HLA-corrected tumor mutation burden and homologous recombination deficiency for the prediction of response to PD-(L)1 blockade in advanced non-small-cell lung cancer patients.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have been shown to be beneficial for some patients with advanced non-small-cell lung cancer (NSCLC). However, the underlying mechanisms mediating the limited response to ICIs remain unclear. PATIENTS AND METHODS: We carried out whole-exome sequencing on 198 advanced NSCLC tumors that had been sampled before anti-programmed cell death 1 (anti-PD-1)/programmed death-ligand 1 (PD-L1) therapy. Detailed clinical characteristics were collected on these patients. We designed a new method to estimate human leukocyte antigen (HLA)-corrected tumor mutation burden (TMB), a modification which considers the loss of heterozygosity of HLA from conventional TMB. We carried out external validation of our findings utilizing 89 NSCLC samples and 110 melanoma samples from two independent cohorts of immunotherapy-treated patients. RESULTS: Homology-dependent recombination deficiency was identified in 37 patients (18.7%) and was associated with longer progression-free survival (PFS; P = 0.049). Using the HLA-corrected TMB, non-responders to ICIs were identified, despite having a high TMB (top 25%). Ten patients (21.3% of the high TMB group) were reclassified from the high TMB group into the low TMB group. The objective response rate (ORR), PFS, and overall survival (OS) were all lower in these patients compared with those of the high TMB group (ORR: 20% versus 59%, P = 0.0363; PFS: hazard ratio = 2.91, P = 0.007; OS: hazard ratio = 3.43, P = 0.004). Multivariate analyses showed that high HLA-corrected TMB was associated with a significant survival advantage (hazard ratio = 0.44, P = 0.015), whereas high conventional TMB was not associated with a survival advantage (hazard ratio = 0.63, P = 0.118). Applying this approach to the independent cohorts of 89 NSCLC patients and 110 melanoma patients, TMB-based survival prediction was significantly improved. CONCLUSION: HLA-corrected TMB can reconcile the observed disparity in relationships between TMB and ICI responses, and is of predictive and prognostic value for ICI therapies.

Vandetanib in pretreated patients with advanced non-small cell lung cancer-harboring RET rearrangement: a phase II clinical trial.

Background: Chromosomal rearrangements involving RET, which are found in about 1% of non-small cell lung cancer (NSCLC), define a unique molecular subset. We performed this study to examine the efficacy and safety of vandetanib 300 mg daily in this patient population. Patients and methods: This study was a multi-center, open-label, phase II clinical trial. Patients were enrolled if they had metastatic or recurrent NSCLC with a RET rearrangement, which was confirmed by fluorescence in situ hybridization, had progressive disease against platinum-based doublet chemotherapy, and had a performance status of 0-2. The primary endpoint was the objective response rate. Results: A total of 18 patients were enrolled in this study between July 2013 and October 2015. Patients were aged 35-71 years; three had a performance status of 2, and the majority were a heavily pretreated population (≥ two different previous chemotherapy regimens in 72% of the patients). Among the 17 evaluable patients, three had a partial response (objective response rate = 18%) and eight had a stable disease (disease control rate = 65%). Among these patients, the partial response or disease stabilization was durable for more than 6 months in eight patients. Vandetanib also showed a progression-free survival of 4.5 months, and an overall survival of 11.6 months during a median follow-up duration of 14 months. The safety profile was comparable with previous studies of vandetanib. Most vandetanib-related adverse events were mild with prevalent hypertension and rash (in >70% of patients). Grade 3 toxicity included hypertension (n = 3), QT prolongation (2), and elevation of aminotransferases (1), and as a consequence the dose was reduced in four patients. There were no adverse events associated with grade 4 or 5 toxicity. Conclusion: Vandetanib is moderately active in pretreated patients with advanced NSCLC-harboring RET rearrangements.

Diagnostic performance of conventional MRI parameters and apparent diffusion coefficient values in differentiating between benign and malignant soft-tissue tumours.

AIM: To compare the abilities of conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) in differentiating between benign and malignant soft-tissue tumours (STT). MATERIAL AND METHODS: A total of 123 patients with STT who underwent 3 T MRI, including diffusion-weighted imaging (DWI), were retrospectively analysed using variate conventional MRI parameters, ADCmean and ADCmin. RESULTS: For the all-STT group, the correlation between the malignant STT conventional MRI parameters, except deep compartment involvement, compared to those of benign STT were statistically significant with univariate analysis. Maximum diameter of the tumour (p=0.001; odds ratio [OR], 8.97) and ADCmean (p=0.020; OR, 4.30) were independent factors with multivariate analysis. For the non-myxoid non-haemosiderin STT group, signal heterogeneity on axial T1-weighted imaging (T1WI; p=0.017), ADCmean, and ADCmin (p=0.001, p=0.001), showed significant differences with univariate analysis between malignancy and benignity. Signal heterogeneity in axial T1WI (p=0.025; OR, 12.64) and ADCmean (p=0.004; OR, 33.15) were independent factors with multivariate analysis. CONCLUSION: ADC values as well as conventional MRI parameters were useful in differentiating between benign and malignant STT. The ADCmean was the most powerful diagnostic parameter in non-myxoid non-haemosiderin STT.

Small-cell lung cancer detection in never-smokers: clinical characteristics and multigene mutation profiling using targeted next-generation sequencing.

BACKGROUND: Once regarded as a smoker's disease, small-cell lung cancer (SCLC) has been occasionally detected in never-smokers as smoking rates decrease worldwide. We investigated the clinical and genetic characteristics of SCLC in never-smokers. PATIENTS AND METHODS: Patients diagnosed with SCLC were grouped into smokers and never-smokers. The clinical outcomes of the two groups were compared. For SCLC in never-smokers, somatic mutation profiling was carried out using the AmpliSeq™ Cancer Hotspot Panel v2 and semiconductor sequencing technology. Epidermal growth factor receptor (EGFR) mutation was confirmed by PNAClamp™. RESULTS: In total, 391 SCLC patients treated over a 5-year period were analyzed. Fifty patients (13%) were never-smokers. The median overall survival was 18.2 months in never-smokers and 13.1 months in smokers (P = 0.054). Never-smoking history was independently a good prognostic factor [hazard ratio = 0.645, 95% confidence interval (CI) 0.456-0.914], as were limited disease (HR = 0.372, 95% CI 0.294-0.471), and lower age (HR = 0.709, 95% CI 0.566-0.888). The objective response rates to first-line etoposide/cisplatin therapy were similar between never-smokers and smokers (75% versus 81%). Of 28 genetically evaluable never-smokers, EGFR mutations were detected in four cases (two L858R, one deletion in exon 19, and one G719A). Other mutations were in TP53 (n = 26), RB1 (n = 7), PTEN (n = 5), MET (n = 4), and SMAD4 (n = 3). CONCLUSIONS: Never-smokers with SCLC are increasingly prevalent and have a better prognosis than smokers with SCLC in Korea. Our study warrants further investigation in this group.

Role of HER3 expression and PTEN loss in patients with HER2-overexpressing metastatic breast cancer (MBC) who received taxane plus trastuzumab treatment.

BACKGROUND: The aim of this study was to investigate the role of human epidermal growth factor receptor (HER3) and PTEN expression in patients with HER2-overexpressing metastatic breast cancer (MBC). METHODS: One hundred twenty-five MBC patients who were treated with taxane plus trastuzumab chemotherapy as first-line therapy were included in this analysis. Immunohistochemical (IHC) staining with HER3 and PTEN antibodies were conducted retrospectively. RESULTS: Patients who had negative HER3 staining (62.4%) had a better progression-free survival (PFS) than did those who had positive HER3 staining (P=0.001; median PFS, 21 vs 11 months). Patients who had a PTEN score >20 (78.1%) showed longer PFS than did those with a PTEN score ≤20 (P=0.006; median PFS, 13 vs 9 months). Patients who had a PTEN score >20 exhibited a longer overall survival (OS) than did those with a PTEN score ≤20 (P=0.005; median OS, 48 vs 25 months). HER3 negativity and PTEN loss were identified as independent risk factors for PFS. PTEN loss was identified as an independent risk factor for OS. CONCLUSION: HER3 and PTEN expressions may be predictive markers, and PTEN expression may be a predictive and prognostic biomarker for trastuzumab treatment in HER2-positive MBCs.

Nationwide precision oncology pilot study: KOrean Precision Medicine Networking Group Study of MOlecular profiling-guided therapy based on genomic alterations in advanced solid tumors (KOSMOS) KCSG AL-20-05.

BACKGROUND: Next-generation sequencing (NGS) has become widely available but molecular profiling-guided therapy (MGT) had not been well established in the real world due to lack of available therapies and expertise to match treatment. Our study was designed to test the feasibility of a nationwide platform of NGS-guided MGT recommended by a central molecular tumor board (cMTB) for metastatic solid tumors. PATIENTS AND METHODS: Patients with advanced or metastatic solid tumors with available NGS results and without standard treatment were enrolled. The cMTB interpreted the patients' NGS reports and recommended the following: (i) investigational medicinal products (IMPs) approved in other indications; (ii) alternative treatments; (iii) clinical trials. The primary variables were the proportion of patients with actionable genomic alterations and those receiving MGT as per cMTB recommendations. Others included treatment duration (TD), overall response rate (ORR), disease control rate (DCR), and safety. RESULTS: From February 2021 to February 2022, 193 cases [99 (51.3%) men; median age 58 years (range 24-88 years); median line of previous treatment 3 (range 0-9)] from 29 sites were enrolled for 60 cMTB sessions. The median time from case submission to cMTB discussion was 7 days (range 2-20 days), and to IMP treatment initiation was 28 days (range 14-90 days). Actionable genetic alterations were found in 145 patients (75.1%). A total of 89 (46.1%) patients received actual dosing of IMPs, and 10 (5.2%) were enrolled in cMTB-recommended clinical trials, achieving an MGT rate of 51.3%. ORR and DCR of IMPs were 10.1% and 72.5%, respectively. The median TD was 3.5 months [95% confidence interval (CI) 2.8-5.5 months], and the 4-month TD rate was 44.9%. The median overall survival of patients who received IMPs was 6.9 months (95% CI 5.2-10.0 months). CONCLUSION: KOSMOS confirmed the feasibility of MGT recommended by the cMTB, achieving a high MGT match rate and promising effectiveness in heavily pretreated advanced cancer patients.

A phase-1b study of everolimus plus paclitaxel in patients with small-cell lung cancer.

BACKGROUND: The mammalian target of rapamycin (mTOR) pathway is dysregulated in small-cell lung cancer (SCLC) and everolimus is an oral mTOR inhibitor. METHODS: This phase-1b study assessed everolimus safety at the levels of 2.5, 5, or 10 mg once daily in combination with paclitaxel (175 mg m(-2)) once every 3 weeks in previously treated SCLC patients. The primary end point was to determine the maximum tolerated dose of everolimus. RESULTS: Among 21 enrolled patients, common drug-related adverse events were anaemia, neutropenia, thrombocytopenia, pain, hyperglycemia, and stomatitis. Out of 11 evaluable patients treated with everolimus at the level of 5 mg, 1 patient experienced dose-limiting toxicity (DLT) of grade 4 febrile neutropenia and grade 3 thrombocytopenia. The other two DLTs (grade 4 thrombocytopenia and grade 3 hyperglycemia) occurred in two out of three patients receiving everolimus 10 mg. The overall objective response rate was 28%. CONCLUSION: Everolimus showed an acceptable safety profile and preliminary antitumour activity at the dose of 5 mg once daily when combined with 3-weekly paclitaxel 175 mg m(-2) in patients with SCLC.

Clinical significance of CD151 overexpression in subtypes of invasive breast cancer.

BACKGROUND: CD151 is a member of the tetraspanin family, which interacts with laminin-binding integrins and other tetraspanins. This protein is implicated in motility, invasion, and metastasis of cancer cells, but the prevalence of CD151 expression in subtypes of breast cancers and its influence on clinical outcome remains to be evaluated. METHODS AND RESULTS: The immunohistochemistry-based tissue microarray analysis showed that 127 (14.3%) cases overexpressed CD151 among 886 breast cancer patients. CD151 overexpression was found to be significantly associated with larger tumour size, higher nodal stage, advanced stage, absence of oestrogen receptor and progesterone receptor, and human epidermal growth factor receptor 2 overexpression. CD151 overexpression resulted in poorer overall survival (OS) (P<0.001) and disease-free survival (P=0.02), and stage II and III patients with CD151 overexpression demonstrated substantially poorer OS (P=0.0474 and 0.0169). In the five subtypes analyses, CD151 overexpression retained its adverse impact on OS in the Luminal A (P=0.0105) and quintuple-negative breast cancer (QNBC) subtypes, one subgroup of triple-negative breast cancer (P=0.0170). Multivariate analysis that included stage, subtype, and adjuvant chemotherapy showed that CD151 overexpression was independently associated with poor OS in invasive breast cancer. CONCLUSION: CD151 overexpression may be a potential molecular therapeutic target for breast cancer, especially in QNBC subtype and more advanced stages of breast cancer.

Adjuvant durvalumab for esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy: a placebo-controlled, randomized, double-blind, phase II study.

BACKGROUND: We evaluated the efficacy of adjuvant durvalumab after neoadjuvant concurrent chemoradiotherapy (CCRT) in patients with esophageal squamous cell carcinoma (ESCC). PATIENTS AND METHODS: This randomized, double-blind, phase II study included patients with ESCC who underwent curative surgery after neoadjuvant CCRT. Patients were randomized to receive either durvalumab (20 mg/kg/i.v. every 4 weeks for 12 months) or placebo in a 1:1 ratio and were stratified by age and pathologic tumor stage. The primary endpoint was disease-free survival (DFS). RESULTS: Between March 2016 and June 2018, 86 patients were randomized to the durvalumab (n = 45) or placebo (n = 41) arm. The median follow-up duration was 38.7 months. There was no difference in DFS [hazard ratio (HR) 1.18, 95% confidence interval (CI) 0.62-2.27, P = 0.61] or overall survival (HR 1.08, 95% CI 0.52-2.24, P = 0.85) between the two arms. Subgroup analysis was performed for patients for whom the post-CCRT programmed death-ligand 1 (PD-L1) expression profile could be assessed (n = 54). In the PD-L1-positive group, based on tumor proportion score ≥1%, durvalumab was associated with longer overall survival compared with the placebo (36-month survival rate: 94% versus 64%; HR 0.42, 95% CI 0.10-1.76), while in the PD-L1-negative group, it was associated with shorter overall survival (42% versus 55%; HR 1.53, 95% CI 0.48-4.83), showing the tendency of interaction between post-CCRT PD-L1 status and adjuvant durvalumab therapy for overall survival (interaction P = 0.18). CONCLUSIONS: We failed to demonstrate that adjuvant durvalumab improved survival after neoadjuvant CCRT in patients with ESCC. However, post-CCRT PD-L1 expression could predict the survival of patients who receive adjuvant durvalumab after neoadjuvant CCRT, which needs to be validated.

Extranodal NK/T-cell lymphoma with cutaneous involvement: 'nasal' vs. 'nasal-type' subgroups--a retrospective study of 18 patients.

BACKGROUND: Extranodal natural killer T (NK/T) cell lymphoma is subcategorized into 'nasal' and 'nasal-type' NK/T-cell lymphomas according to the primary sites of anatomical involvement. OBJECTIVES: The aim of this study was to characterize the cutaneous manifestations of the skin involving extranodal NK/T-cell lymphoma and to define the distinctive features of 'nasal' and 'nasal-type'. In addition, the prognostic factors that affect overall survival were investigated. METHODS: A retrospective case study of 18 patients with extranodal NK/T-cell lymphoma with cutaneous involvement was performed. RESULTS: The NK/T-cell lymphomas usually occurred in middle-aged, male patients. Most of the patients presented with either cellulitis or ulcer. A facial predilection for the location of the lesion was noted. The characteristic features of the 'nasal-type' compared with the 'nasal' were a localized involvement of the skin, less aggressive clinical course and better survival outcome. CONCLUSIONS: Extranodal NK/T-cell lymphomas are extremely aggressive regardless of their subgroup. However, the 'nasal-type' NK/T-cell lymphoma was clinically less aggressive, more localized and had a better outcome compared with the other type. Cellulitis and ulcer were the major cutaneous manifestations.

Correction: ESRP1 is overexpressed in ovarian cancer and promotes switching from mesenchymal to epithelial phenotype in ovarian cancer cells.

Since publication of the original article, the authors have noticed that there were errors in the labelling of Figures 6D and 6E. The correct figure and its legend are reproduced here. The authors wish to apologise for any inconvenience caused.

A genomic analysis of adult T-cell leukemia.

Adult T-cell leukemia (ATL) is an intractable malignancy of CD4+ T cells that is etiologically associated with infection by human T-cell leukemia virus-type I. Most individuals in the chronic stage of ATL eventually undergo progression to a highly aggressive acute stage. To clarify the mechanism responsible for this stage progression, we isolated CD4+ cells from individuals in the chronic (n=19) or acute (n=22) stages of ATL and subjected them to profiling of gene expression with DNA microarrays containing >44,000 probe sets. Changes in chromosome copy number were also examined for 24 cell specimens with the use of microarrays harboring approximately 50,000 probe sets. Stage-dependent changes in gene expression profile and chromosome copy number were apparent. Furthermore, expression of the gene for MET, a receptor tyrosine kinase for hepatocyte growth factor (HGF), was shown to be specific to the acute stage of ATL, and the plasma concentration of HGF was increased in individuals in either the acute or chronic stage. HGF induced proliferation of a MET-positive ATL cell line, and this effect was blocked by antibodies to HGF. The HGF-MET signaling pathway is thus a potential therapeutic target for ATL.

Autocrine and/or paracrine growth of aggressive ATLL cells caused by HGF and c-Met.

Adult T-cell leukemia/lymphoma (ATLL) is a neoplasia characterized by the massive invasion of various organs by tumor cells. Previously, we found that expression of the gene for c-Met, a receptor tyrosine kinase for hepatocyte growth factor (HGF), was specific to the acute type among 41 patients with ATLL by microarray. First in the present study, we analyzed the survival of the patients in relation to expression of c-Met and HGF in ATLL cells. Expression of the former but not the latter was associated with poor prognosis. Then, we analyzed the growth of ATLL cells caused by HGF and c-Met. c-Met was expressed in 0/7 chronic ATLLs, 12/14 acute ATLLs, 1/1 IL-2-independent ATLL cell line and 1/7 IL-2-dependent ATLL cell lines as assessed by flow cytometry. HGF induced the proliferation of primary cells from most acute cases examined as well as the c-Met-positive KK1 cell line in contrast to c-Met-negative cells. HGF induced autophosphorylation of c-Met in c-Met-positive cells from an acute case and KK1 cells. The plasma level of HGF was elevated in acute as compared to chronic cases. The levels of HGF and/or IL-6 which induces the production of HGF by stromal cells, were elevated in the supernatant of short-term cultured cells from certain patients with acute or chronic disease. Finally, infiltrated ATLL cells and adjacent stromal cells in liver were shown to be positive for c-Met/HGF and HGF, respectively, in acute cases. Autocrine and/or paracrine growth caused by HGF and c-Met was suggested in aggressive ATLL cells secreting HGF and/or IL-6, respectively.

Evaluation of ER and Ki-67 proliferation index as prognostic factors for survival following neoadjuvant chemotherapy with doxorubicin/docetaxel for locally advanced breast cancer.

BACKGROUND: The aim of the study was to identify reliable predictive biological markers for treatment outcome following neoadjuvant adriamycin/docetaxel (AT) chemotherapy in locally advanced breast cancer patients. MATERIALS AND METHODS: This study was a phase II study on AT neoadjuvant chemotherapy in locally advanced breast cancer patients. Patients received 50 mg/m(2) of doxorubicin intravenously (IV) over 15 min followed by docetaxel 75 mg/m(2) infused over 1 h, repeated every 3 weeks for three cycles. Surgery was performed within 3-4 weeks following the last cycle of chemotherapy. We analyzed the pre-treatment and post-treatment expression levels of ER, PgR, HER-2, Ki-67 proliferation index, and p53 and examined the correlation between the markers and clinical parameters with treatment response, overall survival and relapse-free survival following neoadjuvant treatment. RESULTS: From July 2001 to September 2004, 61 patients were enrolled. The meaningful parameters adversely influencing survival were post-treatment ER(-) status (P = 0.013) and post-treatment Ki-67 index above 1.0% (P = 0.013). At the multivariate level, the post-treatment Ki-67 proliferation index < or = 1.0 was the only meaningful prognostic factor for better survival (P = 0.033). Notably, tumors with Ki-67 index < or = 1.0 were more likely to express ER with statistical significance (P = 0.002). Tumors with ER(+) and Ki-67 index < or = 1.0 showed the highest survival rate, followed by ER(+) and Ki-67 index > 1.0%, ER(-) and Ki-67 < or = 1.0%, and ER(-) and Ki-67 > 1.0% with the worst survival (P = 0.033). CONCLUSION: Collectively, post-treatment ER status and Ki-67 proliferation index were prognostic of overall survival following neoadjuvant AT chemotherapy.

Epigenetic silencing of AXIN2 in colorectal carcinoma with microsatellite instability.

Mutation or epigenetic silencing of mismatch repair genes, such as MLH1 and MSH2, results in microsatellite instability (MSI) in the genome of a subset of colorectal carcinomas (CRCs). However, little is yet known of genes that directly contribute to tumor formation in such cancers. To characterize MSI-dependent changes in gene expression, we have now compared transcriptomes between fresh CRC specimens positive or negative for MSI (n=10 for each) with the use of high-density oligonucleotide microarrays harboring >44,000 probe sets. Correspondence analysis of the expression patterns of isolated MSI-associated genes revealed that the transcriptome of MSI+ CRCs is clearly distinct from that of MSI- CRCs. Such MSI-associated genes included that for AXIN2, an important component of the WNT signaling pathway. AXIN2 was silenced, apparently as a result of extensive methylation of its promoter region, specifically in MSI+ CRC specimens. Forced expression of AXIN2, either by treatment with 5'-azacytidine or by transfection with AXIN2 cDNA, resulted in rapid cell death in an MSI+ CRC cell line. These data indicate that epigenetic silencing of AXIN2 is specifically associated with carcinogenesis in MSI+ CRCs.

ESRP1 is overexpressed in ovarian cancer and promotes switching from mesenchymal to epithelial phenotype in ovarian cancer cells.

This corrects the article DOI: 10.1038/oncsis.2017.87.

ESRP1 is overexpressed in ovarian cancer and promotes switching from mesenchymal to epithelial phenotype in ovarian cancer cells.

Epithelial splicing regulatory protein 1 (ESRP1) and 2 (ESRP2), epithelial cell-specific regulators of alternative splicing, are downregulated during the epithelial-mesenchymal transition (EMT). These factors have roles in tumor progression and metastasis in some cancers; however, their expression and function in ovarian cancer (OC) remain unclear. We found that ESRP1 and ESRP2 mRNAs were expressed at higher levels in OC cells than in immortalized ovarian surface epithelial (IOSE) cells, and confirmed their overexpression in OC tissues at the protein level. The Cancer Genome Atlas (TCGA) data analysis revealed frequent gene amplification of ESRP1 in OC tissues; however, we detected no significant correlation between ESRP1 gene copy number and gene expression in OC cells. Importantly, expression of ESRP1 and ESRP2 was inversely correlated with DNA methylation in OC cells, and ESRP2 overexpression in OC tissues was significantly associated with DNA hypomethylation. Notably, survival analysis using TCGA data from 541 OC tissues revealed that high ESRP1 expression was significantly associated with shorter 5-year survival of patients. Ectopic ESRP1 expression in mesenchymal OC cells promoted cell proliferation but suppressed cell migration. Furthermore, we found that ESRP1 drives a switch from mesenchymal to epithelial phenotype characterized by reduced cell migration in association with induction of epithelial cell-specific variant of CD44 and ENAH. Taken together, our findings suggest that an epigenetic mechanism is involved in ESRP1 overexpression, and that ESRP1 has a role in OC progression.

Malignant lymphoma of the central nervous system: difficult histologic diagnosis after glucocorticoid therapy prior to biopsy.

Four cases of central nervous system (CNS) lymphoma are reported which presented obstacles in diagnosis due to steroid treatment prior to biopsy. Reliable diagnoses were provided by molecular analysis. Malignant lymphoma of the CNS may be indistinguishable from other conditions, even in view of the gravity of the diagnosis. All patients had a previous history of glucocorticoid injection, for 2-18 days prior to stereotactic brain biopsy. The pathologic examination revealed in all cases axonal destruction and reactive gliosis with a variable infiltration of B- or T lymphocytes and macrophages. Characteristically, scattered degenerating small round cells with pyknotic or fragmented nuclei were also observed. However, the molecular assessment of paraffin-embedded tissues revealed the monoclonal IgH gene rearrangement, which allowed the confident diagnosis of B cell lymphoma. The histopathological findings of the present cases suggest that the tumor cells might be selectively destroyed by steroid treatment, which may render diagnosis impossible. Thus, molecular genetic investigation constitutes an important tool for establishing a diagnosis of CNS lymphoma obscured by steroid administration. This is especially true in cases where a paucity of tumor cells is observed or when monoclonality fails to be demonstrated by immunohistochemical tests.

Changes in tumour expression of programmed death-ligand 1 after neoadjuvant concurrent chemoradiotherapy in patients with squamous oesophageal cancer.

BACKGROUND: Programmed death-ligand 1 (PD-L1) expression has been suggested as a potential predictive biomarker of response to anti-PD-1/PD-L1 therapy. In this study, we investigated whether the expression of PD-L1 in tumour cells is affected by neoadjuvant concurrent chemoradiotherapy (CCRT) or chemotherapy in oesophageal squamous cell carcinoma. PATIENTS AND METHODS: Between 2004 and 2014, we collected the medical records of locally advanced oesophageal cancer patients consecutively diagnosed and treated with neoadjuvant CCRT or chemotherapy, followed by curative resection. PD-L1 expression in acquired tissue specimens was evaluated by immunohistochemistry using the H-score. The changes in PD-L1 expression between paired samples were evaluated and we also analysed PD-L1 expression in surgical tumour specimens to evaluate its prognostic role. RESULTS: Twenty-eight paired tumour tissues that were acquired before and after neoadjuvant therapy were available: 19 patients with CCRT and 9 with chemotherapy before complete oesophagectomy. The PD-L1 H-score increased significantly from baseline tumour tissues to surgical tumour tissues after neoadjuvant CCRT (P = 0.007, median H-score from 28 to 52), whereas it decreased significantly after neoadjuvant chemotherapy (P = 0.048, median H-score from 53 to 22). In a total of 73 patients, including 45 additional cases for the prognosis analysis, patients with higher PD-L1 H-scores (≥ 20) had poorer overall survival (median 16.7 versus 32.9 months, P = 0.02) than those with lower H-scores (<20). CONCLUSIONS: PD-L1 expression in tumour cells increased in oesophageal cancer patients who received neoadjuvant CCRT. Further studies with more cases are necessary to validate these findings.

Regulation of glpD and glpE gene expression by a cyclic AMP-cAMP receptor protein (cAMP-CRP) complex in Escherichia coli.

The glpE gene of E. coli was found to be transcribed divergently with respect to glpD, which is adjacent to glpE head-to-head on the E. coli chromosome. We constructed glpD- and/or glpE-lacZ fusion plasmids, which provided glpD and lacZ as reporter genes. The expression of glpD and glpE, under the control of the cAMP-CRP complex, was examined by measuring the activities in E. coli cells of beta-galactosidase encoded by lacZ and glycerol-3-phosphate dehydrogenase encoded by glpD. In the double-reporter-gene system, the expression of glpD and glpE was found to be positively regulated by cAMP-CRP. We also confirmed that intracellular levels of the translation products and the transcripts from glpD and glpE were positively regulated by cAMP-CRP. The cAMP-mediated induction of gene expression of glpD and glpE was significantly affected by structural alterations of the single CRP-binding site between glpD and glpE. These results indicate that the single CRP-binding site is a cis-acting element involved in the positive regulation of the expression of both glpD and glpE at the transcriptional level.