Olivier Dejardin

The effect of geographical accessibility to care and patients' social environment on survival has been little studied for hematological malignancies. The objective was to investigate the influence of these factors on excess mortality for these patients in France. This study included 13 French cancer registries. Hodgkin's lymphomas, myeloid haemopathies, multiple myeloma, chronic lymphatic leukemia, diffuse large B‐cell lymphoma and follicular lymphoma diagnosed between 2013 and 2015 are included ( N = 19,041). Social environment was measured using the European Deprivation Index. The access of secondary care was measured by travel time to the nearest reference care center, and access to primary care was estimated using Spatial Accessibility multiscALar (SCALe) index and Accessibilité Potentielle Localisée (APL). The effects of these indicators on excess mortality were investigated using additive excess hazard models with multidimensional penalized splines. For myeloid haemopathies, only the social environment had a significant effect on excess mortality. For diffuse large B‐cell lymphoma, the travel time to nearest reference care center had an impact on excess mortality. Finally, for follicular lymphoma, an increase of APL index was associated with a decrease of mortality. Our study showed that the social environment and the geographical accessibility to care were prognostic factors for survival in certain hematological malignancies.

ObjectivesTo examine the association between self-reported mobile phone use and brain tumour risk in the UK Biobank Cohort.MethodsA total of 467,801 participants aged 40–69 years from the UK Biobank Cohort were included (recruited 2006–2010, followed up to 2023). ICD10 codes were used to identify all brain tumours and its subtypes (glioma (glioblastoma as subgroup), meningioma, acoustic neuroma). Regular mobile phone use was defined as making or receiving calls at least once per week. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazard regression models, with age as underlying time scale.ResultsOver a median follow-up of 13 years (5,583,093 person-years), 1,607 brain tumours were identified. Longest regular mobile phone use (>8 years) at baseline compared with never regular use was not associated with overall brain tumour risk (HR: 0.93, 95% CI: 0.79 to1.08) or any subtype (glioma (0.85, 95% CI: 0.69 to 1.04), glioblastoma (0.87, 95% CI: 0.69 to 1.11), meningioma (1.04, 95% CI: 0.79 to1.38), acoustic neuroma (0.91, 95% CI: 0.43 to 1.92).ConclusionThe result from this large-scale analysis adds to the evidence supporting absence of an association between mobile phone use and overall brain tumour risk or any subtype. Limitations in the exposure assessment remain, warranting further follow-up of studies with improved RF-EMF assessment.

Guidelines for systematic microsatellite instability (MSI) testing in colorectal cancer have emerged in recent years, and more specifically in France since November 2021. Besides detection of Lynch syndrome for early detection of other cancer and family screening, MSI is associated with different treatment options depending on cancer stage. The aim of this study was to describe MSI testing frequency in patients with colorectal cancer in a French region in the years leading up to the publication of official guidelines. Cases from the Calvados digestive cancer registry were studied between 2019 and 2021. Age, sex, socioeconomic deprivation, tumour location, stage at diagnosis, progression, type of hospital for surgery and for multidisciplinary meetings were collected. These characteristics were compared between cases that underwent testing and those that didn’t, and between unstable and stable cases when tested, using descriptive analyses. A total of 1169 cases were included, of which 60% were tested for MSI. Younger patients (80% of patients under the age of 65 vs. 57% of patients over the age of 80) and more advanced stages were more frequently tested (52% stage I vs. 70% stage IV). A higher proportion of cases was tested in 2021 than in 2019 and 2020. A higher proportion of colon cancer cases were tested than rectal cancer (75% vs. 61%). Of the 816 cases tested, 13.6% had MSI. A higher percentage of colon cancer cases were unstable compared to rectal cancer cases (19% vs. 2%). When the analysis was restricted to the year 2021, 18% of cases remained untested. The only significant differences remaining in 2021 were for location (more frequent for colon than for rectal cancer cases), and for stage at diagnosis (performed less for stage I). This population-based French study reveals disparities before emergence of official national guidelines and the reduction in these disparities in the most recent years. However, achievement of systematic testing was not yet attained in 2021. The online version contains supplementary material available at 10.1186/s12885-025-14895-2.

Background Several tools are used to assess postoperative weight loss after bariatric surgery, including the percentage of excess body weight loss (%EWL), percentage of total weight loss (%TWL), and percentage of excess body mass index (BMI) loss (%EBMIL). A repeated series of measurements should be considered to assess weight loss as accurately as possible. This study aimed to test weight loss metrics. Methods Data were obtained from a prospective database of patients with obesity who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) between 2016 and 2017 in a French tertiary referral bariatric center. A multilevel mixed-effects linear regression model with repeated measures was used to analyze repeated weight measurements over time. Results A total of 435 patients underwent LRYGB (n = 266) or LSG (n = 169). At 2 years, the average %EWL, %EBMIL, and %TWL were 56.8%, 61.3%, and 26.6%, respectively. Patients who underwent LSG experienced lower weight loss (β: − 4233 in %TWL model, β: − 6437 in %EWL model, and β: − 6989 in %EBMIL model) than those who underwent LRYGB. In multivariate mixed analysis, preoperative BMI was not significantly associated with %TWL at 2 years (β, − 0.09 [− 0.22–0.03] p = 0.1). Preoperative BMI was negatively associated with both %EWL (β, − 1.61 [− 1.84–− 1.38] p < 0.0001) and %EBMIL (β, − 1.91 [− 2.16–− 1.66] p < 0.0001). Conclusion This is the first study to assess %TWL use for postoperative weight measurement, using a multilevel mixed-effects linear regression model %TWL is the measure of choice to assess weight loss following bariatric surgery.

Accessibility to care is a major public health issue. Various tools to assess it are available, but they do not solve the problem of scale. Moreover, accessibility is a multidimensional concept that is not taken into account with current tools. The SCALE index aims to overcome these two limitations by proposing a synthetic measure on a more precise scale than the administrative unit or the sub-municipal scale. Under the assumption of access to care facilities for all and access to the nearest facilities, the potential accessibility distance was calculated for each couple (residential area, accessible facilities). This was defined as the average distance by road that the population has to travel to access care. To take the availability of resources into account, these distances were weighted by the theoretical pressure on the facilities. The SCALE index was then calculated using a linear combination of the distances of potential accessibility to care facilities It highlights differences in accessibility at the national and regional scale. Using this index, it was possible to provide maps for all French regions and the major cities in a story-map. The major conurbation around Paris and the main urban centers has high accessibility. Low accessibility forms a “Y” shape. In conclusion, the SCALE index measures accessibility at the scale of a small geographic unit taking the proximity and the availability of health professionals into account. It is also possible to take into account the diversity of accessibility in a given territory.