Characterizing multi-PIK3CA mutations across cancer types: Toward precision oncology.

BACKGROUND: PIK3CA mutations are implicated in various cancers, but the implications of multiple concurrent mutations and their orientations within the gene have not been fully explored. METHODS: In this study, we analyzed multi-PIK3CA mutations across a diverse pan-cancer cohort comprising 3564 tumors. RESULTS: Multi-PIK3CA mutations were present in 10.3% of all PIK3CA-mutant tumors, predominantly occurring in breast and gynecological cancers. Notably, mutations within the helical domain (E542:E545) exclusively occurred in the trans-orientation, contrasting with mutations in the kinase ABD and C2 domains, which mainly appeared in the cis orientation. CONCLUSIONS: The distinct pattern of mutation orientations in PIK3CA suggests variable oncogenic potential, with helical domain mutations in the trans-orientation potentially being less oncogenic. These findings highlight the importance of mutation orientation in the PIK3CA gene as potential biomarkers for targeted therapy. This understanding is crucial for designing clinical trials that leverage PI3K inhibitors, aiming for more effective and precise cancer treatment.

Medium-Term Outcomes of Concomitant Aortic Valve Repair in Patients with Continuous-Flow Left Ventricular Assist Device.

OBJECTIVE: Our objective was to analyze the development of aortic insufficiency in patients who received central aortic valve repair when undergoing continuous-flow left ventricular assist device implantation. METHODS: We conducted a retrospective review of patients who underwent HeartMate II or 3 (Abbott Lab) implantation between 2004 and 2022. Ninety-four patients were excluded from analysis for history of aortic valve procedures, a bicuspid aortic valve, baseline trace aortic insufficiency, or other concomitant aortic valve procedure. Patients who had ≥ mild aortic insufficiency had concomitant aortic valve repair. Clinical characteristics, serial echocardiograms, and outcomes were determined. RESULTS: Of the 656 patients who underwent HeartMate II or 3 implantation, 105 patients (59 HeartMate II and 46 HeartMate 3) met study criteria. Median age was 68 years [60-74 years], 91.4% [n=96] were male, 54.4% [n=56] were white, and 68.6% [n=72] received support as destination therapy. Preoperative aortic insufficiency degree was 54.3% (n=57) mild, 23.8% (n=25) mild-to-moderate, 20.0% (n=21) moderate, 1.0% (n=1) moderate-to-severe, 1.0% (n=1) severe. In hospital mortality was 5.7% [n=6]. Freedom from ≥ moderate aortic insufficiency was 96.4% (95%CI: 92.5%-100%), 93.3% (95%CI: 87.6%-99.2%), and 91.0% (95%CI: 84.1%-98.5%) at 1-year, 2-year, and 3-year post-implantation, respectively. One HeartMate II patient experienced severe aortic insufficiency and was treated with a heart transplant. Three-year survival was 63.4% [95%CI: 52.9%-75.9%]. CONCLUSIONS: Central aortic valve repair may be an effective technique to mitigate aortic insufficiency in HeartMate II and 3. A larger cohort study with longer duration of follow up is warranted to further investigate the clinical impact.

Blood flow assessment technology in aortic surgery: a narrative review.

Background and Objective: Blood flow assessment is an emerging technique that allows for assessment of hemodynamics in the heart and blood vessels. Recent advances in cardiovascular imaging technologies have made it possible for this technique to be more accessible to clinicians and researchers. Blood flow assessment typically refers to two techniques: measurement-based flow visualization using echocardiography or four-dimensional flow magnetic resonance imaging (4D flow MRI), and computer-based flow simulation based on computational fluid dynamics modeling. Using these methods, blood flow patterns can be visualized and quantitative measurements of mechanical stress on the walls of the ventricles and blood vessels, most notably the aorta, can be made. Thus, blood flow assessment has been enhancing the understanding of cardiac and aortic diseases; however, its introduction to clinical practice has been negligible yet. In this article, we aim to discuss the clinical applications and future directions of blood flow assessment in aortic surgery. We then provide our unique perspective on the technique's translational impact on the surgical management of aortic disease. Methods: Articles from the PubMed database and Google Scholar regarding blood flow assessment in aortic surgery were reviewed. For the initial search, articles published between 2013 and 2023 were prioritized, including original articles, clinical trials, case reports, and reviews. Following the initial search, additional articles were considered based on manual searches of the references from the retrieved literature. Key Content and Findings: In aortic root pathology and ascending aortic aneurysms, blood flow assessment can elucidate postoperative hemodynamic changes after surgical reconfiguration of the aortic valve complex or ascending aorta. In cases of aortic dissection, analysis of blood flow can predict future aortic dilatation. For complicated congenital aortic anomalies, surgeons may use preoperative imaging to perform "virtual surgery", in which blood flow assessment can predict postoperative hemodynamics for different surgical reconstructions and assist in procedural planning even before entering the operating room. Conclusions: Blood flow assessment and computational modeling can evaluate hemodynamics and flow patterns by visualizing blood flow and calculating biomechanical forces in patients with aortic disease. We anticipate that blood flow assessment will become an essential tool in the treatment planning and understanding of the progression of aortic disease.

Clinical and Diagnostic Utility of Genomic Profiling for Digestive Cancers: Real-World Evidence from Japan.

The usefulness of comprehensive genomic profiling (CGP) in the Japanese healthcare insurance system remains underexplored. Therefore, this large-scale study aimed to determine the usefulness of CGP in diagnosing digestive cancers. Patients with various cancer types recruited between March 2020 and October 2022 underwent the FoundationOne® CDx assay at the Keio PleSSision Group (19 hospitals in Japan). A scoring system was developed to identify potentially actionable genomic alterations of biological significance and actionable genomic alterations. The detection rates for potentially actionable genomic alterations, actionable genomic alterations, and alterations equivalent to companion diagnosis (CDx), as well as the signaling pathways associated with these alterations in each digestive cancer, were analyzed. Among the 1587 patients, 547 had digestive cancer. The detection rates of potentially actionable genomic alterations, actionable genomic alterations, and alterations equivalent to CDx were 99.5%, 62.5%, and 11.5%, respectively. APC, KRAS, and CDKN2A alterations were frequently observed in colorectal, pancreatic, and biliary cancers, respectively. Most digestive cancers, except esophageal cancer, were adenocarcinomas. Thus, the classification flowchart for digestive adenocarcinomas proposed in this study may facilitate precise diagnosis. CGP has clinical and diagnostic utility in digestive cancers.

Clinical utility of the Oncomine Dx Target Test multi-CDx system and the possibility of utilizing those original sequence data.

BACKGROUND: Companion diagnostic tests play a crucial role in guiding treatment decisions for patients with non-small cell lung cancer (NSCLC). The Oncomine Dx Target Test (ODxTT) Multi-CDx System has emerged as a prominent companion diagnostic method. However, its efficacy in detecting driver gene mutations, particularly rare mutations, warrants investigation. AIMS: This study aimed to assess the performance of the ODxTT in detecting driver gene mutations in NSCLC patients. Specifically, we aimed to evaluate its sensitivity in detecting epidermal growth factor receptor (EGFR) mutations, a key determinant of treatment selection in NSCLC. MATERIALS AND METHODS: We conducted a retrospective analysis of NSCLC patients who underwent testing with the ODxTT at Keio University Hospital between May 2020 and March 2022. Patient samples were subjected to both DNA and RNA tests. Driver gene mutation status was assessed, and instances of missed mutations were meticulously examined. RESULTS: Of the 90 patients, five had nucleic acid quality problems, while 85 underwent both DNA and RNA tests. Driver gene mutations were detected in 56/90 (62.2%) patients. Of the 34 patient specimens, driver mutations were not detected using the ODxTT; however, epidermal growth factor receptor (EGFR) mutations were detected using polymerase chain reaction-based testing in two patients, and a KRAS mutation was detected by careful examination of the sequence data obtained using the ODxTT in one patient. For the above three cases, carefully examining the gene sequence information obtained using the ODxTT could identify driver mutations that were not mentioned in the returned test results. Additionally, we confirmed comparable instances of overlook results for EGFR mutations in the dataset from South Korea, implying that this type of oversight could occur in other countries using the ODxTT. EGFR mutation was missed in ODxTT in Japan (6.3%, 2/32), South Korea (2.0%, 1/49), and overall (3.7%, 3/81). CONCLUSION: Even if sufficient tumor samples are obtained, rare EGFR mutations (which are excluded from the ODxTT's genetic mutation list) might not be detected using the current ODxTT system due to the program used for sequence analysis. However, such rare EGFR mutations can still be accurately detected on ODxTT's sequence data using next-generation sequencing.

Mitral regurgitation mechanisms related to systolic anterior motion in hypertrophic cardiomyopathy.

Background: Systolic anterior motion (SAM) of the mitral valve can result in mitral regurgitation (MR) and adverse outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM). However, the mechanism and characteristics of MR severity mediated by SAM are unresolved. This study aimed to elucidate the anatomic and hemodynamic associations of MR and the impact of septal myectomy on changes in MR severity in patients with HCM. Methods: We retrospectively reviewed patients who underwent septal myectomy with SAM and interpretable imaging between 2017-2022. Significant MR was defined as moderate or more MR. The mitral valve, papillary muscle, and left ventricular geometry were quantitatively evaluated via echocardiography and cardiac computed tomography. Results: Out of 34 patients, two groups were identified: those with preoperative significant MR (n=16) and those without significant MR (n=18). Patients with significant preoperative MR exhibited worse heart failure symptoms at baseline than those without. Following myectomy, these patients showed higher residual left ventricular outflow tract (LVOT) gradients at rest and with provocative measures than those without preoperative MR. Multivariate regression analysis revealed a significant association between the tenting area and MR severity. Additionally, the chordal cutting procedure alleviated the tenting area [2.1 (1.8-2.6) vs. 1.4 (1.2-1.6) cm2] compared to those without it. Conclusions: Our preliminary data suggested that chordal cutting with septal myectomy was associated with an improvement in the tenting area, contributing to MR severity. This procedure may serve as an effective therapy for patients with SAM and significant MR.

Dabrafenib and trametinib administration in patients with BRAF V600E/R or non-V600 BRAF mutated advanced solid tumours (BELIEVE, NCCH1901): a multicentre, open-label, and single-arm phase II trial.

Background: BRAF V600 mutations are common in melanoma, thyroid, and non-small-cell lung cancers. Despite dabrafenib and trametinib being standard treatments for certain cancers, their efficacy across various solid tumours remains unelucidated. The BELIEVE trial assessed the efficacy of dabrafenib and trametinib in solid tumours with BRAF V600E/R or non-V600 BRAF mutations. Methods: Between October 1, 2019, and June 2022, at least 50 patients with measurable and seven without measurable diseases examined were enrolled in a subcohort of the BELIEVE trial (NCCH1901, jRCTs031190104). BRAF mutated solid tumour cases other than BRAF V600E mutated colorectal cancer, melanoma, and non-small cell lung cancer cases were included. Patients with solid tumours received dabrafenib (150 mg) twice daily and trametinib (2 mg) once daily until disease progression or intolerable toxicity was observed. The primary endpoint was overall response rate (ORR), and secondary endpoints included progression-free survival (PFS), 6-month PFS, and overall survival (OS). Bayesian analysis was performed using a prior distribution with a 30% expected response rate [Beta (0.6, 1.4)]. Findings: Fourty-seven patients with measurable disease, mainly with the BRAF V600E mutation (94%), and three others with non-V600E BRAF mutations (V600R, G466A, and N486_P490del) were enrolled. The primary sites included the thyroid gland, central nervous system, liver, bile ducts, colorectum, and pancreas. The confirmed ORR was 28.0%; the expected value of posterior distribution [Beta (14.6, 37.4)] was 28.1%, although the primary endpoint was achieved, not exceeding an unexpectedly high response rate of 60% obtained using Bayesian analysis. The disease control rate (DCR) was 84.0%. The median PFS was 6.5 months (95% confidence interval [CI]; 4.2-7.2 months, 87.8% at 6 months). Responses were observed across seven tumour types. Median OS was 9.7 months (95% CI, 7.5-12.2 months). Additional patients without measurable diseases had a median PFS of 4.5 months. Adverse events (AEs) were consistent with previous reports, with 45.6% of patients experiencing grade ≥3 AEs. Interpretation: This study reported promising efficacy against BRAF V600-mutant tumours. Dabrafenib and trametinib would offer a new therapeutic option for rare cancers, such as high-grade gliomas, biliary tract cancer, and thyroid cancer. Funding: This study was funded by the Japan Agency for Medical Research and Development (22ck0106622h0003) and a Health and Labour Sciences Research Grant (19EA1008).

Significance of isolated postoperative atrial fibrillation in thoracic aortic aneurysm repair.

OBJECTIVE: Although postoperative atrial fibrillation has been shown to be associated with worse survival after thoracic aortic surgery, its effect on outcomes independently from other postoperative complications is not well understood. METHODS: This is a single-center retrospective study of patients who underwent open thoracic aortic aneurysm repair between March 2005 and March 2021. Postoperative atrial fibrillation was defined as new-onset atrial fibrillation that developed during the index hospital stay. Patients with preoperative atrial fibrillation were excluded. Postoperative major complications included reoperation for bleeding, respiratory failure, acute renal failure, and stroke. Variables associated with postoperative atrial fibrillation were analyzed with multivariable regression. Survival of patients without major complications was compared between patients without atrial fibrillation and patients with postoperative atrial fibrillation after propensity score matching for baseline and intraoperative characteristics. RESULTS: Of 1454 patients, 520 (35.8%) were observed to have postoperative atrial fibrillation. Patients with postoperative atrial fibrillation had a higher rate of postoperative major complications than those without atrial fibrillation (20.2% vs 12.2%, P < .001). Ten-year survival was 82.0% in patients with postoperative atrial fibrillation and 87.0% in patients without atrial fibrillation (P = .008). In the cohort of patients without complications, 10-year survival was similar between patients with and without postoperative atrial fibrillation after propensity score matching (83.6% vs 83.8%, P = .75). CONCLUSIONS: Postoperative atrial fibrillation is common after open proximal thoracic aortic aneurysm repair. Although development of major postoperative complications is associated with postoperative atrial fibrillation and decreased long-term survival, isolated postoperative atrial fibrillation does not appear to influence long-term survival.

Patient survey on cancer genomic medicine in Japan under the national health insurance system.

In Japan, comprehensive genomic profiling (CGP) tests have been reimbursed under the national health care system for solid cancer patients who have finished standard treatment. More than 50,000 patients have taken the test since June 2019. We performed a nation-wide questionnaire survey between March 2021 and July 2022. Questionnaires were sent to 80 designated Cancer Genomic Medicine Hospitals. Of the 933 responses received, 370 (39.7%) were web based and 563 (60.3%) were paper based. Most patients (784, 84%) first learned about CGP tests from healthcare professionals, and 775 (83.1%) gave informed consent to their treating physician. At the time of informed consent, they were most worried about test results not leading to novel treatment (536, 57.4%). On a scale of 0-10, 702 respondents (75.2%) felt that the explanations of the test result were easy to understand (7 or higher). Ninety-one patients (9.8%) started their recommended treatment. Many patients could not receive recommended treatment because no approved drugs or clinical trials were available (102/177, 57.6%). Ninety-eight patients (10.5%) did not wish their findings to be disclosed. Overall satisfaction with the CGP test process was high, with 602 respondents (64.5%) giving a score of 7-10. The major reason for choosing 0-6 was that the CGP test result did not lead to new treatment (217/277, 78.3%). In conclusion, satisfaction with the CGP test process was high. Patients and family members need better access to information. More patients need to be treated with genomically matched therapy.

Germline BRCA2 variant with low variant allele frequency detected in tumor-only comprehensive genomic profiling.

Germline BRCA1/2 variants in comprehensive genomic profiling (CGP) often exhibit variant allele frequency (VAF) exceeding 50%. However, when genomic loss occurs at the ipsilateral allele, including the germline variant in tumor cells, the VAF is low. This case report presents a patient with uterine sarcoma with a pathogenic BRCA2 mutation and low VAF in tumor-only CGP, which was later identified as a germline variant. When genomic alterations in BRCA1/2 are identified in tumor-only CGP, the possible germline origin of the variants should be considered, even if their VAF is very low.

Acute right ventricular geometric change predicts outcomes in HeartMate 3 patients.

BACKGROUND: The physiological response of the right ventricle (RV) following left ventricular assist device (LVAD) implantation is difficult to predict. We aimed to investigate RV geometric and functional changes after LVAD insertion and their effects on clinical outcomes. METHODS: We retrospectively reviewed 188 patients who underwent HeartMate 3 implantation at our center between November 2014 and September 2021. The RV end-diastolic diameter (RVEDD) and RV end-diastolic area (RVEDA) were measured on preoperative and predischarge transthoracic echocardiography. The nonadapted group included patients with increased RVEDD and RVEDA at discharge. The composite outcome was defined as death or readmission due to worsening right heart failure. RESULTS: There were 82 patients (44%) who had a nonadapted and 106 patients (56%) who had an adapted RV. Preoperatively, the nonadapted group had smaller RVEDD (46 vs 49 mm, p < 0.001) and RVEDA (27 vs 31 cm2, p < 0.001). At discharge, the nonadapted group had larger RVEDD (51 vs 43 mm, p < 0.001) and RVEDA (33 vs 27 cm2, p < 0.001). Kaplan-Meier analysis demonstrated worse 3-year survival (77% vs 91%, p = 0.006) and freedom from composite outcome (58% vs 85%, p < 0.001) in the nonadapted group. A multivariable Cox proportional hazards model showed that nonadaption (hazard ratio [HR] 3.09, 95% confidence interval [CI] 1.29-7.40, p = 0.01) and age (HR 3.73, 95% CI 1.42-9.77, p = 0.007) were independent predictors of composite outcome. CONCLUSIONS: Acute RV dimensional changes after LVAD insertion may represent intrinsic RV function and may be a useful prognostic marker.

BRCA1/2 reversion mutations in a pan-cancer cohort.

Tumor sensitivity to platinum (Pt)-based chemotherapy and poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors is increased by homologous recombination deficiency-causing mutations; in particular, reversion mutations cause drug resistance by restoring protein function. Treatment response is predicted by breast cancer susceptibility gene 1/2 (BRCA1/2) mutations; however, BRCA1/2 reversion mutations have not been comprehensively studied in pan-cancer cohorts. We aimed to characterize BRCA1/2 reversion mutations in a large pan-cancer cohort of Japanese patients by retrospectively analyzing sequencing data for BRCA1/2 pathogenic/likely pathogenic mutations in 3738 patients with 32 cancer types. We identified somatic mutations in tumors or circulating cell-free DNA that could restore the ORF of adverse alleles, including reversion mutations. We identified 12 (0.32%) patients with somatic BRCA1 (n = 3) and BRCA2 (n = 9) reversion mutations in breast (n = 4), ovarian/fallopian tube/peritoneal (n = 4), pancreatic (n = 2), prostate (n = 1), and gallbladder (n = 1) cancers. We identified 21 reversion events-BRCA1 (n = 3), BRCA2 (n = 18)-including eight pure deletions, one single-nucleotide variant, six multinucleotide variants, and six deletion-insertions. Seven (33.3%) reversion deletions showed a microhomology length greater than 1 bp, suggesting microhomology-mediated end-join repair. Disease course data were obtained for all patients with reversion events: four patients acquired mutations after PARP-inhibitor treatment failure, two showed somatic reversion mutations after disease progression, following Pt-based treatment, five showed mutations after both treatments, one patient with pancreatic cancer and BRCA1 reversion mutations had no history of either treatment. Although reversion mutations commonly occur in BRCA-associated cancers, our findings suggest that reversion mutations due to Pt-chemotherapy might be correlated with BRCA1/2-mediated tumorigenesis even in non-BRCA-associated histologies.

Does lateral approach preserve the right ventricular function after HeartMate 3 insertion?

OBJECTIVES: Lateral thoracotomy (LT) approach may preserve the right ventricular (RV) function after left ventricular assist device (LVAD) implantation. This study evaluated the short- and long-term RV function using echocardiography after LVAD implantation via LT or median sternotomy (sternotomy). METHODS: The patients who underwent HeartMate 3 implantation were retrospectively reviewed. The RV function was assessed before and 1 month and 1 year after LVAD implantation. The primary and secondary outcomes were all-cause mortality and a composite of death or readmission due to RV failure, respectively. RESULTS: Of the 195 patients, 55 (28%) underwent LT and 140 (72%) underwent sternotomy. There were no significant differences in the preoperative RV geometry or function. One month after the LVAD implantation, the LT group had a smaller RV end-diastolic dimension [42 (29-48) vs 47 (42-52) mm; P = 0.003] and RV end-diastolic area [25 (21-28) vs 29 (24-36) cm2; P < 0.001] and a greater RV fractional area change [30 (25-34)% vs 28 (23-31)%; P = 0.04] and peak systolic tissue velocity [8 (7-9) vs 7 (6-8) cm/s; P = 0.01]. Twenty-four patients died and 46 met the composite end point. Kaplan-Meier curve analysis did not reveal significant differences between LT and sternotomy in the 2-year survival (93% vs 83%; log-rank test, P = 0.28) and adverse event rate (76% vs 71%; log-rank test, P = 0.65). CONCLUSIONS: LT approach yielded a better-preserved RV function at 1 month; however, there were no significant differences in the 2-year survival and adverse event rates.

FOLFIRINOX in Pancreatic Cancer: Risk Factors for Febrile Neutropenia and Severe Neutropenia - Nationwide Study Analysis.

BACKGROUND/AIM: FOLFIRINOX (FFX) is a standard treatment for patients with advanced pancreatic cancer. However, it often causes serious hematological adverse events. This study aimed to identify the risk factors for febrile neutropenia (FN) and grade 4 (G4) neutropenia during treatment with FFX in the real world. PATIENTS AND METHODS: We analyzed data obtained from a nationwide multicenter observational study (JASPAC 06) that included 399 patients with unresectable or recurrent pancreatic cancer who received FFX at 27 institutions in Japan. RESULTS: Nadir neutrophil counts occurred from day 8 to day 22 of cycle 1, and granulocyte colony-stimulating factor was administered to over a quarter of the patients in the first cycle. Of 399 patients, FN and G4 neutropenia occurred in 51 (13%) and 108 (27%) patients, respectively. Most FN (83%) and G4 neutropenia (75%) occurred in the first or second cycles. Multivariate logistic regression analyses showed that total bilirubin (TB) > the upper limit of normal range (ULN) and no dose modification from the original regimen were significantly associated with FN, and that TB > ULN, no dose modification from the original regimen, low platelet count (<15×104/µl), and recurrent disease after pancreatectomy were independent risk factors for G4 neutropenia. CONCLUSION: No dose modification from the original regimen and TB > ULN were risk factors for FN and G4 neutropenia.

Preoperative left ventricular diastolic dimension index is associated with outcomes after HeartMate 3 implantation.

OBJECTIVES: We investigated the association between indexed left ventricular diastolic dimension and clinical outcomes after HeartMate 3 implantation. METHODS: We retrospectively reviewed patients implanted with the HeartMate 3 at our centre between November 2014 and September 2021. Left ventricular diastolic dimension was assessed via preoperative transthoracic echocardiography and left ventricular diastolic dimension index was calculated as left ventricular diastolic dimension/body surface area. The primary outcome was a composite of death or readmission due to right heart failure or stroke. The cut-off left ventricular diastolic dimension index value most closely associated with outcomes was determined by receiver-operating characteristic curve and restricted cubic spline analyses. RESULTS: Left ventricular diastolic dimension index measurements were available for 252 of 253 (99.6%) patients. Using a left ventricular diastolic dimension index cut-off value of 33.5 mm/m2, the cohort was divided: left ventricular diastolic dimension index ≤ (n = 131) or > (n = 121) 33.5 mm/m2. While there were no significant differences in age, INTERMACS level and preoperative haemodynamics between groups, patients with smaller left ventricular diastolic dimension index were more likely to have a larger body surface area (2.1 vs 1.9 m2, P < 0.001), ischaemic cardiomyopathy [64 (49%) vs 40 (33%), P = 0.01] and smaller left atrium volume index [40.5 (32.3-54.0) ml/m2 vs 54.0 (43.0-66.8) ml/m2, P < 0.001]. Smaller left ventricular diastolic dimension index patients had significantly worse survival (74% vs 88%, log-rank P = 0.009) and freedom from adverse events (55% vs 73%, log-rank P = 0.005) at 3-year follow-up. Smaller left ventricular diastolic dimension index was independently associated with the composite outcome (Hazard ratio 2.24, P = 0.002). CONCLUSIONS: Smaller preoperative left ventricular diastolic dimension index is associated with worse outcomes in patients undergoing HeartMate 3 implantation.

Human resources for administrative work to carry out a comprehensive genomic profiling test in Japan.

Comprehensive genomic profiling (CGP) tests have been nationally reimbursed in Japan since June 2019 under strict restrictions, and over 46,000 patients have taken the test. Core Hospitals and Designated Hospitals host molecular tumor boards, which is more time-consuming than simply participating in them. We sent a questionnaire to government-designated Cancer Genomic Medicine Hospitals, including all 12 Core Hospitals, all 33 Designated Hospitals, and 117 of 188 Cooperative Hospitals. The questionnaire asked how much time physicians and nonphysicians spent on administrative work for cancer genomic medicine. For every CGP test, 7.6 h of administrative work was needed. Physicians spent 2.7 h/patient, while nonphysicians spent 4.9 h/patient. Time spent preparing for molecular tumor boards, called Expert Panels, was the longest, followed by time spent participating in Expert Panels. Assuming an hourly wage of ¥24,000/h for physicians and ¥2800/h for nonphysicians, mean labor cost was ¥78,071/patient. On a monthly basis, more time was spent on administrative work at Core Hospitals compared with Designated Hospitals and Cooperative Hospitals (385 vs. 166 vs. 51 h/month, respectively, p < 0.001). Consequently, labor cost per month was higher at Core Hospitals than at Designated Hospitals and Cooperative Hospitals (¥3,951,854 vs. ¥1,687,167 vs. ¥487,279/month, respectively, p < 0.001). Completing a CGP test for a cancer patient in Japan is associated with significant labor at each hospital, especially at Core Hospitals. Streamlining the exchange of information and simplifying Expert Panels will likely alleviate this burden.

Clinical predominance of whole-exome sequencing to evaluate microsatellite instability status.

The microsatellite instability (MSI)/mismatch repair (MMR) status is one of the critical genomic biomarkers for predicting patient response to immune checkpoint inhibitors (ICIs). In this study, we aimed to investigate the concordance among the MSIsensor score obtained from whole-exome sequencing (WES), which could be a futuristic clinical cancer sequencing method, using only tumor tissues, MSI-PCR results, and immunohistochemistry (IHC) results to analyze various solid cancer types. We first endeavored to set the cut-off value of MSIsensor to determine functional deficient mismatch repair (f-dMMR) status. The MSI status of 1054 patients analyzed using WES was evaluated using MSIsensor. In addition, 87 of these patients were further analyzed using MSI-PCR and MMR IHC to calculate the sensitivity and specificity of the MSIsensor cut-off score. Our results showed that score 12.5 was an adequate cut-off score equivalent to PCR-confirmed MSS/MSI-low and MSI-high statuses, with sensitivity, specificity, and area under the curve values of 95.2%, 100%, and 0.998, respectively. Moreover, we identified false-positive cases of tumors with high mutational burden with an MSIsensor score <12.5, and optional IHC examination could rescue these cases. In conclusion, the MSIsensor score obtained using WES with tumor tissue showed a high clinical validity, with a cut-off value of 12.5 for f-dMMR detection, in combination with optional IHC analysis for MMR. Our novel algorithm will provide insights into the development of ICIs for cancer treatment, particularly when WES becomes a more common cancer genomic test in the near future.

Molecular mechanism of a large conformational change of the quinone cofactor in the semiquinone intermediate of bacterial copper amine oxidase.

Copper amine oxidase from Arthrobacter globiformis (AGAO) catalyses the oxidative deamination of primary amines via a large conformational change of a topaquinone (TPQ) cofactor during the semiquinone formation step. This conformational change of TPQ occurs in the presence of strong hydrogen bonds and neighboring bulky amino acids, especially the conserved Asn381, which restricts TPQ conformational changes over the catalytic cycle. Whether such a semiquinone intermediate is catalytically active or inert has been a matter of debate in copper amine oxidases. Here, we show that the reaction rate of the Asn381Ala mutant decreases 160-fold, and the X-ray crystal structures of the mutant reveals a TPQ-flipped conformation in both the oxidized and reduced states, preceding semiquinone formation. Our hybrid quantum mechanics/molecular mechanics (QM/MM) simulations show that the TPQ conformational change is realized through the sequential steps of the TPQ ring-rotation and slide. We determine that the bulky side chain of Asn381 hinders the undesired TPQ ring-rotation in the oxidized form, favoring the TPQ ring-rotation in reduced TPQ by a further stabilization leading to the TPQ semiquinone form. The acquired conformational flexibility of TPQ semiquinone promotes a high reactivity of Cu(i) to O2, suggesting that the semiquinone form is catalytically active for the subsequent oxidative half-reaction in AGAO. The ingenious molecular mechanism exerted by TPQ to achieve the "state-specific" reaction sheds new light on a drastic environmental transformation around the catalytic center.

Comparing the Efficacy and Safety of Gemcitabine plus Nab-Paclitaxel versus Gemcitabine Alone in Older Adults with Unresectable Pancreatic Cancer.

BACKGROUND: Gemcitabine plus nab-paclitaxel (GnP) has been a standard treatment for unresectable pancreatic cancer (uPC); however, the current treatment status and usefulness in older adults with uPC remain unclear. Therefore, we aimed to investigate the patient background and compare the efficacy and safety of GnP versus other treatments in older adults with uPC. PATIENTS AND METHODS: In this prospective observational study, we enrolled 233 eligible patients aged ≥76 years with pathologically proven, clinically uPC, and no history of chemotherapy from 55 Japanese centers during September 2018-September 2019. The main endpoints were overall survival (OS), progression-free survival (PFS), and safety. Geriatric assessments were performed upon registration and after 3 months. To adjust for confounders, we conducted propensity score-matched analyses. RESULTS: GnP, gemcitabine alone (Gem), best supportive care, and other therapies were administered to 116, 72, 16, and 29 patients, respectively. In the propensity score-matched analysis, 42 patients each were selected from the GnP and Gem groups. The median OS was longer in the GnP group than in the Gem group (12.2 vs. 9.4 months; hazard ratio [HR], 0.65; 95% CI, 0.37-1.13). The median PFS was significantly longer in the GnP group than in the Gem group (9.2 vs. 3.7 months; HR, 0.38; 95% CI, 0.23-0.64). The incidence of severe adverse events was higher with GnP than with Gem; however, the difference was not significant. CONCLUSION: GnP is more efficacious than Gem in patients aged ≥76 years with uPC despite demonstrating a higher incidence of severe adverse events.