered by cancer registries over the period 2000-2005. The district variability of the ALD/I ratio was studied, adjusted for age (mixed-effects Poisson model), and compared with the district variability in incidence rate. The epidemiological context is also considered in addition to statistical analyses. RESULTS: District-level estimation using the ALD/I ratio was considered valid for eight cancer sites out of the 24 studied (lip-oral cavity-pharynx, oesophagus, stomach, colon-rectum, lung, breast, ovary and testis) and incidence maps were provided for these cancer sites. CONCLUSION: Estimating cancer incidence at a sub-national level remains a difficult task without a national registry and there are few studies on this topic. Our validation approach may be applied in other countries, using health insurance or hospital discharge data as correlate of incidence.

Joint use of epidemiological and hospital medico-administrative data to estimate prevalence. Application to French data on breast cancer.

BACKGROUND: Estimate complete, limited-duration, and hospital prevalence of breast cancer in a French Département covered by a population-based cancer registry and in whole France using complementary information sources. METHODS: Incidence data from a cancer registry, national incidence estimations for France, mortality data, and hospital medico-administrative data were used to estimate the three prevalence indices. The methods included a modelling of epidemiological data and a specific process of data extraction from medico-administrative databases. RESULTS: Limited-duration prevalence at 33 years was a proxy for complete prevalence only in patients aged less than 70 years. In 2007 and in women older than 15 years, the limited-duration prevalence at 33 years rate per 100,000 women was estimated at 2372 for Département Isère and 2354 for whole France. The latter rate corresponded to 613,000 women. The highest rate corresponded to women aged 65-74 years (6161 per 100,000 in whole France). About one third of the 33-year limited-duration prevalence cases were diagnosed five years before and about one fourth were hospitalized for breast-cancer-related care (i.e., hospital prevalence). In 2007, the rate of hospitalized women was 557 per 100,000 in whole France. Among the 120,310 women hospitalized for breast-cancer-related care in 2007, about 13% were diagnosed before 2004. CONCLUSION: Limited-duration prevalence (long- and short-term), and hospital prevalence are complementary indices of cancer prevalence. Their efficient direct or indirect estimations are essential to reflect the burden of the disease and forecast median- and long-term medical, economic, and social patient needs, especially after the initial treatment.

A Suitable Approach to Estimate Cancer Incidence in Area without Cancer Registry.

Objective. Use of cancer cases from registries and PMSI claims database to estimate Département-specific incidence of four major cancers. Methods. Case extraction used principal diagnosis then surgery codes. PMSI cases/registry cases ratios for 2004 were modelled then Département-specific incidence for 2007 estimated using these ratios and 2007 PMSI cases. Results. For 2007, only colon-rectum and breast cancer estimations were satisfactorily validated for infranational incidence not ovary and kidney cancers. For breast, the estimated national incidence was 50,578 cases and the incidence rate 98.6 cases per 100,000 person per year. For colon-rectum, incidence was 21,172 in men versus 18,327 in women and the incidence rate 38 per 100,000 versus 24.8. For ovary, the estimated incidence was 4,637 and the rate 8.6 per 100,000. For kidney, incidence was 6,775 in men versus 3,273 in women and the rate 13.3 per 100.000 versus 5.2. Conclusion. Incidence estimation using PMSI patient identifiers proved encouraging though still dependent on the assumption of uniform cancer treatments and coding.

Breast cancer incidence using administrative data: correction with sensitivity and specificity.

OBJECTIVE: To estimate breast cancer incidence in the general population using a method that corrects for lack of sensitivity and specificity in the identification of incident breast cancer in inpatient claims data. STUDY DESIGN AND SETTINGS: Two-phase study: phase 1 to identify incident cases in claims data, and phase 2 to estimate sensitivity and specificity in a subset of the population. Two algorithms (1: principal diagnosis; 2: principal diagnosis+specific surgery procedures) were used to identify incident cases in claims of women aged 20 years or older, living in a French district covered by a cancer registry. Sensitivity and specificity were estimated in one district and used to correct incident cases identified. RESULTS: The sensitivity and specificity for algorithms 1 and 2 were 69.0% and 99.89%, and 64.4% and 99.93%, respectively. In contrast to specificity, the sensitivity for both algorithms was lower for women younger than 40 years and older than 65 years. Cases reported by cancer registries were closer to cases identified with algorithm 2 (-3.2% to +20.1%) and to corrected numbers with algorithm 1 (-1% to +15%). CONCLUSION: To obtain reliable estimates of breast cancer incidence in the general population, sensitivity and specificity, which reflect medical and coding practice variations, are necessary.

An update of cancer mortality among the French cohort of uranium miners: extended follow-up and new source of data for causes of death.

The follow-up of the French cohort of uranium miners has been extended to 1994, and a new source of information for causes of death has been used. The paper presents the new results regarding the risk of death among the cohort, and analyses the impact of the methodological changes on these results. The extension of the follow-up results in a substantial increase in statistical power compared with previous analysis (+25% for person-years and +74% for the number of deaths). The use of the National Mortality Database as the principal source for causes of death allows to reduce the potential bias in the calculation of standardized mortality ratios (SMR). As a consequence, an excess risk of deaths from laryngeal cancer, suggested in the first analysis, is not confirmed. The analysis shows the existence of an excess risk of deaths from lung cancer among French uranium miners (85 observed deaths, SMR = 1.9, 95% confidence interval CI: 1.5-2.3), and an increase of this risk with cumulative exposure to radon (excess relative risk per 100 working level month = 0.6, 95% CI: 0.1-1.2). These results confirm the existence of a risk of death from lung cancer in a population chronically exposed to relatively low levels of radon.