Chlordecone exposure and adverse effects in French West Indies populations

International audienceChlordecone (Kepone) is an organochlorine insecticide that has been used as insecticide and fungicide. In the French West Indies, Guadeloupe and Martinique, it was intensively applied to banana fields from 1973 to 1993 to control root borers. This pesticide undergoes no significant biotic or abiotic degradation in the environment and is still present in soils where it was applied. It was only in 1999 that health and environmental authorities became aware of the extent of the chlordecone pollution of environmental media, including soils, waterways, and the food chain. Earlier observations and toxicological studies have demonstrated that chlordecone is a reproductive and developmental toxicant, neurotoxic and carcinogenic in rodents, and is an endocrine-disrupting chemical because of its estrogenic properties both in vitro and in vivo. Several surveys have confirmed that the French West Indian population continues to be exposed to this chemical though consumption of contaminated foodstuffs. Here, we report the findings of various epidemiological studies conducted in the French West Indies to assess the impact of environmental exposure to chlordecone on the health of the population

Environment as a Risk Factor for Male Infertility

Infertility affects 15% of couples in Western countries. Infertility is defined as the inability to conceive after 1 year of attempts without contraception, but it is not synonymous with sterility. Between 30 and 50% of infertile couples are infertile due to male reasons, mainly due to sperm production disorders. Although some risk factors, most of which are infectious, have been identified, there is still much uncertainty about the origins of male infertility

Organochlorine pesticide exposure and risk of prostate cancer development and progression: a systematic review

Background: There is an increasing body of evidence linking the exposure of an individual to pesticides such as organochlorine pesticides (OPCs) and an increased risk of developing diseases such as cancer. Exposure to OPCs has been suggested to increase the risk of developing hormone-dependant cancers such as prostate cancer (PCa). However, there is a relative paucity of information about the influence of exposure to these pesticides on the evolution of PCa, including risk of tumour development, progression to metastasis, and disease recurrence following therapy. Methods: We used several databases such as PubMed MEDLINE Database, Web of Science, and Scopus, in order to conduct a systematic review of the available epidemiological data implicating an association between exposure to OCPs and biochemical recurrence (BCR) of PCa. We searched all peer-reviewed articles published up to July 31st 2020. Pre-defined eligibility criteria for the inclusion of studies were that they be original studies, reviews, previous meta-analyses, or case–control or cohort studies. Results: Agent Orange is the most widely-studied OCP in the context of any possible causal role in the recurrence of PCa following radical prostatectomy, or in the progression to advanced disease. Only two studies didn’t demonstrate a significant association between exposure to OCPs and subsequent BCR following radical prostatectomy. Another study identified a significant association between exposure to Oxychlordane and PCB44 and progression to advanced PCa. Conclusion: This review confirmed a relative lack of high-quality evidence regarding this topic. However, the available evidence to date suggests the presence of a potential causal relationship between exposure to OPCs and PCa development and progression.

Pesticide exposure of pregnant women in Guadeloupe: Ability of a food frequency questionnaire to estimate blood concentration of chlordecone

Context Chlordecone, an environmentally persistent organochlorine insecticide used intensively in banana culture in the French West Indies until 1993, has permanently polluted soils and contaminated foodstuffs. Consumption of contaminated food is the main source of exposure nowadays. We sought to identify main contributors to blood chlordecone concentration (BCC) and to validate an exposure indicator based on food intakes.Material and methods We used a food frequency questionnaire (FFQ) completed by a sample of 194 pregnant women to estimate their dietary exposure to chlordecone and compared it to blood levels. In a first approach, chlordecone daily intake was estimated as the product of daily eaten quantity of 214 foodstuffs, multiplied by their chlordecone content, and summed over all items. We then predicted individual blood chlordecone concentration with empirical weight regression models based on frequency of food consumption, and without contamination data.Results Among the 191 subjects who had BCC determination, 146 (76%) had detectable values and mean BCC was 0.86†ng/mL (range < LOD-13.2). Mean per capita dietary intake of chlordecone was estimated at 3.3†[mu]g/day (range: 0.1-22.2). Blood chlordecone levels were significantly correlated with food exposure predicted from the empirical weight models (r=0.47, p<0.0001) and, to a lesser extent, with chlordecone intake estimated from food consumption and food contamination data (r=0.20, p=0.007). Main contributors to chlordecone exposure included seafood, root vegetables, and Cucurbitaceous.Conclusion These results show that the Timoun FFQ provides valid estimates of chlordecone exposure. Estimates from empirical weight models correlated better with blood levels of chlordecone than did estimates from the dietary intake assessment

Parallel assessment of male reproductive function in workers and wild rats exposed to pesticides in banana plantations in Guadeloupe

<p>Abstract</p> <p>Background</p> <p>There is increasing evidence that reproductive abnormalities are increasing in frequency in both human population and among wild fauna. This increase is probably related to exposure to toxic contaminants in the environment. The use of sentinel species to raise alarms relating to human reproductive health has been strongly recommended. However, no simultaneous studies at the same site have been carried out in recent decades to evaluate the utility of wild animals for monitoring human reproductive disorders. We carried out a joint study in Guadeloupe assessing the reproductive function of workers exposed to pesticides in banana plantations and of male wild rats living in these plantations.</p> <p>Methods</p> <p>A cross-sectional study was performed to assess semen quality and reproductive hormones in banana workers and in men working in non-agricultural sectors. These reproductive parameters were also assessed in wild rats captured in the plantations and were compared with those in rats from areas not directly polluted by humans.</p> <p>Results</p> <p>No significant difference in sperm characteristics and/or hormones was found between workers exposed and not exposed to pesticide. By contrast, rats captured in the banana plantations had lower testosterone levels and gonadosomatic indices than control rats.</p> <p>Conclusion</p> <p>Wild rats seem to be more sensitive than humans to the effects of pesticide exposure on reproductive health. We conclude that the concept of sentinel species must be carefully validated as the actual nature of exposure may varies between human and wild species as well as the vulnerable time period of exposure and various ecological factors.</p

From a genomic risk model to clinical trial implementation in a learning health system: the ProGRESS Study

ABSTRACT: Background: As healthcare moves from a one-size-fits-all approach towards precision care, individual risk prediction is an important step in disease prevention and early detection. Biobank-linked healthcare systems can generate knowledge about genomic risk and test the impact of implementing that knowledge in care. Risk-stratified prostate cancer screening is one clinical application that might benefit from such an approach. Methods: We developed a clinical translation pipeline for genomics-informed prostate cancer screening in a national healthcare system. We used data from 585,418 male participants of the Veterans Affairs (VA) Million Veteran Program (MVP), among whom 101,920 self-identify as Black/African-American, to develop and validate the Prostate CAncer integrated Risk Evaluation (P-CARE) model, a prostate cancer risk prediction model based on a polygenic score, family history, and genetic principal components. The model was externally validated in data from 18,457 PRACTICAL Consortium participants. A novel blended genome-exome (BGE) platform was used to develop a clinical laboratory assay for both the P-CARE model and rare variants in prostate cancer-associated genes, including additional validation in 74,331 samples from the All of Us Research Program. Results: In overall and ancestry-stratified analyses, the polygenic score of 601 variants was associated with any, metastatic, and fatal prostate cancer in MVP and PRACTICAL. Values of the P-CARE model at ≥80th percentile in the multiancestry cohort overall were associated with hazard ratios (HR) of 2.75 (95% CI 2.66-2.84), 2.78 (95% CI 2.54-2.99), and 2.59 (95% CI 2.22-2.97) for any, metastatic, and fatal prostate cancer in MVP, respectively, compared to the median. When high– and low-risk groups were defined as P-CARE HR&gt;1.5 and HR&lt;0.75 for metastatic prostate cancer, the 220,062 (37.6%) high-risk vs.146,826 (25.1%) low-risk participants in MVP had a 47.9% vs. 14.1%, 9.3% vs. 2.0%, and 3.6% vs. 0.8% cumulative cause-specific incidence of any, metastatic, and fatal prostate cancer by age 90, respectively. The clinical assay and reports are now being implemented in a clinical trial of precision prostate cancer screening in the VA healthcare system (Clinicaltrials.govNCT05926102). Conclusions: A model consisting of a polygenic score, family history, and genetic principal components describes a clinically important gradient of prostate cancer risk in a diverse patient population and demonstrates the potential of learning health systems to implement and evaluate precision health care approaches

Evaluating Approaches for Constructing Polygenic Risk Scores for Prostate Cancer in Men of African and European Ancestry

Genome-wide polygenic risk scores (GW-PRSs) have been reported to have better predictive ability than PRSs based on genome-wide significance thresholds across numerous traits. We compared the predictive ability of several GW-PRS approaches to a recently developed PRS of 269 established prostate cancer-risk variants from multi-ancestry GWASs and fine-mapping studies (PRS269). GW-PRS models were trained with a large and diverse prostate cancer GWAS of 107,247 cases and 127,006 controls that we previously used to develop the multi-ancestry PRS269. Resulting models were independently tested in 1,586 cases and 1,047 controls of African ancestry from the California Uganda Study and 8,046 cases and 191,825 controls of European ancestry from the UK Biobank and further validated in 13,643 cases and 210,214 controls of European ancestry and 6,353 cases and 53,362 controls of African ancestry from the Million Veteran Program. In the testing data, the best performing GW-PRS approach had AUCs of 0.656 (95% CI = 0.635-0.677) in African and 0.844 (95% CI = 0.840-0.848) in European ancestry men and corresponding prostate cancer ORs of 1.83 (95% CI = 1.67-2.00) and 2.19 (95% CI = 2.14-2.25), respectively, for each SD unit increase in the GW-PRS. Compared to the GW-PRS, in African and European ancestry men, the PRS269 had larger or similar AUCs (AUC = 0.679, 95% CI = 0.659-0.700 and AUC = 0.845, 95% CI = 0.841-0.849, respectively) and comparable prostate cancer ORs (OR = 2.05, 95% CI = 1.87-2.26 and OR = 2.21, 95% CI = 2.16-2.26, respectively). Findings were similar in the validation studies. This investigation suggests that current GW-PRS approaches may not improve the ability to predict prostate cancer risk compared to the PRS269 developed from multi-ancestry GWASs and fine-mapping

Trans-ancestry genome-wide association meta-analysis of prostate cancer identifies new susceptibility loci and informs genetic risk prediction.

Prostate cancer is a highly heritable disease with large disparities in incidence rates across ancestry populations. We conducted a multiancestry meta-analysis of prostate cancer genome-wide association studies (107,247 cases and 127,006 controls) and identified 86 new genetic risk variants independently associated with prostate cancer risk, bringing the total to 269 known risk variants. The top genetic risk score (GRS) decile was associated with odds ratios that ranged from 5.06 (95% confidence interval (CI), 4.84-5.29) for men of European ancestry to 3.74 (95% CI, 3.36-4.17) for men of African ancestry. Men of African ancestry were estimated to have a mean GRS that was 2.18-times higher (95% CI, 2.14-2.22), and men of East Asian ancestry 0.73-times lower (95% CI, 0.71-0.76), than men of European ancestry. These findings support the role of germline variation contributing to population differences in prostate cancer risk, with the GRS offering an approach for personalized risk prediction

Characterizing Prostate Cancer Risk Through Multi-Ancestry Genome-Wide Discovery of 187 Novel Risk Variants

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P = 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups