Secondary auditory cortex mediates a sensorimotor mechanism for action timing.

The ability to accurately determine when to perform an action is a fundamental brain function and vital to adaptive behavior. The behavioral mechanism and neural circuit for action timing, however, remain largely unknown. Using a new, self-paced action timing task in mice, we found that deprivation of auditory, but not somatosensory or visual input, disrupts learned action timing. The hearing effect was dependent on the auditory feedback derived from the animal's own actions, rather than passive environmental cues. Neuronal activity in the secondary auditory cortex was found to be both correlated with and necessary for the proper execution of learned action timing. Closed-loop, action-dependent optogenetic stimulation of the specific task-related neuronal population within the secondary auditory cortex rescued the key features of learned action timing under auditory deprivation. These results unveil a previously underappreciated sensorimotor mechanism in which the secondary auditory cortex transduces self-generated audiomotor feedback to control action timing.

Low-coverage whole-genome sequencing of extracellular vesicle-associated DNA in patients with metastatic cancer.

Low-coverage whole-genome sequencing (LC-WGS) can provide insight into oncogenic molecular changes. Serum extracellular vesicles (EV) represent a novel liquid biopsy source of tumoral DNA. This study compared copy number alteration (CNA) profiles generated from LC-WGS of formalin-fixed paraffin-embedded (FFPE) tumoral DNA and EV-DNA obtained from cancer patients. Patients with squamous cell carcinoma of the base of tongue (n = 3) and cutaneous squamous cell carcinoma (n = 2) were included. LC-WGS (0.5-1X coverage) was performed on FFPE-DNA and serum EV-DNA. Similarity between CNA profiles was analysed using QDNAseq. FFPE samples had a mean CNA of 31 (range 17-50) over 1.9 × 109 (range 1.0-2.6 × 109) bp in length, and EV samples had a mean CNA value of 17 (range 7-19) over 7.6 × 108 (range 2.9-15 × 108) bp in length. A mean of 8 (range 0-21) CNA over 5.9 × 108 (range 1.6-14 × 108) bp in length was found to overlap between EV and FFPE-derived samples per patient. Although the mean correlation efficient between samples was r = 0.34 (range - .08 to 0.99), this was not statistically significant (p > 0.05). Regions of highest deletion and duplication in FFPE samples were not well reflected in the EV-DNA. Selected CNA regions in EV-associated DNA were reflective of the primary tumor, however appreciation of global CNA and areas of most significant change was lost. The utility of LC-WGS of EV-derived DNA is likely limited to molecular alterations of known interest.

Comparison of Circulating Tumour DNA and Extracellular Vesicle DNA by Low-Pass Whole-Genome Sequencing Reveals Molecular Drivers of Disease in a Breast Cancer Patient.

There is increasing recognition of circulating tumour DNA (ctDNA) as a non-invasive alternative to tumour tissue for the molecular characterisation and monitoring of disease. Recent evidence suggests that cancer-associated changes can also be detected in the DNA contained within extracellular vesicles (EVs). As yet, there has been limited investigation into the relationship between EV DNA and ctDNA, and no studies have examined the EV DNA of breast cancer patients. The aim of this study was to use low-pass whole-genome sequencing to identify copy number variants (CNVs) in serial samples of both ctDNA and EV DNA from a patient with breast cancer. Of the 52 CNVs identified in tumour DNA, 36 (69%) were detected in at least one ctDNA sample and 13 (25%) in at least one EV DNA sample. The number of detectable variants in ctDNA and EV DNA increased over the natural history of the patient's disease, which was associated with progression to cerebral metastases. This case study demonstrates that, while CNVs are detectable in patient EV DNA, ctDNA has greater sensitivity than EV DNA for serial monitoring of breast cancer.

A comparative study of extracellular vesicle-associated and cell-free DNA and RNA for HPV detection in oropharyngeal squamous cell carcinoma.

PURPOSE: This study compares the detection sensitivity of two separate liquid biopsy sources, cell-free (cf) DNA/RNA and extracellular vesicle (EV)-associated DNA/RNA (EV-DNA/RNA), to identify circulating Human Papilloma Virus (HPV) DNA/RNA in plasma obtained from patients with oropharyngeal squamous cell carcinoma (OPCSCC). We also report on the longitudinal changes observed in HPV-DNA levels in response to treatment. EXPERIMENTAL DESIGN: A prospective study was conducted that included 22 patients with locally advanced disease and six patients with metastatic OPCSCC. Twenty-three patients had HPV-related OPCSCC defined by p16 immunohistochemistry. Levels of circulating HPV-DNA and HPV-RNA from plasma-derived cf-DNA/RNA and EV-DNA/RNA were quantified using digital droplet PCR. RESULTS: Circulating HPV-DNA was detected with higher sensitivity in cf-DNA compared to EV-DNA at 91% vs. 42% (p = <0.001). Similarly, circulating tumoral HPV-RNA was detected at a higher sensitivity in cf-RNA compared to EV-RNA, at 83% vs. 50% (p = 0.0019). In the locally advanced cohort, 100% (n = 16) of HPV-OPCSCC patients demonstrated a reduction in circulating HPV-DNA levels in cf-DNA following curative treatment, with 81% of patients demonstrating complete clearance to undetectable levels. However, in metastatic HPV-OPCSCC patients (n = 4), HPV-DNA levels did not correlate with treatment response. CONCLUSION: Our study demonstrates that although HPV-DNA/RNA can be detected in EV associated DNA/RNA, cf-DNA/RNA is the more sensitive liquid biopsy medium. As circulating HPV-DNA levels were found to only correlate with treatment response in the locally advanced but not metastatic setting in our small cohort of patients, the use of HPV-DNA as a dynamic biomarker to monitor treatment response requires further evaluation.

Combined ipilimumab and nivolumab first-line and after BRAF-targeted therapy in advanced melanoma.

The combination of ipilimumab and nivolumab is a highly active systemic therapy for metastatic melanoma but can cause significant toxicity. We explore the safety and efficacy of this treatment in routine clinical practice, particularly in the setting of serine/threonine-protein kinase B-Raf (BRAF)-targeted therapy. Consecutive patients with unresectable stage IIIC/IV melanoma commenced on ipilimumab and nivolumab across 10 tertiary melanoma institutions in Australia were identified retrospectively. Data collected included demographics, response and survival outcomes. A total of 152 patients were included for analysis, 39% were treatment-naïve and 22% failed first-line BRAF/MEK inhibitors. Treatment-related adverse events occurred in 67% of patients, grade 3-5 in 38%. The overall objective response rate was 41%, 57% in treatment-naïve and 21% in BRAF/MEK failure patients. Median progression-free survival was 4.0 months (95% CI, 3.0-6.0) in the whole cohort, 11.0 months (95% CI, 6.0-NR) in treatment-naïve and 2.0 months (95% CI, 1.4-4.6) in BRAF/MEK failure patients. The combination of ipilimumab and nivolumab can be used safely and effectively in a real-world population. While first-line efficacy appears comparable to trial populations, BRAF-mutant patients failing prior BRAF/MEK inhibitors show less response.

Real-world efficacy and toxicity of combined nivolumab and ipilimumab in patients with metastatic melanoma.

BACKGROUND: There is limited real-world data on the efficacy and safety of combination programmed cell death protein-1 (PD-1) inhibitor, nivolumab and the cytotoxic T-lymphocyte antigen (CTLA-4) inhibitor ipilimumab. METHOD: We retrospectively identified patients (pts) with metastatic melanoma treated with three-weekly nivolumab (1 mg/kg) in combination with ipilimumab (3 mg/kg) for four cycles followed by nivolumab monotherapy (3 mg/kg) fortnightly. Patient demographics and treatment parameters were collected and outcomes determined. RESULTS: A total of 45 pts received combination treatment with a median follow up of 8.7 months (range 0.33-25.9 months). A total of 67% were male, and BRAF V600 mutations detected in 38%. At treatment commencement, 14 (31%) pts had brain metastases, 51% had an elevated LDH and 18 (40%) were treatment-naive. Almost a third (30%) required corticosteroids for symptom control or management of prior toxicities. Nineteen (42%) patients had prior anti-PD-1 therapy. The disease control rate (DCR) was 54% and objective response rate (ORR) was 29%. Of pts treated with prior immune checkpoint inhibitors, the DCR and ORR were 50% and 33%, respectively. Intracranial responses were observed in 18% (n = 2). The median progression-free survival (PFS) was 5.8 months (95% Confidence interval (CI), 2.9-14.1 months). PFS was higher in treatment naïve patients compared to those who had prior immunotherapy (6.2 months vs 4.9 months, P = 0.59). The median OS was 17.4 months (95% CI, 7.1-NR). pts requiring corticosteroids had a shorter PFS (4.9 months vs 6.8 months) and OS (7.1 months vs NR, P = 0.01).Treatment-related adverse events of any grade were experienced by 88% of pts, with 54% having grade 3-4 adverse events. Treatment discontinuation due to adverse events occurred in 44% of pts. CONCLUSION: In this study, responses to combination immunotherapy were lower than reported. Patients treated with prior immunotherapy had similar responses as treatment-naïve pts. The toxicity profile seen in this study is similar to those reported in clinical trials.

Young adults diagnosed with high grade gliomas: Patterns of care, outcomes, and impact on employment.

There is limited information on the patterns of care and outcomes of high grade gliomas (HGGs) in young adults, in particular, the impact it has on a person's employment. We retrospectively identified young adult patients (age ≤ 40 years old) with newly diagnosed high grade gliomas treated between January 2013 and June 2018 across four major neuro-oncology centres in Australia. Patient demographics, tumour characteristics and treatment parameters were collected and outcomes determined. A total of 113 patients were identified with a median follow up of 27.0 months (range 1.0-70.2 months). The median age was 31 years, majority were male (65%) and employed (71.6%). IDH mutations were detected in 66 (62%) cases. The median progression-free survival (PFS) was 38.0 months (95% CI 23.3-52.7 months) and median overall survival (OS) was not reached. Patients with IDH wild type anaplastic astrocytoma and glioblastoma had a significantly shorter median PFS (19.3 months vs. NR, p = 0.001) and median OS (43.5 months vs NR, p = 0.007) than those with IDH mutated grade III anaplastic astrocytoma and oligodendroglioma. There was no significant difference in median OS or PFS between patients who underwent gross or subtotal tumour resection. Significantly, after diagnosis only 36 (32%) patients reported being employed. Young patients with IDH wild type astrocytomas and glioblastoma had better outcomes than reported historical controls. Most patients did not continue in employment post diagnosis.

Body composition and nutritional status in malignant pleural mesothelioma: implications for activity levels and quality of life.

BACKGROUND/OBJECTIVES: Malignant pleural mesothelioma (MPM) is an incurable cancer and optimizing daily physical activity and quality of life are key goals of patient management. Little is known about the prevalence of pre-sarcopenia and malnutrition in MPM or their associations with patient outcomes. This study aimed to determine the prevalence of pre-sarcopenia and malnutrition in MPM and investigate if activity levels and quality of life differed according to body composition and nutritional status. SUBJECTS/METHODS: Patients with a diagnosis of MPM were recruited. Pre-sarcopenia was defined as low appendicular skeletal muscle mass (≤ 7.26 kg/m2 for men and ≤ 5.45 kg/m2 for women), measured by dual energy X-ray absorptiometry. Malnutrition was defined as a rating of B or C on the Patient-Generated Subjective Global Assessment. Outcome measures included objective activity levels (Actigraph GT3X) and health-related quality of life (HRQoL; Functional Assessment of Cancer Therapy General). RESULTS: Sixty-one people participated (79% male, median age 69 [IQR 62-74] years and median BMI 25.8 [IQR 24.3-28.4] kg/m2). Fifty-four percent were pre-sarcopenic and 38% were malnourished. Percent of time spent in light activity/day was lower in participants with pre-sarcopenia compared with non-sarcopenic participants (median 25.4 [IQR 19.8-32.1]% vs. 32.3 [27.1-35.6]%; p = 0.008). Participants with malnutrition had poorer HRQoL than well-nourished participants (mean 69.0 (16.3) vs. 84.4 (13.3); p < 0.001). CONCLUSION: Participants with MPM had high rates of pre-sarcopenia and malnutrition. Pre-sarcopenia was associated with poorer activity levels, whilst malnutrition was associated with poorer quality of life. Interventions that aim to address reduced muscle mass and weight loss, should be tested in MPM to assess their impact on patient outcomes.

PD-L1 expression associated with worse survival outcome in malignant pleural mesothelioma.

AIM: There is currently a need to identify prognostic biomarkers to assist in a risk adopted approach in treatment of malignant pleural mesothelioma (MPM). Expression of programmed death ligand 1 (PD-L1) has been studied as a prognostic biomarker in a number of tumors given its central role in antitumoral immune response evasion. Four previously published analyses found PD-L1 positivity to be an adverse survival prognostic factor in MPM. This study aims to further investigate the relationship between PD-L1 expression in mesothelioma tissues and survival outcome. METHODS: Clinical data of MPM patients from a single institution between 2006 and 2016 were reviewed. Patient's archived tissues were stained with PD-L1 (Clone Ventana SP263). PD-L1 positivity was defined as > 1% membranous staining regardless of intensity. RESULTS: Data from fifty eight patients were analyzed. Median age was 73, majority was male (49, 84%) and had ECOG between 0 and 2 (46, 79%). Most common histopathological subtype was epithelioid (42, 72%), 9 (16%) biphasic subtype and 7 (12%) sarcomatoid. Thirty one patients (53%) received best supportive care and twenty seven patients (47%) received chemotherapy or combination treatment. Forty-two patients had positive PD-L1 expression (72.4%). The median survival time for PD-L1 negative group is 15.5 months and 6 months for the positive group. Positive PD-L1 expression is independently correlated with worse prognosis (HR = 2.02; 95% CI, 1.005-4.057; P-value = 0.0484). CONCLUSIONS: Our analysis found a higher percentage of MPM patients with positive PD-L1 (> 1%) compared to other studies. Highly positive PD-L1 expression was associated with statistically significantly lower median survival time.

End-of-life care of oncology inpatients: Are we getting it right?

AIM: To examine the current patterns of end-of-life care of medical oncology patients dying in an Australian tertiary acute hospital setting in order to determine potential areas for improvement. METHODS: A retrospective observational study was undertaken of 295 consecutive adult medical oncology inpatients dying between 2010 and 2015. Charts were reviewed for evidence of (1) resuscitation plans, (2) acute interventions in the 48-h period prior to death, (3) palliative care involvement and (4) recognition of the dying patient and comfort care plans. RESULTS: At the time of death, 98% of patients had a resuscitation plan, 71% of which were completed by the medical oncology team. Fifty-nine percent of medical emergency team reviews occurred in patients without a documented resuscitation plan. Within 48 h of death, active interventions were still being given to 64% of patients in the total patient population. Comfort care plans were documented in 86% of patients; however, 62% of these were only documented within 48 h of death and 20% of patients with a documented comfort care plan still received noncomfort measures. CONCLUSION: There was a high level of documented resuscitation plans, comfort care plans and recognition of dying. However, active interventions were common within 48 h of death, and comfort care plans and recognition of dying often occurred late. These data indicate a gap between documenting a resuscitation plan and providing timely and appropriate end-of-life care. Understanding the gaps in delivering appropriate care provides an opportunity for improving end-of-life care.

Tumour associated lymphocytes in the pleural effusions of patients with mesothelioma express high levels of inhibitory receptors.

OBJECTIVE: Pleural effusion (PE) is a common feature of malignant pleural mesothelioma. These effusions typically contain lymphocytes and malignant cells. We postulated that the PE would be a source of lymphocytes for analysis of tumor immune milieu. The aim of this study was to compare the phenotype and T cell receptor usage of pleural effusion T cells with paired concurrently drawn peripheral blood lymphocytes. We used multi-parameter flow cytometry and high-throughput T cell receptor sequencing to analyse peripheral blood and pleural effusion mononuclear cells. RESULTS: Both CD8+ and CD4+ T cells from effusion showed increased expression of T cell inhibitory receptors PD-1, LAG-3 and Tim-3 compared to blood. Comprehensive T cell receptor sequencing on one of the patients showed a discordant distribution of clonotypes in the antigen-experienced (PD-1+) compartment between effusion and blood, suggesting an enrichment of antigen specific clonotypes in the effusion, with potential as an immunological response biomarker.

Two cases of clinical myasthenia gravis associated with pembrolizumab use in responding melanoma patients.

Immune checkpoint inhibitors have changed the landscape of the treatment of multiple solid malignancies, and have been used increasingly in the recent years. Although usually well tolerated, given the relative inexperience of using immune checkpoint inhibitors, we are still learning of new side effects from the treatment. We report on two cases of ocular myasthenia gravis that occurred after treatment with pembrolizumab, an antiprogrammed-death (anti-PD1) monoclonal antibody for advanced melanoma in responding patients. One case is in an 81-year-old man and the second case in an 86-year-old woman, both with BRAF-negative metastatic melanoma receiving pembrolizumab. These two cases of ocular only associated myasthenic syndrome appeared 7 and 11 weeks after the initiation of pembrolizumab. We conclude that the condition is most likely associated with pembrolizumab as symptoms started after treatment with pembrolizumab, neither patient had other evidence of neurological cause for presentation, and symptoms also improved rapidly with administration of steroids. Both patients showed good oncological response to anti-PD1 treatment and one patient successfully continued to receive ongoing treatment with no further complications.