Medicine (RMH) - Research Publications
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ItemNo Preview AvailableA tumor focused approach to resolving the etiology of DNA mismatch repair deficient tumors classified as suspected Lynch syndrome.( 2023-03-01)Routine screening of tumors for DNA mismatch repair (MMR) deficiency (dMMR) in colorectal (CRC), endometrial (EC) and sebaceous skin (SST) tumors leads to a significant proportion of unresolved cases classified as suspected Lynch syndrome (SLS). SLS cases (n=135) were recruited from Family Cancer Clinics across Australia and New Zealand. Targeted panel sequencing was performed on tumor (n=137; 80xCRCs, 33xECs and 24xSSTs) and matched blood-derived DNA to assess for microsatellite instability status, tumor mutation burden, COSMIC tumor mutational signatures and to identify germline and somatic MMR gene variants. MMR immunohistochemistry (IHC) and MLH1 promoter methylation were repeated. In total, 86.9% of the 137 SLS tumors could be resolved into established subtypes. For 22.6% of these resolved SLS cases, primary MLH1 epimutations (2.2%) as well as previously undetected germline MMR pathogenic variants (1.5%), tumor MLH1 methylation (13.1%) or false positive dMMR IHC (5.8%) results were identified. Double somatic MMR gene mutations were the major cause of dMMR identified across each tumor type (73.9% of resolved cases, 64.2% overall, 70% of CRC, 45.5% of ECs and 70.8% of SSTs). The unresolved SLS tumors (13.1%) comprised tumors with only a single somatic (7.3%) or no somatic (5.8%) MMR gene mutations. A tumor-focused testing approach reclassified 86.9% of SLS into Lynch syndrome, sporadic dMMR or MMR-proficient cases. These findings support the incorporation of tumor sequencing and alternate MLH1 methylation assays into clinical diagnostics to reduce the number of SLS patients and provide more appropriate surveillance and screening recommendations.
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ItemShould I take aspirin? A qualitative study on the implementation of a decision aid on taking aspirin for bowel cancer prevention(BMJ PUBLISHING GROUP, 2023-11)OBJECTIVES: Australian guidelines recommend 50-70 years consider taking aspirin to reduce their bowel cancer risk. We trialled a decision aid in general practice to facilitate the implementation of these guidelines into clinical practice. This publication reports on the qualitative results from the process evaluation of the trial. We aimed to explore general practitioners' (GPs) and their patients' approach to shared decision-making (SDM) about taking aspirin to prevent bowel cancer and how the decision aids were used in practice. METHODS: Semistructured interviews were conducted with 17 participants who received the decision aid and 12 GPs who participated in the trial between June and November 2021. The interviews were coded inductively, and emerging themes were mapped onto the Revised Programme Theory for SDM. RESULTS: The study highlighted the dynamics of SDM for taking aspirin to prevent bowel cancer. Some participants discussed the decision aid with their GPs as advised prior to taking aspirin, others either took aspirin or dismissed it outright without discussing it with their GPs. Notably, participants' trust in their GPs, and participants' diverse worldviews played pivotal roles in their decisions. Although the decision aid supported SDM for some, it was not always prioritised in a consultation. This was likely impacted during the trial period as the COVID-19 pandemic was the focus for general practice. CONCLUSION: In summary, this study illustrated the complexities of SDM through using a decision aid in general practice to implement the guidelines for low-dose aspirin to prevent bowel cancer. While the decision aid prompted some participants to speak to their GPs, they were also heavily influenced by their unwavering trust in the GPs and their different worldviews. In the face of the COVID-19 pandemic, SDM was not highly prioritised. This study provides insights into the implementation of guidelines into clinical practice and highlights the need for ongoing support and prioritisation of cancer prevention in general practice consultations. TRIAL REGISTRATION NUMBER: ACTRN12620001003965.
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ItemNo Preview AvailableSMARTERscreen protocol: A three-arm cluster randomised controlled trial of patient SMS messaging in general practice to increase participation in the Australian National Bowel Cancer Screening Program.(Research Square Platform, 2023-10-16)Abstract Background: Australia persistently has one of the highest rates of colorectal cancer (CRC) in the world. Australia’s National Bowel Cancer Screening Program (NBCSP) sends a biennial Faecal Immunochemical Test (FIT) – the ‘NBCSP kit’ - to everyone eligible for the Program between 50-74 years old, however participation in the program is low, especially in the 50- to 60-year-old age group. Our previous efficacy trial (‘SMARTscreen’) demonstrated an absolute increase in uptake of 16.5% (95% confidence interval:2.02-30.9%) for people sent an SMS with motivational and instructional videos, from their general practice prior to receiving their NBCSP kit, compared to those receiving usual care. Building on the strengths of the SMARTscreen trial and addressing limitations, the ‘SMARTERscreen’ trial will test the effect on participation in the NBCSP of sending either an SMS only or an SMS with online video material to general practice patients due to receive their NBCSP compared to ‘usual care’. Methods: SMARTERscreen is a three-arm stratified cluster randomised controlled trial involving 63 general practices in two states in Australia. Eligible patients who are aged 49-60 years and due to receive their NBCSP kit within next two weeks during the intervention period. General practices will be equally randomised to three trial arms (21:21:21, average 260 patients/practice). The two interventions include: i) an SMS with an encouraging message from their general practice, or ii) the same SMS with web-links to additional motivational and instructional videos. The control arm will receive ‘usual care’. Using the intention-to-treat approach, primary analysis will estimate the three pair-wise between-arm differences in the proportion of eligible patients who participate in the NBCSP within 6-months of when their kit is sent, utilising screening data from the Australian National Cancer Screening Register (NCSR). Patient intervention adherence to the interventions will also be evaluated. Findings will be incorporated into the Policy1-Bowel microsimulation model to estimate the long-term health benefits and cost-effectiveness of the interventions. Discussion: SMARTERscreen will provide high-level evidence determining whether an SMS or an SMS with web-based material sent to general practice patients prior to receiving their NBCSP kit increases participation in bowel cancer screening. Trial registration: Australian New Zealand Clinical Trials Registry: ACTRN12623000036617, 13th January 2023. Trial URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385119&isClinicalTrial=False
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ItemNo Preview AvailableThe Colorectal cancer RISk Prediction (CRISP) trial: a randomised controlled trial of a decision support tool for risk-stratified colorectal cancer screening(ROYAL COLL GENERAL PRACTITIONERS, 2023-08)BACKGROUND: A risk-stratified approach to colorectal cancer (CRC) screening could result in a more acceptable balance of benefits and harms, and be more cost-effective. AIM: To determine the effect of a consultation in general practice using a computerised risk assessment and decision support tool (Colorectal cancer RISk Prediction, CRISP) on risk-appropriate CRC screening. DESIGN AND SETTING: Randomised controlled trial in 10 general practices in Melbourne, Australia, from May 2017 to May 2018. METHOD: Participants were recruited from a consecutive sample of patients aged 50-74 years attending their GP. Intervention consultations included CRC risk assessment using the CRISP tool and discussion of CRC screening recommendations. Control group consultations focused on lifestyle CRC risk factors. The primary outcome was risk-appropriate CRC screening at 12 months. RESULTS: A total of 734 participants (65.1% of eligible patients) were randomised (369 intervention, 365 control); the primary outcome was determined for 722 (362 intervention, 360 control). There was a 6.5% absolute increase (95% confidence interval [CI] = -0.28 to 13.2) in risk-appropriate screening in the intervention compared with the control group (71.5% versus 65.0%; odds ratio [OR] 1.36, 95% CI = 0.99 to 1.86, P = 0.057). In those due CRC screening during follow-up, there was a 20.3% (95% CI = 10.3 to 30.4) increase (intervention 59.8% versus control 38.9%; OR 2.31, 95% CI = 1.51 to 3.53, P<0.001) principally by increasing faecal occult blood testing in those at average risk. CONCLUSION: A risk assessment and decision support tool increases risk-appropriate CRC screening in those due screening. The CRISP intervention could commence in people in their fifth decade to ensure people start CRC screening at the optimal age with the most cost-effective test.
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ItemDNA Mismatch Repair Gene Variant Classification: Evaluating the Utility of Somatic Mutations and Mismatch Repair Deficient Colonic Crypts and Endometrial Glands(MDPI, 2023-10)Germline pathogenic variants in the DNA mismatch repair (MMR) genes (Lynch syndrome) predispose to colorectal (CRC) and endometrial (EC) cancer. Lynch syndrome specific tumor features were evaluated for their ability to support the ACMG/InSiGHT framework in classifying variants of uncertain clinical significance (VUS) in the MMR genes. Twenty-eight CRC or EC tumors from 25 VUS carriers (6xMLH1, 9xMSH2, 6xMSH6, 4xPMS2), underwent targeted tumor sequencing for the presence of microsatellite instability/MMR-deficiency (MSI-H/dMMR) status and identification of a somatic MMR mutation (second hit). Immunohistochemical testing for the presence of dMMR crypts/glands in normal tissue was also performed. The ACMG/InSiGHT framework reclassified 7/25 (28%) VUS to likely pathogenic (LP), three (12%) to benign/likely benign, and 15 (60%) VUS remained unchanged. For the seven re-classified LP variants comprising nine tumors, tumor sequencing confirmed MSI-H/dMMR (8/9, 88.9%) and a second hit (7/9, 77.8%). Of these LP reclassified variants where normal tissue was available, the presence of a dMMR crypt/gland was found in 2/4 (50%). Furthermore, a dMMR endometrial gland in a carrier of an MSH2 exon 1-6 duplication provides further support for an upgrade of this VUS to LP. Our study confirmed that identifying these Lynch syndrome features can improve MMR variant classification, enabling optimal clinical care.
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ItemNo Preview AvailableSMARTERscreen protocol: a three-arm cluster randomised controlled trial of patient SMS messaging in general practice to increase participation in the Australian National Bowel Cancer Screening Program(BMC, 2023-11-13)BACKGROUND: Australia persistently has one of the highest rates of colorectal cancer (CRC) in the world. Australia's National Bowel Cancer Screening Program (NBCSP) sends a biennial Faecal Immunochemical Test (FIT)-the 'NBCSP kit'-to everyone eligible for the programme between 50 and 74 years old; however, participation in the programme is low, especially in the 50- to 60-year-old age group. Our previous efficacy trial ('SMARTscreen') demonstrated an absolute increase in uptake of 16.5% (95% confidence interval = 2.02-30.9%) for people sent an SMS with motivational and instructional videos, from their general practice prior to receiving their NBCSP kit, compared to those receiving usual care. Building on the strengths of the SMARTscreen trial and addressing limitations, the 'SMARTERscreen' trial will test the effect on participation in the NBCSP of sending either an SMS only or an SMS with online video material to general practice patients due to receive their NBCSP compared to 'usual care'. METHODS: SMARTERscreen is a three-arm stratified cluster randomised controlled trial involving 63 general practices in two states in Australia. Eligible patients are patients who are aged 49-60 years and due to receive their NBCSP kit within the next 2 weeks during the intervention period. General practices will be equally randomised to three trial arms (21:21:21, estimated average 260 patients/practice). The two interventions include (i) an SMS with an encouraging message from their general practice or (ii) the same SMS with weblinks to additional motivational and instructional videos. The control arm will receive 'usual care'. Using the intention-to-treat approach, primary analysis will estimate the three pair-wise between-arm differences in the proportion of eligible patients who participate in the NBCSP within 6 months of when their kit is sent, utilising screening data from the Australian National Cancer Screening Register (NCSR). Patient intervention adherence to the interventions will also be evaluated. Findings will be incorporated into the Policy1-Bowel microsimulation model to estimate the long-term health benefits and cost-effectiveness of the interventions. DISCUSSION: SMARTERscreen will provide high-level evidence determining whether an SMS or an SMS with web-based material sent to general practice patients prior to receiving their NBCSP kit increases participation in bowel cancer screening. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12623000036617. Registered on 13 January 2023. Trial URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=385119&isClinicalTrial=False.
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ItemA mosaic pathogenic variant in MSH6 causes MSH6-deficient colorectal and endometrial cancer in a patient classified as suspected Lynch syndrome: a case report(SPRINGER, 2023-10)Germline pathogenic variants in the DNA mismatch repair (MMR) genes (Lynch syndrome) predispose to colorectal (CRC) and endometrial (EC) cancer. However, mosaic variants in the MMR genes have been rarely described. We identified a likely de novo mosaic MSH6:c.1135_1139del p.Arg379* pathogenic variant in a patient diagnosed with suspected Lynch syndrome/Lynch-like syndrome. The patient developed MSH6-deficient EC and CRC at 54 and 58 years of age, respectively, without a detectable germline MMR pathogenic variant. Multigene panel sequencing of tumor and blood-derived DNA identified an MSH6 somatic mutation (MSH6:c.1135_1139del p.Arg379*) common to both the EC and CRC, raising suspicion of mosaicism. A droplet digital polymerase chain reaction (ddPCR) assay detected the MSH6 variant at 5.34% frequency in normal colonic tissue, 3.49% in saliva and 1.64% in blood DNA, demonstrating the presence of the MSH6 variant in all three germ layers. This study highlights the utility of tumor sequencing to guide sensitive ddPCR testing to detect low-level mosaicism in the MMR genes. Further investigation of the prevalence of MMR mosaicism is needed to inform routine diagnostic approaches and genetic counselling.
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ItemThe Risk-Reducing Effect of Aspirin in Lynch Syndrome Carriers: Development and Evaluation of an Educational Leaflet.(Wiley, 2022-06)Carriers of germline mutations in genes associated with Lynch syndrome are at increased risk for colorectal, endometrial, ovarian, and other cancers. There is evidence that daily consumption of aspirin may reduce cancer risk in these individuals. There is a need for educational resources to inform carriers of the risk-reducing effects of aspirin or to support decision-making. An educational leaflet describing the risks and benefits of using aspirin as risk-reducing medicine in carriers of Lynch-syndrome-related mutations is developed and pilot tested in 2017. Carriers are ascertained through a familial cancer clinic and surveyed using a mailed, self-administered questionnaire. The leaflet is highly rated for its content, clarity, length, relevance, and visual appeal by more than 70% of the participants. Most participants (91%) report "a lot" or "quite a bit" of improvement in perceived understanding in knowledge about who might benefit from taking aspirin, its benefits, how long to take it, the reduction in bowel cancer risk, and the optimal dosage. A few (14%) participants seek more information on the dosage of aspirin. This leaflet will be useful as an aid to facilitate discussion between patients and their health care professionals about the use of aspirin as a risk-reducing medication.
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ItemThe Effects of the COVID Pandemic on Patients with IBD: Lessons Learned and Future Directions.(MDPI AG, 2022-11-27)The COVID-19 pandemic has caused extended global disruption and changed healthcare behaviour and delivery in patients with inflammatory bowel disease, many of whom take immune modifying treatment. Although there were fears about the vulnerability of IBD patients to SARS-CoV-2 infection, we have learnt that overall IBD patients are equivalent to the general population in both viral acquisition and infection outcomes. Overall IBD patients obtain effective vaccine-induced immune responses, although in some groups an additional vaccine dose is required to constitute a primary course. The pandemic has led to significant changes in healthcare delivery, some of which will be enduring. As we grapple with the challenges of recovery, the lessons learnt will continue to be important in optimising outcomes in future outbreaks.
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ItemA scoping review and meta-analysis on the prevalence of pan-tumour biomarkers (dMMR, MSI, high TMB) in different solid tumours(NATURE PORTFOLIO, 2022-11-28)Immune checkpoint inhibitors have been approved in the USA for tumours exhibiting mismatch repair deficiency (dMMR), microsatellite instability (MSI), or high tumour mutational burden (TMB), with regulatory and reimbursement applications in multiple other countries underway. As the estimated budget impacts of future reimbursements depend on the size of the potential target population, we performed a scoping review and meta-analysis of the prevalence of these pan-tumour biomarkers in different cancers. We systematically searched Medline/Embase and included studies reporting the prevalence of dMMR/MSI/high TMB in solid tumours published 01/01/2018-31/01/2021. Meta-analyses were performed separately for the pan-cancer prevalence of each biomarker, and by cancer type and stage where possible. The searches identified 3890 papers, with 433 prevalence estimates for 32 different cancer types from 201 studies included in meta-analyses. The pooled overall prevalence of dMMR, MSI and high TMB (≥ 10 mutations/Mb) in pan-cancer studies was 2.9%, 2.7% and 14.0%, respectively. The prevalence profiles of dMMR/MSI and high TMB differed across cancer types. For example, endometrial, colorectal, small bowel and gastric cancers showed high prevalence of both dMMR and MSI (range: 8.7-26.8% and 8.5-21.9%, respectively) and high TMB (range: 8.5-43.0%), while cervical, esophageal, bladder/urothelial, lung and skin cancers showed low prevalence of dMMR and MSI (< 5%), but high prevalence of high TMB (range: 23.7-52.6%). For other cancer types, prevalence of all three biomarkers was generally low (< 5%). This structured review of dMMR/MSI/high TMB prevalence across cancers and for specific cancer types and stages provide timely evidence to inform budget impact forecasts in health technology assessments for drug approvals based on these pan-tumour biomarkers.