Fiona Lalloo

Gynaecological cancer surveillance for women with Lynch syndrome: systematic review and cost-effectiveness evaluation

Background Lynch syndrome is an inherited condition which leads to an increased risk of colorectal, endometrial and ovarian cancer. Risk-reducing surgery is generally recommended to manage the risk of gynaecological cancer once childbearing is completed. The value of gynaecological colonoscopic surveillance as an interim measure or instead of risk-reducing surgery is uncertain. We aimed to determine whether gynaecological surveillance was effective and cost-effective in Lynch syndrome. Methods We conducted systematic reviews of the effectiveness and cost-effectiveness of gynaecological cancer surveillance in Lynch syndrome, as well as a systematic review of health utility values relating to cancer and gynaecological risk reduction. Study identification included bibliographic database searching and citation chasing (searches updated 3 August 2021). Screening and assessment of eligibility for inclusion were conducted by independent researchers. Outcomes were prespecified and were informed by clinical experts and patient involvement. Data extraction and quality appraisal were conducted and results were synthesised narratively. We also developed a whole-disease economic model for Lynch syndrome using discrete event simulation methodology, including natural history components for colorectal, endometrial and ovarian cancer, and we used this model to conduct a cost–utility analysis of gynaecological risk management strategies, including surveillance, risk-reducing surgery and doing nothing. Results We found 30 studies in the review of clinical effectiveness, of which 20 were non-comparative (single-arm) studies. There were no high-quality studies providing precise outcome estimates at low risk of bias. There is some evidence that mortality rate is higher for surveillance than for risk-reducing surgery but mortality is also higher for no surveillance than for surveillance. Some asymptomatic cancers were detected through surveillance but some cancers were also missed. There was a wide range of pain experiences, including some individuals feeling no pain and some feeling severe pain. The use of pain relief (e.g. ibuprofen) was common, and some women underwent general anaesthetic for surveillance. Existing economic evaluations clearly found that risk-reducing surgery leads to the best lifetime health (measured using quality-adjusted life-years) and is cost-effective, while surveillance is not cost-effective in comparison. Our economic evaluation found that a strategy of surveillance alone or offering surveillance and risk-reducing surgery was cost-effective, except for path_PMS2 Lynch syndrome. Offering only risk-reducing surgery was less effective than offering surveillance with or without surgery. Limitations Firm conclusions about clinical effectiveness could not be reached because of the lack of high-quality research. We did not assume that women would immediately take up risk-reducing surgery if offered, and it is possible that risk-reducing surgery would be more effective and cost-effective if it was taken up when offered. Conclusions There is insufficient evidence to recommend for or against gynaecological cancer surveillance in Lynch syndrome on clinical grounds, but modelling suggests that surveillance could be cost-effective. Further research is needed but it must be rigorously designed and well reported to be of benefit. Study registration This study is registered as PROSPERO CRD42020171098. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR129713) and is published in full in Health Technology Assessment; Vol. 28, No. 41. See the NIHR Funding and Awards website for further award information.

BRCA1 and BRCA2 pathogenic variant carriers and endometrial cancer risk: A cohort study

An association between BRCA pathogenic variants and an increased endometrial cancer risk, specifically serous-like endometrial cancer, has been postulated but remains unproven, particularly for BRCA2 carriers. Mechanistic evidence is lacking, and any link may be related to tamoxifen exposure or testing bias. Hysterectomy during risk-reducing bilateral salpingo-oophorectomy is, therefore, of uncertain benefit. Data from a large, prospective cohort will be informative. Data on UK BRCA pathogenic variant carriers were interrogated for endometrial cancer diagnoses. Standardised incidence ratios (SIRs) were calculated in four distinct cohorts using national endometrial cancer rates; either from 1/1/1980 or age 20, prospectively from date of personal pathogenic variant report, date of family pathogenic variant report or date of risk-reducing salpingo-oophorectomy. Somatic BRCA sequencing of 15 serous endometrial cancers was performed to detect pathogenic variants. Fourteen cases of endometrial cancer were identified in 2609 women (1350 BRCA1 and 1259 BRCA2), of which two were prospectively diagnosed. No significant increase in either overall or serous-like endometrial cancer risk was identified in any of the cohorts examined (SIR = 1.70, 95% confidence interval = 0.74-3.33; no cases of serous endometrial cancer diagnosed). Results were unaffected by the BRCA gene affected, previous breast cancer or tamoxifen use. No BRCA pathogenic variants were detected in any of the serous endometrial cancers tested. Women with a BRCA pathogenic variant do not appear to have a significant increased risk of all-type or serous-like endometrial cancer compared with the general population. These data provide some reassurance that hysterectomy is unlikely to be of significant benefit if performed solely as a preventive measure.

BRCA1/2 in non-mucinous epithelial ovarian cancer: tumour with or without germline testing?

National guidelines recommend testing all cases of non-mucinous epithelial ovarian cancer (NMEOC) for germline (blood) and somatic (tumour) BRCA1/2 pathogenic variants (PVs). We performed paired germline and somatic BRCA1/2 testing in consecutive cases of NMEOC (n = 388) to validate guidelines. Thirty-four somatic BRCA1/2 (sBRCA) PVs (9.7%) were detected in 350 cases with germline BRCA1/2 (gBRCA) wild-type. All sBRCA PVs were detected in non-familial cases. By analysing our regional germline BRCA1/2 database there were 92/1114 (8.3%) gBRCA PVs detected in non-familial cases (only 3% ≥70 years old) and 245/641 (38.2%) in familial cases. Germline non-familial cases were dominated by BRCA2 in older women (8/271 ≥ 70 years old, all BRCA2). The ratio of sBRCA-to-gBRCA was ≤1.0 in women aged <70 years old, compared to 5.2 in women aged ≥70 years old (P = 0.005). The likelihood of missed germline BRCA1/2 PVs (copy-number variants missed on most somatic assays) by testing only tumour DNA was 0.4% in women aged ≥70 years old. We recommend reflex tumour BRCA1/2 testing in all NMEOC cases, and that gBRCA testing is not required for women aged ≥70 years old with no identifiable tumour BRCA1/2 PV and/or family history of breast, ovarian, prostate and/or pancreatic cancer.

Extended panel testing in ovarian cancer reveals BRIP1 as the third most important predisposition gene

The prevalence of germline pathogenic variants (PVs) in homologous recombination repair (HRR) and Lynch syndrome (LS) genes in ovarian cancer (OC) is uncertain. An observational study reporting the detection rate of germline PVs in HRR and LS genes in all OC cases tested in the North West Genomic Laboratory Hub between September 1996 and May 2024. Effect sizes are reported using odds ratios (ORs) and 95% confidence intervals (95% CI) for unselected cases tested between April 2021 and May 2024 versus 50,703 controls from the Breast Cancer Risk after Diagnostic Gene Sequencing study. 2934 women were tested for BRCA1/2 and 433 (14.8%) had a PV. In up to 1572 women tested for PVs in non-BRCA1/2 HRR genes, detection rates were PALB2 = 0.8%, BRIP1 = 1.1%, RAD51C = 0.4% and RAD51D = 0.4%. In 940 unselected cases, BRIP1 (OR = 8.7, 95% CI 4.6-15.8) was the third most common OC predisposition gene followed by RAD51C (OR = 8.3, 95% CI 3.1-23.1), RAD51D (OR = 6.5, 95% CI 2.1-19.7), and PALB2 (OR = 3.9, 95% CI 1.5-10.3). No PVs in LS genes were detected in unselected cases. Panel testing in OC resulted in a detection rate of 2% to 3% for germline PVs in non-BRCA1/2 HRR genes, with the largest contributor being BRIP1. Screening for LS in unselected cases of OC is unnecessary.