An overall strategy based on regression models to estimate relative survival and model the effects of prognostic factors in cancer survival studies.

Relative survival provides a measure of the proportion of patients dying from the disease under study without requiring the knowledge of the cause of death. We propose an overall strategy based on regression models to estimate the relative survival and model the effects of potential prognostic factors. The baseline hazard was modelled until 10 years follow-up using parametric continuous functions. Six models including cubic regression splines were considered and the Akaike Information Criterion was used to select the final model. This approach yielded smooth and reliable estimates of mortality hazard and allowed us to deal with sparse data taking into account all the available information. Splines were also used to model simultaneously non-linear effects of continuous covariates and time-dependent hazard ratios. This led to a graphical representation of the hazard ratio that can be useful for clinical interpretation. Estimates of these models were obtained by likelihood maximization. We showed that these estimates could be also obtained using standard algorithms for Poisson regression

Cancer incidence and mortality trends in France over 1990-2018 for solid tumors: the sex gap is narrowing

OBJECTIVE: To analyze trends in cancer incidence and mortality (France, 1990-2018), with a focus on men-women disparities. METHODS: Incidence data stemmed from cancer registries (FRANCIM) and mortality data from national statistics (CépiDc). Incidence and mortality rates were modelled using bidimensional penalized splines of age and year (at diagnosis and at death, respectively). Trends in age-standardized rates were summarized by the average annual percent changes (AAPC) for all-cancers combined, 19 solid tumors, and 8 subsites. Sex gaps were indicated using male-to-female rate ratios (relative difference) and male-to-female rate differences (absolute difference) in 1990 and 2018, for incidence and mortality, respectively. RESULTS: For all-cancers, the sex gap narrowed over 1990-2018 in incidence (1.6 to 1.2) and mortality (2.3 to 1.7). The largest decreases of the male-to-female incidence rate ratio were for cancers of the lung (9.5 to 2.2), lip - oral cavity - pharynx (10.9 to 3.1), esophagus (12.6 to 4.5) and larynx (17.1 to 7.1). Mixed trends emerged in lung and oesophageal cancers, probably explained by differing risk factors for the two main histological subtypes. Sex incidence gaps narrowed due to increasing trends in men and women for skin melanoma (0.7 to 1, due to initially higher rates in women), cancers of the liver (7.4 to 4.4) and pancreas (2.0 to 1.4). Sex incidence gaps narrowed for colon-rectum (1.7 to 1.4), urinary bladder (6.9 to 6.1) and stomach (2.7 to 2.4) driven by decreasing trends among men. Other cancers showed similar increasing incidence trends in both sexes leading to stable sex gaps: thyroid gland (0.3 to 0.3), kidney (2.2 to 2.4) and central nervous system (1.4 to 1.5). CONCLUSION: In France in 2018, while men still had higher risks of developing or dying from most cancers, the sex gap was narrowing. Efforts should focus on avoiding risk factors (e.g., smoking) and developing etiological studies to understand currently unexplained increasing trends

The performance of multiple imputation for missing covariate data within the context of regression relative survival analysis.

Relative survival assesses the effects of prognostic factors on disease-specific mortality when the cause of death is uncertain or unavailable. It provides an estimate of patients' survival, allowing for the effects of other independent causes of death. Regression-based relative survival models are commonly used in population-based studies to model the effects of some prognostic factors and to estimate net survival. Most often, studies focus on routinely collected prognostic factors for which the proportion of missing values is usually low (around 5 per cent). However, in some cases, additional factors are collected with a greater proportion of missingness. In the present article, we systematically assess the performance of multiple imputation in regression analysis of relative survival through a series of simulation experiments. According to the assumptions concerning the missingness mechanism (completely at random, at random, and not at random) and the missingness pattern (monotone, non-monotone), several strategies were considered and compared: all cases analysis, complete cases analysis, missing data indicator analysis, and multiple imputation by chained equations (MICE) analysis. We showed that MICE performs well in estimating the hazard ratios and the baseline hazard function when the missing mechanism is missing at random (MAR) conditionally on the vital status. In the situations where the missing mechanism was not MAR conditionally on vital status, complete case behaves consistently. As illustration, we used data of the French Cancer Registries on relative survival of patients with colorectal cancer

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 and mortality in France over the 1980-2012 period: solid tumors.

BACKGROUND: Cancer incidence and mortality estimates for 19 cancers (among solid tumors) are presented for France between 1980 and 2012. METHODS: Incidence data were collected from 21 local registries and correspond to invasive cancers diagnosed between 1975 and 2009. Mortality data for the same period were provided by the Institut national de la santé et de la recherche médicale. The national incidence estimates were based on the use of mortality as a correlate of incidence. The observed incidence and mortality data were modeled using an age-period-cohort model. The numbers of incident cases and deaths for 2010-2012 are the result of short-term projections. RESULTS: In 2012, the study estimated that 355,000 new cases of cancer (excluding non-melanoma skin cancer) and 148,000 deaths from cancer occurred in France. The incidence trend was not linear over the study period. After a constant increase from 1980 onwards, the incidence of cancer in men declined between 2005 and 2012. This recent decrease is largely related to the reduction in the incidence of prostate cancer. In women, the rates stabilized, mainly due to a change in breast cancer incidence. Mortality from most cancer types declined over the study period. A combined analysis of incidence and mortality by cancer site distinguished cancers with declining incidence and mortality (e.g., stomach) and cancers with increasing incidence and mortality (e.g., lung cancer in women). Some other cancers had rising incidence but declining mortality (e.g., thyroid). CONCLUSION: This study reveals recent changes in cancer incidence trends, particularly regarding breast and prostate cancers

Time trends and short term projections of cancer prevalence in France

IF 2.888 (2017)International audienceBackgroundThis study analyzes time trends in cancer prevalence in France and provides short-term projections up to the year 2017. The 15-year prevalence for 24 cancers was estimated from the French cancer registries network (FRANCIM) incidence and survival data.MethodWe estimated prevalence using the P = I × S relationship, with flexible modeling of incidence and survival. Based on observations of the incidence and survival up to 2010, different scenarios for evolution up to 2017 were studied, combining stable and dynamic incidence and survival. The determinants of variations in prevalence (incidence, survival and demography) were quantified.ResultsAt the end of 2017, an estimated 1,396,000 men and 1,359,000 women having had cancer in the previous 15 years were alive, respectively 5.4% and 4.8% of the population. Twelve percent had been diagnosed in the preceding year and 23% between 10 and 15 years. Between 2010 and 2017, changes in incidence and survival depended on the cancer site. The effect of the demographic change was null for those under age 65, whereas above age 65, the contribution of this factor was 20% in men and 17% in women at 15 years. The different projection scenarios led to very different estimates for some cancers for which incidence strongly varied in the last decades.ConclusionPrevalent cases are numerous in a country such as France, where incidence and survival are high. Due to the sensitivity of prevalence to changes in incidence and survival, we recommend that the results of projections are presented under different scenarios. We propose a robust and flexible prevalence estimate

Erratum to “Time trends and short term projections of cancer prevalence in France” [Cancer Epidemiol. 56 (2018) 97–105]

IF 2.888 (2017)International audienc

Unbiased estimates of long-term net survival of hematological malignancy patients detailed by major subtypes in France.

Long-term population-based survival data detailed by cancer subtype are important to measure the overall outcomes of malignancy managements. We provide net survival estimates at 1, 3, 5 and 10-year postdiagnosis on 37,549 hematological malignancy (HM) patients whose ages were >15 years, diagnosed between 1989 and 2004 and actively followed until 2008 by French population-based cancer registries. These are, to our knowledge, the first unbiased estimates of 10-year net survival in HMs detailed by subtypes. HMs were classified according to the International Classification of Diseases-Oncology 3. Net survival was estimated with the unbiased Pohar-Perme method. The results are reported by sex and age classes. The changes of these indicators by periods of diagnosis were tabulated and the trends of the net mortality rates over time since diagnosis graphed. In all, 5- and 10-year age-standardized net survivals after HMs varied widely from 81 and 76% for classical Hodgkin lymphoma (CHL) to 18 and 14% for acute myeloid leukemia (AML). Even in HMs with the most favorable prognoses, the net survival decreased between 5- and 10-year postdiagnosis. Women had better prognoses than men and age at diagnosis was an unfavorable prognostic factor for most HMs. In patients <55 years old, the net mortality rate decreased to null values 5-year postdiagnosis in AML and 10-year postdiagnosis in CHL, precursor non-HL, chronic myelogenous leukemia, diffuse large B-cell lymphoma and follicular lymphoma. The prognoses improved for various HMs over the study period. The obtained unbiased indicators are important to evaluate national cancer plans

Trends of incidence and survival in squamous-cell carcinoma of the anal canal in France: a population-based study.

Data on anal cancer epidemiology are rare. The aim of this study was to report on trends of incidence and survival for anal cancer in France before the implementation of the human papilloma virus vaccine. This analysis was carried out on 1150 squamous-cell carcinomas of the anal canal diagnosed from 1989 to 2004 in a population of 5.7 million people covered by eight population-based cancer registries. Time trends in incidence were modeled using an age-period-cohort model. Net survival rates were obtained using the recently validated unbiased Pohar-Perme estimator. The incidence of squamous-cell carcinoma of the anal canal increased from 0.2 to 0.5/100 000 person-years among men and from 0.7 to 1.3/100 000 person-years among women from 1982 to 2012. Among women, the increase peaked after 2005, with an annual percentage change of +3.4% between 2005 and 2012, as compared with +2.6% among men. The net survival was 56% (95% confidence interval, 49-64) at 5 years and 48% (33-70) at 10 years among men. It was higher among women, at 65% (61-69) and 56% (50-63) at 5 and 10 years, respectively. The prognosis improved between 1989-1997 and 1998-2004. This improvement was slightly greater for men than for women, thus progressively reducing the gap between sexes. The incidence of squamous-cell anal canal cancer increased slightly among both sexes, but the increase was more marked among women than among men. The potential benefit of prophylactic female human papilloma virus vaccination against cervical cancer in France should be further evaluated