Cascade testing for hereditary cancer in Singapore: how population genomics help guide clinical policy.

Hereditary Cancer makes up around 5-10% of all cancers. It is important to diagnose hereditary cancer in a timely fashion, as not only do patients require long-term care from a young age, but their relatives also require management. The main approach to capture at-risk relatives is cascade testing. It involves genetic testing of relatives of the first detected carrier of a pathogenic variant in a family i.e. the proband. The current standard of care for cascade testing is a patient-mediated approach. Probands are then advised to inform and encourage family members to undergo genetic testing. In Singapore, cascade testing is inefficient, around 10-15%, lower than the 30% global average. Here, we describe the cascade testing process and its effort to increase testing in Singapore. Precision Health Research, Singapore (PRECISE), was set up to coordinate Singapore's National Precision Medicine strategy and has awarded five clinical implementation pilots, with one of them seeking to identify strategies for how cascade testing for hereditary cancer can be increased in a safe and cost-efficient manner. Achieving this will be done through addressing barriers such as cost, manpower shortages, exploring a digital channel for contacting at-risk relatives, and getting a deeper insight into why genetic testing gets declined. If successful, it will likely result in care pathways that are a cost-effective public health intervention for identifying individuals at risk. Surveillance and management of those unaffected at-risk individuals, if caught early, will result in improved patient outcomes, and further reduce the healthcare burden for the economy.

Strategies to improve implementation of cascade testing in hereditary cancer syndromes: a systematic review.

Hereditary cancer syndromes constitute approximately 10% of all cancers. Cascade testing involves testing of at-risk relatives to determine if they carry the familial pathogenic variant. Despite growing efforts targeted at improving cascade testing uptake, current literature continues to reflect poor rates of uptake, typically below 30%. This study aims to systematically review current literature on intervention strategies to improve cascade testing, assess the quality of intervention descriptions and evaluate the implementation outcomes of listed interventions. We searched major databases using keywords and subject heading of "cascade testing". Interventions proposed in each study were classified according to the Effective Practice and Organization of Care (EPOC) taxonomy. Quality of intervention description was assessed using the TIDieR checklist, and evaluation of implementation outcomes was performed using Proctor's Implementation Outcomes Framework. Improvements in rates of genetic testing uptake was seen in interventions across the different EPOC taxonomy strategies. The average TIDieR score was 7.3 out of 12. Items least reported include modifications (18.5%), plans to assess fidelity/adherence (7.4%) and actual assessment of fidelity/adherence (7.4%). An average of 2.9 out of 8 aspects of implementation outcomes were examined. The most poorly reported outcomes were cost, fidelity and sustainability, with only 3.7% of studies reporting them. Most interventions have demonstrated success in improving cascade testing uptake. Uptake of cascade testing was highest with delivery arrangement (68%). However, the quality of description of interventions and assessment of implementation outcomes are often suboptimal, hindering their replication and implementation downstream. Therefore, further adoption of standardized guidelines in reporting of interventions and formal assessment of implementation outcomes may help promote translation of these interventions into routine practice.

A Systematic Review of Diagnostic Modalities and Strategies for the Assessment of Complications in Adult Patients with Neurofibromatosis Type 1.

BACKGROUND: Neurofibromatosis Type 1 is an autosomal dominant tumour-predisposition condition commonly diagnosed in childhood and fully penetrant by adulthood. Long-term monitoring through imaging is inconsistent and varies between high- and low-income countries. Implementation of a clinical practice guideline through a multidisciplinary clinic is instrumental to the care of adult Neurofibromatosis Type 1 patients. We aim to systematically review international diagnostic modalities and strategies to evaluate any association between a country's socioeconomic status and diagnostic modalities or strategies used for Neurofibromatosis Type 1 patients. METHODS: We searched PubMed, Embase, Web of Science, and Cochrane. Relevant clinical information on the surveillance of adult Neurofibromatosis Type 1 patients worldwide was reviewed, extracted, and synthesised. RESULTS: We identified 51 papers reporting on 7724 individuals. Multiple imaging modalities are actively employed in high-income and upper-middle-income countries for surveying adult Neurofibromatosis Type 1 patients. We did not find any relevant papers from low- and middle-income countries. CONCLUSIONS: This systematic review suggests that there is robust data on diagnostic modalities for adult Neurofibromatosis Type 1 patients in high-income countries, but not for low- and middle-income countries. There is a lack of data on consolidated diagnostic strategies from both high- and low-income countries. Efforts should be made to publish data on usual clinical practice in low- and middle-income countries to develop clinical practice guidelines describing best medical practice to fit a local context.

Age-specific breast and ovarian cancer risks associated with germline BRCA1 or BRCA2 pathogenic variants - an Asian study of 572 families.

Background: Clinical management of Asian BRCA1 and BRCA2 pathogenic variants (PV) carriers remains challenging due to imprecise age-specific breast (BC) and ovarian cancer (OC) risks estimates. We aimed to refine these estimates using six multi-ethnic studies in Asia. Methods: Data were collected on 271 BRCA1 and 301 BRCA2 families from Malaysia and Singapore, ascertained through population/hospital-based case-series (88%) and genetic clinics (12%). Age-specific cancer risks were estimated using a modified segregation analysis method, adjusted for ascertainment. Findings: BC and OC relative risks (RRs) varied across age groups for both BRCA1 and BRCA2. The age-specific RR estimates were similar across ethnicities and country of residence. For BRCA1 carriers of Malay, Indian and Chinese ancestry born between 1950 and 1959 in Malaysia, the cumulative risk (95% CI) of BC by age 80 was 40% (36%-44%), 49% (44%-53%) and 55% (51%-60%), respectively. The corresponding estimates for BRCA2 were 29% (26-32%), 36% (33%-40%) and 42% (38%-45%). The corresponding cumulative BC risks for Singapore residents from the same birth cohort, where the underlying population cancer incidences are higher compared to Malaysia, were higher, varying by ancestry group between 57 and 61% for BRCA1, and between 43 and 47% for BRCA2 carriers. The cumulative risk of OC by age 80 was 31% (27-36%) for BRCA1 and 12% (10%-15%) for BRCA2 carriers in Malaysia born between 1950 and 1959; and 42% (34-50%) for BRCA1 and 20% (14-27%) for BRCA2 carriers of the same birth cohort in Singapore. There was evidence of increased BC and OC risks for women from >1960 birth cohorts (p-value = 3.6 × 10-5 for BRCA1 and 0.018 for BRCA2). Interpretation: The absolute age-specific cancer risks of Asian carriers vary depending on the underlying population-specific cancer incidences, and hence should be customised to allow for more accurate cancer risk management. Funding: Wellcome Trust [grant no: v203477/Z/16/Z]; CRUK (PPRPGM-Nov20∖100002).

Recent updates on central nervous system prophylaxis in patients with high-risk diffuse large B-cell lymphoma.

The use of central nervous system (CNS) prophylaxis for patients with diffuse large B-cell lymphoma (DLBCL) remains controversial. Although uncommon, CNS relapses are invariably fatal in this otherwise curable disease. Accurate identification of patients at risk and the optimal approach to CNS prophylaxis therefore remains an area of unmet need. The existing literature, largely retrospective in nature, provides mixed conclusions regarding the efficacy of CNS prophylaxis. The utility of CNS prophylaxis has itself been challenged. In this review, we dissect the issues which render the value of CNS prophylaxis uncertain. We first compare international clinical guidelines for CNS prophylaxis. We then interrogate the factors that should be used to identify high-risk patients accurately. We also explore how clinical patterns of CNS relapse have changed in the pre-rituximab and rituximab era. We then discuss the efficacy of CNS-directed approaches, intensification of systemic treatment and other novel approaches in CNS prophylaxis. Improved diagnostics for early detection of CNS relapses and newer therapeutics for CNS prophylaxis are areas of active investigation. In an area where prospective, randomized studies are impracticable and lacking, guidance for the use of CNS prophylaxis will depend on rigorous statistical review of retrospective data.

A Systematic Review and Meta-Analysis of Mapping Biopsy for Primary Extramammary Paget's Disease in Reducing Recurrence Following Surgical Excision.

Objective: To examine the association between the performance of mapping biopsies and surgical outcomes postexcision of extramammary Paget's disease (EMPD). Background: Primary EMPD is a rare entity associated with poorly defined surgical margins and difficult-to-access sites of lesions. Surgical resection with clear margins remains the preferred management method. The use of mapping biopsies might be beneficial, particularly in lowering disease recurrence. Methods: Available literature was reviewed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology before a fixed-effect meta-analysis was performed to identify the presence of a correlation between performing mapping biopsies and positive margins on permanent sections as well as disease-free survival. Additional study results not included in the quantitative assessment were qualitatively assessed and reported. Results: A total of 12 studies were shortlisted for final analysis. 294 patients who underwent mapping biopsies and 48 patients who did not undergo mapping biopsies were included in the assessment. Forest plot analysis revealed a pooled rate ratio of 0.50 (95% CI, 0.32-0.77) in the prevalence of positive margins in patients with mapping biopsies performed as compared to patients without. The pooled rate ratio of the prevalence of disease-free survival in patients with mapping biopsies performed as compared to patients without was 1.38 (95% CI, 1.03-1.84). Qualitative assessment of the remaining selected studies revealed equivocal results. Conclusions: Mapping biopsies are able to improve EMPD surgical excision outcomes but given the rarity of the disease and heterogeneity of mapping biopsy procedures, further confirmation with randomized controlled trials or a larger patient pool is necessary.

Pazopanib elicits remarkable response in metastatic porocarcinoma: a functional precision medicine approach.

Metastatic porocarcinomas (PCs) are vanishingly rare, highly aggressive skin adnexal tumors with mortality rates exceeding 70%. Their rarity has precluded the understanding of their disease pathogenesis, let alone the conduct of clinical trials to evaluate treatment strategies. There are no effective agents for unresectable PCs. Here, we successfully demonstrate how functional precision medicine was implemented in the clinic for a metastatic PC with no known systemic treatment options. Comprehensive genomic profiling of the tumor specimen did not yield any actionable genomic aberrations. However, ex vivo drug testing predicted pazopanib efficacy, and indeed, administration of pazopanib elicited remarkable clinicoradiological response. Pazopanib and its class of drugs should be evaluated for efficacy in other cases of PC, and the rationale for efficacy should be determined when PC tumor models become available. A functional precision medicine approach could be useful to derive effective treatment options for rare cancers.

Cancer patients' experience of receiving variant of uncertain significance results: An Asian perspective.

Due to a lack of ancestry-matched, functional, and segregation data, Asians have a higher rate of receiving a variant of uncertain significance (VUS) result following panel testing. Managing VUS results presents challenges, as it often leads to increased anxiety and distress among cancer patients undergoing genetic testing. This exploratory study aims to investigate the experience of Asian cancer patients upon receiving a VUS result. A qualitative, semi-structured interview study was conducted, involving cancer patients who had received a VUS result through the Cancer Genetics Service of the National Cancer Centre Singapore. Twenty participants were interviewed, and their responses were transcribed and analyzed using thematic analysis to identify key themes. Thematic analysis revealed five major themes: (1) VUS results are interpreted as uncertain outcomes; (2) a VUS result provides relief and prompts positive behavioral adjustments; (3) patients employ fatalism and religion as coping mechanisms to navigate uncertainty; (4) genetic counselors, family, and the community offer reassurance and support; (5) patients value updates on variant classifications for future management. While this novel study provides unique insights into the perspectives of Asian patients who receive VUS results, it also highlights patients' effective management of VUS results and uncertainty, which has implications for improving counseling practices in Asia. Emphasis must be placed on accurate interpretation and clear communication of VUS results to dispel the possibility of misconceptions, misdiagnosis, and mismanagement in cancer care.

Metastatic Gastric Mucosal Melanoma: A Rare Case Presenting With Diffuse Gastric Polyposis.

We report a 66-year-old Chinese lady who presented with a three-month history of postprandial vomiting, early satiety, anorexia and weight loss, and significant physical findings of hepatomegaly and ascites. Gastroscopy revealed gastric polyposis with both hyperpigmented and unpigmented lesions over the gastric fundus, body, and proximal antrum, biopsies of which yielded malignant melanoma histologically. Cross-sectional imaging with CT also demonstrated extensive hepatic and bony metastases. No cutaneous or ocular primary was detected. She was treated with a combination of ipilimumab and nivolumab but developed interval progression of hepatic metastases after two cycles of immunotherapy. The patient eventually succumbed two months after diagnosis.

Clinical features and prognostic outcomes of angioimmunoblastic T cell lymphoma in an Asian multicenter study.

In our Asian multicenter retrospective study, we investigated the clinical prognostic factors affecting the outcomes of AITL patients and identified a novel prognostic index relevant in the Asian context. In our 174-patient cohort, the median PFS and OS was 1.8 years and 5.6 years respectively. Age > 60, bone marrow involvement, total white cell count >12 × 109/L and raised serum lactate dehydrogenase were associated with poorer PFS and OS in multivariate analyses. This allowed for a prognostic index (AITL-PI) differentiating patients into low (0-1 factors, n = 64), moderate (2 factors, n = 59) and high-risk (3-4 factors, n = 49) subgroups with 5-year OS of 84.0%, 44.0% and 28.0% respectively (p < 0.0001). POD24 proved to be strongly prognostic (5-year OS 24% vs 89%, p < 0.0001). Exploratory gene expression studies were performed and disparate immune cell profiles and cell signaling signatures were seen in the low risk group as compared to the intermediate and high risk groups.