The avoiding late diagnosis of ovarian cancer (ALDO) project; a pilot national surveillance programme for women with pathogenic germline variants in BRCA1 and BRCA2.

BACKGROUND: Our study aimed to establish 'real-world' performance and cost-effectiveness of ovarian cancer (OC) surveillance in women with pathogenic germline BRCA1/2 variants who defer risk-reducing bilateral salpingo-oophorectomy (RRSO). METHODS: Our study recruited 875 female BRCA1/2-heterozygotes at 13 UK centres and via an online media campaign, with 767 undergoing at least one 4-monthly surveillance test with the Risk of Ovarian Cancer Algorithm (ROCA) test. Surveillance performance was calculated with modelling of occult cancers detected at RRSO. The incremental cost-effectiveness ratio (ICER) was calculated using Markov population cohort simulation. RESULTS: Our study identified 8 OCs during 1277 women screen years: 2 occult OCs at RRSO (both stage 1a), and 6 screen-detected; 3 of 6 (50%) were ≤stage 3a and 5 of 6 (83%) were completely surgically cytoreduced. Modelled sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for OC were 87.5% (95% CI, 47.3 to 99.7), 99.9% (99.9-100), 75% (34.9-96.8) and 99.9% (99.9-100), respectively. The predicted number of quality-adjusted life years (QALY) gained by surveillance was 0.179 with an ICER cost-saving of -£102,496/QALY. CONCLUSION: OC surveillance for women deferring RRSO in a 'real-world' setting is feasible and demonstrates similar performance to research trials; it down-stages OC, leading to a high complete cytoreduction rate and is cost-saving in the UK National Health Service (NHS) setting. While RRSO remains recommended management, ROCA-based surveillance may be considered for female BRCA-heterozygotes who are deferring such surgery.

Germline variant testing in serrated polyposis syndrome.

BACKGROUND AND AIM: Serrated polyposis syndrome (SPS) is now known to be the commonest polyposis syndrome. Previous analyses for germline variants have shown no consistent positive findings. To exclude other polyposis syndromes, 2019 British Society of Gastroenterology (BSG) guidelines advise gene panel testing if the patient is under 50 years, there are multiple affected individuals within a family, or there is dysplasia within any of the polyps. METHODS: A database of SPS patients was established at the Oxford University Hospitals NHS Foundation Trust. Patients were referred for genetic assessment based on personal and family history and patient preference. The majority were tested for a hereditary colorectal cancer panel including MUTYH, APC, PTEN, SMAD4, BMPR1A, STK11, NTLH1, POLD1, POLE, GREM1 (40-kb duplication), PMS2, and Lynch syndrome mismatch repair genes. RESULTS: One hundred and seventy-three patients were diagnosed with SPS based on World Health Organization 2019 criteria between February 2010 and December 2020. The mean age of diagnosis was 54.2 ± 16.8 years. Seventy-three patients underwent genetic testing and 15/73 (20.5%) were found to have germline variants, of which 7/73 (9.6%) had a pathogenic variant (MUTYH n = 2, SMAD4 n = 1, CHEK2 n = 2, POLD1 n = 1, and RNF43 n = 1). Only 60% (9/15) of these patients would have been recommended for gene panel testing according to current BSG guidelines. CONCLUSIONS: A total of 20.5% of SPS patients tested were affected by heterozygous germline variants, including previously unreported associations with CHEK2 and POLD1. This led to a change in management in seven patients (9.6%). Current recommendations may miss SPS associated with germline variants, which is more common than previously anticipated.

The use of panel testing in familial breast and ovarian cancer.

Advances in sequencing technology have led to the introduction of panel testing in hereditary breast and ovarian cancer. While direct-to-consumer testing services have become widely available, the clinical validity of many of the genes on panel tests remains contentious and risk management guidelines are often lacking. This article gives an overview of advantages with panel testing as well as important challenges, including clinical translation of test results.

Infantile neuroaxonal dystrophy caused by uniparental disomy.

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive neurodegenerative disorder caused by mutations in the phospholipase A2 group 6 (Pla2G6) gene. Affected individuals usually present between the ages of 6 months and 2 years with rapid cognitive and motor regression and axial hypotonia. Gait disturbance, limb spasticity, cerebellar signs, and optic atrophy are other common features associated with INAD. Although magnetic resonance imaging (MRI) can sometimes contribute towards the diagnosis, the confirmation of INAD is by Pla2G6 gene analysis. In this case report, we describe the first individual (female) with INAD due to a combination of uniparental heterodisomy and isodisomy; we discuss the possible underlying mechanism and highlight the importance of parental carrier testing in accurately predicting the recurrence risk in these families. We also confirm the recent report of hypertrophy of the clava (also known as the 'gracile tubercle') as a useful MRI sign in INAD.

Dermatosparaxis (Ehlers-Danlos type VIIC): prenatal diagnosis following a previous pregnancy with unexpected skull fractures at delivery.

Dermatosparaxis Ehlers-Danlos syndrome (or EDS VIIC), a rare autosomal recessive connective tissue disorder, is characterized by extreme skin fragility, premature rupture of membranes in pregnancy, and spontaneous rupture of internal organs. Here we report a second patient with EDS VIIC presenting with congenital skull fractures and skin lacerations at birth, complications which may occur more frequently than previously thought in this condition. We also discuss the role of prenatal diagnosis in the management of a subsequent normal pregnancy.

Poly(ADP-ribose) polymerase is hyperactivated in homologous recombination-defective cells.

Poly(ADP-ribose) (PAR) polymerase 1 (PARP1) is activated by DNA single-strand breaks (SSB) or at stalled replication forks to facilitate DNA repair. Inhibitors of PARP efficiently kill breast, ovarian, or prostate tumors in patients carrying hereditary mutations in the homologous recombination (HR) genes BRCA1 or BRCA2 through synthetic lethality. Here, we surprisingly show that PARP1 is hyperactivated in replicating BRCA2-defective cells. PARP1 hyperactivation is explained by the defect in HR as shRNA depletion of RAD54, RAD52, BLM, WRN, and XRCC3 proteins, which we here show are all essential for efficient HR and also caused PARP hyperactivation and correlated with an increased sensitivity to PARP inhibitors. BRCA2-defective cells were not found to have increased levels of SSBs, and PAR polymers formed in HR-defective cells do not colocalize to replication protein A or gammaH2AX, excluding the possibility that PARP hyperactivity is due to increased SSB repair or PARP induced at damaged replication forks. Resistance to PARP inhibitors can occur through genetic reversion in the BRCA2 gene. Here, we report that PARP inhibitor-resistant BRCA2-mutant cells revert back to normal levels of PARP activity. We speculate that the reason for the sensitivity of HR-defective cells to PARP inhibitors is related to the hyperactivated PARP1 in these cells. Furthermore, the presence of PAR polymers can be used to identify HR-defective cells that are sensitive to PARP inhibitors, which may be potential biomarkers.