Prognostic significance of Ki-67 nuclear proliferative antigen, bcl-2 protein, and p53 expression in follicular and diffuse large B-cell lymphoma

Comparison of Ki67 Proliferation Index in Gastrointestinal Non-Hodgkin Large B-Cell Lymphomas: The Conventional Method of Evaluation or AI Evaluation?

The most common NHL subtype in SEEU is DLBCL (39%), and it manifests with a variety of cellular morphologies and a high proliferation index. Also, the GI tract is the most common site of extranodal NHLs, and most NHLs involving the GI tract are of B-cell lineage, of which diffuse large B-cell lymphoma is the most common subtype, irrespective of location. The last few years have seen digital pathology as a vital technology that has a positive impact on diagnostics, but studies on the use of DP for lymphoma identification, however, are still restricted to only determining whether a tumor is present or absent. Using the example of cases of malignant NHL, we aim to investigate the diagnostic utility of DP using QuPath software in evaluating the proliferation index and the prognostic significance and to show that improved visualization and analysis contribute to the convergence of these complementary diagnostic modalities for lymphomas. The average proliferation index (Ki67) was 58.33% with values between 10% and 85%. After the stratification of the cases, an increased proliferation index was observed in the majority of cases (53.33%), and this aspect was associated with the advanced age of the patients (p = 0.045). Visual assessment provides lower Ki67 values than automated digital image analysis. However, the agreement coefficient between the conventional method and the AI method indicates an excellent level of reliability (ICC1-0.970, ICC2-0.990). The multivariate analysis revealed that in the cases where the proliferation index Ki67 is high (˃70%), the IPI score represents an important risk factor predicting mortality (HR = 10.597, p = 0.033).

Risk factors for POD24 in patients with previously untreated follicular lymphoma: a systematic review and meta-analysis

Progression of disease within 24 months (POD24) is strongly associated with a poor outcome in patients with follicular lymphoma (FL). Our study aimed to identify the potential risk factors for POD24 in patients with FL. Medline, EMBASE and the Cochrane Library were systematically searched from the earliest record to September 2020. Studies investigating the prognostic factors for POD24 in patients with newly diagnosed grade 1-3a FL were included. Among 10,014 pieces of literature, a total of 90 studies investigating 82 risk factors were included for qualitative analysis. Meta-analyses were performed in 31 studies with 11 factors. Results showed that elevated sIL-2R, β2m and LDH, total metabolic tumour volume > 510 cm³, vitamin D < 20 ng/mL, grade 3a and lymphoma-associated macrophages/high-power field ≥ 15 were significantly associated with an increased risk of POD24. No significant association was found between POD24 and the ALC/AMC ratio, sex, T effector signature or EZH2 genetic alteration. Additionally, minimal residual disease, Ki-67, PD-1 and TP53 were analysed narratively. Overall, this is the first study that comprehensively analysed the prognostic factors associated with POD24 in FL patients. We have confirmed the significance value of several common prognostic factors as well as others not commonly included in clinical study, helping to construct an integrated and more efficient model.

Comparison of Ki-67 Labeling Index Patterns of Diffuse Large B-Cell Lymphomas and Burkitt Lymphomas Using Image Analysis: A Multicenter Study

Diffuse large B-cell lymphoma (DLBCL) is the most common high-grade B-cell lymphoma found in Korea; it manifests with a variety of cellular morphologies and a high proliferation index. It is difficult to differentiate between DLBCL and Burkitt lymphoma (BL) based on immunohistochemistry, histology, and Epstein-Barr virus infection status owing to the overlap in findings. In this study, we performed comparative morphometric analysis to understand the proportional difference in Ki-67 staining between DLBCL and BL. We analyzed Ki-67-stained slides of 103 DLBCLs and 29 BLs that were pathologically confirmed using a three-tier classification system (negative, 1+, 2+, and 3+) to compare Ki-67 expression between BL and activated B-cell and germinal center B-cell subtypes of DLBCL and DLBCL with high proliferation indices (>90% of 2+ and 3+ cells). Patients with DLBCL were older than those with BL (62.1 versus 51.0 years). The number and proportion of negative cells (passenger and true negative cells) were significantly lower in BLs than those in DLBCLs (337.4, 5.9% versus 690.3, 12.4%). The number and proportion of 3+ cells were significantly higher in BLs than those in DLBCLs (5213.6, 96.3% versus 3132.4, 62.0%). BLs and DLBCLs with a high proliferation index showed similar results as those between BLs and overall DLBCLs. We were able to differentiate BLs and DLBCLs with 98.1% sensitivity and 100.0% specificity using an optimal cut-off of 97.9% of 2+/3+ Ki-67-positive cells. Thus, the Ki-67 labeling index may be a good differential biomarker for DLBCLs and BLs.

Complexities in the diagnosis of large B-cell lymphomas, classic Hodgkin lymphomas and overlapping peripheral T-cell lymphomas simplified: An evidence-based guide

The diagnosis of a large B-cell lymphoma and classic Hodgkin lymphoma (CHL) is often straightforward. However, in select circumstances, these simple diagnoses can be quite complex. In part, diagnostic difficulty may be due to uncertainty in the evaluation of morphologic and immunophenotypic features along a biologic continuum, or alternatively arise from uncertainty in predicting the behavior and outcomes of patients. Here, we systematically discuss and review areas of diagnostic difficulty in the diagnosis of large B-cell lymphomas (LBCL), classic Hodgkin lymphomas (CHL) and peripheral T-cell lymphomas (PTCL). We provide careful data-driven analyses and evidence-based approaches to help guide pathologists and clinicians. We discuss: 1) marginal zone lymphomas with increased large cells versus diffuse large B-cell lymphoma (DLBCL), 2) chronic lymphocytic leukemia with expanded proliferation centers versus diffuse large B-cell lymphoma (DLBCL), 3) chronic lymphocytic leukemia with Hodgkin/Reed-Sternberg-like cells versus CHL arising from chronic lymphocytic leukemia, 4) complex cases of follicular lymphoma versus DLBCL, 5) PTCL with large B-cell proliferations versus PTCL with LBCL, 6) PTCL with Hodgkin/Reed-Sternberg-like cells versus CHL, and finally 7) blastoid/pleomorphic mantle cell lymphoma versus DLBCL. Our evidence and data driven approach may serve as a useful diagnostic guide.

A Multicenter Retrospective Study of 58 Patients With Primary Thyroid Diffuse Large B Cell Lymphoma

Background: Primary thyroid diffuse large B cell lymphoma (DLBCL) is a rare type of extranodal lymphoma; optimal treatment methods and the key prognostic factors have not been established. Methods: The clinical data of 58 patients with primary thyroid DLBCL from January 2007 to December 2017 were collected. The Kaplan-Meier method and log-rank tests were used for the survival analysis. Cox regression analysis was performed to evaluate the prognostic factors. Results: The follow-up time was 6-120 months; 5-year overall survival (OS) and progression-free survival (PFS) were 73 and 61%, respectively. Single-factor analysis showed that IPI, Ki-67, treatment modalities, Hans classification, Myc/Bcl-2 protein co-expression, and administration of rituximab had a significant effect on the 5-year OS and PFS (P < 0.05), while age, sex, Bcl-2 protein expression, Myc protein expression, tumor stage, tumor size, Hashimoto's thyroiditis, and B symptoms were not associated with prognosis (P > 0.05). Multivariate risk regression analysis revealed that Myc/Bcl-2 protein co-expression, treatment modalities, and rituximab were independent prognostic factors (P < 0.05). Conclusions: Patients with primary thyroid DLBCL who received combination chemotherapy with radiotherapy had a better prognosis. Surgical treatment alone was not associated with the prognosis and is used only for diagnosis. Rituximab could improve the survival time of patients.

Bendamustine plus Rituximab Versus R-CHOP as First-Line Treatment for Patients with Follicular Lymphoma Grade 3A: Evidence from a Multicenter, Retrospective Study

BACKGROUND

Rituximab plus bendamustine (R-B) has been demonstrated to improve outcomes and reduce toxicity compared with rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHOP) in follicular lymphoma (FL). Nevertheless, in clinical practice, many centers still prefer R-CHOP to R-B in patients with FL grade 3A (FL3A). Therefore, we retrospectively assessed patients with FL3A treated with either R-CHOP or R-B in five European cancer centers and compared their outcomes.

MATERIALS AND METHODS

We retrospectively assessed 132 patients affected by FL grade 3A treated with either R-B or R-CHOP in the first line and evaluated outcome and toxicity according to the type of treatment. This study included 101 patients who were a subgroup of a previously published cohort.

RESULTS

R-B was less toxic and achieved a similar percentage of complete remissions compared with R-CHOP (97% vs. 96%, p = .3). During follow-up, 10 (16%) patients relapsed after R-B and 29 (41%) after R-CHOP (p = .001), leading to a median progression-free survival (PFS) of 15 versus 11.7 years, respectively (p = .03). Furthermore, R-B overcame the negative prognostic impact of BCL2 expression (15 vs. 4.8 years; p = .001). However, median overall survival was similar between both groups (not reached for both; p = .8).

CONCLUSION

R-B as a first-line treatment of FL3A is better tolerated than R-CHOP and seems to induce more profound responses, leading to a significantly lower relapse rate and prolonged PFS. Therefore, R-B is a valid treatment option for FL grade 3A.

IMPLICATIONS FOR PRACTICE

Rituximab plus bendamustine (R-B) has shown to be less toxic and more effective than rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHOP) in follicular lymphoma grade 3A. Although both regimens can induce a complete remission in >95% of patients, relapses occur more frequently after R-CHOP than R-B, leading to a significantly longer progression-free survival in the latter. R-B is also able to overcome the impact of negative prognosticators, such as BCL2 expression. However, because of the indolent course of this disease and efficient salvage treatments, overall survival was similar in both treatment groups. Therefore, R-B is a valid treatment option in this patient setting.

Prognostic Significance of in situ Phenotypic Marker Expression in Diffuse Large B-cell Lymphomas

Diffuse large B-cell lymphomas (DLBCL) are the most common lymphoid malignancies, and encompass all malignant lymphomas characterized by large neoplastic cells and B-cell derivation. In the last decade, DLBCL has been subjected to intense clinical, phenotypic and molecular studies, and were found to represent a heterogeneous group of tumors. These studies suggested new disease subtypes and variants with distinct clinical characteristics, morphologies, immunophenotypes, genotypes or gene expression profiles, associated with distinct prognoses or unique sensitivities to particular therapy regimens. Unfortunately, the reliability and reproducibility of the molecular results remains unclear due to contradictory reports in the literature resulting from small sample sizes, referral and selection biases, and variable methodologies and cut-off levels used to determine positivity. Here, we review phenotypic studies on the prognostic significance of protein expression profiles in DLBCL and reconsider our own retrospective data on 301 primary DLBCL cases obtained on a previously validated tissue microarray in light of powerful statistical methods of determining optimal cut-off values of phenotypic factors for prediction of outcome.

Grading of follicular lymphoma in cytological samples

OBJECTIVE

The treatment of follicular lymphoma (FL) depends on its grade. The current World Health Organization (WHO) 2008 Classification of Tumours of Haematopoietic and Lymphoid Tissues recommends the grading of FL on histological samples according to the Mann and Berard method, taking into consideration the number of centroblasts. There is no generally accepted method for the grading of FL in fine needle aspiration biopsy (FNAB) samples. The aim of the present study was to devise a grading system for FL in cytological samples.

METHODS

Flow cytometry (FC) was performed on 60 FNAB samples of patients with primary FL. We assumed that FL cells larger than reactive T lymphocytes on FC histograms corresponded to centroblasts. The percentage of large cells was calculated and compared with histological grade, proliferative activity and number of centroblasts per high-power field (HPF) on histological slides, and with survival.

RESULTS

The histological analysis of lymph nodes revealed 20 patients with high-grade and 40 patients with low-grade FL. The percentage of large cells in FNAB samples correlated significantly with histological grade (P = 0.02), MIB1 status (P < 0.001) and the number of centroblasts per HPF (P < 0.001). An age over 60 years and a percentage of large cells over 50% in FNAB samples were found to have a statistically significant impact on survival by univariate analysis (P = 0.001 and P = 0.006, respectively).

CONCLUSIONS

The percentage of large lymphoma cells in FNAB samples of FL determined by FC can be used as a reliable method for FL grading, as it is comparable with the histological grading system.

miR-31 and miR-17-5p levels change during transformation of follicular lymphoma

The 30% of patients whose indolent follicular lymphoma transforms to aggressive diffuse large B-cell lymphoma (DLBCL) have poor survival. Reliable predictors of follicular B-cell lymphoma transformation to DLBCL are lacking, and diagnosis of those that will progress is challenging. MicroRNA, which regulates gene expression, has critical functions in the growth and progression of many cancers and contributes to the pathogenesis of lymphoma. Using 5 paired samples from patients who presented with follicular lymphoma and progressed to DLBCL, we identified specific microRNA differentially expressed between the two. Specifically, miR-17-5p levels were low in follicular lymphoma and increased as the disease transformed. In contrast, miR-31 expression was high in follicular lymphoma and decreased as the lymphoma progressed. These results were confirmed in additional unpaired cases of low-grade follicular lymphoma (n = 13) and high-grade follicular lymphoma grade 3 or DLBCL (n = 17). Loss of miR-31 expression in DLBCL was not due to deletion of the locus. Changes in miR-17-5p and miR-31 were not correlated with immunophenotype, genetics, or status of the MYC oncogene. However, increased miR-17-5p expression did significantly correlate with increased expression of p53 protein, which is indicative of mutant TP53. Two pro-proliferative genes, E2F2 and PI3KC2A, were identified as direct messenger RNA targets of miR-31, suggesting that these may contribute to follicular lymphoma transformation. Our results indicate that changes in miR-31 and miR-17-5p reflect the transformation of follicular lymphoma to an aggressive large B-cell lymphoma and may, along with their targets, be viable markers for this process.

Prognostic effect of Ki-67 expression in rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone-treated diffuse large B-cell lymphoma is limited to non-germinal center B-cell-like subtype in late-elderly patients

This study evaluated the effect of age and cell of origin on the prognostic significance of Ki-67 labeling index (Ki-67 LI) on overall survival (OS) of diffuse large B-cell lymphoma (DLBCL) in a cohort of 697 patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP). Multivariate analysis revealed no prognostic significance of high Ki-67 LI (≥ 85%) for OS. However, on subgroup analysis, high Ki-67 LI was significantly associated with poor OS in late-elderly patients (aged ≥ 70 years) (p = 0.021) and non-germinal center B-cell-like (GCB) subtype (p = 0.015). In particular, high Ki-67 LI was associated with a poor prognosis in late-elderly patients with non-GCB subtype. No correlation was observed in young adults (aged < 60 years) or early-elderly (aged 60-70 years) patients or GCB subtype. The present study shows that high Ki-67 LI is a risk factor for poor OS in the late-elderly age group and non-GCB subtype in patients with DLBCL treated with R-CHOP.

Prognostic significance of Ki-67 antigen expression in extranodal natural killer/T-cell lymphoma, nasal type

Extranodal natural killer (NK)/T-cell lymphoma, nasal-type (ENKTL) is a clinically heterogeneous disease with poor prognosis and requires risk stratification in affected patients. Recent studies have shown that Ki-67 may serve as a prognostic marker in certain types of lymphoma. We analyzed Ki-67 expression and its correlation with prognosis in 182 patients with ENKTL from January 2002 to June 2013. The patients were classified into two groups through a median value: low (<60%) versus high Ki-67 (≥60%). High Ki-67 expression was more common in patients with B symptoms (p=0.02), bulky disease (p=0.001), and extraupper aerodigestive tract NK/T-cell lymphoma (p=0.001). High Ki-67 expression was significantly associated with poor overall survival (p<0.0001) and progression-free survival (p<0.0001). For patients with low-risk IPI or KPI, Ki-67 at diagnosis could contribute to distinguish patients with favorable outcomes from those with poor outcomes. The results of multivariate analysis showed that the high Ki-67 expression is an independent prognostic factor for overall survival and progression-free survival. (OS, p=0.001; PFS, p=0.003). Our data showed that Ki-67 is an effective prognostic indicator of survival in ENKTL patients. This prognostic index may be helpful in identifying high-risk patients with ENKTL.

Frequent disruption of the RB pathway in indolent follicular lymphoma suggests a new combination therapy

Loss of cell cycle controls is a hallmark of cancer and has a well-established role in aggressive B cell malignancies. However, the role of such lesions in indolent follicular lymphoma (FL) is unclear and individual lesions have been observed with low frequency. By analyzing genomic data from two large cohorts of indolent FLs, we identify a pattern of mutually exclusive (P = 0.003) genomic lesions that impair the retinoblastoma (RB) pathway in nearly 50% of FLs. These alterations include homozygous and heterozygous deletions of the p16/CDKN2a/b (7%) and RB1 (12%) loci, and more frequent gains of chromosome 12 that include CDK4 (29%). These aberrations are associated with high-risk disease by the FL prognostic index (FLIPI), and studies in a murine FL model confirm their pathogenic role in indolent FL. Increased CDK4 kinase activity toward RB1 is readily measured in tumor samples and indicates an opportunity for CDK4 inhibition. We find that dual CDK4 and BCL2 inhibitor treatment is safe and effective against available models of FL. In summary, frequent RB pathway lesions in indolent, high-risk FLs indicate an untapped therapeutic opportunity.

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.

Software-automated counting of Ki-67 proliferation index correlates with pathologic grade and disease progression of follicular lymphomas

OBJECTIVES

To examine the accuracy of software-assisted measurement of the Ki-67 proliferation index (PI) and its correlation with the grade and clinical progression of follicular lymphoma (FL).

METHODS

High-power field equivalents were extracted from H&E- and Ki-67-immunostained slides of FL, and a nuclear quantitation algorithm was used to calculate a PI. Representative fields were manually counted for validation with close agreement.

RESULTS

The PI was significantly higher in World Health Organization grade 3 FL than grade 1 to 2 FL. Disease progression, as defined by subsequent treatment with radiation or cytotoxic chemotherapy, was also significantly associated with elevated PI but not pathologic grade.

CONCLUSIONS

These data show that software-automated quantitation of Ki-67 can provide both a useful adjunct to pathologic grade in FL and improved prognostic information for patients.

SUV on dual-phase FDG PET/CT correlates with the Ki-67 proliferation index in patients with newly diagnosed non-Hodgkin lymphoma

PURPOSE

PET using 18F-FDG integrated with CT is beneficial for staging patients with non-Hodgkin lymphoma (NHL). The Ki-67 index is used to assess the proliferation potential of tumor cells. The aim of this study was to evaluate the correlation of the Ki-67 index in tissue samples with the SUV at different sites on dual-phase FDG PET/CT of patients with newly diagnosed NHL.

MATERIALS AND METHODS

From September 2009 to March 2011, patients with newly diagnosed NHL who had received dual-phase FDG PET/CT for staging and biopsy samples that were evaluated for the Ki-67 expression were enrolled. The SUVmax of the biopsy site, the tumorous lesion sites, and 3 different bone marrow sites (right iliac crest, sternum, and L1) were measured. The SUVmean of the liver and spleen were also measured.

RESULTS

There were a total of 27 patients in this study. Significant correlations were observed between the Ki-67 index and the SUVmax of the right iliac crest in patients with early-stage disease (stage I and II) patients, the SUVmax of the biopsy and whole-body lesion sites in patients with late-stage disease (stage III and IV), and the retention index of SUVmax of the right iliac crest in patients whose bone marrow were involved by lymphoma cells.

CONCLUSIONS

For patients with newly diagnosed NHL, the significant correlation between the Ki-67 index and the SUV in this study suggests that dual-phase FDG PET/CT may be used as a noninvasive measurement of tumor proliferation.

Centroblastic diffuse large B cell lymphoma displays distinct expression pattern and prognostic role of apoptosis resistance related proteins

Centroblastic diffuse large B cell lymphoma (DLBCL) samples were analyzed by immunohistochemistry to evaluate the expression of p53, Bcl-2, Survivin, XIAP, and Ki-67. Survivin was the only protein which expression exhibited a trend for impact in progression-free (p = .077) and overall survival (p = .054). In the Mann-Whitney test, Survivin expression correlated with a negative overall survival (p = .045). These results appeared to be intimately related to Survivin cytoplasmic localization. Moreover, the anti-apoptotic proteins Bcl-2 and Survivin were less frequent in centroblastic DLBCL. Our results indicate that centroblastic DLBCL may be a disease with characteristic biology and clinical course and, therefore, specific prognostic factors.

High Ki-67 expression in diffuse large B-cell lymphoma patients with non-germinal center subtype indicates limited survival benefit from R-CHOP therapy

OBJECTIVES

Rituximab has significantly improved the survival of patients with DLBCL, especially those with non-germinal center B-cell-like (non-GCB) subtype. The impact of Ki-67 expression, an index of proliferation, on the clinical outcomes of patients with DLBCL has largely been unexplored. This study aimed to investigate whether Ki-67 expression is an indicator of outcome in DLBCL patients (especially non-GCB DLBCL patients) treated with standard chemotherapy combined with rituximab.

METHODS

Expression of Ki-67 protein was examined immunohistochemically in 118 tumor specimens from patients newly diagnosed with DLBCL and treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone).

RESULTS

Overall survival (OS) and progression-free survival (PFS) were lower in patients with high Ki-67 expression than in those with low Ki-67 expression (3-year OS: 65.2% vs. 81.7%, P = 0.030; 3-year PFS: 56.4% vs. 73.3%, P = 0.020), similar in patients with GCB subtype and those with the non-GCB subtype (OS: P = 0.330; PFS: P = 0.287). According to Ki-67 expression status by immunophenotype subgroups, patients with high Ki-67 expression in non-GCB subgroup had the most unfavorable PFS and OS, comparing with the other three subgroups (P = 0.004 and P = 0.002, respectively). In multivariate analysis, non-GCB with high Ki-67 expression was an independent prognostic predictor of inferior survival in DLBCL patients treated with R-CHOP.

CONCLUSION

For DLBCL patients with non-GCB DLBCL and high Ki-67 expression, the survival benefit from R-CHOP therapy is limited.

Immunophenotyping of chronic B-cell neoplasms: flow cytometry versus immunohistochemistry

Morphological differentiation between benign and malignant lymphoproliferative disorders (LPDs) can be challenging. Immunophenotyping (IPT) by either technique, flow cytometry or immunohistochemistry (IHC), is an important step in solving such difficulty. Thirty-five newly diagnosed patients with chronic B-cell neoplasms (11 chronic lymphocytic leukemia, 22 non Hodgkin lymphoma and 2 hairy cell leukemia) were included in this study with age range from 20 to 70 years. Monoclonal antibodies surface expression using lymphoproliferative disorders panel (CD45, CD19, CD5, CD10, CD11c, CD20, CD22, CD23, CD38, CD79b, FMC7, CD103, CD25, kappa and lambda light chains) by flow cytometry was done on bone marrow samples. CD20, CD5, CD23, Bcl-2, Bcl-6, kappa and lambda light chain immunostaining were performed on fixed bone marrow trephine biopsy specimen. The sensitivity of IHC was 81.8% in chronic lymphocytic leukemia (CLL) and 100% in non Hodgkin lymphoma (NHL) as regards CD20, 100% in both groups as regards CD5, 46% in CLL and 66.7% in NHL as regards CD23, 33.3% in CLL and 50% in NHL as regards kappa chain, 20% in CLL and 33.3% in NHL as regards lambda chain. We found that IHC and flow cytometry are equally effective in diagnosing CLL; however, IHC might be slightly more sensitive than flow cytometry in detecting bone marrow infiltration in NHL and hairy cell leukemia (HCL).

No Prognostic Impact of p53 and P-Glycoprotein Expression in Patients with Diffuse Large B-Cell Lymphoma

The aim of this study was to determine the clinical significances of p53 and p-glycoprotein (P-gp) expression on outcome predictors for patients with DLBC. We assessed the immunohistochemical expression of p53 and P-gp using formalin-fixed, paraffin-embedded specimens in 108 patients diagnosed with de novo DLBC. A high expression of p53 was found in 53.7% of the patients. No expression of P-gp was demonstrated in any of the specimens. There were no significant differences in the complete remission (CR) rate (P = 0.79), overall survival (OS) (P = 0.73), or disease-free survival (DFS) (P = 31) between the p53-positive and p53-negative groups. The final model from multivariate analysis that revealed poor performance status was significantly associated with CR (P < 0.001) and OS (P < 0.001). Moreover, the advanced stage was a significant predictor of DFS (P = 0.03). This study demonstrated no impact of the expression of p53 on either response or survival rates.

Significance of Bcl-2 and Bcl-6 immunostaining in B-Non Hodgkin's lymphoma

The determination of prognosis for B-Non-Hodgkin's lymphoma (NHL) is known to be related to the multiple differences in tumor cell biology. Bcl-2 and Bcl-6 are two markers linked to germinal center B cells. Both markers are thought to have an effect on prognosis of mature B-cell neoplasms. Forty-four patients with chronic B-cell neoplasm were included; Bcl-2 and Bcl-6 expression by immunohistochemistry was examined. Bcl-2 protein was positive in 36.4% (16 of 44) of cases (62.5% of follicular lymphoma, 16.7% of mantle cell lymphoma and 30% of diffuse large B-cell lymphoma); the positive group implying a bad prognostic effect of the marker in NHL. Bcl-6 was positive in 13.6% (6 of 44) of cases (11.1% of mantle cell lymphoma and 40% of diffuse large B-cell lymphoma) and its positivity implies a better disease course. Bcl-2 and Bcl-6 can be used as prognostic marker in NHL.

Follicular programmed death 1-positive lymphocytes in the tumor microenvironment are an independent prognostic factor in follicular lymphoma

We enumerated programmed death 1 (PD-1)-positive follicular helper T cells, a potentially important regulator of immune response, in the tumor microenvironment of a series of 91 newly diagnosed follicular lymphomas managed at a single institution. Clinical data were obtained for sex, age, Follicular Lymphoma International Prognostic Index (FLIPI) risk group, presence of bulky disease, presence of B symptoms, and overall survival. Immunohistochemical staining for PD-1 was performed on tissue microarray sections, and the mean number of follicular PD-1-positive cells per 9 high-power fields (1000×, 3 follicles with 3 fields per follicle) was quantified. B-cell CLL/lymphoma 2 (BCL-2) expression, CD68(+) extrafollicular lymphoma-associated macrophages, and forkhead box P3 (FOXP3)+ regulatory T cells were evaluated as reported previously. Ninety-one patients were evaluated, with a median age at diagnosis of 58 years and median survival of 11.6 years. PD-1-positive cells correlated with the number of FOXP3+ regulatory T cells (P = .01). On multivariate analysis, independent poor prognostic factors were age 55 years or greater (hazard ratio, 2.77; 95% confidence interval, 1.34-5.73; P = .006), bulky disease (hazard ratio, 2.27; 95% confidence interval, 1.03-5.00; P = .04), CD68(+) extrafollicular lymphoma-associated macrophages greater than 16.8 cells/high-power field (hazard ratio, 2.15; 95% confidence interval, 1.14-4.06; P = .02), and PD-1-positive cells greater than 35.6 cells/high-power field (hazard ratio, 1.98; 95% confidence interval, 1.09-3.60; P = .03). These factors allowed construction of a risk score defining 3 distinct prognostic groups with 10-year overall survival of 85%, 60%, and 15%. PD-1-positive follicular helper T cells and CD68(+) extrafollicular lymphoma-associated macrophages appear to predict overall survival in follicular lymphoma, and our findings support strategies aimed at modulating their function in follicular lymphoma. Future studies, performed prospectively on uniformly treated patient cohorts, should be performed to validate these findings.

Primary central nervous system lymphoma: immunohistochemical profile and prognostic significance

Primary central nervous system lymphoma (PCNSL) is a rare subtype of non-Hodgkin lymphoma (NHL) with extranodal location affecting only the CNS, meninges and eye, without visceral or lymph node involvement. Its incidence has increased sharply over the past three decades, especially in immunocompetent subjects. Most PCNSL cases are diffuse large B-cell lymphomas (DLBCLs). However, it differs from nodal DLBCL in that it has a worse prognosis. DLBCLs are a heterogeneous entity and according to new genomic discoveries, classifications into prognostic subgroups have been embarked upon. Two prognostic algorithms were then prepared using a panel of immunohistochemical markers (CD10, Bcl6, MUM1/IRF-4, and Bcl2), thus categorizing DLBCL into two subgroups, GCB (germinal centre B-cell-like) or non-GCB, and into Group 1 or Group 2. Our goal is to apply both of these two sub-classifications to 39 PCNSLs, in order to assess their usefulness and prognostic relevance. 74.3% of our PCNSLs were of a non-GCB phenotype, corresponding to an activated postgerminal origin. They were evenly distributed across G1 and G2. Two- and 5-year overall survival rates were 34.8% and 19.6%, respectively. Younger age (<65) and a therapeutic combination of chemotherapy and radiotherapy significantly improved our patients' survival rates. The other clinical or biological markers tested had no prognostic impact. The two classifications did not reveal any significant survival difference. The recent discovery of a specific "transcriptional signature" of PCNSL, marking them out of DLBCL could account for the irrelevance of such prognostic classifications to PCNSL.

Prognostic significance of immunohistochemical classification of diffuse large B-cell lymphoma

AIM

To evaluate the clinical significance of immunoperoxidase staining for CD10, bcl-6, mum-1 and bcl-2 to subdivide DLBCL into prognostic subgroups, we analysed 50 DLBCL cases using immunohistochemical methods.

METHODS AND RESULTS

Fifty DLBCL patients were evaluated retrospectively. The expression of CD10 was associated with better OS (p=0.04) whereas expression of mum-1 was associated with worse OS (p=0.009). There were no significance of OS in case of expression of bcl-6 (p=0.05) and bcl-2 (p=0.3). They were subclassified using CD10, mum-1, bcl-6 as germinal center B-cell like (GCB) lymphoma (30%) and non-GCB lymphoma (70%). The OS and EFS (event free survival) were longer in GCB group (p=0.002) and 5-year OS for GCB group was 92% compared with only 44% for the non-GCB group (p=0.02). The OS of the GCB group also was longer compared to that of the non-GCB group in low IPI subgroup (p=0.01).

CONCLUSION

The existence of survival differences between GCB a non-GCB group also in the patients with low IPI score, showed the importance of prognostic classification in the risk-adaptive treatment approaches. The classification as GCB and non-GCB based immunostains may enable to define more accurate prognostic groups in DLBCL.

[Prognostic factors in patients with diffuse large B-cell lymphoma]

Diffuse large B-cell lymphoma is an aggressive type of lymphoma, potentially curable, with heterogeneous prognosis. The aim of this study was to determine prognostic significance of clinical, laboratory and immunohystochemical factors. The retrospective study was done in 50 patients with diffuse large B-cell lymphoma. The following parameters were investigated: demographic (age, sex), clinical (time to diagnosis, B symptoms, clinical stage), laboratory (erythrocyte sedimentarion rate, haemoglobin, lactate dehydrogenase, albumine), standard and revised international prognostic index, and immunohystochemical parameters, cluster designation 20, B-cell-2, and Ki67 expression. There were 20 females and 30 males, their average age being 54 (22-83) years. The majority of patients had advanced disease: B symptoms in 76%, III and IV stage in 78%, increased lactate dehydrogenase in 74%, high risk standard international prognostic index in 62% of patients. B-cell leukemia/lymphoma 2 expression was found in 57%, and high Ki67 in 62% of patients. Rituximab-Cyclophosphamnide, Hydroxydaunorubicin, Vincristine, Prednisolone and Rituximab-Cyclophosphamide, Hydroxydaunorubicin, Vincristine, Etoposide, Prednisolone were conducted in 72% (36), and Cyclophosphamide, Hydroxydaunorubicin, Vincristine, Prednisolone and Cyclophosphamide, Hydroxydaunorubicin, Vincristine, Prednisolone-like treatment in 28% (14) of patients. The complete remission rate was 74%, and the partial remission rate was 9%. A significant difference in survival was found between low intermediate and high intermediate S-IPI risk groups, good and bad risk R-IPI, and patients with complete remission and patients with other treatment responses. The other parameters, including Bcl-2 and Ki67 expression, and type of treatment did not show significant influence on survival. The expected five-year survival was 69%. Our results have shown that international prognostic index, and complete remission status have prognostic significance in diffuse large B-cell lymphomas.

Unique morphological spectrum of lymphomas in Nijmegen breakage syndrome (NBS) patients with high frequency of consecutive lymphoma formation

Nijmegen breakage syndrome (NBS) is an autosomal recessive disorder characterized by microcephaly, immunodeficiency, radiation hypersensitivity, chromosomal instability and increased incidence of malignancies. In Poland 105 NBS cases showing mutations in the NBS gene (nibrin, NBN), have been diagnosed, approximately 53% of which have developed cancer, mainly (>90%) lymphoid malignancies. This study is based upon the largest reported group of NBS-associated lymphomas. The predominant lymphoma types found in these 14 NBS children were diffuse large B cell lymphoma (DLBCL) and T cell lymphoblastic lymphoma (T-LBL/ALL), all showing monoclonal Ig/TCR rearrangements. The spectrum of NBS lymphomas is completely different from sporadic paediatric lymphomas and lymphomas in other immunodeficient patients. Morphological and molecular analysis of consecutive lymphoproliferations in six NBS patients revealed two cases of true secondary lymphoma. Furthermore, 9/13 NBS patients with lymphomas analysed by split-signal FISH showed breaks in the Ig or TCR loci, several of which likely represent chromosome aberrations. The combined data would fit a model in which an NBN gene defect results in a higher frequency of DNA misrejoining during double-strand break (DSB) repair, thereby contributing to an increased likelihood of lymphoma formation in NBS patients.

Malignant lymphomas (ML) and HIV infection in Tanzania

Background

HIV infection is reported to be associated with some malignant lymphomas (ML) so called AIDS-related lymphomas (ARL), with an aggressive behavior and poor prognosis. The ML frequency, pathogenicity, clinical patterns and possible association with AIDS in Tanzania, are not well documented impeding the development of preventive and therapeutic strategies.

Methods

Sections of 176 archival formalin-fixed paraffin-embedded biopsies of ML patients at Muhimbili National Hospital (MNH)/Muhimbili University of Health and Allied Sciences (MUHAS), Tanzania from 1996–2001 were stained for hematoxylin and eosin and selected (70) cases for expression of pan-leucocytic (CD45), B-cell (CD20), T-cell (CD3), Hodgkin/RS cell (CD30), histiocyte (CD68) and proliferation (Ki-67) antigen markers. Corresponding clinical records were also evaluated. Available sera from 38 ML patients were screened (ELISA) for HIV antibodies.

Results

The proportion of ML out of all diagnosed tumors at MNH during the 6 year period was 4.2% (176/4200) comprising 77.84% non-Hodgkin (NHL) including 19.32% Burkitt's (BL) and 22.16% Hodgkin's disease (HD). The ML tumors frequency increased from 0.42% (1997) to 0.70% (2001) and 23.7% of tested sera from these patients were HIV positive. The mean age for all ML was 30, age-range 3–91 and peak age was 1–20 years. The male:female ratio was 1.8:1. Supra-diaphragmatic presentation was commonest and histological sub-types were mostly aggressive B-cell lymphomas however, no clear cases of primary effusion lymphoma (PEL) and primary central nervous system lymphoma (PCNSL) were diagnosed.

Conclusion

Malignant lymphomas apparently, increased significantly among diagnosed tumors at MNH between 1996 and 2001, predominantly among the young, HIV infected and AIDS patients. The frequent aggressive clinical and histological presentation as well as the dominant B-immunophenotype and the HIV serology indicate a pathogenic association with AIDS. Therefore, routine HIV screening of all malignant lymphoma patients at MNH is necessary to enable comprehensive ARL diagnosis and formulation of preventive and therapeutic protocols.

BNIP3 expression in follicular lymphoma

AIMS

To investigate the role of BNIP3, a 19-kDa interacting protein of the Bcl-2 family, alongside Bcl-2 in follicular lymphoma in comparison with reactive lymphoid hyperplasia. The results were compared with those from p53 and caspase-3 (apoptotic markers) and Ki67 (proliferation marker).

METHODS AND RESULTS

Immunohistochemistry using monoclonal antibodies showed BNIP3 to be strongly expressed in most follicular lymphomas but to be weak to negative in all of the reactive cases. There was also an inverse relationship with Bcl-2 expression. There was no correlation of BNIP3 immunoreactivity with proliferation and caspase and p53 were virtually negative in all follicular lymphomas and reactive lymphoid cases.

CONCLUSIONS

BNIP3 is strongly expressed in most follicular lymphomas, especially those that are Bcl-2 negative. BNIP3 may serve as a marker of more aggressive behaviour in follicular lymphoma and be useful diagnostically in the distinction from reactive lymphadenitis.

Utility of SKP2 and MIB-1 in grading follicular lymphoma using quantitative imaging analysis

Follicular lymphoma is classified into grades (G)1, 2, and 3 based on the number of centroblasts in neoplastic follicles. However, the accuracy of manually counting these centroblasts is limited by certain cells (large centrocytes, follicular dendritic cells, and histiocytes) that could mimic centroblast morphology. The reproducibility of follicular lymphoma grading is dependent upon observer experience; therefore, significant variations occur. This study is to explore a more objective, reliable way of grading follicular lymphoma using a quantitative imaging system in conjunction with immunostains with antibodies to proliferation markers MIB-1 and S-phase kinase-associated protein 2 (SKP2). Fifty-eight follicular lymphomas (G1, n = 23; G2, n = 18; and G3, n = 17) were studied on formalin-fixed, paraffin-embedded sections. Positive nuclear staining of both Ki-67 and SKP2 was recorded using the quantitative Clarient ACIS II system (Aliso Viejo, CA, USA). Ten high-power fields (x400) from randomly selected neoplastic follicles were counted by a pathologist blinded to the previously assigned morphologic grade. The results show that the percentages of Ki-67+ and SKP2+ cells significantly differ among the different grades of follicular lymphoma. A higher grade of follicular lymphoma is associated with a higher percentage of Ki-67+ and SKP2+ cells. The overall SKP2+% cells are substantially lower than Ki-67+% cells in the same grade of follicular lymphoma. Statistical significance is observed in Ki-67+ cells between follicular lymphoma G1 and follicular lymphoma G3 and between G1 and G2. In contrast, statistical significance is noted in SKP2+% cells between follicular lymphoma G1 and follicular lymphoma G3 and between follicular lymphoma G2 and follicular lymphoma G3. The findings suggest that the SKP2 expression has better discrimination with grades of follicular lymphoma than Ki-67 expression. Compared with traditional methods, quantitation of SKP2 expression using a quantitative image analysis system might be a useful and objective approach in grading follicular lymphoma.

Ki-67 proliferative marker in lymph node aspirates of patients with non-Hodgkin's lymphoma

Proliferative activity of lymphoma cells was tested by immunocytochemical staining with Ki-67 monoclonal antibody in 63 aspirates of peripheral lymph nodes sampled from patients suffering from non-Hodgkin's lymphoma. Referring to the dominant cell population in nodal aspirates, a rising trend of Ki-67 proliferative marker was noted from the small cells (X = 13.20) and small cells with notched nucleus (X = 43.52) and large cells (X = 79.47) with histopathologic equivalents corresponding to aggressive lymphoma. Statistical testing of the difference in the Ki-67 proliferative marker against demographic and clinical-laboratory characteristics of the studied patients revealed the levels of significance for the performance status, bone marrow infiltration, and albumin serum value. Correlation of cytomorphological and immunocytochemical results was tested against International Prognostic Index (IPI). Statistically significant correlation of Ki-67 with cytomorphology and REAL-immunocytochemical classification of lymphoma was confirmed, but not with the IPI index. In order to determine the prognostic importance of Ki-67 marker, the patients were classified into those with low Ki-67 (<20% of proliferating cells), mean proliferation index Ki-67 (range 20-59%), and high proliferative index Ki-67 (positive in over 60% of lymphoma cells). Testing Ki-67 with survival we have found that the low proliferative index was associated with the longest survival, median about 36 mo; for proliferative marker values ranging between 20 and 59%, the median survival was 30.4 mo; and survival of patients with the high proliferative index was only 12.9 mo.

Ki67 staining pattern as a diagnostic tool in the evaluation of lymphoproliferative disorders

AIMS

To evaluate a group of lymphoid proliferations using only Ki67-stained slides to determine the value of the pattern of proliferating cells in diagnosis. Ki67 immunohistochemistry allows evaluation of the distribution of proliferating cells in addition to simply determining the proliferation rate of cells.

METHODS AND RESULTS

Three observers, using a Ki67-stained slide only, studied 149 cases from five diagnostic groupings: follicular hyperplasia, mixed pattern hyperplasia, localized Castleman's disease, follicular lymphoma and marginal zone lymphoma. The sensitivity for benign lesions varied from 94% to 97% among the three observers. Follicular lymphomas were recognized as neoplastic with a sensitivity of 96% and 100% by two of the observers. Marginal zone lymphoma was recognized as neoplastic in 67-73% of cases.

CONCLUSIONS

The Ki67 stain alone is a powerful tool for distinguishing benign from malignant proliferations within the selected groups. Nuances and pitfalls in the interpretation of Ki67 staining pattern are discussed.

Immunohistochemical Expression of p53, bcl-2, and p21 waf1 in 48 Argentinean Children With Non-Hodgkin Lymphoma

BACKGROUND

Lymphoma accounts for 10% of all childhood cancers in developed countries. In Argentina, the incidence is 13.6%; of these, 53% are non-Hodgkin lymphomas (NHL) and 47% are Hodgkin lymphomas. Overexpression of p53, p21, and bcl-2 has been studied mainly in adults with NHL and correlated with clinical features and survival. The authors' aim was to analyze overexpression of these cellular oncogenes in children with NHL.

METHODS

Formalin-fixed paraffin-embedded lymph node biopsies from 48 children with NHL were studied by immunohistochemistry with monoclonal antibodies for p53, bcl-2, and p21.

RESULTS

Overexpression of p53 was detected in 81% of cases; bcl-2 positivity was 46% and p21 positivity was 42%. The p53/p21 expression patterns (types IV and V patterns), which correspond to the overexpression of nonfunctional p53, accounted for 46% of NHL. None of the studied oncogene patterns correlated with poor clinical patient outcome or histologic subtype.

CONCLUSIONS

Of 81% of cases with p53 overexpression, 46% exhibited a nonfunctional p53 pattern, and this may contribute to dysregulation of proliferation, bcl-2 expression in up to 46% of cases may reflect a failure of bcl-2 downregulation in pre-B and immature B cells.

Low histologic grade follicular lymphoma with high proliferation index: morphologic and clinical features

Histologic grading has been used as a guide for clinical management in follicular lymphoma (FL). Proliferation index (PI) of FL generally correlates with tumor grade; however, in cases of discordance, it is not clear whether histologic grade or PI correlates with clinical aggressiveness. To objectively evaluate these cases, we determined PI by Ki-67 immunostaining in 142 cases of FL (48 grade 1, 71 grade 2, and 23 grade 3). A total of 24 cases FL with low histologic grade but high PI (LG-HPI) were identified, a frequency of 18%. On histologic examination, LG-HPI FL often exhibited blastoid features. Patients with LG-HPI FL had inferior disease-specific survival but a higher 5-year disease-free rate than low-grade FL with concordantly low PI (LG-LPI). However, transformation to diffuse large B-cell lymphoma was uncommon in LG-HPI cases (1 of 19; 5%) as compared with LG-LPI cases (27 of 74; 36%). In conclusion, LG-HPI FL appears to be a subgroup of FL with clinical behavior more akin to grade 3 FL. We propose that these LG-HPI FL cases should be classified separately from cases of low histologic grade FL with concordantly low PI.

Expression of minichromosome maintenance protein 2 as a marker for proliferation and prognosis in diffuse large B-cell lymphoma: a tissue microarray and clinico-pathological analysis

Background

Minichromosome maintenance (MCM) proteins are essential for the initiation of DNA replication and have been found to be relevant markers for prognosis in a variety of tumours. The aim of this study was to assess the proliferative activity of diffuse large B-cell lymphoma (DLBCL) in tissue microarray (TMA) using one of the minichromosome maintenance proteins (Mcm2) and to explore its potential value to predict prognosis.

Methods

Immunohistochemistry for Mcm2 was performed on TMAs constructed from 302 cases of DLBCL. A monoclonal mouse antibody was used after heat induced antigen retrieval. Mcm2 expression was scored quantitatively. Positivity for Mcm2 was defined as presence of nuclear expression of Mcm2 in greater than or equal to 40 % of tumour cells. A statistical analysis was carried out of the association of Mcm2 and the clinico-pathological characteristics.

Results

Mcm2 expression was clearly evident in the nuclei of proliferating non-neoplastic cells and tumour cells. Positivity for Mcm2 was found in 46% (98/211) of analysable cases. A significant correlation existed between Mcm2 expression and presence of bulky disease (p = 0.003). Poor disease specific survival was observed in patients with DLBCL positive for Mcm2 expression in the univariate analysis (p = 0.0424).

Conclusion

Mcm2 expression can be used to assess tumour proliferation and may be useful as an additional prognostic marker to refine the prediction of outcome in DLBCL.

Expression of PKC-beta or cyclin D2 predicts for inferior survival in diffuse large B-cell lymphoma

We sought to determine whether identification of poor-risk subgroups of diffuse large B-cell lymphoma (DLBCL) using immunohistochemical stains would have practical utility with regard to prognosis and therapeutic decisions. Tissue microarray blocks were created using replicate samples of formalin-fixed, paraffin-embedded tissue from 200 cases of de novo DLBCL. The sections were stained with antibodies to proteins that are expressed by activated or proliferating B cells including MUM1, FOXP1, bcl-2, survivin, protein kinase C-beta (PKC-beta), cyclin D2, cyclin D3, and Ki-67. In univariate analysis, tumor expression of cyclin D2 (P = 0.025) or PKC-beta (P = 0.015) was associated with a worse overall survival, whereas none of the other markers was predictive of overall survival. Patients with DLBCL that expressed either cyclin D2 or PKC-beta had a 5-year overall survival of only 30% as compared to 52% for those who were negative for both markers (P = 0.0019). In multivariate analysis, the expression of cyclin D2 or PKC-beta was an independent predictor of poor overall survival (P = 0.035). Cyclin D2 and PKC-beta expression will be useful in designing a 'biological prognostic index' for patients with DLBCL.

Primary breast diffuse large B-cell lymphoma shows a non-germinal center B-cell phenotype

Primary breast diffuse large B-cell lymphoma has a poor prognosis relative to other extranodal diffuse large B-cell lymphoma. Recently, diffuse large B-cell lymphoma has been subclassified as germinal center B-cell-like and nongerminal center B-cell types using tissue microarrays. The 5-year overall survival rate of the germinal center B-cell group is better than that of the nongerminal center B-cell group. To elucidate the reason for which primary breast diffuse large B-cell lymphoma has a poor clinical outcome, we investigated 15 patients with primary breast diffuse large B-cell lymphoma (stage IE; 13 cases, stage IIE; two cases) by immunohistochemistry using various markers including CD10, Bcl-6, MUM1 and MIB-1 and by molecular analysis of the immunoglobulin heavy chain gene variable region. Immunohistochemistry showed 0/15 (positive cases/examined cases) for CD10, 5/15 for Bcl-6, 15/15 for MUM1, 10/15 for Bcl-2, 2/15 for CD5 and 4/15 for CD40. The expression pattern of CD10(-) MUM1(+) in primary breast diffuse large B-cell lymphoma corresponded to the nongerminal center B-cell group. Moreover, the MIB-1 index was distributed from 60 to 95% with a mean of 79%, indicating a high proliferation of the lymphoma cells. The immunoglobulin heavy chain gene variable region of primary breast diffuse large B-cell lymphoma had a mutation frequency of 1-10% (seven cases) and 0-1 additional mutations in ongoing mutation analysis (five cases). Primary breast diffuse large B-cell lymphoma had characteristics of the nongerminal center B-cell group. In conclusion, primary breast diffuse large B-cell lymphoma has a nongerminal center B-cell phenotype and has a high MIB-1 index. These features might therefore be associated with poor prognosis.

High expression of cyclin B1 predicts a favorable outcome in patients with follicular lymphoma

Substantial research has been dedicated to the study of the relationship between genetic mechanisms regulating cell functions in tumors and how those tumors respond to various treatment regimens. Because these mechanisms are still not well understood, we have chosen to study the genetic makeup of 57 tumor samples from patients with follicular lymphoma (FL). Our goal was to develop a prognostic tool, which can be used as an aid in determining FL patients with tumors genetically predisposed to a successful treatment with the CHOP (cyclophosphamide, vincristine, doxorubicin, prednisone) regimen. To select relevant genes, high-density oligonucleotide arrays were used. There were 14 genes highly expressed in FL patients that responded well to CHOP chemotherapy, and 11 of these were involved in G2/M transition of the cell cycle, in mitosis, or in DNA modulation. A high expression of CCNB1 (cyclin B1), CDC2, CDKN3A, CKS1B, ANP32E, and KIAA0101, but not of the proliferation-related antigen Ki-67, was associated with better survival rate in a univariate analysis. CCNB1 expression had an independent prognostic value when included in a multivariate analysis together with the 5 parameters of the follicular lymphoma international prognostic index.

Efficacy of rituximab plus chemotherapy in follicular lymphoma depends on Ki-67 expression

Rituximab is widely used for the treatment of B-cell non-Hodgkin's lymphoma (NHL), and encouraging results have been obtained. However, some CD20-positive NHL show minimal response to rituximab, indicating that the treatment effect depends on the presence or absence of an unidentified factor. We analyzed the relationship between the effect of rituximab plus chemotherapy and expression of Ki-67, p53 and bcl-2 and several clinical variables in cases of B-NHL, particularly follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL). Forty-four patients were included in the present study, and the overall treatment response rate was 68%. Twelve of 30 patients (40%) achieved a complete response, five (16%) reached an unconfirmed complete response and 13 (43%) achieved a partial response. A high serum lactate dehydrogenase level and International Prognostic Index of high or high intermediate risk were associated with a decreased response in the case of FL. Immunohistochemical assays were performed in 18 FL patients (55%) and 15 DLBCL patients (45%). Significant correlation was found between an inferior response to treatment and high Ki-67 expression in the cases of FL (P = 0.006). p53 and bcl-2 expression did not correlate significantly with the response rate. The cell cycle appears to be an important factor in the efficacy of rituximab treatment. Ki-67 expression might be a predictor of efficacy of rituximab plus chemotherapy.

Disappearance of CD21-positive follicular dendritic cells preceding the transformation of follicular lymphoma: immunohistological study of the transformation using CD21, p53, Ki-67, and P-glycoprotein

Some follicular lymphomas histologically transform into diffuse aggressive lymphomas, the prognosis of which is poor. There are, however, no reliable histological criteria for predicting which cases will later undergo such transformation. In low-grade B-cell lymphomas, follicular dendritic cells form dense mesh-like networks that contain accumulating neoplastic B-cells. These are rare in high-grade lymphomas. We immunohistochemically analyzed CD21-positive follicular dendritic cells in 32 follicular lymphomas, including 3 transformed lymphomas, in addition to immunohistological study using P-glycoprotein, p53, and Ki-67. We found that the mesh-like networks in follicles are more clearly defined in low-grade lymphomas than in high-grade lymphomas (p = 0.015). Neoplastic follicles in 2 transformed lymphomas lost the networks of follicular dendritic cells before transformation despite the existence of morphologically clear follicles. This differed from the non-transformed cases of the same cytological grades. Prognosis was statistically better for patients with low-grade tumor than for those with high-grade tumor (p = 0.026), and there was a trend toward poorer survival among CD21-negative cases (p = 0.186). P-glycoprotein, p53, and Ki-67 expressions did not provide sufficient information to predict the transformation of follicular lymphoma. The presence of CD21-positive follicular dendritic cells in neoplastic follicles might help predict the potential of follicular lymphoma to transform to diffuse large B-cell lymphoma.

Prognostic significance of the F-box protein Skp2 expression in diffuse large B-cell lymphoma

The F-box protein Skp2 positively regulates the G1-S transition by promoting degradation of the cyclin-dependent kinase inhibitor p27(kip1) (p27). Recent evidence has suggested an oncogenic role of Skp2 in not only carcinogenesis but also lymphomagenesis. In this study, we performed immunohistochemical analysis on the cell-cycle-associated proteins, Skp2, p27, and Ki-67, in 27 patients with de novo diffuse large B-cell lymphoma (DLBCL), evaluating the correlation between the clinical characteristics and expression levels of these proteins. The patients were classified into two groups according to the positivity for Skp2 expression: a high Skp2 expression group (>60% positive for Skp2 in lymphoma cells) and a low Skp2 expression group (< or = 60%). A high level of Skp2 expression significantly correlated with advanced clinical stage (P = 0.029), although the increase did not correlate with age, gender, LDH levels, presence of extranodal disease, or performance status and resulted in no correlation with the International Prognostic Index-based risk grading. However, it was noteworthy that the high Skp2 expression group demonstrated a significantly worse prognosis than the low Skp2 expression group (P = 0.0007). The expression level of Skp2 correlated with that of Ki-67 but not necessarily with that of p27. The p27 expression level did not correlate patients' prognosis. Taken together, it was suggested that Skp2 was a valuable and independent marker predicting the outcome in DLBCL.

Cdc2 Expression in Primary Thyroid Lymphoma: Its Relationship with Biological Aggressiveness and G2 Cyclins

Previous studies have demonstrated that the G2-M modulators contribute to the progression of human neoplasms. In this study, we investigated the expression of these modulators, cyclin-dependent kinase 1 (cdc2), and G2 cyclins, cyclin A and cyclin B1, in primary thyroid lymphoma. Cdc2 immunoexpression was observed in 51.0% of the 49 cases examined and was related to grade of malignancy, high Ki-67 labeling index, and aberrant p53 expression. The incidences of immunoexpression of cyclin A and cyclin B1 were 63.3% and 40.9%, respectively, and they were also related to the above three parameters. Furthermore, a correlation was found between the immunoexpression of cdc2 and G2 cyclins. These findings suggest that the cdc2 and G2 cyclins play an important role in the progression of thyroid malignant lymphoma.

Follicular lymphoma in Osaka, Japan: histological features and chronological change

Follicular lymphoma (FL) is defined as a neoplastic proliferation of follicle center cells with varying follicular areas. To learn the time trend of FL in the Osaka area, an adult T-cell leukemia/lymphoma (ATL) nonendemic area of Japan, we examined the frequency of FL among all non-Hodgkin's lymphomas (NHLs) during the period 1964 to 1987 (n = 1,000) and 1999 to 2001 (n = 659). The frequency of FL with varying follicular areas increased from 1964-1987 to 1999-2001. There was a significant difference in frequency of total cases of FL (14.2% versus 18.8%) (P < .05) and FL with no to 25% follicular area (2.3% versus 5.0%) (P < .01). According to the Berard criteria, cytologic grade of FL was defined by counting the number of centroblasts (CB) in 10 neoplastic follicles as follow: < or = 5 CB per high power field (HPF), grade 1; 6-15 CB, grade 2; >15 CB, grade 3. Immunohistochemical staining with monoclonal antibodies for bcl-2 and CD10 was performed. There was an inverse correlation between follicular area and cytological grade (P < .0001) and bcl-2 expression and cytological grade (P < .01). That is, the larger the follicular area in cases with a lower cytological grade, the stronger was bcl-2 expression in a lower cytological grade. There was a significant correlation between follicular area and stage of disease (P < .05). That is, the follicular area was larger in cases in an advanced stage. This study showed the increase in frequency of FL in Osaka, Japan. Change of lifestyle in Japan may be one of the causative factors for the increase.