Practical guide for the diagnosis and management of primary ciliary dyskinesia

OBJECTIVE

Primary ciliary dyskinesia (PCD) is a relatively rare genetic disorder that affects approximately 1 in 20,000 people. Approximately 50 genes are currently known to cause PCD. In light of differences in causative genes and the medical system in Japan compared with other countries, a practical guide was needed for the diagnosis and management of Japanese PCD patients.

METHODS

An ad hoc academic committee was organized under the Japanese Rhinologic Society to produce a practical guide, with participation by committee members from several academic societies in Japan. The practical guide including diagnostic criteria for PCD was approved by the Japanese Rhinologic Society, Japanese Society of Otolaryngology-Head and Neck Surgery, Japanese Respiratory Society, and Japanese Society of Pediatric Pulmonology.

RESULTS

The diagnostic criteria for PCD consist of six clinical features, six laboratory findings, differential diagnosis, and genetic testing. The diagnosis of PCD is categorized as definite, probable, or possible PCD based on a combination of the four items above. Diagnosis of definite PCD requires exclusion of cystic fibrosis and primary immunodeficiency, at least one of the six clinical features, and a positive result for at least one of the following: (1) Class 1 defect on electron microscopy of cilia, (2) pathogenic or likely pathogenic variants in a PCD-related gene, or (3) impairment of ciliary motility that can be repaired by correcting the causative gene variants in iPS cells established from the patient's peripheral blood cells.

CONCLUSION

This practical guide provides clinicians with useful information for the diagnosis and management of PCD in Japan.

Psychological characteristics of Japanese patients and their family members receiving genetic counseling: A single-institute exploratory study

In Japan, clinical genetic services became available in the 1970s, and genomic medicine, including genetic counseling (GC), developed rapidly. However, research on the outcomes of GC in Japan is limited. Japan has a unique cultural context, and appropriate GC methods have not yet been optimized for this population. The current study aimed to evaluate the psychological status of Japanese patients and their companions undergoing GC and the outcomes of GC. We used the Quality of Care Through the Patients' Eyes-gene cancer (QUOTE-gene^CA ), the Genetic Counseling Outcome Scale-24 (GCOS-24), and the State-Trait Anxiety Inventory (STAI) to evaluate patients and their companions' needs and preferences regarding GC, empowerment, and anxiety, respectively. We evaluated stress status during GC by measuring saliva cortisol levels. QUOTE-gene^CA results for patients (n = 69) and a group of patients and their companions (n = 96) revealed that participants felt that it was important that skilled medical staff explained medical information and provided advice in an easily understandable manner. Japanese patients and their companions regarded the procedural aspects of counseling as most important and their autonomy in decision-making as less important. GCOS-24 results revealed a significant increase in empowerment scores in 38 patients (by 9.63 points) from pre- to post-GC (p < 0.001; Cohen's d = 0.79). STAI results revealed a significant decrease in state anxiety for patients (6.11 points; p < 0.001; Cohen's d = 0.66). Cortisol levels in patients significantly decreased after GC (p = 0.001). The improvement of empowerment scores from pre- to post-GC among patients and their companions were significantly negatively correlated with pre-GC empowerment scores (p < 0.001), trait anxiety scores (p = 0.001), and the number of people living together (p = 0.011). The change of cortisol levels during GC in patients and their companions was significantly positively correlated with trait anxiety score (p = 0.027). This study suggested that these characteristics of Japanese patients and their companions may predict GC outcomes.

Prognostic potential of METTL3 expression in patients with gastric cancer

Methyltransferase-like 3 (METTL3) is a crucial component of the m6A methyltransferase complex, which serves pivotal roles in tumor progression. The present study investigated the prognostic significance of METTL3 expression in gastric cancer (GC). The expression levels of METTL3 were assessed by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) tissue specimens from 158 patients with GC. Propensity score matching (PSM) analysis was performed to clarify its prognostic potential. METTL3 gene expression was also investigated in fresh frozen specimens from another independent cohort of 57 patients with GC to establish its clinical relevance. Knockdown of METTL3 by small interfering RNA transfection was performed to evaluate its function in vitro. METTL3 expression was significantly higher in cancerous tissues compared with in corresponding normal mucosa (P<0.0001), and high METTL3 expression was an independent prognostic factor for overall and disease-free survival in the FFPE cohort of patients with GC. PSM analysis revealed that elevated METTL3 expression was significantly associated with poor survival outcomes, which was subsequently validated in another cohort of fresh frozen specimens. Knockdown of METTL3 inhibited proliferation, invasion, migration and anoikis resistance in GC cells. In conclusion, METTL3 expression may be used as a clinically feasible prognostic marker and could serve as a potential therapeutic target in patients with GC.

Cancer‑associated gene analysis of cervical cytology samples and liquid‑based cytology significantly improve endometrial cancer diagnosis sensitivity

To the best of our knowledge, there are no useful screening methods for early detection of endometrial cancer in asymptomatic individuals. The present study evaluated the usefulness of genetic analysis of liquid-based cytology (LBC) specimens by assessing whether pathological genetic mutations detected in cancer tissue sections were detected in LBC specimens from the cervix and uterus. The primary endpoint was genetic analysis of cervical cytology specimens and LBC for the detection of endometrial cancer. Endometrial thickening (>11 mm) assessed using transvaginal ultrasonography was present in 60% of cases and adenocarcinoma assessed using cervical cytology was present in 50% of cases. In 70% of cases, pathogenic mutations detected in cancer tissue sections were also detected in cervical and/or endometrial LBC specimens. The pathogenic variants identified were PTEN in four cases, tumor protein P53, PI3K catalytic subunit α and fibroblast growth factor receptor 2 in two cases each and APC regulator of WNT signaling pathway, KRAS and catenin β1 in one case each. In the present study, a combination of endometrial thickening assessed by transvaginal ultrasonography, cervical cytology and genetic analysis resulted in a high sensitivity of 90% for detection of endometrial cancer. The combination of these tests is more expensive than conventional methods, but delayed detection of uterine cancer requires multidisciplinary treatment, which increases healthcare costs. Increased spending on early detection of uterine cancer is better economically and may improve patient quality of life.

Precision cancer genome testing needs proficiency testing involving all stakeholders

To implement precision oncology, analytical validity as well as clinical validity and utility are important. However, proficiency testing (PT) to assess validity has not yet been systematically performed in Japan. To investigate the quality of next-generation sequencing (NGS) platforms and cancer genome testing prevalent in laboratories, we performed pilot PT using patient samples. We prepared genomic DNA from the cancer tissue and peripheral blood of 5 cancer patients and distributed these to 15 laboratories. Most participating laboratories successfully identified the pathogenic variants, except for two closely located KRAS variants and 25 bp delins in EGFR. Conversely, the EGFR L858R variant was successfully identified, and the allele frequency was similar for all the laboratories. A high DNA integrity number led to excellent depth and reliable NGS results. By conducting this pilot study using patient samples, we were able to obtain a glimpse of the current status of cancer genome testing at participating laboratories. To enhance domestic cancer genome testing, it is important to conduct local PT and to involve the parties concerned as organizers and participants.

Abstract 653: Clinical value and oncogenic role of METTL3 expression in gastric cancer patients

Background: Gastric cancer (GC) is one of the most common cancers and leading cause of cancer-related deaths worldwide, primarily because of rapid disease progression to advanced stages and highly malignant potential. Methyltransferase-like 3 (METTL3) is a crucial component of the m6A methyltransferase complex, and plays pivotal roles in tumour progression. This study investigated the prognostic significance of METTL3 expression in gastric cancer (GC).

Methods: We assessed expression levels of METTL3 by immunohistochemistry in formalin-fixed paraffin-embedded (FFPE) tissue specimens from one hundred fifty-eight GC patients. Propensity score matching (PSM) analysis was performed to clarify its prognostic potential. The METTL3 gene expression was also investigated in fresh frozen specimens from another independent cohort of fifty-seven GC patients to establish its clinical relevance. Knockdown of METTL3 by siRNA transfection was performed to evaluate its function in vitro.

Results: METTL3 expression was significantly higher in cancerous tissues vs. corresponding normal mucosa (P&lt;0.0001), and high METTL3 staining group was significantly associated with males (P=0.029), an advanced T stage (P=0.0002), the presence of venous invasion (P&lt;0.0001), lymphatic vessel invasion (P=0.011), lymph node metastasis (P=0.004), distant metastasis (P=0.0004), and advanced TNM stage classification (P=0.0001) in the FFPE cohort of GC patients. Survival curve analysis showed that patients with increased expression of METTL3 showed poorer prognosis in terms of both overall survival (OS: P&lt;0.0001, log-rank test) and disease-free survival (DFS: P=0.0005, log-rank test) compared to those with low expression. Multivariate analysis revealed that increased expression of METTL3 was an independent prognostic factor for overall survival (OS: hazard ratio (HR), 3.24; 95% confidence interval (CI), 1.57-6.68; p=0.001) and disease-free survival (DFS: HR, 2.4; 95% CI, 1.12-5.16; p=0.025) in the FFPE cohort of GC patients. PSM analysis revealed that elevated METTL3 expression was significantly associated with poor survival outcomes (OS: P=0.05; DFS: P=0.038; log-rank test), which was subsequently validated in another cohort of fresh frozen specimens (OS: p=0.007; DFS: p=0.029; log-rank test). The knockdown of METTL3 inhibited proliferation, invasion, migration, and anoikis resistance in GC cells.

Conclusion: METTL3 expression may be used as a clinically feasible prognostic marker and could serve as a potential therapeutic target in GC patients.

Citation Format: Yoshinaga Okugawa, Yuji Toiyama, Chengzeng Yin, Ma Ruiya, Akul Goel, Takashi Ichikawa, Hiroki Imaoka, Takahito Kitajima, Tadanobu Shimura, Mikio Kawamura, Hiromi Yasuda, Hiroyuki Fujikawa, Takeshi Yokoe, Ikuyo Mochiki, Masaki Ohi, Kaname Nakatani. Clinical value and oncogenic role of METTL3 expression in gastric cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 653.

Modified intramuscular adipose tissue content as a feasible surrogate marker for malnutrition in gastrointestinal cancer

BACKGROUND & AIMS

Myosteatosis is gathering attention as a feasible indicator for sarcopenia and increased risk of morbidity. However, the prognostic value of intramuscular adipose tissue content (IMAC) as an assessment method for myosteatosis remains controversial. The objectives of this study are to compare the prognostic value of intramuscular adipose tissue content (IMAC) with our newly-developed modified IMAC (mIMAC), and to assess the clinical significance of mIMAC in colorectal cancer (CRC) and gastric cancer (GC).

METHODS

We evaluated 892 patients with CRC or GC, and assessed preoperative IMAC and mIMAC to compare their prognostic and predictive values for postoperative infectious complications in both cohorts.

RESULTS

Both preoperative IMAC and mIMAC were sex- and disease-dependent, and positively or negatively correlated with age in CRC and GC patients (IMAC: CRC: r = 0.33, P < 0.0001; GC: r = 0.304, P < 0.0001; mIMAC: CRC: r = -0.364, P < 0.0001; GC: r = -0.263, P < 0.0001). In contrast to IMAC, lower preoperative mIMAC was significantly associated with disease-development factors, and was an independent prognostic factor for both overall survival (OS) and disease-free survival (DFS) in both CRC (OS: hazard ratio (HR): 1.95, 95% confidence interval (CI): 1.25-3.03, p = 0.003; DFS: HR: 1.93, 95% CI: 1.22-3.04, p = 0.005) and GC patients (OS: HR: 2.11, 95% CI: 1.22-3.68, P = 0.008; DFS: HR: 2.03, 95% CI: 1.18-3.5, P = 0.011). Patients with postoperative remote infections had a poorer prognosis compared with those without in both cohorts (CRC: HR: 2.67, 95% CI: 1.46-4.89, P = 0.002; GC: HR: 3.01, 95% CI: 1.47-6.19, P = 0.003), and low mIMAC was an independent risk factor for postoperative remote infection in both cancers (CRC: odds ratio (OR): 2.56, 95% CI: 1.06-6.23, P = 0.038; GC: OR: 2.8, 95% CI: 1.03-7.58, P = 0.043). Finally, we assessed the correlation between IMAC or mIMAC and the representative frailty markers body mass index (BMI), serum albumin, and prognostic nutritional index (PNI). We found a positive correlation between preoperative mIMAC and all of these markers in both cohorts (CRC: BMI: r = 0.193, P < 0.0001; serum albumin: r = 0.42, P < 0.0001; PNI: r = 0.39, P < 0.0001; GC: BMI: r = 0.22, P < 0.0001; serum albumin: r = 0.212, P < 0.0001; PNI: r = 0.287, P < 0.0001).

CONCLUSIONS

Preoperative mIMAC could be useful for perioperative and postoperative management in CRC and GC.

A pediatric case of primary ciliary dyskinesia caused by novel copy number variation in PIH1D3

An 11-month-old boy with productive cough was referred to our hospital. He had nasal obstruction immediately after birth, and wheezing, wet cough, and rhinorrhea were observed daily after the neonatal period. Clinical and imaging findings revealed secretory otitis media, chronic sinusitis, and bronchiectasis. Primary ciliary dyskinesia was suspected. Transmission electron microscopy of nasal cilia showed defects of the outer and inner dynein arms. Genetic examinations of the family revealed copy number variation in PIH1 domain-containing 3 (PIH1D3) in the proband and mother. This is the first report of a Japanese patient with primary ciliary dyskinesia caused by copy number variation in PIH1D3.

MPL exon 10 mutations other than canonical MPL W515L/K mutations identified by in-house MPL exon 10 direct sequencing in essential thrombocythemia

MPL exon 10 mutations are one of the driver mutations in essential thrombocythemia (ET) or myelofibrosis (MF). We have established an in-house MPL mutation analysis system, covering the entire region of MPL exon 10 by direct sequencing. Since 2009, MPL exon 10 mutation analysis has been performed for diagnosis of myeloproliferative neoplasms (MPN) without JAK2 V617F or CALR exon 9 mutations. So far, 11 cases of MPL exon 10 mutation have been found in 51 patients with suspected MPN. In patients with ET, we detected five non-canonical MPL mutations including one novel mutation, MPL R514_P518delinsK, and one canonical MPL W515L mutation. Notably, three ET patients without canonical MPL mutations had thrombotic events. Meanwhile, in primary or secondary MF, only canonical MPL W515L/K mutations were found. Further cases need to be examined to elucidate the full MPL mutation profile in MPN. However, our data indicate that analysis of the whole of MPL exon 10 is warranted for the diagnosis of MPL mutations, especially in ET, and that the use of Japanese commercial laboratory tests that only detect canonical MPL W515L/K mutations may miss a significant percentage of MPL exon 10 mutations, which could delay the administration of anti-thrombotic therapy.

Electrical field distribution of Change-N1 and its prepulse inhibition

An abrupt change in a sound feature (Test) in a continuous sound elicits an auditory evoked potential, peaking at approx. 100-180 ms (Change-N1) after the change onset. Change-N1 is attenuated by a preceding weak change stimulus (Prepulse), in the phenomenon known as prepulse inhibition (PPI). In this electroencephalographic study, we compared these two indexes among scalp electrodes. Change-N1 was elicited by an abrupt 10-dB increase in sound pressure in repeats of a 70-dB click sound at 100 Hz and was recorded using 22 electrodes in 31 healthy subjects. The prepulse was a 10-dB decrease in three consecutive clicks at 30, 40, and 50 ms before the Test onset. Four stimuli (Test alone, Test with Prepulse, Prepulse alone, and background alone) were presented randomly through headphones at an even probability. The results demonstrated that: (1) Electrodes at the frontal/central midline were reconfirmed to be suitable to record Change-N1; (2) Change-N1 showed right-hemisphere predominance; (3) There was no difference in the %PPI among regions (prefrontal/frontal/central) and hemispheres (midline/left/right); and (4) the Change-N1 amplitude and its PPI at prefrontal electrodes were positively correlated with those at the frontal electrodes. These results support the use of Change-N1 and its PPI as a tool to evaluate the change detection sensitivity and inhibitory function in individuals. The use of prefrontal electrodes can be an option for a screening test.

Real-world data on microsatellite instability status in various unresectable or metastatic solid tumors

Microsatellite instability‐high (MSI‐H) is an important biomarker for predicting the effect of immune checkpoint inhibitors (ICIs) on advanced solid tumors. Microsatellite instability‐high is detected in various cancers, but its frequency varies by cancer type and stage. Therefore, precise frequency is required to plan ICI therapy. In this study, the results of MSI tests actually carried out in clinical practice were investigated. In total, 26 469 samples of various cancers were examined between December 2018 and November 2019 to determine whether programmed cell death‐1 blockade was indicated. The results of MSI tests were obtained for 26 237 (99.1%) of these samples. The male : female ratio was 51:49 and mean age was 64.3 years. In all samples, the overall frequency of MSI‐H was 3.72%. By gender, the frequency of MSI‐H was higher in female patients (4.75%) than in male patients (2.62%; P < .001). A comparison by age revealed that the frequency of MSI‐H was significantly higher in patients younger than 40 years of age (6.12%) and 80 years or older (5.77%) than in patients aged between 60 and 79 years (3.09%; P < .001). Microsatellite instability‐high was detected in 30 cancer types. Common cancer types were: endometrial cancer, 16.85%; small intestinal cancer, 8.63%; gastric cancer, 6.74%; duodenal cancer, 5.60%; and colorectal cancer, 3.78%. Microsatellite instability‐high was detected in cancer derived from a wide variety of organs. The frequency of MSI‐H varied by cancer type and onset age. These data should prove especially useful when considering ICI treatment.

The real-world data on microsatellite instability status in various unresectable or metastatic solid tumors

Microsatellite instability-high (MSI-H) is an important biomarker for predicting the effect of immune-checkpoint inhibitors (ICIs) on advanced solid tumors. MSI-H is detected in various cancers, but its frequency varies by cancer type and stage. Therefore, precise frequency is required to plan ICIs therapy. In this study, the results of MSI test actually conducted in clinical practice were investigated. In total, 26,469 samples of various cancers were examined to determine if PD-1 blockade was indicated between December 2018 to November 2019. The results of MSI test were obtained for 26,237 (99.1%) among them. The male to female ratio was 51:49 and mean age was 64.3 years. In all the samples, overall frequency of MSI-H was 3.72%. By gender, the frequency of MSI-H was higher in female patients (4.75%) than in male patients (2.62%) (P < 0.001). A comparison by age revealed that the frequency of MSI-H was significantly higher in patients aged less than 40 years (6.12%) and 80 years or older (5.77%) than in patients aged between 60 and 79 years (3.09%) (P < 0.001). MSI-H was detected in 30 cancer types. Common cancer types were endometrial cancer, 16.85%; small intestinal cancer, 8.63%; gastric cancer, 6.74%; duodenal cancer, 5.60%; and colorectal cancer, 3.78%. MSI-H was detected in cancer derived from a wide variety of organs. The frequency of MSI-H varied by cancer types and onset age. These data should prove especially useful when considering ICI treatment. Supporting Information.

Japanese Society of Medical Oncology Clinical Guidelines: Molecular Testing for Colorectal Cancer Treatment, 4th edition

Molecular testing to select the appropriate targeted and standard of care therapies is essential for managing patients with colorectal cancer (CRC). The Japanese Society of Medical Oncology previously published clinical guidelines for molecular testing in CRC. In the third edition published in 2018, RAS and BRAF V600E mutations should be tested prior to first‐line chemotherapy to assess the benefit of anti–epidermal growth factor receptor (EGFR) antibody therapy in patients with unresectable CRC. Microsatellite instability (MSI) testing was recommended in patients with curatively resected stage II CRC because deficient mismatch repair is associated with low risk of recurrence. MSI testing was also recommended in patients with CRC suspected to be Lynch syndrome. The main aim of this fourth edition is to reflect recent advances in comprehensive genomic profiling (CGP) tests and liquid biopsy. Here, CGP tests performed on tumor tissues are strongly recommended to assess the benefit of molecular targeted drugs in patients with CRC. Circulating tumor DNA (ctDNA)‐based CGP tests are also proposed. ctDNA testing is recommended to determine the optimal treatment based on the risk of recurrence for curatively resected CRC and evaluate the suitability and monitor the therapeutic effects of anti–EGFR antibodies in patients with unresectable CRC. While both MSI testing and immunohistochemistry are strongly recommended to determine the indication of immune checkpoint inhibitors in patients with unresectable CRC, next‐generation sequencing‐based tests are weakly recommended because these tests have not been validated in clinical trials.

Risk factors for cisplatin-induced acute kidney injury: A pilot study on the usefulness of genetic variants for predicting nephrotoxicity in clinical practice

Several studies have reported risk factors for predicting cisplatin-induced acute kidney injury (AKI), including old age, female sex, smoking, hypoalbuminemia, hypokalemia, hypomagnesemia, a high body surface area, advanced cancer and the total dose of cisplatin administered. Recently, some studies have focused on the associations between genetic alterations in the genes coding for renal drug transporters, such as organic cation transporter 2 (OCT2), and the nephrotoxicity of cisplatin. However, genetic variants have not been fully elucidated for clinical use. Patients who had received cisplatin (≥50 mg/m²)-containing chemotherapy as a first-line treatment were considered as eligible for the present study. The occurrence of AKI and its associations with baseline characteristics, conventional biomarkers and single-nucleotide variants (SNV) were assessed. AKI was defined as an increase in the serum creatinine level of >0.3 mg/dl or to 1.5-2 times the baseline level. Genotyping was conducted using the DMET platform (DMET Plus), which characterizes 1,936 genetic variants (1,931 SNV and 5 copy number variations) in 231 genes. Between April 2014 and June 2016, a total of 28 patients (22 men and 6 women) were enrolled. AKI occurred in 8 of the 28 enrolled patients (28.6%). Univariate analyses demonstrated that the urinary β2-microglobulin level and body surface area were significantly higher in the AKI group (P<0.05). As regards the associations between AKI and SNV, none of the examined SNV were found to be associated with cisplatin-induced AKI. The findings of the present study suggested that certain clinical factors were associated with the onset of AKI, but no associations were identified with genetic factors, including OCT2. Although this was a small pilot study, the findings indicated that genetic factors may not be of value for predicting AKI in clinical practice.

Weaker prepulse exerts stronger suppression of a change-detecting neural circuit

Change-N1 peaking 90-180 ms after changes in a sound feature of a continuous sound is clearly attenuated by a preceding change stimulus (called a "prepulse"). Here, we investigated the effects of a preceding decrease in sound pressure on the degree of inhibition of the subsequent Change-N1 amplitude. Using 100-Hz click train sounds, we obtained Change-N1s from 11 healthy volunteers. The two types of test stimuli were an abrupt 10-dB increase from the baseline (70 dB) and the insertion of a 0.45-ms inter-aural time difference in the middle of the sound. Three consecutive clicks at 30, 40, and 50 ms before the change onset that was used as a prepulse were weaker than the background by 5 or 10 dB. The Change-N1 elicited by the two test stimuli was attenuated more strongly by the weaker prepulse, which was not congruent with the theory that the inhibition of the subsequent sensory/sensory-motor processing depends on the sound pressure level of a prepulse. These results suggest that a change in any type of sound feature elicits a change-related response that is inhibited by any type of preceding change stimulus, which reflects auto-inhibition of the change-responding circuit.

Attitudes toward and current status of disclosure of secondary findings from next-generation sequencing: a nation-wide survey of clinical genetics professionals in Japan

The management of secondary findings (SFs), which are beyond the intended purpose of the analysis, from clinical comprehensive genomic analysis using next generation sequencing (NGS) presents challenges. Policy statements regarding their clinical management have been announced in Japan and other countries. In Japan, however, the current status of and attitudes of clinical genetics professionals toward reporting them are unclear. We conducted a questionnaire survey of clinical genetics professionals at two time points (2013 and 2019) to determine the enforcement of the SF management policy in cases of comprehensive genetic analysis of intractable diseases and clinical cancer genome profiling testing. According to the survey findings, 40% and 70% of the respondents stated in the 2013 and 2019 surveys, respectively, that they had an SF policy in the field of intractable diseases, indicating that SF policy awareness in Japan has changed significantly in recent years. Furthermore, a total of 80% of respondents stated that their facility had established a policy for clinical cancer genome profiling testing in the 2019 survey. In both surveys, the policies included the selection criteria for genes to be disclosed and the procedure to return SFs, followed by recommendations and proposals regarding SFs in Japan and other countries. To create a better list of the genes to be disclosed, further examination is needed considering the characteristics of each analysis.

Nationwide large-scale investigation of microsatellite instability status in more than 18,000 patients with various advanced solid cancers

803

Background: The recent success of immunotherapy in high-frequency microsatellite instability (MSI-H) and/or mismatch repair protein deficient (MMR-D) tumors now supports testing for MSI in all advanced solid tumors. We previously reported using the quasi-monomorphic variation range (QMVR), the MSI status can be determined without matched normal DNA (Bando H, et al. Cancer Sci. 2018). Here, we investigate the proportion of the MSI status across various advanced solid tumors by this method. Methods: The MSI analysis was performed centrally by CLIA-certified, CAP-accredited, the single laboratory using tumor DNA from formalin-fixed paraffin embedded (FFPE) tissues with the MSI test kit (FALCO), which includes fluorescent-labelled primers for co-amplification of five mononucleotide markers (NR-21, BAT-25, MONO-27, NR-24 and BAT-26). The MSI-H was defined as positive if 2 or more makers showed instable. Results: A total of 18,250 patients with advanced solid tumors were registered from Dec 2018 to Aug 2019, and the MSI status was confirmed in 18,088 patients (99%). Among them, 51.9% were male, with median of 62.0 y/o. Overall prevalence of the MSI-H was3.3% (2.3% in male and 4.5% in female); the highest was 16.2% (149/916) in endometrial cancer, followed by 13% (13/100) in small intestinal cancer, 5.9% (74/1277) in gastric cancer, 3.3% (236/7190) in colorectal cancer, 2.6% (4/154) in prostate cancer, 2.5% (20/806) in ovarian cancer, 2.1% (9/426) in cervical cancer, 1.6% (13/831) in biliary tract cancer, 1.5% (4/271) in hepatocellular carcinoma, 0.9% (16/1852) in pancreas cancer. Interestingly, among biliary tract cancers, all MSI-H cases were arising from gall bladder (13/152) but no other sites. High prevalence was observed in cancer of teens or twenties (7.9%) and over 80y/o (5.6%), compare with others (3.0%) in this study (p < 0.001, both). Conclusions: These data show the MSI-H advanced solid tumors are distributed across a much broader tumor spectrum, and confirm the clinical relevance of the screening in patients with most advanced solid tumors, which can select patients sensitive to immune checkpoint blockade, regardless of the cancers' tissue of origin.

Copy number variation in DRC1 is the major cause of primary ciliary dyskinesia in the Japanese population

Background

Primary ciliary dyskinesia (PCD) is a rare genetic disorder caused by functional impairment of cilia throughout the body. The involvement of copy number variation (CNV) in the development of PCD is largely unknown.

Methods

We examined 93 Japanese patients with clinically suspected PCD from 84 unrelated families. CNV was examined either by exome sequencing of a PCD gene panel or by whole‐exome sequencing (WES). The identified alterations were validated by PCR and Sanger sequencing. Nasal ciliary ultrastructure was examined by electron microscopy.

Results

Analysis of CNV by the panel or WES revealed a biallelic deletion in the dynein regulatory complex subunit 1 (DRC1) gene in 21 patients, which accounted for 49% of the PCD patients in whom a disease‐causing gene was found. Sanger sequencing of the PCR product revealed a 27,748‐bp biallelic deletion including exons 1–4 of DRC1 with identical breakpoints in all 21 patients. The ciliary ultrastructure of the patients with this CNV showed axonemal disorganization and the loss or gain of central microtubules.

Conclusion

The deletion of DRC1 is the major cause of PCD in Japan and this alteration can cause various ciliary ultrastructural abnormalities.

Generation of a Triple-Transgenic Zebrafish Line for Assessment of Developmental Neurotoxicity during Neuronal Differentiation

: The developing brain is extremely sensitive to many chemicals. Exposure to neurotoxicants during development has been implicated in various neuropsychiatric and neurological disorders, including autism spectrum disorders and schizophrenia. Various screening methods have been used to assess the developmental neurotoxicity (DNT) of chemicals, with most assays focusing on cell viability, apoptosis, proliferation, migration, neuronal differentiation, and neuronal network formation. However, assessment of toxicity during progenitor cell differentiation into neurons, astrocytes, and oligodendrocytes often requires immunohistochemistry, which is a reliable but labor-intensive and time-consuming assay. Here, we report the development of a triple-transgenic zebrafish line that expresses distinct fluorescent proteins in neurons (Cerulean), astrocytes (mCherry), and oligodendrocytes (mCitrine), which can be used to detect DNT during neuronal differentiation. Using in vivo fluorescence microscopy, we could detect DNT by 6 of the 10 neurotoxicants tested after exposure to zebrafish from 12 h to 5 days' post-fertilization. Moreover, the chemicals could be clustered into three main DNT groups based on the fluorescence pattern: (i) inhibition of neuron and oligodendrocyte differentiation and stimulation of astrocyte differentiation; (ii) inhibition of neuron and oligodendrocyte differentiation; and (iii) inhibition of neuron and astrocyte differentiation, which suggests that reporter expression reflects the toxicodynamics of the chemicals. Thus, the triple-transgenic zebrafish line developed here may be a useful tool to assess DNT during neuronal differentiation.

Japanese Society of Medical Oncology Clinical Guidelines: Molecular Testing for Colorectal Cancer Treatment, Third Edition

The Japanese Society of Medical Oncology (JSMO) previously published 2 editions of the clinical guidelines: "Japanese guidelines for testing of KRAS gene mutation in colorectal cancer" in 2008 and "Japanese Society of Medical Oncology Clinical Guidelines: RAS (KRAS/NRAS) mutation testing in colorectal cancer patients" in 2014. These guidelines have contributed to the proper use of KRAS and RAS mutation testing, respectively. Recently, clinical utility, particularly for colorectal cancer (CRC) patients with BRAF V600E mutation or DNA mismatch-repair (MMR) deficiency, has been established. Therefore, the guideline members decided these genetic alterations should also be involved. The aim of this revision is to properly carry out testing for BRAF V600E mutation and MMR deficiency in addition to RAS mutation. The revised guidelines include the basic requirements for testing for these genetic alterations based on recent scientific evidence. Furthermore, because clinical utility of comprehensive genetic testing using next-generation sequencing and somatic gene testing of analyzing circulating tumor DNA has increasingly evolved with recent advancements in testing technology, we noted the current situation and prospects for these testing technologies and their clinical implementation in the revised guidelines.

Congenital Thrombophilia in Patients With Superior Mesenteric Venous Thrombosis or Portal Vein Thrombosis

We explored the relationship between abdominal vein thromboses, including portal vein thrombosis (PVT) and superior mesenteric vein thrombosis (SMVT), and thrombophilia. The frequency of thrombophilia, such as antithrombin (AT), protein C (PC), or protein S (PS) gene mutations, was examined in 21 patients with PVT, 6 patients with SMVT, and 6 patients with both PVT and SMVT. Low levels of AT, PC, or PS were frequently detected in patients with PVT or mesenteric vein thrombosis, and 4 mutations in the PS gene, 3 mutations in the PC gene, and 2 mutations in AT the gene were detected. Protein S Tokushima was detected in 3 of 4 patients with a PS gene mutation and was associated with 2 other PS gene mutations. The onset of PVT or SMVT was almost idiopathic in patients with congenital thrombophilia. Both PVT and SMVT were frequently caused by an AT, a PC, or a PS mutation, and the onset of these thromboses due to thrombophilia was frequently idiopathic.

Intravenous Administration of Tacrolimus Stabilizes Control of Blood Concentration Regardless of CYP3A5 Polymorphism in Living Donor Liver Transplantation: Comparison of Intravenous Infusion and Oral Administration in Early Postoperative Period

BACKGROUND

We compared achievement rate of sufficient tacrolimus blood concentration in the early postoperative period and incidence of acute cellular rejection within 1 month after living donor liver transplantation (LDLT) between tacrolimus intravenous (IV) and oral administration groups.

METHODS

From October 2005 to November 2016, 61 LDLT patients administered tacrolimus, who could be genotyped for CYP3A5*3 and *1, were chosen from the electronic record database. The patients were then divided into the 2 groups (an IV group [n = 38] and an oral group [n = 23]). We defined patients with 1*1 or *1*3 as expressors and those with *3*3 as nonexpressors. Sufficient trough level tacrolimus blood concentration on postoperative day (POD) 3 was defined as 10-20 ng/mL.

RESULTS

Comparable concentrations were seen between the 2 groups, with mean blood concentration 13.7 ± 8.5 ng/mL in the oral group and 15.2 ± 4.3 ng/mL in the IV group. Achievement rate of sufficient tacrolimus concentration on POD 3 was significantly higher in the IV group than in oral group: 97% (37 of 38) vs 65% (15 of 23), respectively (P = .001). When we focused on achievement rate in the oral group according to CYP3A5 polymorphism, the frequency of expressors (17%) was significantly lower than that of nonexpressors (82%) (P = .016). However, in the IV group this negative influence was totally eliminated, resulting in high achievement rates regardless of CYP3A5 polymorphism. In terms of incidence of acute cellular rejection, there was no significant difference between the 2 groups (IV 32% vs oral 17%, P = .250).

CONCLUSION

IV administration of tacrolimus allowed us to obtain more stable control of blood concentration regardless of CYP3A5 genotype.

Molecular characterization of coagulation factor XII deficiency in a Japanese family

We report the identification in a Japanese family of a novel homozygous W486C mutation in the protease domain of coagulation factor XII (FXII), which was associated with the reduction of plasma FXII activity and antigen level to less than 5% of normal. Sequences of each exon for FXII gene was analysed in family members by polymerase chain reaction (PCR) amplification followed by a direct sequencing method. Sequence analysis showed a homozygous substitution of G to C at nucleotide position 10587 (cDNA position 1458) in proband’s FXII gene, resulting in a Trp to Cys substitution in the catalytic domain of FXII. PCR-fragment length polymorphism analysis of 55 healthy volunteers showed no such mutation. Transient expression of FXII in HK-293T cells and analysis of FXII antigen in culture media and cell lysates showed reduced secretion of mutant protein by more than 84% relative to that of wild type protein although the intracellular contents were similar. Our results suggest that the reduced secretion of FXII protein was due to incorrect folding caused by the introduction of Cys486. We designated this mutation as FXII Mie-1.

Monitoring of peripheral blood cluster of differentiation 4+ adenosine triphosphate activity and CYP3A5 genotype to determine the pharmacokinetics, clinical effects and complications of tacrolimus in patients with autoimmune diseases

A total of 25 patients with autoimmune diseases receiving tacrolimus were screened using a peripheral blood cluster of differentiation 4⁺ adenosine triphosphate (ATP) activity assay (IMK assay) between October 2013 and July 2014. The autoimmune diseases of patients were as follows: Rheumatoid arthritis (n=15), lupus nephritis (n=6), ulcerative colitis (n=2) and myasthenia gravis (n=2). Patients were divided into two groups based on CYP3A5 genotype [expression of *1 allele: Expressor (EX; n=6) and non-expressor (NEX; n=19)]. The tacrolimus concentration and concentration/dose ratio was significantly lower in the EX group compared with the NEX group (P=0.0108 and 0.0056, respectively). In addition, all enrolled patients that presented with adverse effects belonged to the NEX group. No significant associations were observed between IMK ATP levels and the concentration or dose of tacrolimus (P=0.1092 and 0.6999, respectively). However, the IMK ATP high-level group exhibited a significantly higher occurrence rate of insufficient effect when compared with the normal and low-level groups (P=0.0014). In conclusion, the clearance of tacrolimus in patients with autoimmune diseases was affected by the CYP3A5 genotype, as previously reported in organ transplant patients. The IMK ATP level may indicate the clinical response irrespective of tacrolimus concentration.

Comparison of three different anti-Xa assays in major orthopedic surgery patients treated with direct oral anticoagulant

Background

Measurement of edoxaban plasma concentration has been gathering attention in major orthopedic surgery patients receiving edoxaban for the prevention of venous thromboembolism (VTE).

Methods

The anti-Xa activity was measured one hour after edoxaban intake using 3 different assays in 200 patients after major orthopedic surgery.

Results

The anti-Xa activities on Day 8 were significantly higher than those on Day 4 and those on Day 4 were significantly higher than those on Day 1. The anti-Xa activities in two assays closely correlated with each other, but the other anti-Xa assay did not correlated with other two assays. The anti-Xa activities as detected in the three Xa assays were significantly higher in the patients without deep vein thrombosis (DVT) than in those with DVT on Day 4. Additionally, there were no significant differences in the anti-Xa activities of assays A, B and C between patients with and without massive bleeding (MB) on Days 1, 4, 8 and 15.

Conclusion

The results of this study suggest that anti-Xa level could be predictive of the risk of VTE, but not of the risk of massive bleeding.

An Evaluation of the Activated Partial Thromboplastin Time Waveform

The activated partial thromboplastin time (APTT) waveform includes several parameters that are related to various underlying diseases. The APTT waveform was examined in various diseases. Regarding the pattern of APTT waveform, a biphasic pattern of the first or second derivative curve (DC) was observed in patients with hemophilia and patients positive for antiphospholipid (aPL) antibodies or coagulation factor VIII (FVIII) inhibitors. The time of the first and second DC and fibrin formation at 1/2 height were prolonged in patients with hemophilia, patients with inhibitors, patients positive for aPL, patients treated with anti-Xa agents, and patients with disseminated intravascular coagulation (DIC). These values all tended to decrease in pregnant women (at 28-36 weeks' gestation). The height of the second derivative peak 1 was significantly lower in patients with hemophilia, patients with FVIII inhibitors, patients positive for aPL, patients treated with anti-Xa agents, and patients with DIC; these values tended to be significantly higher in pregnant women. The height of the first DC was significantly lower in patients who were positive for FVIII inhibitors and was significantly higher in patients treated with anti-Xa agents and pregnant women. The height of the first and second DC was useful for the analysis of hemophilia, FVIII inhibitor, and aPL.

The Evaluation of D-Dimer Levels for the Comparison of Fibrinogen and Fibrin Units Using Different D-Dimer Kits to Diagnose VTE

The cutoff values of D-dimer levels for diagnosing or predicting the occurrence of deep vein thrombosis (DVT) were evaluated in preoperative patients and compared to those in non-DVT patients. The levels of 8 different D-dimers were measured using the latex agglutination method or enzyme immunoassay before surgery in 262 orthopedic surgery patients to diagnose subclinical DVT or predict postoperative DVT. There were 15 patients with subclinical DVT and 47 with postoperative DVT, but 200 patients had no DVT at all. All 8 plasma D-dimer values were significantly higher in the patients with subclinical or postoperative DVT than in those without DVT or in healthy volunteers. There were differences in the cutoff values between the assays highly sensitive for low D-dimer levels and wild-range assays of D-dimers. Some D-dimer assays might therefore be more useful than others for diagnosing low levels of D-dimer. Although the measurement of D-dimer levels was useful for diagnosing subclinical DVT and predicting the risk of DVT, the cutoff values for the diagnosis or prediction of DVT varied. The cutoff values for the prediction of postoperative DVT were ≥1.7 µg/mL (D-dimer A-D) and ≥1.0 µg/mL (D-dimer E-H).

A 2,7-diamino-1,4,8-triazanaphthalene derivative selectively binds to cytosine bulge DNA only at a weakly acidic pH

The synthesis and properties of 2,7-diamino-1,4,8-triazanaphthalene (azaDANP) are described. AzaDANP is protonated only at a weakly acidic pH to bind to the cytosine bulge DNA duplex selectively. Upon binding of azaDANP to the cytosine bulge DNA, a new absorption band at 407 nm appears, and the absorption change of azaDANP on binding to the target is very sensitive to environmental pH with a bell-shaped pH-absorption profile.

Fluorescence turn-on hairpin-probe PCR

A new fluorescence turn-on type of PCR monitoring system (Hpro-PCR) using a hairpin probe and a primer having a tag sequence at the 5′ end with the fluorescent molecule 2,7-diamino-1,8-naphthyridine derivative (DANP) has been developed.

The Evaluation of Fibrin-Related Markers for Diagnosing or Predicting Acute or Subclinical Venous Thromboembolism in Patients Undergoing Major Orthopedic Surgery

OBJECTIVE

The cutoff values of fibrin-related markers (FRMs) diagnosing or predicting the occurrence of a venous thromboembolism (VTE) were evaluated.

MATERIALS AND METHODS

Fibrin-related markers such as fibrin monomer complex (FMC), D-dimer, and fibrinogen and fibrin degradation products (FDPs) before surgery were measured in 326 patients undergoing orthopedic surgery to diagnose subclinical VTE or predict postoperative VTE.

RESULTS

Although the FMC, D-dimer, and FDP levels were all useful for the diagnosis of acute VTE, the FDP level was not useful for diagnosing subclinical VTE or predicting postoperative VTE. The results of several D-dimer assays closely correlated with other D-dimer assays. There were various cutoff ranges for diagnosing or predicting VTE. Some D-dimer assays were useful for diagnosing low levels of D-dimer and others were useful for diagnosing moderate to high D-dimer levels. Increased D-dimer levels were useful for diagnosing acute (cutoff values: 2.0-5.9 μg/mL) or about 10% of subclinical VTE (cutoff values: 3.4-5.3 μg/mL), for predicting about 10% of postoperative VTE (cutoff values: 3.4-5.3 μg/mL), and for excluding VTE.

CONCLUSION

Although increased D-dimer levels were useful for diagnosing subclinical VTE and predicting the risk of VTE, there were various cutoff values for the diagnosis or prediction of VTE.

Whole-exome sequencing identification of novel DNAH5 mutations in a young patient with primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare genetic disorder caused by structural and/or functional impairment of cilia throughout the whole body. Early diagnosis of PCD is important for the prevention of long-term sequelae, however early diagnosis is a challenge due to the phenotypic heterogeneity of PCD. In the current study, the patient with PCD was diagnosed at nine years old following several efforts to control intractable airway symptoms. The patient experienced a chronic productive cough beginning in early childhood and had multiple episodes of pneumonia and otitis media with effusion and sinusitis. No situs inversus or other heterotaxias were reported. Serial chest X-rays exhibited persistent atelectasis and bronchiectasis in the right middle lobe. When the patient was nine years old, electron microscopy of his cilia and genetic analysis were conducted. Electron microscopy of a biopsy specimen from the nasal mucosa indicated loss of the outer dynein arms. Whole-exome analysis of the genome demonstrated the presence of compound heterozygous mutations in DNAH5: NM_001369.2:c.5983C>T, p.Arg1995X in exon 36 and NM_001369.2:c.9101delG, p.Gly3034ValfsX22 in exon 54; neither of which have been previously reported in the literature in a Japanese patient. Notably, this case is, to the best of our knowledge, the first reported case of PCD caused by the DNAH5 mutation in a Japanese patient.

[New Horizon in Clinical Examination -Chairmen's Introductory Remarks -]

Translational research is leading to new technology and generating in practical diagnostic tests with clinical utility. This paper introduces three cutting-edge technologies: liquid biopsy, amino acid profiling, and con- tinuous glucose monitoring (CGM). Liquid biopsy was reviewed as one of the "10 Breakthrough Technologies in 2015" by MIT. This technol- ogy is based on fast DNA-sequencing machines or high-sensitivity PCR and non-invasive tests that detect fragments of DNA or cells in blood or other bodily fluids. Cell-free DNA refers to segments of DNA that are mainly derived from apoptotic and necrotic cells, and it is used for the detection and monitoring of cancer. Profiling of plasma-free amino acid is a promising approach because amino acid profiling links all organ sys- tems and amino acids have important roles in metabolism. Furthermore, amino acid profiles are known to be influenced by specific diseases, including cancers. CGM systems use a tiny sensor inserted under the skin to continuously check glucose levels in tissue fluid and convert blood glucose levels. CGM can provide valuable information at any points during the day and facilitate better treatment decisions and glucose control. [Review].

Elevated Plasma Levels of Fibrin Degradation Productsby Granulocyte-Derived Elastase in Patients with Disseminated Intravascular Coagulation

Plasma levels of granulocyte-derived elastase (GE-XDP), D-dimer, and soluble fibrin (SF) were examined in 177 patients with disseminated intravascular coagulation (DIC) of various etiologies. Plasma levels of GE-XDP and D-dimer, but not SF, were significantly high in patients with sepsis and solid cancer. The ratio of GE-XDP/D-dimer was significantly high in patients with trauma, burn, and sepsis, suggesting that fibrinolysis due to GE-XDP may be dominant in DIC. Plasma levels of GE-XDP and D-dimer, but not SF, were significantly high in patients with overt DIC and correlated with DIC score. Plasma levels of GE-XDP, but not SF, correlated significantly with D-dimer. Plasma levels of D-dimer, but not SF, correlated significantly with plasmin plasmin inhibitor complex (PPIC). Plasma levels of GEXDP and D-dimer, but not SF, were significantly high in nonsurvivors. Plasma levels of GE-XDP, but not SF, correlated significantly with sepsis-related organ failure assessment (SOFA) score. These results suggest that GE-XDP is a potentially useful marker for the diagnosis of overt-DIC and as a predictor of organ failure-related outcome.