Spatial transcriptomics reveals discrete tumour microenvironments and autocrine loops within ovarian cancer subclones.

High-grade serous ovarian carcinoma (HGSOC) is genetically unstable and characterised by the presence of subclones with distinct genotypes. Intratumoural heterogeneity is linked to recurrence, chemotherapy resistance, and poor prognosis. Here, we use spatial transcriptomics to identify HGSOC subclones and study their association with infiltrating cell populations. Visium spatial transcriptomics reveals multiple tumour subclones with different copy number alterations present within individual tumour sections. These subclones differentially express various ligands and receptors and are predicted to differentially associate with different stromal and immune cell populations. In one sample, CosMx single molecule imaging reveals subclones differentially associating with immune cell populations, fibroblasts, and endothelial cells. Cell-to-cell communication analysis identifies subclone-specific signalling to stromal and immune cells and multiple subclone-specific autocrine loops. Our study highlights the high degree of subclonal heterogeneity in HGSOC and suggests that subclone-specific ligand and receptor expression patterns likely modulate how HGSOC cells interact with their local microenvironment.

TRACEBACK: Testing of Historical Tubo-Ovarian Cancer Patients for Hereditary Risk Genes as a Cancer Prevention Strategy in Family Members.

PURPOSE: Tubo-ovarian cancer (TOC) is a sentinel cancer for BRCA1 and BRCA2 pathogenic variants (PVs). Identification of a PV in the first member of a family at increased genetic risk (the proband) provides opportunities for cancer prevention in other at-risk family members. Although Australian testing rates are now high, PVs in patients with TOC whose diagnosis predated revised testing guidelines might have been missed. We assessed the feasibility of detecting PVs in this population to enable genetic risk reduction in relatives. PATIENTS AND METHODS: In this pilot study, deceased probands were ascertained from research cohort studies, identification by a relative, and gynecologic oncology clinics. DNA was extracted from archival tissue or stored blood for panel sequencing of 10 risk-associated genes. Testing of deceased probands ascertained through clinic records was performed with a consent waiver. RESULTS: We identified 85 PVs in 84 of 787 (11%) probands. Familial contacts of 39 of 60 (65%) deceased probands with an identified recipient (60 of 84; 71%) have received a written notification of results, with follow-up verbal contact made in 85% (33 of 39). A minority of families (n = 4) were already aware of the PV. For many (29 of 33; 88%), the genetic result provided new information and referral to a genetic service was accepted in most cases (66%; 19 of 29). Those who declined referral (4 of 29) were all male next of kin whose family member had died more than 10 years before. CONCLUSION: We overcame ethical and logistic challenges to demonstrate that retrospective genetic testing to identify PVs in previously untested deceased probands with TOC is feasible. Understanding reasons for a family member's decision to accept or decline a referral will be important for guiding future TRACEBACK projects.

Advance care planning documentation strategies; goals-of-care as an alternative to not-for-resuscitation in medical and oncology patients. A pre-post controlled study on quantifiable outcomes.

BACKGROUND: Health services in Tasmania, Victoria and now Western Australia are changing to goals-of-care (GOC) advance care planning (ACP) documentation strategies. AIM: To compare the clinical impact of two different health department-sanctioned ACP documentation strategies. METHODS: A non-blinded, pre-post, controlled study over two corresponding 6-month periods in 2016 and 2017 comparing the current discretional not-for-resuscitation (NFR) with a new, inclusive GOC strategy in two medical/oncology wards at a large private hospital. Main outcomes were the uptake of ACP forms per hospitalisation and the timing between hospital admission, ACP form completion and in-patient death. Secondary outcomes included utilisation of the rapid response team (RRT), palliative and critical care services. RESULTS: In total, 650 NFR and 653 GOC patients underwent 1885 admissions (mean Charlson Comorbidity Index = 3.7). GOC patients had a higher uptake of ACP documentation (346 vs 150 ACP forms per 1000 admissions, P < 0.0001) and a higher proportion of ACP forms completed within the first 48 h of admission (58 vs 39%, P = 0.0002) but a higher incidence of altering the initial ACP level of care (P = 0.003). All other measures, including ACP documentation within 48 h of death (P = 0.50), activation of RRT (P = 0.73) and admission to critical (P = 0.62) or palliative (P = 0.81) care services, remained similar. GOC documentation was often incomplete, with most sub-sections left blank between 74 and 87% of occasions. CONCLUSION: Despite an increased uptake of the GOC form, overall use remained low, written completion was poor, and most quantitative outcomes remained statistically unchanged. Further research is required before a wider GOC implementation can be supported in Australia's healthcare systems.