Real-World Implementation of Digital Pathology: Results From an Intercontinental Survey

The past 70 years have been characterized by rapid advancements in computer technology, and the health care system has not been immune to this trend. However, anatomical pathology has remained largely an analog discipline. In recent years, this has been changing with the growing adoption of digital pathology, partly driven by the potential of computer-aided diagnosis. As part of an international collaboration, we conducted a comprehensive survey to gain a deeper understanding of the status of digital pathology implementation in Europe and Asia. A total of 127 anatomical pathology laboratories participated in the survey, including 75 from Europe and 52 from Asia, with 72 laboratories having established digital pathology workflow and 55 without digital pathology. Laboratories using digital pathology for diagnostic (n = 29) and nondiagnostic (n = 43) purposes were thoroughly questioned about their implementation strategies and institutional experiences, including details on equipment, storage, integration with laboratory information system, computer-aided diagnosis, and the costs of going digital. The impact of the digital pathology workflow was also evaluated, focusing on turnaround time, specimen traceability, quality control, and overall satisfaction. Laboratories without access to digital pathology were asked to provide insights into their perceptions of the technology, expectations, barriers to adoption, and potential facilitators. Our findings indicate that although digital pathology is still the future for many, it is already the present for some. This decade may be a time when anatomical pathology finally embraces digital revolution on a larger scale.

Eosinophil-rich variant of nodal marginal zone lymphoma: a clinicopathological study of 11 cases

AIMS

Tissue eosinophilia is commonly observed in T-cell and classic Hodgkin lymphomas, but rarely in B-cell lymphomas. Herein, we present the first report of a case series on nodal marginal zone lymphoma (NMZL) with tissue eosinophilia.

METHODS AND RESULTS

All 11 patients in this study had nodal disease at primary presentation. The mean age at diagnosis was 64 years. The mean follow-up period was 39 months, and all patients were alive. Nine of the 11 patients (82%) showed no recurrence, but the other two patients experienced recurrence in the lymph nodes or skin. Marked eosinophilic infiltration was observed in all biopsied lymph nodes. Nine of the 11 patients had a preserved nodular architecture with expanded interfollicular areas. The other two patients showed diffuse lymphoma cell infiltration with effacement of nodal architecture. One of them was diagnosed as having diffuse large B-cell lymphoma transformed from NMZL because large cells accounted for >50% of the lymphoma cells and formed sheet-like patterns. Cells were positive for CD20 and BCL2 and negative for CD5, CD10, and BCL6. Some patients showed myeloid cell nuclear differentiation antigen (MNDA) positivity. All patients showed B-cell monoclonality via flow cytometry, southern blotting, and/or polymerase chain reaction (PCR).

CONCLUSION

All patients showed distinctive morphological features and could be misdiagnosed with peripheral T-cell lymphoma due to their eosinophil-rich backgrounds. The predominance of B cells, absence of histiocytes, and high endothelial venules in the interfollicular areas are key factors for diagnosis. B-cell monoclonality is the most reliable evidence of differentiation. We designated this type of lymphoma as an eosinophil-rich variant of NMZL.

RENEB Inter-Laboratory Comparison 2021: Inter-Assay Comparison of Eight Dosimetry Assays

Tools for radiation exposure reconstruction are required to support the medical management of radiation victims in radiological or nuclear incidents. Different biological and physical dosimetry assays can be used for various exposure scenarios to estimate the dose of ionizing radiation a person has absorbed. Regular validation of the techniques through inter-laboratory comparisons (ILC) is essential to guarantee high quality results. In the current RENEB inter-laboratory comparison, the performance quality of established cytogenetic assays [dicentric chromosome assay (DCA), cytokinesis-block micronucleus assay (CBMN), stable chromosomal translocation assay (FISH) and premature chromosome condensation assay (PCC)] was tested in comparison to molecular biological assays [gamma-H2AX foci (gH2AX), gene expression (GE)] and physical dosimetry-based assays [electron paramagnetic resonance (EPR), optically or thermally stimulated luminescence (LUM)]. Three blinded coded samples (e.g., blood, enamel or mobiles) were exposed to 0, 1.2 or 3.5 Gy X-ray reference doses (240 kVp, 1 Gy/min). These doses roughly correspond to clinically relevant groups of unexposed to low exposed (0-1 Gy), moderately exposed (1-2 Gy, no severe acute health effects expected) and highly exposed individuals (>2 Gy, requiring early intensive medical care). In the frame of the current RENEB inter-laboratory comparison, samples were sent to 86 specialized teams in 46 organizations from 27 nations for dose estimation and identification of three clinically relevant groups. The time for sending early crude reports and more precise reports was documented for each laboratory and assay where possible. The quality of dose estimates was analyzed with three different levels of granularity, 1. by calculating the frequency of correctly reported clinically relevant dose categories, 2. by determining the number of dose estimates within the uncertainty intervals recommended for triage dosimetry (±0.5 Gy or ±1.0 Gy for doses <2.5 Gy or >2.5 Gy), and 3. by calculating the absolute difference (AD) of estimated doses relative to the reference doses. In total, 554 dose estimates were submitted within the 6-week period given before the exercise was closed. For samples processed with the highest priority, earliest dose estimates/categories were reported within 5-10 h of receipt for GE, gH2AX, LUM, EPR, 2-3 days for DCA, CBMN and within 6-7 days for the FISH assay. For the unirradiated control sample, the categorization in the correct clinically relevant group (0-1 Gy) as well as the allocation to the triage uncertainty interval was, with the exception of a few outliers, successfully performed for all assays. For the 3.5 Gy sample the percentage of correct classifications to the clinically relevant group (≥2 Gy) was between 89-100% for all assays, with the exception of gH2AX. For the 1.2 Gy sample, an exact allocation to the clinically relevant group was more difficult and 0-50% or 0-48% of the estimates were wrongly classified into the lowest or highest dose categories, respectively. For the irradiated samples, the correct allocation to the triage uncertainty intervals varied considerably between assays for the 1.2 Gy (29-76%) and 3.5 Gy (17-100%) samples. While a systematic shift towards higher doses was observed for the cytogenetic-based assays, extreme outliers exceeding the reference doses 2-6 fold were observed for EPR, FISH and GE assays. These outliers were related to a particular material examined (tooth enamel for EPR assay, reported as kerma in enamel, but when converted into the proper quantity, i.e. to kerma in air, expected dose estimates could be recalculated in most cases), the level of experience of the teams (FISH) and methodological uncertainties (GE). This was the first RENEB ILC where everything, from blood sampling to irradiation and shipment of the samples, was organized and realized at the same institution, for several biological and physical retrospective dosimetry assays. Almost all assays appeared comparably applicable for the identification of unexposed and highly exposed individuals and the allocation of medical relevant groups, with the latter requiring medical support for the acute radiation scenario simulated in this exercise. However, extreme outliers or a systematic shift of dose estimates have been observed for some assays. Possible reasons will be discussed in the assay specific papers of this special issue. In summary, this ILC clearly demonstrates the need to conduct regular exercises to identify research needs, but also to identify technical problems and to optimize the design of future ILCs.

RENEB Inter-Laboratory Comparison 2021: The FISH-Based Translocation Assay

Translocation analysis using fluorescence in situ hybridization (FISH) is the method of choice for dose assessment in case of chronic or past exposures to ionizing radiation. Although it is a widespread technique, unlike dicentrics, the number of FISH-based inter-laboratory comparisons is small. For this reason, although the current Running the European Network of Biological and Physical retrospective Dosimetry (RENEB) inter-laboratory comparison 2021 was designed as a fast response to a real emergency scenario, it was considered a good opportunity to perform an inter-laboratory comparison using the FISH technique to gain further experience. The Bundeswehr Institute of Radiobiology provided peripheral blood samples from one healthy human volunteer. Three test samples were irradiated with blinded doses of 0, 1.2, and 3.5 Gy, respectively. Samples were then sent to the seven participating laboratories. The FISH technique was applied according to the standard procedure of each laboratory. Both, the frequency of translocations and the estimated dose for each sample were sent to the coordinator using a special scoring sheet for FISH. All participants sent their results in due time. However, although it was initially requested to send the results based on the full analysis, evaluating 500 equivalent cells, most laboratories only sent the results based on triage, with a smaller number of analyzed cells. In the triage analysis, there was great heterogeneity in the number of equivalent cells scored. On the contrary, for the full analysis, this number was more homogeneous. For all three samples, one laboratory showed outlier yields compared to the other laboratories. Excluding these results, in the triage analysis, the frequency of translocations in sample no. 1 ranged from 0 to 0.013 translocations per cell, and for samples no. 2 and no. 3 the genomic mean frequency were 0.27 ± 0.03 and 1.47 ± 0.14, with a coefficient of variation of 0.29 and 0.23 respectively. Considering only results obtained in the triage analysis for sample no. 1, all laboratories, except one, classified this sample as the non-irradiated one. For sample no. 2, excluding the outlier value, the mean reported dose was 1.74 ± 0.16 Gy indicating a mean deviation of about 0.5 Gy to the delivered dose of 1.2 Gy. For sample no. 3 the mean dose estimated was 4.21 ± 0.21 Gy indicating a mean deviation of about 0.7 Gy to the delivered dose of 3.5 Gy. In the frame of RENEB, this is the second FISH-based inter-laboratory comparison. The whole exercise was planned as a response to an emergency, therefore, a triage analysis was requested for all the biomarkers except for FISH. Although a full analysis was initially requested for FISH, most of the laboratories reported only a triage-based result. The main reason is that it was not clearly stated what was required before starting the exercise. Results show that most of the laboratories successfully discriminated unexposed and irradiated samples from each other without any overlap. A good agreement in the observed frequencies of translocations was observed but there was a tendency to overestimate the delivered doses. Efforts to improve the harmonization of this technique and subsequent exercises to elucidate the reason for this trend should be promoted.

RENEB Inter-Laboratory Comparison 2021: The Dicentric Chromosome Assay

After large-scale radiation accidents where many individuals are suspected to be exposed to ionizing radiation, biological and physical retrospective dosimetry assays are important tools to aid clinical decision making by categorizing individuals into unexposed/minimally, moderately or highly exposed groups. Quality-controlled inter-laboratory comparisons of simulated accident scenarios are regularly performed in the frame of the European legal association RENEB (Running the European Network of Biological and Physical retrospective Dosimetry) to optimize international networking and emergency readiness in case of large-scale radiation events. In total 33 laboratories from 22 countries around the world participated in the current RENEB inter-laboratory comparison 2021 for the dicentric chromosome assay. Blood was irradiated in vitro with X rays (240 kVp, 13 mA, ∼75 keV, 1 Gy/min) to simulate an acute, homogeneous whole-body exposure. Three blood samples (no. 1: 0 Gy, no. 2: 1.2 Gy, no. 3: 3.5 Gy) were sent to each participant and the task was to culture samples, to prepare slides and to assess radiation doses based on the observed dicentric yields from 50 manually or 150 semi-automatically scored metaphases (triage mode scoring). Approximately two-thirds of the participants applied calibration curves from irradiations with γ rays and about 1/3 from irradiations with X rays with varying energies. The categorization of the samples in clinically relevant groups corresponding to individuals that were unexposed/minimally (0-1 Gy), moderately (1-2 Gy) or highly exposed (>2 Gy) was successfully performed by all participants for sample no. 1 and no. 3 and by ≥74% for sample no. 2. However, while most participants estimated a dose of exactly 0 Gy for the sham-irradiated sample, the precise dose estimates of the samples irradiated with doses >0 Gy were systematically higher than the corresponding reference doses and showed a median deviation of 0.5 Gy (sample no. 2) and 0.95 Gy (sample no. 3) for manual scoring. By converting doses estimated based on γ-ray calibration curves to X-ray doses of a comparable mean photon energy as used in this exercise, the median deviation decreased to 0.27 Gy (sample no. 2) and 0.6 Gy (sample no. 3). The main aim of biological dosimetry in the case of a large-scale event is the categorization of individuals into clinically relevant groups, to aid clinical decision making. This task was successfully performed by all participants for the 0 Gy and 3.5 Gy samples and by 74% (manual scoring) and 80% (semi-automatic scoring) for the 1.2 Gy sample. Due to the accuracy of the dicentric chromosome assay and the high number of participating laboratories, a systematic shift of the dose estimates could be revealed. Differences in radiation quality (X ray vs. γ ray) between the test samples and the applied dose effect curves can partly explain the systematic shift. There might be several additional reasons for the observed bias (e.g., donor effects, transport, experimental conditions or the irradiation setup) and the analysis of these reasons provides great opportunities for future research. The participation of laboratories from countries around the world gave the opportunity to compare the results on an international level.

Accurate deep learning model using semi-supervised learning and Noisy Student for cervical cancer screening in low magnification images

Deep learning technology has been used in the medical field to produce devices for clinical practice. Deep learning methods in cytology offer the potential to enhance cancer screening while also providing quantitative, objective, and highly reproducible testing. However, constructing high-accuracy deep learning models necessitates a significant amount of manually labeled data, which takes time. To address this issue, we used the Noisy Student Training technique to create a binary classification deep learning model for cervical cytology screening, which reduces the quantity of labeled data necessary. We used 140 whole-slide images from liquid-based cytology specimens, 50 of which were low-grade squamous intraepithelial lesions, 50 were high-grade squamous intraepithelial lesions, and 40 were negative samples. We extracted 56,996 images from the slides and then used them to train and test the model. We trained the EfficientNet using 2,600 manually labeled images to generate additional pseudo labels for the unlabeled data and then self-trained it within a student-teacher framework. Based on the presence or absence of abnormal cells, the created model was used to classify the images as normal or abnormal. The Grad-CAM approach was used to visualize the image components that contributed to the classification. The model achieved an area under the curve of 0.908, accuracy of 0.873, and F1-score of 0.833 with our test data. We also explored the optimal confidence threshold score and optimal augmentation approaches for low-magnification images. Our model efficiently classified normal and abnormal images at low magnification with high reliability, making it a promising screening tool for cervical cytology.

Hodgkinoid histiocytosis: an atypical nodal CD30 and S100-positive histiocytosis with eosinophilia

Histocytes and dendritic cells may display cytological atypia and aberrant immunophenotype even in reactive processes. Herein, we describe two cases of "Hodgkinoid histiocytosis" that show distinctive clinicopathological features, mimicking the morphologically classic Hodgkin lymphoma (CHL) but suggesting reactive histiocytic/dendritic cell proliferation in lymph nodes. Both the patients presented with peripheral lymphadenopathy and blood eosinophilia with skin manifestations. Lymph node biopsy revealed scattered large histiocytes resembling Hodgkin cells with a round or stellate shape, abundant cytoplasm, and distinct nucleoli admixed in a predominant inflammatory background. The Hodgkinoid histiocytes occasionally showed emperipolesis. They expressed CD30, S100, and PD-L1 proteins but lacked PAX5 and CD1a expressions, Epstein-Barr association, BRAF V600E mutation, and PD-L1 gene amplification. Neither of the patients showed overt progression to malignant hematopoietic neoplasms during the disease course. An identical case series of four patients has been reported to date. Both these series highlight the potential of being interpreted as CHL due to the presence of Hodgkinoid histiocytes with CD30 positivity.

Rituximab maintenance improves outcomes of transformed diffuse large B-cell lymphoma: a retrospective study of 519 cases with de novo diffuse large B-cell lymphoma and 62 cases with concurrent diffuse large B-cell lymphoma and follicular lymphoma

Although outcomes of transformed diffuse large B-cell lymphoma (DLBCL) from follicular lymphoma (FL) were improved using rituximab-combined immunochemotherapy, the efficacy of subsequent rituximab maintenance (RM) remains unclear. We retrospectively analyzed the prognoses of 519 patients with de novo DLBCL and 62 patients with concurrent DLBCL and FL (concurrent-DLBCL/FL). Progression-free survival (PFS) was shorter in patients with concurrent-DLBCL/FL than in de novo DLBCL (p=.030). Twenty-four patients with concurrent-DLBCL/FL received RM after induction therapy, and they achieved better OS and PFS (p=.010 and p<.001, respectively) with lower risk of relapse (p<.001) than the non-RM group. Moreover, concurrent-DLBCL/FL showed better subsequent OS and PFS after recurrence than de novo DLBCL (p=.0083 and p=.0044, respectively). Our study indicates that in the face of a high relapse rate, concurrent-DLBCL/FL is manageable and benefits from RM.

Progression-free survival at 24 months as a predictor of survival outcomes after CHOP treatment in patients with peripheral T-cell lymphoma: a single-center validation study in a Japanese population

Peripheral T-cell lymphoma (PTCL) is a group of aggressive lymphomas commonly treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP). Progression-free survival at 24 months (PFS24) constitutes a survival predictor for some lymphomas but has not been examined in Asian populations. We retrospectively investigated whether PFS24 was predictive of survival outcomes after CHOP treatment in 73 Japanese patients with PTCL. Patients without PFS24 had shorter median subsequent overall survival (OS) (20.2 vs. 121.0 months, p < 0.001) and shorter median subsequent progression-free survival (5.0 vs. 17.1 months, p = 0.03). Patients without PFS24 had worse overall (62.5% vs. 100%) and complete response rates (45.8% vs. 96.0%) (both p < 0.001). PFS24 absence (hazard ratio: 3.34, p = 0.004) and poor performance status (hazard ratio: 3.17, p = 0.04) were independently predictive of shorter OS. These findings suggest that PFS24 is predictive of survival after CHOP treatment in Japanese patients with PTCL.

Impact of Omission/Reduction of Vincristine From R-CHOP in Treatment of DLBCL

BACKGROUND

The R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) is the standard therapy for patients with diffuse large B-cell lymphoma (DLBCL). However, vincristine is sometimes omitted or reduced owing to side effects.

MATERIALS AND METHODS

We retrospectively reviewed newly diagnosed patients with DLBCL with R-CHOP-like chemotherapy in our institute from January 2005 to February 2018 to investigate whether the omission/reduction of vincristine reduced the efficacy of the treatment. We compared the overall survival (OS) with and without the omission/reduction of vincristine from the R-CHOP regimen.

RESULTS

A total of 576 cases were reviewed, and vincristine was omitted/reduced in 50 (9%) patients. The 4-year OS with and without vincristine omission/reduction for relative dose intensity < 80%, 50%, and 25% was 70% versus 82% (P = .035), 70% versus 82% (P = .085), and 53% versus 82% (P = .0007). In a multivariate analysis, adjusting for international prognostic index risk factors, a statistically significant, poor OS was indicated in the patients with relative dose intensity < 25%.

CONCLUSIONS

Excessive dose omission/reduction of vincristine might lead to a substantial loss of efficacy of R-CHOP therapy.

Insignificance of surveillance imaging in patients with diffuse large B-cell lymphoma who achieved first complete remission: a retrospective cohort study

The aim of this study was to evaluate the value of scheduled imaging for patients who achieved first complete remission after CHOP-like chemotherapy plus rituximab. In this retrospective cohort study, we included 759 patients newly diagnosed with de novo diffuse large B-cell lymphoma (DLBCL) at the Cancer Institute, Japanese Foundation for Cancer Research. Relapsed patients were divided into two groups based on method of diagnosis: clinical symptoms (symptom group, n = 57) or scheduled imaging (imaging group, n = 27). Our primary goal was to compare overall survival and relapse-free survival between the two groups. No significant difference in outcomes was found between the symptom and imaging groups. Median overall survival [7.5 years; 95% confidence interval (CI) 4.0-9.7 vs. 9.1 years; 95% CI 2.7 to not reached; P = 0.747), and median relapse-free survival (1.8 years; 95% CI 1.4-2.5 vs. 2.4 years; 95% CI 1.2-4.4; P = 0.108). Surveillance imaging in patients with DLBCL who achieved first complete remission did not demonstrate an advantage in terms of overall survival or relapse-free survival.

TP53 and OSBPL10 alterations in diffuse large B-cell lymphoma: prognostic markers identified via exome analysis of cases with extreme prognosis

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype characterized by both biological and clinical heterogeneity. In refractory cases, complete response/complete response unconfirmed rates in salvage therapy remain low. We performed whole-exome sequencing of DLBCL in a discovery cohort comprising 26 good and nine poor prognosis cases. After candidate genes were identified, prognoses were examined in 85 individuals in the DLBCL validation cohort. In the discovery cohort, five patients in the poor prognosis group harbored both a TP53 mutation and 17p deletion. Sixteen mutations were identified in OSBPL10 in nine patients in the good prognosis group, but none in the poor prognosis group. In the validation cohort, TP53 mutations and TP53 deletions were confirmed to be poor prognostic factors for overall survival (OS) (P = 0.016) and progression-free survival (PFS) (P = 0.023) only when both aberrations co-existed. OSBPL10 mutations were validated as prognostic markers for excellent OS (P = 0.037) and PFS (P = 0.041). Significant differences in OS and PFS were observed when patients were stratified into three groups-OSBPL10 mutation (best prognosis), the coexistence of both TP53 mutation and TP53 deletion (poorest prognosis), and others. In this study, the presence of both TP53 mutation and 17p/TP53 deletion, but not the individual variants, was associated with poor prognosis in DLBCL patients after treatment with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) or similar regimens. We also identified OSBPL10 mutation as a marker for patients with excellent prognosis in the R-CHOP era.

Clinical and prognostic significance of aberrant T-cell marker expression in 225 cases of de novo diffuse large B-cell lymphoma and 276 cases of other B-cell lymphomas

Expression of T-cell markers, generally investigated for immunophenotyping of T-cell lymphomas, is also observed in several types of B-cell lymphomas, including diffuse large B-cell lymphoma (DLBCL). We previously reported that CD5 expression in DLBCL is an inferior prognostic factor in the era of rituximab. However, data regarding the frequencies, histological relevance, and prognostic importance of T-cell markers other than CD5 are currently unavailable. In the present study, we comprehensively evaluated the expression of T-cell markers (CD2, CD3, CD4, CD5, CD7, and CD8) in 501 B-cell lymphomas, including 225 DLBCLs, by flow cytometry and subsequent immunohistochemistry. T-cell markers other than CD5, such as CD2, CD4, CD7, and CD8, were expressed in 27 (5%) patients, and notably, all of these cases were classified as large B-cell lymphoma subtypes: 25 DLBCLs and 2 intravascular large B-cell lymphomas. CD5 and other T-cell markers were expressed in 15% (31/225) and 10% (25/225) of DLBCL cases, respectively. Five of them co-expressed CD5 and other T-cell markers. Retrospectively analyzing the prognostic relevance of T-cell markers in 169 patients with primary DLBCL treated with rituximab-based chemotherapy, we showed that only CD5 was a strong predictor of poor survival. This study provides information about the occurrence of T-cell markers other than CD5 in B-cell lymphomas, their frequent histological subtypes, and their prognostic significance in DLBCL. CD5 was reconfirmed as a negative prognostic marker in DLBCL patients receiving rituximab-inclusive chemotherapy, whereas T-cell markers other than CD5 were found to have no impact on clinicopathological and survival analyses.

Epstein-Barr virus-negative extranodal "true" natural killer-cell lymphoma harbouring a KDM6A mutation

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL) is an extranodal aggressive T or NK-cell lymphoma that is characteristically associated with Epstein-Barr virus (EBV) infection and cytotoxic tissue-destructive features. Although ENKTL is described as a distinct entity according to the 2008 WHO classification, a considerable complexity is associated with the differential diagnosis of other T-cell lymphomas with respect to tumour cell origins, locations, and the presence of EBV infection, as well as molecular and cytogenetic abnormalities. Here, we report a rare case of EBV-negative ENKTL, where the absence of EBV in the true NK-lineage cells was confirmed by extensive phenotypic and genotypic analyses. Furthermore, using the next-generation sequencing approach, we identified mutations in the tumour suppressor genes KDM6A and TP53. The clinicopathological characteristics were almost similar to those of EBV-positive ENKTL, except for the absence of EBV and histologically apparent angioinvasiveness. This is the first reported ENKTL case with mutations in the KDM6A gene. KDM6A is one of the histone-modifying genes that are mutated in many human diseases including haematological cancers. Epigenetic regulation of gene expression has recently been demonstrated in ENKTL, and a similar pathway is thought to play an oncogenic role in EBV-negative ENKTL. Our report shows the extent of comprehensive examination required before making a definitive diagnosis for NK- and T-cell neoplasms and broadens the therapeutic options for potential targets.

Efficacy of chemotherapy in extremely elderly patients with diffuse large B-cell lymphoma

The safety and effective dose of chemotherapy in treating non-Hodgkin lymphoma in elderly patients is yet to be established. In this study, we assessed the prognosis of diffuse large B-cell lymphoma (DLBCL) in elderly patients (≥75 years) treated with an optimal dose of R-CHOP. No significant differences were observed in progression-free survival between elderly patients and patients aged <74 years with DLBCL. Furthermore, no differences were observed between full-dose R-CHOP and 80% dose R-CHOP groups. Median relative dose intensity was 0.80 in elderly patients with DLBCL. Thus, our data suggested that 80% dose R-CHOP is tolerable and effective in these patients.

Low absolute peripheral blood CD4+ T-cell count predicts poor prognosis in R-CHOP-treated patients with diffuse large B-cell lymphoma

The absolute peripheral blood lymphocyte count at diagnosis is known to be a strong prognostic factor in patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP), but it remains unclear as to which peripheral blood lymphocyte population is reflective of DLBCL prognosis. In this cohort, 355 patients with DLBCL treated with R-CHOP from 2006 to 2013 were analyzed. The low absolute CD4+ T-cell count (ACD4C) at diagnosis negatively correlated with the overall response rate and the complete response rate significantly (P<0.00001). An ACD4C<343 × 106/l had a significant negative impact on the 5-year progression-free survival and the overall survival as compared with an ACD4C⩾343 × 106/l (73.7% (95% confidence interval (CI)=66.7-79.5) versus 50.3% (95% CI=39.0-60.6), P<0.00001 and 83.3% (95% CI=77.1-88.0) versus 59.0% (95% CI=47.9-68.5), P<0.00000001, respectively). Multivariate analysis revealed that the ACD4C was an independent prognostic marker (hazard ratio=2.2 (95% CI=1.3-3.7), P<0.01). In conclusion, a low ACD4C at diagnosis served as an independent poor prognostic marker in patients with DLBCL.

Anaplastic large cell lymphoma: pathology, genetics, and clinical aspects

Anaplastic large cell lymphoma (ALCL) was first described in 1985 as a large-cell neoplasm with anaplastic morphology immunostained by the Ki-1 antibody, which recognizes CD30. In 1994, the nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK) fusion receptor tyrosine kinase was identified in a subset of patients, leading to subdivision of this disease into ALK-positive and -negative ALCL in the present World Health Organization classification. Due to variations in morphology and immunophenotype, which may sometimes be atypical for lymphoma, many differential diagnoses should be considered, including solid cancers, lymphomas, and reactive processes. CD30 and ALK are key molecules involved in the pathogenesis, diagnosis, and treatment of ALCL. In addition, signal transducer and activator of transcription 3 (STAT3)-mediated mechanisms are relevant in both types of ALCL, and fusion/mutated receptor tyrosine kinases other than ALK have been reported in ALK-negative ALCL. ALK-positive ALCL has a better prognosis than ALK-negative ALCL or other peripheral T-cell lymphomas. Patients with ALK-positive ALCL are usually treated with anthracycline-based regimens, such as combination cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) or CHOEP (CHOP plus etoposide), which provide a favorable prognosis, except in patients with multiple International Prognostic Index factors. For targeted therapies, an anti-CD30 monoclonal antibody linked to a synthetic antimitotic agent (brentuximab vedotin) and ALK inhibitors (crizotinib, alectinib, and ceritinib) are being used in clinical settings.

Frequent BCOR aberrations in extranodal NK/T-Cell lymphoma, nasal type

Extranodal natural killer/T cell lymphoma (ENKTL) is a rare subtype of lymphoma. Recurrent mutations in the JAK-STAT pathway, recently reported in ENKTL cases, are interesting in terms of both pathogenesis and inhibitor therapy. However, the frequencies of these mutations are low and variable among reports, and other pathognomonic mutations in ENKTL remain to be elucidated. In the present study, targeted capture sequencing of 602 cancer-related genes from 25 frozen ENKTL samples was performed, 11 of which were matched to normal samples. Several recurrent somatic mutations involving BCOR (32%), TP53 (16%), DDX3X (12%), FAT4 (8%), NRAS (8%), MLL3 (12%), and MIR17HG (8%) were identified. The pattern of BCOR aberrations (1 nonsense and 5 frame-shift mutations, a mutation leading to a splicing error, and gene loss) suggested that loss of function of BCOR was the functionally important outcome of such changes. The literature was reviewed and the public data on BCOR aberrations was reanalyzed and it was found that the aberrations were frequently found in myeloid neoplasms, but, interestingly, were highly specific to ENKTL among lymphoid malignancies. Given the high frequency and pattern of aberration, BCOR is likely to play an important role in ENKTL pathogenesis as a tumor suppressor gene.

Extranodal NK/T-cell lymphoma, nasal type, manifesting as rapidly progressive dementia without any mass or enhancing brain lesion

Among the many potential etiologies for rapidly progressive dementia (RPD), primary central nervous system extranodal NK/T-cell lymphoma, nasal-type (ENKL) is a rare entity. We present the first reported case of autopsy-proven RPD due to ENKL without any mass or enhancing lesion of the brain. A 54-year-old immunocompetent man presented with RPD, myoclonus and ataxia. The mini-mental state examination (MMSE) score was 22/30. His brain MRI revealed progressive brain atrophy without gadolinium enhancement or mass lesion. Five months after the initial evaluation, cognitive impairment further worsened with an MMSE score of 3/30. At the advanced stage, lumbar MRI showed swollen cauda equina with gadolinium enhancement. The number of Epstein-Barr virus (EBV) DNA in cerebrospinal fluid had gradually increased. Twelve months after onset, the patient died of respiratory failure. Pathological findings revealed that lymphoma cells had diffusely invaded the meninges, parenchyma of the brain, spinal cord and cauda equina. Cells were positive for CD3, CD56 and EBV-encoded small RNAs and negative for CD20. No evidence of malignancy was identified in the visceral organs. This report indicates that ENKL should be recognized as one of the rare causes of RPD. Early testing for EBV-DNA in cerebrospinal fluid and imaging of cauda equina would be useful diagnostic tools.

Intravascular Large B-cell Lymphoma of the Bilateral Ovaries and Uterus in an Asymptomatic Patient with a t(11;22)(q23;q11) Constitutional Translocation

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of extranodal diffuse large B-cell lymphoma, which is characterized by the intravascular growth of lymphoma cells, aggressive behavior, and an often fatal course. Patients with IVLBCL are usually symptomatic. Although any organ may be involved, localized lesions in the bilateral ovaries and uterus are extremely rare. We experienced a rare case of IVLBCL involving the bilateral ovaries and uterus in an asymptomatic patient with a t(11;22)(q23;q11) constitutional balanced translocation. Its association with the disease remains unknown. Even in asymptomatic situations, IVLBCL is possible, and the uterus and ovaries can be involved.

Pathology of indolent B-cell neoplasms other than follicular lymphoma

Indolent B-cell lymphomas include follicular lymphoma (FL), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and marginal zone lymphomas (MZLs). They are a diverse group of disorders with different clinical, morphological, immunophenotypic and genetic features. However, because of several histological similarities, such as in cell size and nodular structure, it may sometimes be difficult to differentiate them and to make a definitive diagnosis. In this review article, we summarize the histopathology of indolent B-cell neoplasms excluding FL and including hairy cell leukemia, and briefly mention recent genetic findings useful for their differential diagnosis. In addition, a provisional subtype of low-grade B-cell lymphoma, "prolymphocytic/paraimmunoblastic lymphoma", is described.

Absolute peripheral monocyte count at diagnosis predicts central nervous system relapse in diffuse large B-cell lymphoma

Recently, elevated peripheral blood monocyte counts at diagnosis have been shown to be an independent marker associated with poor prognosis in patients with both non-Hodgkin and Hodgkin lymphoma. In this study, we retrospectively analyzed the data from a total of 550 patients with diffuse large B-cell lymphoma and evaluated the relationship between central nervous system relapse and absolute monocyte counts at diagnosis. Twenty-six patients developed central nervous system relapse. The central nervous system relapse-free survival rate was significantly lower in patients with the absolute monocyte counts ≥ 0.51 × 10(9)/L (87.8% versus 96.4%; P<0.001). This association was independently significant after adjusting for other significant factors, including systemic relapse as a time-dependent covariate by multivariate analysis (hazard ratio 2.46; 95% confidence intervals 1.05-5.75; P=0.039). These results suggest that the absolute monocyte count at diagnosis is an independent significant risk factor for central nervous system relapse in patients with diffuse large B-cell lymphoma.

MIB-1 labeling index as a prognostic factor for patients with follicular lymphoma treated with rituximab plus CHOP therapy

The MIB-1 labeling index, which is based on Ki67 immunostaining, is widely used to evaluate the proliferation of tumor cells in lymphoma. However, its clinical significance has not been fully assessed. We retrospectively evaluated the prognostic impact of the MIB-1 labeling index at the time of diagnosis, in 98 patients with follicular lymphoma (FL) grade 1-3b who were treated uniformly with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy. The 5-year progression-free survival (PFS) for an MIB-1 labeling index of ≥10% (n = 60) and <10% (n = 38) was 35% and 61%, respectively (P = 0.015). The 5-year overall survival (OS) for an MIB-1 labeling index of ≥10% and <10% was 77% and 92%, respectively (P = 0.025). Pathological grading was not correlated with PFS or OS. In multivariate analysis, an MIB-1 labeling index of ≥10% was independently associated with poor PFS and OS. In conclusion, an MIB-1 labeling index of 10% is a useful cut-off level for predicting the prognosis of patients with FL.

Non-gastric advanced mucosa-associated lymphoid tissue (MALT) lymphoma has worse prognosis than gastric MALT lymphoma even when treated with rituximab-containing chemotherapy

The aim of this study was to assess the clinical characteristics, treatment results, and analyze the prognostic factors among patients with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). We retrospectively reviewed 98 patients with MALT lymphoma consecutively diagnosed at the Cancer Institute Hospital. Eighty-one patients (82%) had localized disease and 17 patients (17%) had advanced disease. The primary site was gastric in 52, and extra-gastric in 46. With a median follow-up of 40 months, the estimated 3-year overall survival (OS) and progression free survival (PFS) of the entire group were 100% and 89%, respectively. Three-year PFS was significantly better in patients with gastric lymphoma than in those with non-gastric lymphoma (95% vs. 82%, p = 0.043). Patients with localized disease had significantly better 3-year PFS than those with advanced disease (94% vs. 73%, p = 0.026). Upon multivariate analysis, non-gastric lymphoma retained prognostic significance for PFS.

Prognostic value of C-reactive protein, lactase dehydrogenase and anemia in recurrent or refractory aggressive lymphoma

OBJECTIVE

Prognostic predictors for newly diagnosed malignant lymphoma are well known. However, they have not been compared for patients with recurrent or refractory malignant lymphoma.

METHODS

We retrospectively analyzed biological prognostic predictors for patients with recurrent or refractory aggressive lymphoma, such as serum levels of C-reactive protein, lactate dehydrogenase, hemoglobin, β2-microglobulin and soluble interleukin-2 receptor before salvage therapy. The primary endpoint was overall survival after salvage treatment. First, univariate and multivariate analyses were performed for each of the parameters, using the log-rank test and Cox regression analysis, respectively. Secondly, we classified the patients into three risk groups on the basis of significant poor predictors.

RESULTS

Sixty-three patients, including 41 patients with diffuse large B-cell lymphoma, were included in this study. Overall survival was significantly worse in patients with elevated C-reactive protein level (hazard ratio 3.757; P = 0.017), elevated lactate dehydrogenase level (hazard ratio 3.948; P = 0.010) and anemia (hazard ratio 3.925; P = 0.016) by multivariate analysis. We classified patients into two groups based on these three biological parameters. The median overall survival of the high- and low-risk patients was 5.8 and 60.1 months, respectively (log-rank test; P < 0.001). The overall response rate was significantly higher among the low-risk patients than among the high-risk patients (71.4 versus 28.6%, P = 0.005). Those results were similar among all aggressive lymphoma and diffuse large B-cell lymphoma.

CONCLUSIONS

Elevated C-reactive protein level, elevated lactate dehydrogenase level and anemia before salvage treatment predicted poorer outcomes among patients with recurrent or refractory aggressive lymphoma.

Establishment of 2 human thyroid-carcinoma cell-lines (8305c, 8505c) bearing p53 gene-mutations

New cell lines, designated 8305C and 8505C, were established from undifferentiated thyroid carcinomas of a 67 year-old-female patient and a 78-year-old-female patient, respectively. Pathologically both these primary undifferentiated carcinoma tissues contained residual well differentiated components, suggesting well differentiated to undifferentiated carcinoma progression. Cell kinetic analysis indicate that the cell population doubling time is 43 h for 8305C and 36 h for 8505C. The saturation density at confluency is 5.7 x 10(4) cells/cm2 for 8305C and 1.1 x 10(5) cells/cm2 for 8505C. To identify genetic changes that may have occurred in these two cell lines, tumor suppressor genes p53, Rb, APC and MCC were analyzed. Sequence analysis confirmed a C:G to T:A transition at the first base of p53 gene codon 273 in 8305C and a C:G to G:C transversion at the first base of p53 codon 248 in 8505C. Polymerase chain reaction-loss of heterozygosity assays confirmed allelic deletion of p53 gene from the 8505C cell line. Loss of heterozygosity of other tumor suppressor genes were not observed. Given that p53 mutations associate with undifferentiated carcinoma but not with well differentiated carcinoma during multistep carcinogenesis of the thyroid, these cell lines should prove useful for research into the role of p53 gene mutations in malignant transformation.

R-CHOP with dose-attenuated radiation therapy could induce good prognosis in gastric diffuse large B cell lymphoma

Background

The treatment strategy for gastric diffuse large cell lymphoma (DLBCL) has not been standardized in such as to the cycles of chemotherapy, dose of radiation, or necessity for the surgery. Although the results of CHOP or R-CHOP treatments have demonstrated the good prognosis, the treatments have been controversial in many cases.

Methods

We retrospectively analyzed 40 gastric DLBCL patients receiving chemotherapy with or without radiation in our institute. Those in stages II-IV were treated with six cycles of R-CHOP without radiation; for those in stage I, we administered three cycles of R-CHOP with radiation.

Results

The three-year overall survival (OS) and progression-free survival (PFS) rates were 95.2 and 91.8%, respectively. Those in stage I obtained 100% of OS. The radiation dose prescribed was 30.6 Gy for CR cases and 39.6 to 40 Gy for PR after chemotherapy. Although survival rates tended to correlate with staging groups or age-adjusted IPI classifications, multivariate statistical analysis did not show clear differences. All 14 patients with initial bleeding were successfully managed without surgery during treatment.

Conclusion

R-CHOP therapy was very effective for gastric DLBCL. It may be not necessary to use more than 30.6 Gy of radiotherapy in the highly chemo-sensitive cases. Less toxic treatments should be made available to gastric DLBCL patients.

Feasibility and efficacy of combined cisplatin and irinotecan chemotherapy for poorly differentiated neuroendocrine carcinomas

OBJECTIVE

No standard treatment has been established for poorly differentiated neuroendocrine carcinoma; the usual recommended treatment is based on the strategy for small cell lung carcinoma. The aim of this study was to evaluate the response of poorly differentiated neuroendocrine carcinoma to the combination of irinotecan and cisplatin in one institution.

METHODS

We retrospectively reviewed 50 poorly differentiated neuroendocrine carcinoma patients treated from September 2005 to April 2011 in our institution. Patients were divided into two stages: limited disease or extensive disease. Forty-four patients received the combination chemotherapy of irinotecan and cisplatin, consisting of 4-week cycles of 60 mg/m(2) irinotecan on days 1, 8, 15 and 60 mg/m(2) cisplatin on day 1.

RESULTS AND CONCLUSION

Median age was 60 years. Median follow-up time was 11.4 months. Overall survival did not reach the median, and 1-year overall survival was 67%. The response rate was 50% (64% at first line), and progression-free survival was 4.8 months (7.3 months at first line). Grade 3-4 hematologic adverse events were seen in 29 patients (66%) and Grade 3-4 non-hematologic adverse events were seen in 20 patients (45%), but no patients died of adverse events. Multivariate analysis showed a statistically significant relationship with neuron-specific enolase elevation and poor overall survival (P= 0.016, hazard ratio 6.261, 95% confidence interval). The combination chemotherapy of irinotecan and cisplatin is moderately effective and feasible, and it should be considered as a treatment option for poorly differentiated neuroendocrine carcinoma.

Segmental copy-number variation observed in Japanese by array-CGH

Segmental copy-number variations (CNVs) may contribute to genetic variation in humans. In this study, we examined 80 unrelated Japanese individuals using a microarray (2,238 Bac-clones) based comparative genomic hybridization (array-CGH) assay. We found a total of 251 CNVs at 30 different regions in the genome; of these, 14 (termed 'rare' CNVs) were found individually located within distinct genomic regions of 14 individuals, while the remaining 16 CNV regions (termed 'polymorphic' CNVs) were observed in two or more individuals. The rare CNVs were confirmed by quantitative polymerase chain reactions, and characterized more precisely than in previous reports using array CGH. Distinctive features of these CNVs were observed: most prominent was that the majority of the rare CNVs presented on Bac-clones that did not overlap with regions of segmental duplication. About 90% of the polymorphic CNVs observed in this population had been previously identified, with the majority of those polymorphic CNVs located in regions of segmental duplication. It is likely, therefore, that rare and polymorphic CNVs arise through different genetic mechanisms. Since more than half of the rare CNVs are novel, it is also likely that different human populations bear different CNVs, as is the case for single-nucleotide-polymorphisms (SNPs) and insertion-deletion (indel) polymorphisms.

Increased susceptibility to apoptosis in CD45(+) myeloma cells accompanied by the increased expression of VDAC1

Expression of CD45 is quite variable in human myeloma cells and cell lines, such as U266, and CD45(+) U266 proliferates in response to a growth factor, interleukin-6. Here, we show that CD45(+) myeloma cell lines were more sensitive to various apoptotic stimuli, such as oxidative stress and endoplasmic reticulum (ER)-stress, than CD45(-) cells. Reactive oxygen species and calcium ion seemed to be involved in the susceptibility to apoptosis of CD45(+) U266. The activation of the src family kinases associated with CD45 phosphatase played an important role in the augmented apoptosis in CD45(+) U266 by oxidative stress. These results indicate that the CD45-expression renders myeloma cells competent for not only mitogenic but also apoptotic stimuli, resulting in either proliferation or apoptosis of CD45(+) myeloma cells dependently upon the circumstantial stimuli. Furthermore, voltage-dependent anion channel (VDAC) 1 was identified as a gene highly expressed in CD45(+) U266 by cDNA subtraction. The increased expression of VDAC1 seemed to augment the sensitivity to the ER-stress because the VDAC1-transfected U266 was more susceptible to the thapsigargin-induced apoptosis. Thus, CD45 expression accompanied by the increased VDAC1 expression sensitizes myeloma cells to the various extracellular stimuli that trigger apoptosis via the mitochondrial pathways.

Elevated in vivo frequencies of mutant T cells with altered functional expression of the T-cell receptor or hypoxanthine phosphoribosyltransferase genes in p53-deficient mice

We have studied the effects of a defect in the p53 gene on spontaneous and radiation-induced somatic mutation frequencies in vivo by measuring T-cell receptor (TCR) and hypoxanthine phosphoribosyltransferase (HPRT) mutant frequencies (MFs) in p53 deficient mice both before and after exposure to X-irradiation. In the absence of irradiation, the TCR and HPRT mutant frequencies were roughly two-fold higher in p53 null (-/-) mice than in wild-type (+/+) mice. Unexpectedly, the TCR and HPRT MFs were slightly lower in heterozygote p53 (+/-) than in wild-type (+/+) mice, however. After 2 weeks 2Gy whole body irradiation the TCR and HPRT MFs were about two-fold higher in the p53 null (-/-) and p53 (+/-) mice than in the wild-type. Taken together, these findings suggest that a defect in the p53 gene may lead to TCR and HPRT mutants being recovered at higher frequencies in both irradiated and unirradiated mice, but it should be emphasized that the effects we have observed are not particularly strong, albeit that they are statistically significant. Interestingly, several of the highest TCR MF values that we observed in the course of our experiments were recorded in p53 (-/-) animals that had developed thymomas and hence appeared to be cancer prone.

X-rays induce dose-dependent and cell cycle-independent accumulation of p21(sdi1/WAF1)

Cell cycle arrest at the G1 checkpoint is governed by a function of wild-type p53. We assessed the behavior of the sdi1 gene, which codes for a 21kDa potent inhibitor of cdk/cyclins, after X-irradiation. X-irradiation induced sdi1 mRNA accumulation and G1 arrest only in cells possessing wild-type p53. Elevation of p21(sdi1/WAF1) was preceded by p53 accumulation, which occurred despite p53 mRNA constancy in normal cells growing in the log phase. The quantity of accumulated p53 and p21(sdi1/WAF1) was radiation dose dependent. A decrease in the S phase cell population in normal cells observed after irradiation reached a minimum at less-than-maximum levels of p53 and p21(sdi1/WAF1). Furthermore, an accumulation of p53 and p21(sdi1/WAF1) was also observed when cells were synchronized in the G0, G1 and S phase and X-irradiated. These results indicated that an X-ray induced p53 and p21(sdi1/WAF1) accumulation mechanism exists throughout the cell cycle, and that the signal strength induced by X-irradiation is dose-dependent.

Differential regulation of human RecQ family helicases in cell transformation and cell cycle

Three human RecQ DNA helicases, WRN, BLM and RTS, are involved in the genetic disorders associated with genomic instability and a high incidence of cancer. RecQL1 and RecQL5 also belong to the human RecQ helicase family, but their correlation with genetic disorders, if any, is unknown. We report here that in human B cells transformed by Epstein-Barr virus (EBV), human fibroblasts and umbilical endothelial cells transformed by simian virus 40, the expression of WRN, BLM, RTS and RecQL1 was sharply up-regulated. In B cells this expression was stimulated within 5-40 h by the tumor promoting agent phorbol myristic acetate (PMA). Interestingly, RecQL5beta, an alternative splicing product of RecQL5 with a nuclear localization signal, is expressed in resting B cells without significant modulation of its synthesis by EBV or PMA, suggesting it has a role in resting cells. We also roughly determined the number of copies per cell for the five RecQ helicase in B cells. In addition, levels of the different RecQ helicases are modulated in different ways during the cell cycle of actively proliferating fibroblasts and umbilical endothelial cells. Our results support the view that the levels of WRN, BLM, RTS and RecQL1 are differentially up-regulated to guarantee genomic stability in cells that are transformed or actively proliferating.