Socioeconomic and geographic disparities of breast cancer incidence according to stage at diagnosis in France.

PURPOSE: Low socioeconomic background (SB) has been associated with lower breast cancer (BC) incidence and higher BC mortality. One explanation of this paradox is the higher frequency of advanced BC observed in deprived women. However, it is still unclear if SB affects similarly BC incidence. This study investigated the link between SB and early/advanced BC incidence from Loire-Atlantique/Vendee Cancer registry data (France). MATERIALS AND METHODS: Fourteen thousand three hundred fifty three women living in the geographic area covered by the registry and diagnosed with a primary BC in 2008-2015 were included. SB was approached by a combination of two ecological indexes (French European Deprivation Index and urban/rural residence place). Mixed effects logistic and Poisson regressions were used, respectively, to estimate the odds of advanced (stage ≥ II) BC and the ratio of incidence rates of early (stage 0-I) and advanced BC according to SB, overall and by age group (< 50, 50-74, ≥ 75). RESULTS: Compared to women living in affluent-urban areas, women living in deprived-urban and deprived-rural areas had a higher proportion of advanced BC [respectively, OR = 1.11 (1.01-1.22), OR = 1.60 (1.25-2.06)] and lower overall (from - 6 to - 15%) and early (from - 9 to - 31%) BC incidences rates Advanced BC incidence rates were not influenced by SB. These patterns were similar in women under 75 years, especially in women living in deprived-rural areas. In the elderly, no association between SB and BC frequency/incidence rates by stage was found. CONCLUSION: Although advanced BC was more frequent in women living in deprived and rural areas, SB did not influence advanced BC incidence. Therefore, differences observed in overall BC incidence according to SB were only due to higher incidence of early BC in affluent and urban areas. Future research should confirm these results in other French areas.

Is survival rate lower after breast cancer in deprived women according to disease stage?

BACKGROUND: Socioeconomic deprivation has been associated with lower breast cancer (BC) survival, but the influence of stage at diagnosis on this association merits further study. Our aim was to investigate this association using the Loire-Atlantique/Vendee Cancer Registry (France). METHODS: Twelve-thousand seven-hundred thirty-eight women living in the area covered by the registry and diagnosed with invasive breast carcinoma between 2008 and 2015 were included in the study. They were censored at maximal 6 years. Deprivation was measured by the French European Deprivation Index. Excess hazard and net survival were estimated for deprivation level, stage and age at diagnosis using a flexible excess mortality hazard model. RESULTS: After adjustment by stage, women living in the most deprived areas had a borderline non-significant higher excess mortality hazard (+25% (95% CI: -3%; +62%)) compared to those living in the least deprived areas. Stage-adjusted 5-year net survival differed significantly between these two subgroups (respectively, 88.2% (95% CI:85.2%-90.5%) and 92.5% (95% CI:90.6%-93.9%)). CONCLUSION: BC survival remained lower in deprived areas in France, despite universal access to cancer care. Intensification of prevention measures could help to reduce advanced BC, responsible for the majority of deaths from BC. A better understanding of remaining social disparities is crucial to implement specific interventions.

How do age and social environment affect the dynamics of death hazard and survival in patients with breast or gynecological cancer in France?

Several studies have investigated the association between net survival (NS) and social inequalities in people with cancer, highlighting a varying influence of deprivation depending on the type of cancer studied. However, few of these studies have accounted for the effect of social inequalities over the follow-up period, and/or according to the age of the patients. Thus, using recent and more relevant statistical models, we investigated the effect of social environment on NS in women with breast or gynecological cancer in France. The data were derived from population-based cancer registries, and women diagnosed with breast or gynecological cancer between 2006 and 2009 were included. We used the European deprivation index (EDI), an aggregated index, to define the social environment of the women included. Multidimensional penalized splines were used to model excess mortality hazard. We observed a significant effect of the EDI on NS in women with breast cancer throughout the follow-up period, and especially at 1.5 years of follow-up in women with cervical cancer. Regarding corpus uteri and ovarian cancer patients, the effect of deprivation on NS was less pronounced. These results highlight the impact of social environment on NS in women with breast or gynecological cancer in France thanks to a relevant statistical approach, and identify the follow-up periods during which the social environment may have a particular influence. These findings could help investigate targeted actions for each cancer type, particularly in the most deprived areas, at the time of diagnosis and during follow-up.

To what extent do age, stage and treatment influence survival after invasive cervical cancer: a French population-based study.

PURPOSE: In an attempt to understand why cervical cancer (CC) survival is decreasing with diagnosis period among older women in France, this study aimed to estimate the effects of main prognostic factors on net survival in CC according to age. METHODS: French cancer registries databases were used to retrospectively analyze women diagnosed with CC in 2011-2012. Net survival was estimated with the Pohar-Perme method and prognostic factors (socio-demographic, clinical variables, stage at diagnosis, therapeutic management) were analyzed with Lambert and Royston's flexible parametric model. RESULTS: One thousand one hundred fifty three women with CC were identified. 30.4% were < 45, 41.4% 45-64, and 28.3% ≥ 65 years. Older women were diagnosed at a more advanced stage than younger women: 54.8% regional (FIGO IB2-IVA), 33.0% distant (IVB) in women ≥ 65 years vs 33.7% and 8.0%, respectively in women < 45 years. Half of women with regional stage of CC received recommended treatment; this rate decreased with increasing age (< 45: 66.1%, 45-64: 62.7%, ≥ 65: 29.2%). Older age was significantly associated with increased risk of death: hazard ratio 1.89 for age ≥ 65, as were regional stage (2.81), distant stage (15.99), and not receiving recommended treatment (2.26). CONCLUSION: Older women with CC diagnosed at advanced stage who do not receive standard of care are at markedly increased risk of death. Special attention to the management of older women is warranted in France, not only to diagnose cancer at an earlier stage (via gynecological follow-up in these menopaused women who remain at risk of CC), but also to ensure they receive standard of care, taking into account their overall state of health.

Association of Mammography Screening With a Reduction in Breast Cancer Mortality: A Modeling Study Using Population-Based Data From 2 French Departments.

Meta-analyses of randomized controlled trials that started from 1963 to 1991 reported a decrease of breast cancer mortality, associated with mammography screening. However, the effectiveness of population-based screening programs conducted currently might have changed due to the higher effectiveness of treatments for late-stage cancers and the better diagnostic performance of mammography. The main objective of this study was to predict the reduction of breast cancer mortality associated with mammography screening in the current French setting. We compared breast cancer mortality in 2 simulated cohorts of women, which differed from each other solely in a 70% biennial participation in screening from 50 to 74 years old. The microsimulation model used for predictions was calibrated with incidence rates of breast cancer according to stage that were observed in Isère and Loire-Atlantique departments, France, in 2007-2013. The model predicted a decrease of breast cancer mortality associated with mammography screening of 18% (95% CI: 5, 31) and 17% (95% CI: 3, 29) for models calibrated with data from Isère and Loire-Atlantique departments, respectively. Our results highlight the interest in biennial mammography screening from ages 50 to 74 years old to decrease breast cancer mortality in the current setting, despite improvements in treatment effectiveness.

Effects of fertility on breast cancer incidence trends: comparing France and US.

PURPOSE: Breast cancer incidence rates are now higher in France than most other European countries as well as the United States (US). Increasing breast cancer incidence rates globally have often been attributed to declining fertility rates. METHODS: We compared temporal trends in breast cancer incidence in France and the US, and examined the extent temporal trends in national fertility rates can explain the temporal trends in breast cancer incidence. This study of temporal trends used estimates of annual percent change (APC) from cancer registry data in France and the US (1978-2016) and national fertility data (1958-2011). We estimated the APCs for all ages (overall APC) and for specific age groups (under 50, 50-64 years, and 65 years and over). RESULTS: The overall APC was over three times higher in France than the US (France APC = 1.63%, 95% CI 1.43-1.84; US APC = 0.51, 95% CI 0.31-0.72). The overall APCs remained positive and statistically significant after adjusting for fertility trends irrespective of assumptions on fertility lags (France APC = 1.61-0.91 for a 5-year to 20-year lag, respectively; US APC = 0.37-0.36 for a 5-year to 20-year lag, respectively). Similarly, among women under 50, the APC was over 3.5 times higher in France than the US (France APC = 1.22, 95% CI 1.07-1.37; US APC = 0.33, 95% CI 0.22-0.44), and APCs remained positive after adjusting for fertility (France APC = 1.21-1.28 for a 5-year to 20-year lag, respectively; US APC = 0.38-0.26 for a 5-year to 20-year lag, respectively). CONCLUSIONS: Based on these trend analyses, changes in fertility rate trends do not fully explain the increase incidence in breast cancer seen in both France and the US, nor the magnitude of difference between the two countries. This was seen overall and in age-specific groups.

Evaluation of long-term living conditions in patients treated for localised prostate cancer.

PURPOSE: To evaluate the evolution of living conditions (LC) in long-term survivors of localised prostate cancer 10 years after treatment compared with those of a same-age control group from the general population. METHODS: Two hundred and eighty-seven patients diagnosed with prostate cancer in 2001 were selected in 11 French cancer registries. They were matched with controls randomly selected for age and residency. Both patients and controls completed a self-administered LC questionnaire concerning their familial, social and professional life, and general and specific quality of life (QoL) and anxiety and depression questionnaires. RESULTS: Compared with controls, patients reported more sexual modifications (p < .0001), but without any difference in marital status. Patients' circle of friends was more stable than that of the controls (91% vs. 63%; p < .0001) and patients reported fewer friendship modifications than controls (p < .0006). Their professional and physical activities were also preserved. They reported more anxiolytic intake (p = .002) but did not consult their general practitioner more often. Type of specialist consulted differed in the two groups. CONCLUSION: Patients treated for localised prostate cancer had the same living conditions as men of the same age. Their social life was satisfying on the whole, albeit they reported more sexual difficulties than their counterparts.

Endocrine treatment and incidence of relapse in women with oestrogen receptor-positive breast cancer in Europe: a population-based study.

PURPOSE: Endocrine therapy (ET) is the mainstream adjuvant treatment for ER-positive breast cancer (BC). We analysed 9293 ER-positive BC patients diagnosed in nine European countries in 2009-2013 to investigate how comorbidities at diagnosis, age, stage and subtype affected ET use over time, and relapse. METHODS: Adjusted odds ratios (ORs) and 95% confidence intervals (95%CIs) of receiving ET were estimated according to Charlson comorbidity, age, stage and subtype using logistic regression. The 2-year cumulative incidence and adjusted sub-hazard ratios (SHRs) of relapse were estimated using competing risk analysis, with all-cause death as the competing event. The z-test was used to assess differences in the proportion of patients receiving ET in 1996-1998 and 2009-2013. RESULTS: Ninety percent of the patients started adjuvant ET, range 96% (Belgium, Estonia, Slovenia, Spain)-75% (Switzerland). ORs of starting ET were lower for women aged > 75 years, with severe comorbidities, or luminal B HER2-positive cancer. The factors independently increasing the risk of relapse were: not receiving ET (SHR 2.26, 95%CI 1.02-5.03); severe comorbidity (SHR 1.94, 95%CI 1.06-3.55); luminal B, either HER2 negative (SHR 3.06, 95%CI 1.61-5.79) or positive (SHR 3.10, 95%CI 1.36-7.07); stage II (SHR 3.20, 95%CI 1.56-6.57) or stage III (SHR 7.41, 95%CI 3.48-15.73). ET use increased significantly but differently across countries from 51-85% in 1996-1998 to 86-96% in 2009-2013. CONCLUSIONS: ER-positive BC patients in Europe are increasingly prescribed ET but between-country disparities persist. Older women and women with severe comorbidity less frequently receive ET. ET omission and severe comorbidity independently predict early disease relapse.

Comorbidities, age and period of diagnosis influence treatment and outcomes in early breast cancer.

Survival for breast cancer (BC) is lower in eastern than northern/central Europe, and in older than younger women. We analysed how comorbidities at diagnosis affected whether selected standard treatments (STs) were given, across Europe and over time, also assessing consequences for survival/relapse. We analysed 7581 stage I/IIA cases diagnosed in 9 European countries in 2009-2013, and 4 STs: surgery; breast-conserving surgery plus radiotherapy (BCS + RT); reconstruction after mastectomy; and prompt treatment (≤6 weeks after diagnosis). Covariate-adjusted models estimated odds of receiving STs and risks of death/relapse, according to comorbidities. Pearson's R assessed correlations between odds and risks. The z-test assessed the significance of time-trends. Most women received surgery: 72% BCS; 24% mastectomy. Mastectomied patients were older with more comorbidities than BCS patients (p < 0.001). Women given breast reconstruction (25% of mastectomies) were younger with fewer comorbidities than those without reconstruction (p < 0.001). Women treated promptly (45%) were younger than those treated later (p = 0.001), and more often without comorbidities (p < 0.001). Receiving surgery/BCS + RT correlated strongly (R = -0.9), but prompt treatment weakly (R = -0.01/-0.02), with reduced death/relapse risks. The proportion receiving BCS + RT increased significantly (p < 0.001) with time in most countries. This appears to be the first analysis of the influence of comorbidities on receiving STs, and of consequences for outcomes. Increase in BCS + RT with time is encouraging. Although women without comorbidities usually received STs, elderly patients often received non-standard less prompt treatments, irrespective of comorbidities, with increased risk of mortality/relapse. All women, particularly the elderly, should receive ST wherever possible to maximise the benefits of modern evidence-based treatments.

Using ecological socioeconomic position (SEP) measures to deal with sample bias introduced by incomplete individual-level measures: inequalities in breast cancer stage at diagnosis as an example.

BACKGROUND: When studying the influence of socioeconomic position (SEP) on health from data where individual-level SEP measures may be missing, ecological measures of SEP may prove helpful. In this paper, we illustrate the best use of ecological-level measures of SEP to deal with incomplete individual level data. To do this we have taken the example of a study examining the relationship between SEP and breast cancer (BC) stage at diagnosis. METHODS: Using population based-registry data, all women over 18 years newly diagnosed with a primary BC in 2007 were included. We compared the association between advanced stage at diagnosis and individual SEP containing missing data with an ecological level SEP measure without missing data. We used three modelling strategies, 1/ based on patients with complete data for individual-SEP (n = 1218), or 2/ on all patients (n = 1644) using an ecological-level SEP as proxy for individual SEP and 3/ individual-SEP after imputation of missing data using an ecological-level SEP. RESULTS: The results obtained from these models demonstrate that selection bias was introduced in the sample where only patients with complete individual SEP were included. This bias is redressed by using ecological-level SEP to impute missing data for individual SEP on all patients. Such a strategy helps to avoid an ecological bias due to the use of aggregated data to infer to individual level. CONCLUSION: When individual data are incomplete, we demonstrate the usefulness of an ecological index to assess and redress potential selection bias by using it to impute missing individual SEP.

Trends in molecular subtypes of breast cancer: description of incidence rates between 2007 and 2012 from three French registries.

BACKGROUND: The incidence and incidence trends of breast cancer according to molecular subtype are unknown at a population level in France. The registry data enables this study and may give this information, that is crucial to describe and understand breast cancer epidemiology. METHODS: We estimated the incidence rates of breast cancer for each molecular subtype using data from three cancer registries in France for the period from 2007 to 2012. Molecular subtypes were defined with immunohistochemical data. Poisson models were estimated to modelize the course of breast cancer incidence and to test the trends. RESULTS: The study included 12,040 patients diagnosed between 2007 and 2012 in the three administrative areas covered by the registries. There was no significant trends in the proportion of each molecular subtype year by year. The age distribution of incident cases was different depending on the molecular subtypes (p < 0.001). The course of incidence between 2007 and 2012 was also different depending on molecular subtype according to the multivariate Poisson model (p < 0.001). CONCLUSION: The description of incident cases of breast cancer according to molecular subtype at a population level showed differences in trends. The trends in incidence differed according to molecular subtype, and this should improve our understanding of overall changes in incidence. This analysis is important to plan screening and treatment resources at a population level.

Adolescent and young adult oncology patients in France: Heterogeneity in pathways of care.

BACKGROUND: In order to evaluate at the population level the impact of the actions developed in France since 2004 to organize the care of adolescents and young adults (AYAs) with cancer, we conducted the present study to provide an unbiased view of the pathway of care of these patients. METHODS: Using a population-based registry, we conducted a review of all cases of cancer diagnosed during 2012 and 2013 in 15- to 24-year-old patients living in nineteen French administrative areas. RESULTS: The median times for diagnosis and treatment of the 993 included AYAs were 9 weeks (3-22) and 1 day (0-20), respectively. Delays in diagnosis were significantly longer in young adults than in adolescents, especially for soft-tissue sarcomas (48.7 weeks vs. 15.4 weeks, P = 0.04) and bone tumors (21.4 weeks vs. 10.1 weeks, P = 0.04). The first physicians seen by patients were mostly general practitioners (67.4%). Most patients (77.5%) were treated in adult units. Management decisions were taken within the context of a multidisciplinary team (MDT) in 85.3% of cases. MDT meetings that involved both pediatric and adult oncologists were uncommon (15.7% of patients). Twenty-six percent of patients were included in randomized or nonrandomized clinical studies. The proportion of inclusion was significantly higher in adolescents (39.5%) than in young adults (16.8%). CONCLUSION: In France, pathways of care for AYAs are heterogeneous. It is necessary to organize a national network of expert centers with adequate medical skills and specific psychosocial support and facilities to provide the best possible care for these patients.

Short-term and long-term survival of interval breast cancers taking into account prognostic features.

PURPOSE: The aim of this population-based study was to estimate short-term and long-term survival of interval breast cancers and to compare them to clinically detected cancers, taking into account prognostic features. METHODS: This study included all interval cancers and clinically detected cancers diagnosed in the Loire-Atlantique population-based cancer registry from 2000 to 2010 in women aged 50-76 years. We used the Pohar-Perme method to estimate 5- and 10 year net survival rates and a flexible parametric model to compare interval cancer and clinically detected cancer prognosis with and without adjustment for the main prognostic factors (age, stage, histological grade, and phenotype). RESULTS: This study included 813 interval cancers and 1,354 clinically detected cancers. Interval cancers were diagnosed at a significantly less advanced stage than clinically detected cancers, but more often with a triple-negative phenotype. Interval cancer age-standardised net survival was 88.0% at 5 years (95% CI 84.9-91.2) and 81.7% at 10 years (95% CI 76.9-86.9), whereas clinically detected cancer age-standardised net survival was 77.8% (95% CI 75.1-80.6) and 64.6% (95% CI 60.7-68.7), respectively. After adjustment for covariates, survival no longer differed between interval cancers and clinically detected cancers at 5 and 10 years. CONCLUSION: Although the interval cancer net survival rate was higher, interval cancers had a similar short-term and long-term prognosis than clinically detected cancers after taking into account the main prognostic factors.

Occupational exposure to endotoxins and lung cancer risk: results of the ICARE Study.

OBJECTIVES: To investigate the role of occupational exposure to endotoxins in lung cancer in a French population-based case-control study (ICARE (Investigation of occupational and environmental causes of respiratory cancers)). METHODS: Detailed information was collected on the occupational history and smoking habits from 2926 patients with histologically confirmed lung cancer and 3555 matched controls. We evaluated each subject's endotoxin exposure after cross referencing International Standard Classification of Occupations (ISCO) codes (for job tasks) and Nomenclature d'Activités Françaises (NAF) codes (for activity sectors). Endotoxin exposure levels were attributed to each work environment based on literature reports. ORs and 95% CIs were estimated using unconditional logistic regression models and controlled for main confounding factors. RESULTS: An inverse association between exposure to endotoxins and lung cancer was found (OR=0.80, 95% CI 0.66 to 0.95). Negative trends were shown with duration and cumulative exposure, and the risk was decreased decades after exposure cessation (all statistically significant). Lung cancer risk was particularly reduced among workers highly exposed (eg, in dairy, cattle, poultry, pig farms), but also in those weakly exposed (eg, in waste treatment). Statistically significant interactions were shown with smoking, and never/light smokers were more sensitive to an endotoxin effect than heavy smokers (eg, OR=0.14, 95% CI 0.06 to 0.32 and OR=0.80, 95% CI 0.45 to 1.40, respectively, for the quartiles with the highest cumulative exposure, compared with those never exposed). Pronounced inverse associations were shown with adenocarcinoma histological subtype (OR=0.37, 95% CI 0.25 to 0.55 in the highly exposed). CONCLUSIONS: Our findings suggest that exposure to endotoxins, even at a low level, reduces the risk of lung cancer.

Are disparities of waiting times for breast cancer care related to socio-economic factors? A regional population-based study (France).

The increasing number of breast cancer cases may induce longer waiting times (WT), which can be a source of anxiety for patients and may play a role in survival. The aim of this study was to examine the factors, in particular socio-economic factors, related to treatment delays. Using French Cancer Registry databases and self-administered questionnaires, we included 1,152 women with invasive non-metastatic breast cancer diagnosed in 2007. Poisson regression analysis was used to identify WTs' influencing factors. For 973 women who had a malignant tissue sampling, the median of overall WT between the first imaging procedure and the first treatment was 44 days (9 days for pathological diagnostic WT and 31 days for treatment WT). The medical factors mostly explained inequalities in WTs. Socio-economic and behavioral factors had a limited impact on WTs except for social support which appeared to be a key point. Better identifying the factors associated with increase in WTs will make it possible to develop further interventional or prospective studies to confirm their causal role in delay and at last reduce disparities in breast cancer management.

Ovarian cancer in France: trends in incidence, mortality and survival, 1980-2012.

OBJECTIVE: The aim of this epidemiological study was to describe the incidence, mortality and survival of ovarian cancer (OC) in France, according to age, period of diagnosis, and histological type. METHODS: Incidence and mortality were estimated from 1980 to 2012 based on data in French cancer registries and from the Centre for Epidemiology of Causes of Death (CépiDc-Inserm) up to 2009. Net survival was estimated from registry data using the Pohar-Perme method, on cases diagnosed between 1989 and 2010, with date of last follow-up set at 30 June 2013. RESULTS: In 2012, 4615 cases of OC were diagnosed in France, and 3140 women died from OC. World population age-standardized incidence and mortality rates declined by respectively 0.6% and 1.2% per year between 1980 and 2012. Net survival at 5years increased slightly, from 40% for the period 1989-1993 to 45% for the period 2005-2010. Net survival varied considerably according to histological type. Germ cell tumors had better net survival at 10years (81%) compared to epithelial tumors (32%), sex cord-stromal tumors (40%) and tumors without biopsy (8%). CONCLUSIONS: Our study shows a decline in incidence and mortality rates from ovarian cancer in France between 1980 and 2012, but net survival remains poor overall, and improved only slightly over the whole study period.

Occupation and head and neck cancer in women-Results of the ICARE study.

BACKGROUND: Few occupational studies have addressed head and neck cancer, and these studies have been predominantly conducted in men. Accordingly, our objective was to investigate the association between head and neck cancer and occupation in women. METHODS: ICARE, a French population-based case-control study, included 296 squamous cell carcinomas of the head and neck in women and 775 controls. Lifelong occupational history was collected. Odds ratios (ORs) and 95% confidence intervals (CI), adjusted for smoking, alcohol drinking and education level, were estimated for occupations and industries. RESULTS: An elevated OR was observed for working proprietors working for 10 years or more (OR = 3.83, 95% CI: 1.12-13.0) with a significant trend with duration of employment (P = 0.047). Elevated but non-significant ORs were observed for street vendors (OR = 3.76, 95% CI: 0.99-14.3, P for trend = 0.13), bakers (OR = 4.19, 95% CI: 0.63-27.9, P for trend = 0.06), and welders and flame cutters (OR = 2.18, 95% CI: 0.33-14.4, P for trend = 0.05). CONCLUSIONS: This exploratory study suggests a role of occupational exposures in the development of HN cancer in women. Further investigations of exposures to specific agents are needed.

Multidimensional penalized splines for survival models: illustration for net survival trend analyses.

BACKGROUND: In descriptive epidemiology, there are strong similarities between incidence and survival analyses. Because of the success of multidimensional penalized splines (MPSs) in incidence analysis, we propose in this pedagogical paper to show that MPSs are also very suitable for survival or net survival studies. METHODS: The use of MPSs is illustrated in cancer epidemiology in the context of survival trends studies that require specific statistical modelling. We focus on two examples (cervical and colon cancers) using survival data from the French cancer registries (cases 1990-2015). The dynamic of the excess mortality hazard according to time since diagnosis was modelled using an MPS of time since diagnosis, age at diagnosis and year of diagnosis. Multidimensional splines bring the flexibility necessary to capture any trend patterns while penalization ensures selecting only the complexities necessary to describe the data. RESULTS: For cervical cancer, the dynamic of the excess mortality hazard changed with the year of diagnosis in opposite ways according to age: this led to a net survival that improved in young women and worsened in older women. For colon cancer, regardless of age, excess mortality decreases with the year of diagnosis but this only concerns mortality at the start of follow-up. CONCLUSIONS: MPSs make it possible to describe the dynamic of the mortality hazard and how this dynamic changes with the year of diagnosis, or more generally with any covariates of interest: this gives essential epidemiological insights for interpreting results. We use the R package survPen to do this type of analysis.

Socioeconomic Deprivation and Invasive Breast Cancer Incidence by Stage at Diagnosis: A Possible Explanation to the Breast Cancer Social Paradox.

In this study, we assessed the influence of area-based socioeconomic deprivation on the incidence of invasive breast cancer (BC) in France, according to stage at diagnosis. All women from six mainland French departments, aged 15+ years, and diagnosed with a primary invasive breast carcinoma between 2008 and 2015 were included (n = 33,298). Area-based socioeconomic deprivation was determined using the French version of the European Deprivation Index. Age-standardized incidence rates (ASIR) by socioeconomic deprivation and stage at diagnosis were compared estimating incidence rate ratios (IRRs) adjusted for age at diagnosis and rurality of residence. Compared to the most affluent areas, significantly lower IRRs were found in the most deprived areas for all-stages (0.85, 95% CI 0.81-0.89), stage I (0.77, 95% CI 0.72-0.82), and stage II (0.84, 95% CI 0.78-0.90). On the contrary, for stages III-IV, significantly higher IRRs (1.18, 95% CI 1.08-1.29) were found in the most deprived areas. These findings provide a possible explanation to similar or higher mortality rates, despite overall lower incidence rates, observed in women living in more deprived areas when compared to their affluent counterparts. Socioeconomic inequalities in access to healthcare services, including screening, could be plausible explanations for this phenomenon, underlying the need for further research.