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D Gareth Evans

Publications and source records attributed to D Gareth Evans.

9 recordsLinked to original sources
PubMed2026

Early-adulthood body mass index, mammographic density and post-menopausal breast cancer risk: a mediation analysis.

BACKGROUND: To explore potential mechanistic pathways and inform prevention strategies, this study examined whether mammographic density (MD) mediates the inverse association between higher early-adulthood body mass index (BMI) and lower post-menopausal breast cancer risk. METHODS: We analysed data from 33,816 post-menopausal women in the UK PROCAS cohort, with self-reported BMI at age 20. MD was measured using full-field digital mammography and assessed using the visual analogue scale (VAS) percentage density and Volpara®-derived fibroglandular volume (FGV). Counterfactual mediation modelling estimated natural direct and indirect effects. RESULTS: Over a median follow-up of 10.44 years, there were 1261 new post-menopausal breast cancers. Higher VAS and FGV were associated with increased breast cancer risk. BMI at age 20 was associated with lower VAS density and reduced breast cancer risk [Hazard Ratio per 5 kg/m²: 0.849 (0.771-0.938)]. The calculated proportion mediated by VAS density was 59.9% (32.6-150), after accounting for intermediate confounding by BMI in later adulthood. FGV was positively associated with higher BMI at cohort entry but not at age 20. CONCLUSIONS: Lower VAS density may partially explain the inverse association between early-adulthood BMI and post-menopausal breast cancer risk. The link between FGV and breast cancer risk may represent a different biological pathway.

Journal Article↗
PubMed2026

RNA splicing evidence enables robust classification of BRCA1 exon 18 variants: Results from the ENIGMA consortium.

The Evidence-based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) research consortium conducted a comprehensive study to characterize spliceogenic variants in BRCA1 exon 18. The absence of systematic RNA-based assessment for these variants has led to inconsistent interpretation, limiting accurate classification and management of individuals and their families. The splicing profile of 166 variants was assessed using minigene assays; 32 were additionally analyzed in blood-derived RNA from 51 individuals and 18 in mouse embryonic stem cell (mESC)-based assays to evaluate homology-directed repair (HDR) capacity. mRNA assessment by RT-PCR in blood samples and minigene assays showed a significant positive correlation, with splicing analysis in mESCs displaying highly concordant results. The mESC-based HDR assay showed that the in-frame exon 18 skipping (&#x394;18) transcript encodes a non-functional protein lacking rescue activity. Linear regression analysis using mESC splicing and functional data indicated that &#x2265;59% of full-length (FL) levels and <34% of &#x394;18 were associated with benign HDR activity. These thresholds differ from those recommended by the ClinGen ENIGMA BRCA1 and BRCA2 Variant Curation Expert Panel American College of Medical Genetics and Genomics (ACMG)/Association for Molecular Pathology (AMP) specifications for applying BP7_strong(RNA): >30% functional transcripts or <70% non-functional transcripts. Incorporation of RNA splicing evidence into variant interpretation increased pathogenic (28.6%-31.7%) and benign (3.7%-24.4%) classifications while reducing likely pathogenic (19.5%-17.7%), uncertain (18.9%-8.5%), and likely benign (29.3%-17.7%) categories. Experimental mRNA profiling impacted the interpretation of 34% of variants and resolved uncertainty in approximately 10% of cases. Exon 18 skipping was less tolerated, indicating that the degree of splice perturbation required to impair BRCA1 function may depend on the nature of the resulting non-functional transcript.

Humans↗
PubMed2026

Health-related quality of life after risk-reducing hysterectomy: a randomised vignette study.

BACKGROUND: Risk-reducing hysterectomy (RRH) is the most effective endometrial cancer preventive strategy. Understanding health-related quality-of-life using health-related utility-scores (HRUS) is essential for counselling, shared decision-making, and informing health-economic evaluations of endometrial cancer prevention. This study aimed to determine HRUS for premenopausal RRH, with and without bilateral salpingo-oophorectomy (BSO). METHODS: Preventing Endometrial-Cancers: Comparing Risk-Reducing Strategies (PRESCORES) (ISRCTN17432105) part-2 is a UK-based randomised vignette study. Following a robust development process, vignettes described four postoperative health-states for a 40-year-old otherwise-healthy woman: "RRH at 1-month", "RRH at 1-year", "RRH-BSO at 1-month", "RRH-BSO at 1-year". These were valued using EQ-5D by participants recruited from the UK general-population and HRUS calculated. Utilities were subsequently adjusted by age-and sex-matched general-population reference values. Association of variables was explored with ordinary-least-squares regression with non-parametric bootstrapping. FINDINGS: Overall, 1001 women were included and randomised to 1-of-4 groups. The mean-age(&#xb1;SD) was 53.6 (&#xb1;11.4) years. Mean(&#xb1;SD) HRUS were 0.942 (&#xb1;0.072) for "RRH at 1-year", 0.841 (&#xb1;0.137) for "RRH-BSO at 1-year", 0.670 (&#xb1;0.149) for "RRH at 1-month", and 0.733 (&#xb1;0.190) for "RRH-BSO at 1-month", with significant difference between each group (p&#xa0;<&#xa0;0.001). Adjusting for age-sex-matched population reference utilities, HRUS were 1.000(95% CI:1.00-1.00), 0.994(95% CI:0.97-1.00), 0.866(95% CI:0.84-0.90) and 0.791(95% CI:0.77-0.81), respectively. Participant factors associated with vignette valuations included age, obesity, heavy menstrual-bleeding, higher income and mixed/other ethnicity. CONCLUSION: This randomised study provides HRUS following premenopausal RRH with and without BSO at two postoperative time-points, with adjustment against the age-and sex-matched general reference-population. These values are of relevance for informing counselling of women at increased endometrial cancer-risk regarding RRH and for health-economic evaluations.

Humans↗
PubMed2025

History and clinical epidemiology of NF2-related schwannomatosis.

NF2-related schwanomatosis (NF2-SWN) (previously Neurofibromatosis 2) as characterised by bilateral vestibular schwannomas (VS) was first described in 1822. However, due to the erroneous conflation of individuals with bilateral eighth nerve tumours with von Recklinghausen disease (currently Neurofibromatosis 1, NF1) in 1917 the literature was confusing for much of the 20th century. Even when the conditions were separated officially in 1987 (with separate localisation of the genes), NF2-SWN remained classified as a neurofibromatosis despite the tumours pathognomonic for NF1, neurofibromas, not being a feature of NF2-schwannomatosis. It is only in 2022 that NF2-SWN was correctly delineated as a schwannomatosis. The epidemiology of NF2-SWN has only been possible to delineate after the separation of NF2-SWN from the much more frequent nerve sheath predisposing tumour condition NF1. Two research groups have published on the birth prevalence and population prevalence of NF2-SWN in the UK and Finland. The most highly ascertained assessment of NF2-SWN cases from the Manchester region of England (population 4.8&#xa0;million) gave a diagnostic prevalence of 1 in 50,500 and calculated birth prevalences of 1 in 27,956 respectively. However, an updated prevalence across England in 2024 (population 55&#xa0;million) gave a prevalence of at least 1 in 58,000. NF2-SWN usually presents with bilateral vestibular schwannoma, but can present with meningioma or spinal tumour or ophthalmic features before a VS diagnosis or with a unilateral VS and other tumours and rarely with a unilateral VS alone. Molecular testing is now extremely helpful in confirming the diagnosis of mosaic (present in up to 50% of de novo cases) versus germline NF2 and distinguishing from other tumour predisposition conditions especially in childhood or cases with less common presentation. This chapter summarises the clinical epidemiology of NF2-SWN differentiating the condition from the overlapping non NF2-SWN.

Humans↗
PubMed2025

Estimands for Clinical Effectiveness of Risk-Reducing Early Salpingectomy in Women With High Risk of Ovarian Cancer.

IMPORTANCE: Risk-reducing early-salpingectomy (RRES) and delayed oophorectomy (DO) is a novel 2-stage alternative prevention strategy to risk-reducing salpingo-oophorectomy (RRSO) that avoids detrimental consequences of premature menopause. However, direct data on the clinical effectiveness for ovarian cancer (OC) risk reduction are lacking. OBJECTIVE: To explore how to define clinical effectiveness from prospective cohort studies using the estimand framework and sample size requirements. DESIGN, SETTING, AND PARTICIPANTS: In this comparative effectiveness research study, estimand and analysis options were considered to evaluate the clinical effectiveness of RRES with DO by extending the UK PROTECTOR cohort study, a multicenter, prospective, observational, national cohort study (N&#x2009;=&#x2009;1250 recruited from January 1, 2019, to December 31, 2024) evaluating RRES and DO for OC surgical prevention. Participants were premenopausal women 30 years or older at increased OC risk due to BRCA1/BRCA2 pathogenic variants. Participants could choose RRES, RRSO, or no surgery at entry. Sample size requirements used initial data (eg, age and BRCA1/2 distribution) from PROTECTOR (analysis undertaken from January 1, 2024, to December 31, 2025). MAIN OUTCOMES AND MEASURES: Incidence of OC after (not at) RRES and before or at DO in women with normal histologic analysis findings at surgery. The proportion of cancers prevented was estimated as the completement of the observed (O) to expected (E; assuming no preventive effect of surgery) number of cancers detected (1&#x2009;-&#x2009;O/E). RESULTS: Initial data were obtained from 889 women in PROTECTOR (overall mean [SD] age, 39 [5] years), with 255 (28.7%) choosing RRSO (mean [SD] age, 42 [4] years), 405 (45.5%) choosing RRES (mean [SD] age, 38 [4] years), and 229 (25.7%) choosing no surgery (mean [SD], 38 [5] years). The preferred estimand outcome was OC incidence after surgery (RRES or RRSO) with a "while on intervention" strategy to account for intercurrent events. The primary target measure was the proportion of cancers prevented for RRES vs no surgery with superiority testing. The secondary target measure was noninferiority of RRES vs RRSO. An estimated 1150 RRES participants with 8 to 10 years of follow-up would provide approximately 92% power to show that 20% or more of cancers are prevented using a 1-sample binomial test of the O:E risk (external reference) at the 5% level under a range of assumptions and at least the same power for a noninferiority margin for the proportion of cancers prevented by RRES of those prevented by RRSO. Estimands based on incidence ratios had an infeasible sample size. CONCLUSIONS AND RELEVANCE: In this comparative effectiveness study of UK BRCA carriers, the estimand differed from other ongoing clinical effectiveness studies of RRES and DO. Advantages include direct use of expected risk at baseline (unknown at design stage), easier interpretation across cohorts than absolute risk differences, and providing a feasible recruitment target for PROTECTOR to evaluate clinical effectiveness.

Humans↗
PubMed2025

The risk of a second primary cancer in PTEN Hamartoma Tumor Syndrome (PHTS).

PURPOSE: Patients with PTEN Hamartoma Tumor Syndrome (PHTS) have high hereditary cancer risks for breast, endometrial, and thyroid cancer. Patients develop multiple primary cancers, but these risks remain uncertain. We aimed to provide the second primary cancer risk. METHODS: This European cohort study assessed second primary cancer risks with Kaplan-Meier analyses using data from medical files, registries and/or patient questionnaires. RESULTS: Overall, 279 adult PHTS patients with (a history of) cancer were included (80% female). Among females, 106 (54%) developed a PHTS-related second primary cancer after a PHTS-related first primary cancer, whereas 10 (29%) males developed a PHTS-related second primary cancer after a PHTS-related first primary cancer. The 5- and 10-year PHTS-related second primary cancer risks were 24.5% (95% CI = 18.1-32.5) and 45.7% (95% CI = 36.9-55.4) in females and 14.5% (95% CI = 5.7-34.1) and 19.8% (95% CI = 8.6-41.9) in males, respectively. Furthermore, 5- and 10-year risks for a second primary breast cancer after a first primary breast cancer were 23.3% (95% CI = 14.9-35.2) and 45.6% (95% CI = 33.0-60.2) in females, respectively. CONCLUSION: This study demonstrated that PHTS patients have high second primary cancer risks, which is driven by breast cancer in females. Hence, identifying patients with PHTS before or at first primary cancer diagnosis is essential to enable potential early detection or prevention of a second primary cancer through surveillance or risk-reducing surgery.

Humans↗