Loss of p16 Immunoexpression and Deletions of CDKN2A in the Progression of Extramammary Paget Disease: An Immunohistochemical and Genetic Study of 24 Invasive/Metastatic Cases

ABSTRACT

Information regarding the genetic alterations in extramammary Paget disease (EMPD) is scarce. This study investigated the significance of CDKN2A and MTAP alterations in EMPD progression using immunohistochemistry and panel DNA sequencing. In total, 24 invasive/metastatic EMPD cases were included in this study. The immunoexpression of p16 and MTAP in the primary in situ, primary invasive, and metastatic tumor components was evaluated. Panel DNA sequencing was performed for metastatic tumor components in 5 of the 24 cases. Immunoexpression of p16 in the in situ tumor component was at least partially preserved in all 19 tested cases (100%). By contrast, the invasive tumor component was diffusely or partially lost in 18 (81.8%) of 22 tested cases. Regarding the foci of lymph node metastasis, 13 (81.2%) of the 16 patients showed a significant loss of p16 expression. Loss of MTAP immunoexpression was observed less frequently compared with the loss of p16 expression. CDKN2A homozygous deletions were confirmed in all 5 tested cases by sequencing, whereas MTAP deletions were detected in only 2 cases. In conclusion, p16 expression loss and CDKN2A deletions can be frequently seen in invasive/metastatic cases of EMPD.

A novel low-power pure-cut hot snare polypectomy for 10-14 mm colorectal adenomas: An ex vivo and a clinical prospective feasibility study (SHARP trial)

BACKGROUND AND AIM

Hot snare polypectomy using blend or coagulation current is widely used; however, it causes deeper tissue heat injury, leading to adverse events. We hypothesized that hot polypectomy using low-power pure cut current (PureCut, effect 1 10 W) could reduce deeper tissue heat injury. We conducted animal experiments to evaluate the deeper tissue heat injury and conducted a prospective clinical study to examine its cutting ability.

METHODS

In a porcine rectum, hot polypectomy using Blend current (EndoCut, effect 3 40 W) and low-power pure cut current was performed. The deepest part of heat destruction and thickness of the non-burned submucosal layer were evaluated histologically. Based on the results, we performed low-power pure cut current hot polypectomy for 10-14 mm adenoma. The primary endpoint was complete resection defined as one-piece resection with negative for adenoma in quadrant biopsies from the defect margin.

RESULTS

In experiments, all low-power pure-cut resections were limited within the submucosal layer whereas blend current resections coagulated the muscular layer in 13% (3/23). The remaining submucosal layer was thicker in low-power pure cut current than in blend current resections. In the clinical study, low-power pure-cut hot polypectomy removed all 100 enrolled polyps. For 98 pathologically neoplastic polyps, complete resection was achieved in 84 (85.7%, 95% confidence interval, 77-92%). The lower limit of the 95% confidence interval was not more than 15% below the pre-defined threshold of 86.6%. No severe adverse events occurred.

CONCLUSIONS

A novel low-power pure-cut hot polypectomy may be feasible for adenoma measuring 10-14 mm. (UMIN000037678).

Brain Metastasis of Non-small Cell Lung Cancer After Disease-Free Survival of 5 years: Case Series and Comprehensive Literature Review

BACKGROUND

In the treatment of nonsmall cell lung cancer (NSCLC), a disease-free survival of 5 years is a criterion for cure. This study aimed to evaluate the characteristics and outcomes of patients with brain metastases of NSCLC after a disease-free survival of 5 years (late recurrent brain metastasis [LRBM]).

METHODS

We reviewed 1281 consecutive patients with brain metastasis of lung cancer at a single institute between November 2014 and December 2022. Relevant articles were retrieved from PubMed. Only peer-reviewed journals published in English were included.

RESULTS

Six patients (0.47%) showed LRBM. Three were male. The median age at lung cancer diagnosis was 45 years. The histological diagnosis of all patients was adenocarcinoma. Driver gene mutations were observed in five patients. The median latency period from lung cancer treatment to the development of brain metastasis was 13 years. All patients had no metastasis to any other organs and underwent craniotomies. The median follow-up duration after craniotomy was 3.5 years. No local intracranial recurrences were observed. Three patients had distant intracranial recurrences at 7, 2, and 0.6 years after craniotomy. Five patients survived for 8, 4, 3, 2, and 0.3 years after craniotomy. One patient experienced re-recurrence in the lung 4 years after craniotomy and died 3.7 years later. In our systematic review, only six studies described LRBM of NSCLC.

CONCLUSIONS

LRBM is rare in patients with NSCLC. In our institution, many of these patients harbored driver gene mutations, and achieved long-term survival with aggressive local therapy. Multicenter analysis is mandatory.

Carcinoid-Like Cell Arrangements in Basal Cell Carcinoma: A Study of 11 Cases

Background. Carcinoid-like pattern in basal cell carcinoma is extremely rare and has only been documented in a textbook. The aim of this study is to reveal the characteristics of the carcinoid-like pattern in basal cell carcinoma as well as to establish the concept of the tumor pattern. Methods. Of 355 basal cell carcinoma cases (355 lesions of 308 patients), 11 tumors with histopathological features of carcinoid-like pattern were retrieved. Results. The patients included 5 males and 6 females with a median age of 73 years (range 38-86 years). Of the 11 lesions, 10 were observed on the head. Histopathologically, a carcinoid-like pattern with branching and anastomosing of trabecular structures was observed in 30% to 95% of the tumor area. No differentiation to sebocytes was observed in any of the tumors. The tumors were well-circumscribed, although 3 lesions contained an infiltrative-type component as well. The carcinoid-like pattern areas in all 11 lesions exhibited diffuse BerEP4 immunoexpression but no KIT, synaptophysin, or vimentin expression. Keratin 20-positive Merkel cells were not observed in the tumor areas. Conclusions. Basal cell carcinoma can show a carcinoid-like pattern cell arrangement. Based on the histopathological and immunohistochemical findings from our study, we collectively conclude that the carcinoid-like pattern in basal cell carcinoma does not seem to represent sebaceous mantle differentiation. Carcinoid-like pattern basal cell carcinoma can be distinguished from other tumors by the favorite site of the head, the co-existence of conventional basal cell carcinoma components, lack of sebaceous differentiation, and diffuse BerEP4 immunoexpression.

A Japanese case of ovarian mucinous adenocarcinoma with germline double variants of MSH2 and BRCA2

Germline double heterozygosity (GDH) is rarely reported in cases of inherited cancer syndromes, and GDH of a mismatch repair gene and BRCA has never been reported in Japan. Nonetheless, the current report demonstrates a case of ovarian mucinous adenocarcinoma with initiated Lynch syndrome (LS)-related surveillance because of a known germline MSH2 variant. Six and a half years after oophorectomy, multiple tumors developed in the patient's lungs, bones, and lymph nodes, and histology results confirmed mucinous adenocarcinoma. Systemic chemotherapy including an anti-PD-L1 antibody was effective for >1 year, but brain metastases developed. Pathology of the brain tumors showed mucinous adenocarcinoma without expression of MSH2 and MSH6, while multi-gene panel testing demonstrated not only high microsatellite instability and a high tumor mutation burden, but also germline BRCA2 variants. Further, germline testing in relatives confirmed both variants were from the paternal line, from which many LS-related cancers develop, but not BRCA-related cancer.

An autopsy case of primary gliosarcoma with multiple extracranial metastases: pathology after administration of bevacizumab and genetic profile

Gliosarcoma (GS), a morphological variant of glioblastoma, pathologically shows a biphasic pattern with gliomatous and sarcomatous components. It has been reported that GS has much higher metastatic capacity than glioblastoma. A few reports on the pathology of the extracranial metastasis of GS have shown that metastatic lesions had a sarcomatous component alone or a mixture of gliomatous and sarcomatous ones. Therefore, it is considered that GS tends to disseminate hematogenously due to its mesenchymal sarcomatous component. Herein, we report an autopsy case of GS with multiple extracranial metastases treated by craniotomy, radiotherapy, and bevacizumab. In this case, metastatic lesions at autopsy contained a gliomatous component alone, but no sarcomatous component. In addition, the sarcomatous component disappeared from the intracranial lesion at autopsy after the administration of bevacizumab. In this report, we discuss the clinical course and pathological findings at the initial state, recurrence, and autopsy, including the results of whole-genome analysis.

A Primary Intraosseous Meningioma: A Rare Case of Malignancy with High Proliferative Ability

Primary intraosseous meningioma (PIM) is a rare tumor that arises in the skull. Histopathologically, it is generally described as a slow-growing, benign lesion. However, on rare occasions, PIM presents as a malignancy with high proliferative ability, which requires maximal resection, adjuvant radiotherapy, and subsequent careful follow-up. Because of the rarity of such cases, they present a diagnostic challenge with unusual pathological findings. Herein, we report a case of a primary intraosseous anaplastic meningioma with extensive invasion inside and outside the skull, along with the results of whole-genome analysis. Histopathological diagnosis was a World Health Organization grade 3 anaplastic meningioma. In the literature, only two cases of anaplastic PIM have been reported, so its characteristics and treatment are poorly understood. Our patient was successfully treated with tumor resection, followed by intensity-modulated radiation therapy. Follow-up imaging studies revealed no recurrence or distant metastasis, including to lung, liver, and bone, at 8 months after the surgery.

Optimization of a fast deuterium diagnostic method based on visible energetic 3He spectroscopy for high electron density plasmas

Fast ions play a crucial role in plasma heating, and their behavior in the plasma must be accurately understood. A diagnostics method based on charge exchange emission from the n = 4 - 3 transition (λ0 = 468.6 nm) of energetic 3He produced by the deuteron-deuteron reaction has been proposed as a for fast deuterons with energies in the order of MeV. The proposed method has the following advantages: No beam emission interferes with the spectra, the direction of the measuring line of sight, and the injection angle of the diagnostic beam can be freely determined. In previous studies, due to competing bremsstrahlung, it was expected that the proposed method will not be practical in the case of high electron density operation. This paper makes the proposed method available for measurement even at high electron densities by optimizing the measurement line of sight direction and the diagnostic beam incidence angle. This allows an electron density five times larger than the range of applications shown in previous studies. This result will contribute to measure of DT alpha in ITER.

Clinicopathologic and genetic characterization of invasive melanoma with BRAF V600K mutation: A study of 16 cases

BACKGROUND

The clinicopathologic and genetic features of cutaneous melanoma with a BRAF V600K mutation are not well-known. We aimed to evaluate these characteristics in comparison with those associated with BRAF V600E.

METHODS

Real-time polymerase chain reaction (PCR) and/or the MassARRAY® system were used to detect BRAF V600K in 16 invasive melanomas and confirm BRAF V600E in another 60 cases. Immunohistochemistry and panel next-generation sequencing were used to evaluate protein expression and tumor mutation burden, respectively.

RESULTS

The median age of melanoma patients harboring the BRAF V600K mutation (72.5 years) was higher than those with the BRAF V600E (58.5 years). The two groups also differed in sex (13/16 [81.3%] male in the V600K group vs. 23/60 [38.3%] in V600E) and in the frequency of scalp involvement (8/16 [50.0%] in V600K vs. 1/60 [1.6%] in V600E). The clinical appearance was similar to a superficial spreading melanoma. Histopathologically, non-nested lentiginous intraepidermal spread and subtle solar elastosis were observed. One patient (1/13, 7.7%) had a pre-existing intradermal nevus. Diffuse PRAME immunoexpression was seen in only one (14.3%) of seven tested cases. Loss of p16 expression was observed in all 12 cases (100%) analyzed. The tumor mutation burden was 8 and 6 mutations/Mb in the two tested cases.

CONCLUSIONS

Melanoma carrying the BRAF V600K mutation showed the predominance on the scalp of elderly men, lentiginous intraepidermal growth, subtle solar elastosis, possible existence of intradermal nevus component, frequent loss of p16 immunoexpression, limited immunoreactivity for PRAME, and intermediate tumor mutation burden.

A case of extensively spreading acinic cell carcinoma of the breast with microglandular features

Acinic cell carcinoma (ACC) is an exceptionally rare type of breast carcinoma with a low-grade morphology and a favorable prognosis. It is postulated to be a type of invasive carcinoma arising in microglandular adenosis (MGA). We report a case of extensively spreading ACC of the breast with MGA-like features. Macroscopically, yellowish nodules were widely distributed throughout the right breast, up to the axilla, without mass formation. Microscopically, the tumor consisted of two distinct carcinoma components: one was multiple nodular lesions showing invasive carcinoma with fused solid nests, and the other was a widely spreading lesion exhibiting MGA-like features with uniform small single glands. Immunohistochemically, both components were negative for ER, PR, and HER2, and expressed EMA, S100 and lysozyme. The distinct morphology and molecular expression indicated ACC. The single glands in the MGA-like area lacked myoepithelial cells but were linearly surrounded by type IV collagen, a basement membrane component. This case supports the hypothesis that ACC and MGA have the same lineage and indicates that ACC is not necessarily a low-grade malignancy and can be aggressive.

Discordance of microsatellite instability and mismatch repair immunochemistry occurs depending on the cancer type

Microsatellite instability (MSI) and deficiency of mismatch repair (dMMR) are key markers for predicting the response of immune checkpoint inhibitors (ICIs) and screening for Lynch syndrome (LS). This study examined the incidences of and factors associated with the concordance of MSI and MMR in human cancers. A total of 518 formalin-fixed cancer tissues were analyzed for MSI and MMR immunohistochemistry (IHC). MSI was analyzed by a PCR-based method using Promega markers. Concordance with MMR expression and factors associated with concordance were analyzed. In 2 colorectal cancer samples, MMR IHC failed due to inadequate staining conditions. In the remaining 516 cancers, a high level of MSI (MSI-H) was identified in 113 cases, and dMMR was identified in 112. The concordance of MSI and MMR IHC was 98.3%. Only 9 cases (4 pancreatobiliary, 3 colorectal, and 2 endometrial cancers) were discordant. Of the 113 MSI-H cases, 4 (3.5%) were proficient MMR (pMMR); of the 403 microsatellite stability (MSS) cases, 5 (1.2%) were dMMR. The independent factors associated with MSI-H/dMMR included meeting Amsterdam II criteria, assay purpose, and sampling method. Multivariate analysis revealed that cancer type (gastrointestinal cancers or others) was associated with concordance of MSI and MMR IHC. Three LS cases with pancreatic or endometrial cancer demonstrated MSS and dMMR, and one biliary cancer showed MSI-H and pMMR. Discordance between MSI and MMR IHC occasionally occurs in pancreaticobiliary and endometrial cancers. When suspected, both MSI and MMR IHC should be done to judge the ICI indication and screen for LS.

Sweat Gland Carcinoma With Neuroendocrine Differentiation of the Areola as a Potential Clinicopathologic Mimicker of Male Breast Carcinoma and Syringocystadenocarcinoma Papilliferum

ABSTRACT

Sweat gland carcinoma with neuroendocrine differentiation (SCAND) is a newly proposed tumor entity of primary cutaneous apocrine/eccrine adnexal tumor with neuroendocrine differentiation. The histopathologic variations are not yet well known. In this article, we present a case of SCAND mimicking male breast cancer and syringocystadenocarcinoma papilliferum. A 68-year-old man presented with a reddish 12-mm nodule on his left areola. No lymph node or distant metastases were observed. The patient was disease free 1 year and 9 months after the tumor was surgically resected but died of cerebral hemorrhage. Histopathological examination revealed a predominantly intradermal tumor with marked syringotropism, mimicking a component of mammary ductal carcinoma in situ. In addition, another tissue section displayed a cup-shaped papillated tumor with syringocystadenocarcinoma papilliferum-like features, which were also seen because of marked syringotropism. Diffuse immunoexpression of cytokeratin 7, cytokeratin 19, chromogranin A, synaptophysin, INSM1, estrogen receptor, carcinoembryonic antigen, epithelial membrane antigen, and GATA3 was observed in the tumor, but no BRAF immunoexpression was seen. The present case would help us to understand the histopathological variation and differential diagnosis of SCAND. The histopathological diagnosis of male breast cancer or syringocystadenocarcinoma papilliferum should be made by ruling out SCAND.

NEIM-07 DIFFERENTIAL DIAGNOSIS OF TUMOR RECURRENCE AND RADIATION NECROSIS AFTER STEREOTACTIC RADIOTHERAPY FOR BRAIN METASTASES WITH 320-ROW ADCT PERFUSION IMAGE AND T1/T2 MATCH: RADIOLOGICAL AND PATHOLOGICAL ANALYSIS

BACKGROUND AND PURPOSE

Radiation necrosis occurs from 6 months to several years following stereotactic irradiation (STI) for brain metastases when tumor recurrences are also most likely. Conventional MR imaging does not provide sufficient information to differentiate between radiation necrosis and tumor recurrence. Methionine-PET, FDG-PET and MR spectroscopy sometimes lead to false positive findings. We applied 320-row area detector CT perfusion imaging for the differentiation because it shows vascularity of lesions in the whole brain. MR T1/T2 match sign also evaluate because it is convenient diagnostic method.

METHOD

Between October 2006 and September 2021, 48 lesions enlarged in 46 patients 3 to 122 months (median: 11 months) after STI. Differential diagnosis was performed with CT perfusion imaging and MR T1/T2 match sign. To calculate the regional cerebral blood volume (rCBV), the regions of interest (ROIs) were located in the enhanced areas. The lesions progressively increased in size or became symptomatic were resected and diagnosed by pathological examination.

RESULTS

Mean age was 63 years, and 60% were male. Primary were lung 31, breast 9, kidney 3, colon 2, melanoma 2, and uterus 1. Mean time to progression from STI was 11 months (range; 3-122). Pathological diagnosis revealed 38 lesions (79%) had tumor recurrence, and 10 (21%) had radiation necrosis. A cut off value rCBV of greater than 3.0 analyzed by ROC curve provided the best sensitivity and specificity for identifying recurrent metastatic tumors, at 89% and 100%, respectively. T1/T2 match sign was provided sensitivity and specificity for identifying recurrent tumors, at 84% and 90%, respectively. To estimate intralesional pathological heterogeneity, contradistinction of CBV map and T1/T2 match sign is useful for the choice of intraoperative maneuver.

CONCLUSION

Perfusion CT imaging and T1/T2 match sign demonstrated reliable methods for differentiating tumor recurrence from radiation necrosis after STI.

Present status of germline findings in precision medicine for Japanese cancer patients: issues in the current system

OBJECTIVE

Since 2019, precision cancer medicine has been covered by national insurance in Japan; however, to date, germline findings have not been fully reported. The aim of this study was to evaluate the current status and raise a problem of germline finding analysis and disclosure in Japanese precision cancer medicine.

METHODS

Germline findings of 52 genes were examined in 296 cases with advanced cancer by a case series study.

RESULTS

Six (2.0%) cases were examined by the Oncoguide™ NCC Oncopanel with germline testing, but no germline findings were reported. The remaining 290 (98.0%) cases were analyzed by FoundationOne® CDx (tumor-only testing), which recognized 404 pathogenic variants; those of BRCA1/2 were recognized in 16 (5.5%) tumors. Our institutional algorithm suggested 39 candidate germline findings in 34 cases, while the public algorithm listed at least 91 candidate germline findings. Four germline findings had been previously identified (BRCA1: 3 and ATM: 1). Nine of 30 cases with candidate germline findings excluding these known germline findings refused or deferred germline testing. Only 4 of 16 cases that received counseling underwent germline testing, and those 4 revealed 3 germline findings (BRCA2, CDK4 and RAD51C); in total, 8 (2.7%) germline findings were revealed. Reasons for refusing genetic counseling and/or germline testing included extra hospital visits, added expense for germline testing due to limited national insurance coverage, poor patient physical condition and no known family members associated with the possible germline finding.

CONCLUSIONS

In current Japanese precision cancer medicine, only a small fraction of the patients undergoes germline testing and demonstrated germline finding. The current results suggested a need for earlier indications for precision cancer medicine, broader insurance coverage and more efficient germline finding prediction algorithms, to increase the number of germline testings and to improve the following managements.

Expression of N-Terminal-Deficient E-Cadherin Protein in Invasive Lobular Carcinoma of the Breast

Invasive lobular carcinoma (ILC) of the breast is characterized by the discohesive growth of tumor cells, which is mainly associated with the complete loss of E-cadherin (E-cad) expression. However, some aberrant expression patterns of E-cad protein that are inconsistent with their morphologies have been reported in ILC. We report herein ILC cases expressing a new type of abnormal E-cad protein that lacks the N-terminal domain, but conserves the C-terminal domain on the cell membrane. Immunohistochemical staining of 299 ILC cases using specific antibodies against the N-terminal or C-terminal region of E-cad revealed that 227 (76%) cases showed loss of the membranous expression of both terminuses (N-/C-) and 72 (24%) cases showed expression of only the C-terminus (N-/C+). In all cases, the expression of p120-catenin and β-catenin coincided with the expression of the C-terminus of E-cad. Clinicopathologic analysis revealed that N-/C+ expression in ILC cells was significantly associated with the histologic subtype (especially mixed-type ILC with another histologic type) and immunohistochemical molecular subtype (especially the triple-negative subtype), but not with prognostic factors (pT or pN). In addition, 12 of 15 cases (80%) with aberrant cytoplasmic localization of the N-terminal of E-cad showed diffuse membranous expression of the C-terminal domain. Additional immunohistochemistry using an antibody recognizing the extracellular juxtamembrane region showed that 28 (39%) of the N-/C+ cases had lost membranous expression, suggesting diversity in the deletion pattern of the N-terminal region. Our findings provide a novel mechanism for the loss of E-cad function because of N-terminal-deficient E-cad protein in ILC.

Microsatellite instability is biased in Amsterdam II-defined Lynch-related cancer cases with family history but is rare in other cancers: a summary of 1000 analyses

Background

Microsatellite instability (MSI) is a key marker for predicting the response of immune checkpoint inhibitors (ICIs) and for screening Lynch syndrome (LS).

Aim

This study aimed to see the characteristics of cancers with high level of MSI (MSI-H) in genetic medicine and precision medicine.

Methods

This study analyzed the incidence of MSI-H in 1000 cancers and compared according to several clinical and demographic factors.

Results

The incidence of MSI-H was highest in endometrial cancers (26.7%, 20/75), followed by small intestine (20%, 3/15) and colorectal cancers (CRCs)(13.7%, 64/466); the sum of these three cancers (15.6%) was significantly higher than that of other types (2.5%)(P < 0.0001). MSI-H was associated with LS-related cancers (P < 0.0001), younger age (P = 0.009), and family history, but not with smoking, drinking, or serum hepatitis virus markers. In CRC cases, MSI-H was significantly associated with a family history of LS-related cancer (P < 0.0001), Amsterdam II criteria [odds ratio (OR): 5.96], right side CRCs (OR: 4.89), and multiplicity (OR: 3.31). However, MSI-H was very rare in pancreatic (0.6%, 1/162) and biliary cancers (1.6%, 1/64) and was null in 25 familial pancreatic cancers. MSI-H was more recognized in cancers analyzed for genetic counseling (33.3%) than in those for ICI companion diagnostics (3.1%)(P < 0.0001). Even in CRCs, MSI-H was limited to 3.3% when analyzed for drug use.

Conclusions

MSI-H was predominantly recognized in LS-related cancer cases with specific family histories and younger age. MSI-H was limited to a small proportion in precision medicine especially for non-LS-related cancer cases.

Sweat-gland carcinoma with neuroendocrine differentiation (SCAND): a clinicopathologic study of 13 cases with genetic analysis

Low-grade neuroendocrine carcinoma of the skin (LGNECS) was proposed in 2017 as a new primary cutaneous neoplasm with neuroendocrine differentiation; however, it is not yet well known due to its rarity. Herein, we perform a detailed clinicopathologic analysis of 13 cases as well as panel DNA sequencing in three cases. The study included 12 males and 1 female with a median age of 71 (43-85) years. All lesions occurred on the ventral trunk. The mean tumor size was 2.2 (0.8-11.0) cm. The histopathology resembled that of well-differentiated neuroendocrine tumors (NETs) in other organs, but intraepidermal pagetoid spreading was seen in 8 (61.5%) cases and stromal mucin deposits in 4 (30.8%). Immunoreactivity for CK7, CK19, EMA, BerEP4, CEA, chromogranin A, synaptophysin, INSM1, GCDFP15, GATA3, ER, and bcl-2 were present in varying degrees in all tested cases. PTEN c.165-1G>A splice site mutation was detected by panel sequencing in one case, and GATA3 P409fs*99 and SETD2 R1708fs*4 in another case. Lymph node metastasis was seen significantly in cases with tumor size >2.0 cm [8/8 (100%) vs. 1/5 (20%)]. All three cases with size >3.0 cm were in unresectable advanced-stage [3/3 (100%) vs. 1/10 (10%)], and two of the three patients succumbed to the disease. The two cases of death revealed mild nuclear atypia (mitosis: 1/10 HPFs) and moderate nuclear atypia (2/10 HPFs). Thus, tumor size would be a better prognostic factor than nuclear atypia, mitotic count, and Ki67 index, unlike in NETs. These clinicopathologic and immunohistochemical features would represent the characteristics as skin adnexal tumors with apocrine/eccrine differentiation rather than NETs; therefore, we rename it as sweat-gland carcinoma with neuroendocrine differentiation (SCAND).

Co-existence of BRAF V600E-mutated malignant melanoma and BRAF V600E-mutated Langerhans cell histiocytosis: A case report

Langerhans cell histiocytosis (LCH) is a neoplastic condition of Langerhans cells, and can be associated with other neoplasms, especially BRAF-mutant hematological tumors and papillary thyroid carcinoma. Here we present the first case of co-existing LCH and low cumulative sun damage (low-CSD) melanoma, both of which had a BRAF V600E mutation. A 49-year-old man had a 45 × 43 × 15 mm semi-pedunculated, pigmented tumor in his back but had no other systemic symptoms. Histopathology revealed a 2-mm-sized incidental focus of LCH within a large lesion of low-CSD melanoma. Diffuse immunoexpression of CD1a, langerin/CD207, S100 protein, and BRAF (VE1) was observed in the focus of LCH. Sanger sequencing with microdissection confirmed BRAF V600E mutation in the component of LCH. Interestingly, the advanced melanoma also harbored the same BRAF V600E mutation, although the significance of this tumor combination is still unknown.

The essential problem of over-measuring the depth of submucosal invasion in pT1 colorectal cancer

A depth of submucosal invasion (DSI) of ≥1000 μm is an important risk factor for lymph node metastasis (LNM) in patients with submucosal invasive (pT1) colorectal cancer (CRC), according to the European Society of Gastrointestinal Endoscopy and the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines. According to the latter, if the location of the muscularis mucosae in the invasive area is not confirmed, the DSI can be measured from the surface. In these cases, a 'remaining intramucosal lesion' (rIL), which is in the invasive area, is sometimes observed. To avoid over-measuring the DSI, we proposed a 'modified DSI' (mDSI), which excludes the rIL from the JSCCR DSI. We investigated the characteristics and effectiveness of the rIL and mDSI by grouping cases with polypoid growth (PG) and non-polypoid growth (NPG) histologically. Three hundred and thirty-nine consecutive patients with pT1 CRC were examined. LNM was detected in 37 cases. The distribution of the DSI and rIL was significantly higher in PG than in NPG cases (P<0.001). There was no difference in the mDSI distribution between the PG-/NPG-type cases. An rIL was observed in 39% (127/301) of cases, in which the location of the muscularis mucosae could not be determined or estimated and the mDIS could be estimated. In 13% (16/127) of cases, the mDSI was effective (JSCCR DSI ≥1000 and mDSI <1000 μm). Among these 16 cases, 11 (69%) did not have risk factors (mDSI, lymphovascular invasion, budding grade, or special histological types) and may have avoided unnecessary surgery.

Signet-ring cell/histiocytoid carcinoma of the axilla: a clinicopathological and genetic analysis of 11 cases, review of the literature, and comparison with potentially related tumours

AIMS

The aim of this study was to determine the clinicopathological and genetic characteristics of axillary signet-ring cell/histiocytoid carcinoma (SRCHC) and the relationship between axillary SRCHC, eyelid SRCHC, and conventional apocrine carcinoma (AC).

METHODS AND RESULTS

Eleven cases of axillary SRCHC, four cases of eyelid SRCHC, eight cases of axillary AC and five cases of invasive lobular carcinoma (ILC) were retrieved. Additionally, 14 axillary and 43 eyelid SRCHC cases from the literature were reviewed. Male predominance was prominent for axillary SRCHC (24:1) and eyelid SRCHC (42:5). Axillary SRCHC formed a circumscribed plaque or nodule, unlike eyelid SRCHC. Lymph node metastasis was predominantly seen in axillary SRCHC cases (72%, 18/25), but not in eyelid SRCHC cases (19%, 9/47). Axillary SRCHC and eyelid SRCHC were histopathologically similar and showed rare tubular formations. Immunoexpression of cytokeratin 7, cytokeratin 19, mucin 1, mucin 5AC, BerEP4 and androgen receptor was seen in all tested cases of the four diseases. Oestrogen and progesterone receptors were negative in both types of SRCHC and AC, but were strongly positive in ILCs. Complete loss of E-cadherin expression was seen in approximately one-quarter of both types of SRCHC and in all ILCs. PIK3CA mutations were detected in all three sequenced cases (two axillary SRCHCs and one eyelid SRCHC).

CONCLUSION

The histopathological, immunohistochemical and genetic findings suggest that both types of SRCHC are phenotypic variants of AC, although there are differences in sex, macroscopic findings and the frequency of lymph node metastasis among the three. In contrast, ILC differs from the other three tumour types.

Fast deuteron diagnostics using visible light spectra of 3He produced by deuteron-deuteron reaction in deuterium plasmas

The fast deuteron (non-Maxwellian component) diagnostic method, which is based on the higher resolution optical spectroscopic measurement, has been developed as a powerful tool. Owing to a decrease in the D-H charge-exchange cross section, the diagnostic ability of conventional optical diagnostic methods should be improved for ∼MeV energy deuterons. Because the ³He-H charge-exchange cross section is much larger than that of D-H in the ∼MeV energy range, the visible light (VIS) spectrum of ³He produced by the dueteron-dueteron (DD) reaction may be a useful tool. Although the density of ³He is small because it is produced via the DD reaction, improvement of the emissivity of the VIS spectrum of ³He can be expected by using a high-energy beam. We evaluate the VIS spectrum of ³He for the cases when a fast deuteron tail is formed and not formed in the ITER-like beam injected deuterium plasma. Even when the beam energy is in the MeV energy range, a large change appears in the half width at half maximum of the VIS spectrum. The emissivity of the VIS spectrum of ³He and the emissivity of bremsstrahlung are compared, and the measurable VIS spectrum is obtained. It is shown that the VIS spectrum of ³He is a useful tool for the MeV beam deuteron tail diagnostics.

Efficacy and safety of cold-snare endoscopic mucosal resection for colorectal adenomas 10 to 14 mm in size: a prospective observational study

BACKGROUND AND AIMS

Cold-snare endoscopic mucosal resection (CS-EMR) has been adapted in a piecemeal fashion as a safe and effective procedure for resection of colorectal polyps ≥10 mm. However, few data are available on en bloc CS-EMR for adenomas of 10 to 14 mm. Thus, this study evaluated the efficacy and safety of CS-EMR for these colorectal adenomas.

METHODS

In this single-arm, prospective, observational study, patients with at least 1 slightly elevated and sessile colorectal adenoma measuring 10 to 14 mm were recruited to undergo CS-EMR. The primary outcome was histological complete resection rate by CS-EMR, which was defined as en bloc resection, with a pathologically negative vertical margin and no neoplastic tissue obtained from 4 quadrants of the mucosal defect margin. Secondary outcomes were en bloc resection rate by CS-EMR, failure rate of CS-EMR, and the incidence of adverse events.

RESULTS

A total of 80 polyps from 72 patients were included. CS-EMR failed in 11 lesions (13.7%), all of which were resected using a high-frequency electric current. The rates of en bloc resection and histologic complete resection by CS-EMR were 82.5% (66 of 80) and 63.8% (51 of 80), respectively. No bleeding occurred during the CS-EMR procedure, and there was no delayed bleeding or perforation at the site where CS-EMR was performed.

CONCLUSIONS

CS-EMR can be safely performed in an en bloc fashion for some colorectal adenomas measuring 10 to 14 mm. However, there is room for improvement regarding the resectability and evaluation of the vertical margin after CS-EMR. (Clinical trial registration number: UMIN000031248.).

Alpha-type-1 Polarized Dendritic Cell-based Vaccination in Newly Diagnosed High-grade Glioma: A Phase II Clinical Trial

BACKGROUND/AIM

Glioblastoma multiforme (GBM) is an intractable tumor that has a very poor prognosis despite intensive treatment with temozolomide plus radiotherapy.

PATIENTS AND METHODS

Sixteen newly diagnosed patients with high-grade gliomas were enrolled in a phase II study of the α-type-1 DC vaccine. Briefly, DCs obtained from the culture of enriched monocytes in the presence of a cytokine cocktail, were pulsed with a cocktail of 5 synthetic peptides and cryopreserved until injection into patients.

RESULTS

The amount of IL-12 produced by activated DCs was higher than that previously reported. Among 15 evaluable patients, 10 showed positive CTL responses to any peptides in an ELISPOT assay. After 6 years of observation, five patients were still alive, and two of these patients were relapse-free. Moreover, a significant survival-prolonging effect was verified in DC-treated glioma patients.

CONCLUSION

Peptide-cocktail-pulsed α-type-1 DC vaccines have a potential therapeutic effect on survival when used in combination with the standard regimen, which is partly based on IL-12-IFN-γ-mediated T-cell activation.

Role of Tumor Mutation Burden Analysis in Detecting Lynch Syndrome in Precision Medicine: Analysis of 2,501 Japanese Cancer Patients

BACKGROUND

Tumor mutation burden (TMB) is the total exonic mutation count per megabase of tumor DNA. Recent advances in precision medicine occasionally detect Lynch syndrome (LS) by germline sequencing for mismatch-repair (g.MMR) genes but not using TMB. The current study analyzes the utility of TMB in detecting LS.

METHODS

Whole-exome sequencing (ion-semiconductor sequencing) was performed for somatic and germline DNA from 2,501 various cancer patients to detect TMB and g.MMR sequencing. MMR IHC was conducted when high TMB (≥10) was detected in LS-related cancers with an additional condition of wild-type BRAF in colorectal cancers. Target sequencing and multiplex ligation-dependent probe amplification (MLPA) were further performed for g.MMR genes in MMR-deficient cancers (TMB-based g.MMR target sequencing). We compared universal sequencing and TMB-based target sequencing in their sensitivity for detecting LS.

RESULTS

LS was detected in 16 (0.6%) of the 2,501 patients: 1.1% (9/826) of colorectal cancer patients, 16.2% (6/37) of endometrial cancer patients, and 14.3% (1/7) of small intestine cancer patients. TMB-based g.MMR target sequencing (81.3%) showed superior sensitivity for detecting LS than universal g.MMR sequencing (56.3%; P = 0.127) but missed 3 LS patients (1 with a low-TMB cancer, 1 with a BRAF-mutant colorectal cancer, and 1 with an MMR-proficient cancer). Ion-semiconductor sequencing could detect single-nucleotide substitutions but not large deletions. POL-mutated cancers showed extremely high TMBs (48.4-749.2).

CONCLUSIONS

g.MMR target sequencing, combined with TMB, somatic BRAF mutation, and MMR IHC is an effective strategy for detecting LS.

IMPACT

TMB can be a biomarker for detecting LS in precision medicine.

Clinicopathological analysis of T2-FLAIR mismatch sign in lower-grade gliomas

T2-FLAIR mismatch sign is known as a highly specific imaging marker of IDH-mutant astrocytomas. This study was intended to clarify what the T2-FLAIR mismatch sign represents by pathological analysis of lower-grade gliomas rediagnosed in accordance with the WHO 2016 classification. We retrospectively analyzed the records of 64 patients diagnosed with WHO grade II and III diffuse gliomas between June 2009 and November 2018. T2-FLAIR mismatch sign was found in 10 (45%) out of 22 patients with IDH-mutant astrocytoma, 1 (5%) out of 20 with oligodendroglioma, and 1 (5%) out of 22 with IDH-wild-type astrocytoma. T2-FLAIR mismatch sign as a marker of IDH-mutant astrocytomas showed positive predictive value of 83%. Among 22 patients with IDH-mutant astrocytomas, microcystic change was found in eight, of which seven showed T2-FLAIR mismatch sign. Microcystic change was significantly associated with T2-FLAIR mismatch sign (P < 0.01). From multi-sampling in a patient, abundant microcysts were observed upon HE staining of specimens from the T2-FLAIR mismatched region, while microcysts were hardly observed from the T2-FLAIR matched one. All three protoplasmic astrocytomas among our IDH-mutant astrocytomas presented T2-FLAIR mismatch sign. In conclusion, T2-FLAIR mismatch sign may reflect microcyst formation in IDH-mutant astrocytomas and be common in IDH-mutant protoplasmic astrocytoma.

Retrospective analysis of salvage surgery for local progression of brain metastasis previously treated with stereotactic irradiation: diagnostic contribution, functional outcome, and prognostic factors

Background

Stereotactic irradiation (STI) is a primary treatment for patients with newly diagnosed brain metastases. Some of these patients experience local progression, which is difficult to differentiate from radiation necrosis, and difficult to treat. So far, just a few studies have clarified the prognosis and effectiveness of salvage surgery after STI. We evaluated the diagnostic value and improvement of functional outcomes after salvage surgery. Based on these results, we reconsidered surgical indication for patients with local progression after STI.

Methods

We evaluated patients with brain metastases treated with salvage surgery for local progression from October 2002 to July 2019. These patients had undergone salvage surgery based on magnetic resonance imaging findings and/or clinical evidence of post-STI local progression and stable systemic disease. We employed two prospective strategies according to the eloquency of the lesions. Lesions in non-eloquent areas had been resected completely with a safety margin, utilizing a fence-post method; while lesions in eloquent areas had been treated with minimal resection and postoperative STI. Kaplan-Meier curves were used for the assessment of overall survival. Prognostic factors for survival were analyzed.

Results

Fifty-four salvage surgeries had been performed on 48 patients. The median age of patients was 63.5 years (range 36–79). The median interval from STI to surgery was 12 months. The median overall survival was 20.2 months from salvage surgery and 37.5 months from initial STI. Primary cancers were lung 31, breast 9, and others 8. Local recurrence developed in 13 of 54 lesions (24%). Leptomeningeal dissemination occurred after surgery in 3 patients (5.6%). Primary breast cancer (breast vs. lung: HR: 0.17), (breast vs. others: HR: 0.08) and RPA class 1–2 (RPA 1 vs. 3, HR:0.13), (RPA 2 vs 3, HR:0.4) were identified as good prognostic factors for overall survival (OS) in multivariate analyses. The peripheral neutrophil-to-lymphocyte ratio (NLR) of ≤3.65 predicted significantly longer OS (median 25.5 months) than an NLR > 3.65 (median 8 months).

Conclusion

We insist that salvage surgery leads to rapid improvement of neurological function and clarity of histological diagnosis. Salvage surgery is recommended for large lesions especially with surrounding edema either in eloquent or non-eloquent areas.

NI-09 CLINICAL SIGNIFICANCE OF T2-FLAIR MISMATCH SIGN IN LOWER GRADE GLIOMAS

Lower grade glioma is classified based on genetic information of mutation of IDH1/2 gene and co-deletion of chromosome 1p19q. Knowledge of these genetic information preoperatively is useful for making surgical planning, treatment strategy and prognostication. Recently, T2-FLAIR mismatch sign has been reported to be specific for astrocytoma with IDH mutation (mut) / non-1p19q co-deletion (co-del). This study aims to verify it in our patients. We retrospectively analyzed 152 patients aged over 15 years who were pathologically diagnosed with WHO grade 2 or 3 gliomas from April 2003 to December 2018. We excluded 88 patients without genetic information or without T2-weighted and FLAIR images. T2-FLAIR mismatch sign was defined as in the original description, namely, with homogeneously hyperintense signal on T2-weighted image and a peripheral hyperintense signal with central hypointensity signal on FLAIR image. Among 22 patients with IDH mut / non-1p19q codel, 10 were positive for T2-FLAIR mismatch sign. On the other hand, only one patient was positive for T2-FLAIR mismatch sign respectively in 19 with IDH mut / 1p19q codel and 23 patients with IDH wild-type. Sensitivity, specificity, positive predictive value, and negative predictive value of T2-FLAIR mismatch for the patients with IDH mut / non-1p19q codel are 0.46 (95% confidence interval: 0.24–0.68), 0.95 (0.84–0.99), 0.83 (0.52–0.98). and 0.77 (0.63–0.88), respectively. In 22 patients with IDH mut / non-1p19q codel, we compared 10 patients with and 12 without T2-FLAIR mismatch sign. Median age was 35 and 39 years old. WHO grade 3 was 3 patients each. Tumor location was frontal lobe in 9 (90%) and 10 patients (83%). A statistically significant difference was not found in these factors. PFS and OS were not reached in both groups. The specificity of the T2-FLAIR mismatch sign for astrocytoma with IDH mut / non-1p19q codel was very high, which may be helpful as preoperative imaging marker.

Associations Between Loss of ARID1A Expression and Clinicopathologic and Genetic Variables in T1 Early Colorectal Cancer

OBJECTIVES

To evaluate the relationships between adenine-thymine-rich interactive domain 1A (ARID1A) expression and the clinicopathologic features in T1 colorectal cancer (CRC) and to investigate whether the presence of ARID1A protein is related to genetic changes.

METHODS

We retrospectively studied 219 surgically resected T1 CRCs. ARID1A expression was assessed by immunohistochemical methods, and the correlation between ARID1A expression and clinicopathologic features was evaluated. The relationship between ARID1A expression and 409 cancer-related gene mutations was also evaluated using next-generation sequencing (NGS).

RESULTS

Immunohistochemical staining indicated negative ARID1A expression in 4.6%. Loss of ARID1A expression was significantly associated with younger age, lymphatic invasion, and lymph node metastasis (LNM). NGS showed that PKHD1, RNF213, and MSH6 mutations were more frequent in ARID1A-negative tumors, whereas KRAS mutations were more common in ARID1A-positive tumors.

CONCLUSIONS

In T1 CRC, negative ARID1A expression was correlated with early onset, lymphatic invasion, and LNM. Mutations in some cancer-related genes were possibly related with ARID1A expression.

Pretreatment intratumoral susceptibility signals correlate with response to high-dose methotrexate and progression-free survival in primary central nervous system lymphoma

We aimed to estimate the frequency of intratumoral susceptibility signals (ITSS) in susceptibility-weighted imaging (SWI) in consecutive patients with primary central nervous system lymphoma (PCNSL), and to determine if pretreatment heterogeneity of PCNSL is predictive of response to chemotherapy by using ITSS on SWI. We retrospectively examined 29 immunocompetent patients with PCNSL who underwent SWI-MRI before treatment. A univariate analysis was conducted with Fisher's exact test. Progression free survival (PFS) was calculated by the Kaplan-Meier method and compared by the log rank test. The patients, including 16 males, were initially treated at a median age of 69 years. All tissue types were diffuse large B-cell lymphoma. Nineteen patients (66%) presented lesions with ITSS. Sixteen patients (55%) received initial treatment with R-MTX (rituximab plus high-dose methotrexate). Seven out of nine patients with ITSS exhibited a poor response, whereas all seven without ITSS exhibited a good response to R-MTX. Regarding the absence of ITSS, the sensitivity, specificity, and diagnostic accuracy for a good response to R-MTX were 0.78, 1.00, and 0.88, respectively. Patients without ITSS showed significantly longer PFS compared to patients with ITSS (median PFS: 28.9 vs 2.1 months, P < 0.01). In conclusion, ITSS in PCNSL patients were more common than previously reported. We have to be careful to use ITSS for differentiating PCNSL and glioblastoma. Presence of ITSS correlated significantly with therapeutic response to R-MTX. ITSS may be a new marker for the response to chemotherapy in patients with PCNSL. A prospective multi-institutional analysis is needed.

Germline mismatch repair gene variants analyzed by universal sequencing in Japanese cancer patients

Background

Lynch syndrome (LS) is the commonest inherited cancer syndrome caused by pathogenic variants of germline DNA mismatch repair (g.MMR) genes. Genome‐wide sequencing is now increasingly applied for tumor characterization, but not for g.MMR. The aim of this study was to evaluate the incidence and pathogenicity of g.MMR variants in Japanese cancer patients.

Methods

Four g.MMR genes (MLH1, MSH2, MSH6, and PMS2) were analyzed by next generation sequencing in 1058 cancer patients (614 male, 444 female; mean age 65.6 years) without past diagnosis of LS. The g.MMR variant pathogenicity was classified based on the ClinVar 2015 database. Tumor MMR immunohistochemistry, microsatellite instability (MSI), and BRAF sequencing were also investigated in specific cases.

Results

Overall, 46 g.MMR variants were detected in 167 (15.8%) patients, 17 likely benign variants in 119 patients, 24 variants of uncertain significance (VUSs) in 68 patients, two likely pathogenic variants in two patients, and three pathogenic variants in three (0.3%) patients. The three pathogenic variants included two colorectal cancers with MLH1 loss and high MSI and one endometrial cancer with MSH6 loss and microsatellite stability. Two likely pathogenic variants were shifted to VUSs by ClinVar (2018). One colon cancer with a likely benign variant demonstrated MLH1 loss and BRAF mutation, but other nonpathogenic variants showed sustained MMR and microsatellite stability.

Conclusions

Universal sequencing of g.MMR genes demonstrated sundry benign variants, but only a small proportion of cancer patients had pathogenic variants. Pathogenicity evaluation using the ClinVar database agreed with MSI, MMR immunohistochemistry, and BRAF sequencing.

Identification of S100A14 as a metastasis-promoting molecule in a murine organotropic metastasis model

Cancer metastasis shows great diversity in target organs, routes and molecular mechanisms depending on the type of cancer and even on the individual patients. To identify key molecules involved in metastasis, we constructed a murine model system including multiple sublines with different organotropism and pathways of metastasis. We selected metastatic sublines from a murine mammary tumor cell line MCH66. Using this model, we extracted metastasis-related molecules by gene expression screening methods and verified their metastasis-promoting effects by gene knockdown or overexpression experiments. For the candidates promoting metastasis, we analyzed molecular functions involved in metastasis: cell growth, motility and invasive activity. We established a metastasis model including low metastatic sublines (66C8, 66LM, 66-4) and highly metastatic counterparts with various organotropism, such as to the lung (66Lu10), liver (HM-KAN5) and general organs (66HM and its clones: HM1-6 and HM1-7). The sublines basically exhibited the invasion-independent metastasis pathway characterized by endothelial cell-covered tumor emboli, whereas 66HM and HM-KAN5 showed an alternative metastasis pathway based on invasion in part and in whole, respectively. Comprehensive gene analysis extracted several molecular candidates responsible for metastasis. S100A14 was identified as one of the promissing candidates promoting lung-metastasis, which was verified by gene knockdown experiments in vivo. In addition, in vivo and in vitro functional analyses demonstrated that S100A14 enhanced scattering, motility and invasiveness of mouse tumor cells. Our model system may be adaptable to the diversity of metastasis in human cancers and useful for exploring the molecular mechanism responsible for metastasis.

Clinicopathological and mutational analyses of colorectal cancer with mutations in the POLE gene

Here, we investigated the clinicopathological and mutation profiles of colorectal cancer (CRC) with POLE mutations. Whole‐exome sequencing was performed in 910 surgically resected primary CRCs. Tumors exceeding 500 counts of nonsynonymous single nucleotide variants (SNVs) were classified as hypermutators, whereas the remaining were classified as nonhypermutators. The hypermutators were subdivided into 2 groups. CRCs harboring more than 20% C‐to‐A and less than 3% C‐to‐G transversions were classified as POLE category tumors, whereas the remaining were classified as common‐hypermutators. Gene expression profiling (GEP) analysis was performed in 892 (98.0%) tumors. Fifty‐seven (6.3%) and 10 (1.1%) tumors were classified common‐hypermutators and POLE category tumors, respectively. POLE category tumors harbored a significantly higher SNV count than common‐hypermutators, and all POLE category tumors were associated with exonuclease domain mutations, such as P286R, F367C, V411L, and S297Y, in the POLE gene. Patients with POLE category tumors were significantly younger than those with nonhypermutators and common‐hypermutators. All POLE mutations in the early‐onset (age of onset ≤50 years old) POLE category (7 tumors) were P286R mutations. GEP analysis revealed that PD‐L1 and PD‐1 gene expression levels were significantly increased in both common‐hypermutators and POLE category tumors compared with those in nonhypermutators. CD8A expression was significantly upregulated in POLE category tumors compared with that in nonhypermutators. Thus, we concluded that CRCs with POLE proofreading deficiency had characteristics distinct from those of other CRCs. Analysis of POLE proofreading deficiency may be clinically significant for personalized management of CRCs.

Effect of neutron and γ -ray on charge-coupled device for vacuum/extreme ultraviolet spectroscopy in deuterium discharges of large helical device

A charge-coupled device (CCD) is widely used as a detector of vacuum spectrometers in fusion devices. Recently, a deuterium plasma experiment has been initiated in a Large Helical Device (LHD). Totally 3.7 × 10¹⁸ neutrons have been yielded with energies of 2.45 MeV (D-D) and 14.1 MeV (D-T) during the deuterium experiment over four months. Meanwhile, γ-rays are radiated from plasma facing components and laboratory structural materials in a wide energy range, i.e., 0.01-12.0 MeV, through the neutron capture. It is well known that these neutrons and γ-rays bring serious problems to the CCD system. Then, several CCDs of vacuum ultraviolet/extreme ultraviolet/X-ray spectrometers installed at different locations on LHD for measurements of spectra and spatial profiles of impurity emission lines are examined to study the effect of neutrons and γ-rays. An additional CCD placed in a special shielding box made of 10 cm thick polyethylene contained 10% boron and 1.5 cm thick lead is also used for the detailed analysis. As a result, it is found that the CCD has no damage in the present neutron yield of LHD, while the background noise integrated for all pixels of CCD largely increases, i.e., 1-3 × 10⁸ counts/s. The data analysis of CCD in the shielding box shows that the background noise caused by the γ-ray is smaller than that caused by the neutron, i.e., 41% from γ-rays and 59% from neutrons. It is also found that the noise can be partly removed by an accumulation of CCD frames or software programming.

A novel MLH1 intronic variant in a young Japanese patient with Lynch syndrome

Lynch syndrome, an autosomal dominantly inherited disease, is characterized by an increased risk of developing colorectal cancer. We found a novel germline variant of MLH1 (IVS6+2T>C) that caused Lynch syndrome in a young Japanese patient who had multiple colorectal cancers. Accurate diagnosis will be highly beneficial in clinical practice for surveillance and genetic counseling of patients and their relatives.

Can positron emission tomography detect colorectal adenomas and cancers?

BACKGROUND AND AIM

Fluorine-18 2-fluoro-2-deoxy-d-glucose positron emission tomography (PET) is effective and less invasive than other modalities used to diagnose tumors, including colorectal cancer (CRC). However, the detectability of adenomas and CRCs, especially in the early stages, is unclear.

METHODS

We evaluated the records of 2323 consecutive eligible patients who underwent both a total colonoscopy (TCS) and PET between October 2002 and September 2012 at a tertiary cancer center. The PET findings were verified by TCS performed independently within 1 year. Target lesions were defined as CRCs and adenomas that were 6 mm or larger in size.

RESULTS

Total colonoscopy detected 532 target lesions ≥ 6 mm in size: 56 T2-T4 CRCs, 39 T1 CRCs, 223 advanced adenomas, and 214 low-grade adenomas. Of the 532 lesions, 216 (40.6%) were PET positive. Of the 369 cases with positive uptakes, PET detected target lesions in the matched segments for 58.5% (216/369). Sensitivity of PET to T2-T4 CRCs, T1 CRCs, advanced adenomas, and low-grade adenomas was 92.9%, 79.5%, 50.7%, and 9.3%, respectively. PET could detect 76.5% (13/17) of T1 CRCs whose size is 10 to 19 mm and 85.0% (17/20) of T1 CRCs equal or larger than 20 mm. The multivariate analysis excluding T2-T4 CRCs showed malignant histology, larger size, protruded lesions, villous histology, and lesions in distal colon were significant factors.

CONCLUSIONS

Sensitivity of PET for detecting T2-T4 and even T1 cancers are promising. However, sensitivity of PET to adenomas, even advanced adenomas, is limited.

Development of beam emission spectroscopy for turbulence transport study in Heliotron J

This paper describes the development study of the beam emission spectroscopy (BES) for the turbulent transport study in Heliotron J. Modification of the sightlines (10 × 4 for edge and 10 × 2 for edge) enables us to obtain 2-dimensional BES imaging. The cooling effect on the reduction in the electrical noise of avalanche photodiode (APD) assembly has been investigated using a refrigerant cooling system. When the temperature of the APD element has set to be -20 °C, the electrical noise can be reduced more than 50%. The measurement error of the phase difference in the case of low signal level has been tested by two light-emitting diode lamps. The APD cooling has an effect to improve the measurement error at the low signal level of APD.

Up-down asymmetry measurement of tungsten distribution in large helical device using two extreme ultraviolet (EUV) spectrometers

Two space-resolved extreme ultraviolet spectrometers working in wavelength ranges of 10-130 Å and 30-500 Å have been utilized to observe the full vertical profile of tungsten line emissions by simultaneously measuring upper- and lower-half plasmas of LHD, respectively. The radial profile of local emissivity is reconstructed from the measured vertical profile in the overlapped wavelength range of 30-130 Å and the up-down asymmetry is examined against the local emissivity profiles of WXXVIII in the unresolved transition array spectrum. The result shows a nearly symmetric profile, suggesting a good availability in the present diagnostic method for the impurity asymmetry study.