High Ki67 proliferation index but not cell-of-origin subtypes is associated with shorter overall survival in diffuse large B-cell lymphoma

Expression and Clinical Significance of ki-67, CD10, BCL6, MUM1, c-MYC, and EBV in Diffuse Large B Cell Lymphoma Patients

INTRODUCTION

Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL) in adults. Although studies regarding the association between the expression of Ki-67, CD10, BCL6, and MUM1 proteins, as well as c-MYC amplification and EBV status with clinicopathologic characteristics have rapidly progressed, their co-expression and prognostic role remain unsatisfactory. Therefore, this study aimed to investigate the association between the expression of all markers and clinicopathologic features and their prognostic value in DLBCL. Also, the co-expression of markers was investigated.

METHODS

The protein expression levels and prognostic significance of Ki-67, CD10, BCL6, and MUM1 were investigated with clinical follow-up in a total of 53 DLBCL specimens (including germinal center B [GCB] and activated B cell [ABC] subtypes) as well as adjacent normal samples using immunohistochemistry (IHC). Besides, the clinical significance and prognostic value of c-MYC and EBV status were also evaluated through chromogenic in situ hybridization (CISH), and their correlation with other markers was also assessed.

RESULTS

The results demonstrated a positive correlation between CD10 and BCL6 expression, with both markers being associated with the GCB subtype (P<0.001 and P=0.001, respectively). Besides, we observe a statistically significant association between MUM1 protein expression and clinicopathologic type (P<0.005) as well as a positive association between c-MYC and recurrence (P=0.028). Our survival analysis showed that patients who had responded to R-CHOP treatment had better overall survival (OS) and progression-free survival (PFS) than those who did not.

CONCLUSION

Collectively, this study's results add these markers' value to the existing clinical understanding of DLBCL. However, further investigations are needed to explore markers' prognostic and biological roles in DLBCL patients.

FAT1 inhibits the proliferation of DLBCL cells via increasing the m6A modification of YAP1 mRNA

Emerging evidence shows that FAT atypical cadherin 1 (FAT1) mutations occur in lymphoma and are associated with poorer overall survival. Considering that diffuse large B cell lymphoma (DLBCL) is the category of lymphoma with the highest incidence rate, this study aims to explore the role of FAT1 in DLBCL. The findings demonstrate that FAT1 inhibits the proliferation of DLBCL cell lines by downregulating the expression of YAP1 rather than by altering its cellular localization. Mechanistic analysis via meRIP-qPCR/luciferase reporter assays showed that FAT1 increases the m6A modification of YAP1 mRNA 3'UTR and the subsequent binding of heterogeneous nuclear ribonucleoprotein D (HNRNPD) to the m6A modified YAP1 mRNA, thus decreasing the stability of YAP1 mRNA. Furthermore, FAT1 increases YAP1 mRNA 3'UTR m6A modification by decreasing the activity of the TGFβ-Smad2/3 pathway and the subsequent expression of ALKBH5, which is regulated at the transcriptional level by Smad2/3. Collectively, these results reveal that FAT1 inhibits the proliferation of DLBCL cells by increasing the m6A modification of the YAP1 mRNA 3'UTR via the TGFβ-Smad2/3-ALKBH5 pathway. The findings of this study therefore indicate that FAT1 exerts anti-tumor effects in DLBCL and may represent a novel target in the treatment of this form of lymphoma.

The significance of upfront autologous stem cell transplantation for high-intermediate/high-risk stage IV diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common (30%-35%) type of B-cell lymphoma. Only about 60% of all newly diagnosed advanced-stage DLBCL can be completely treated with x6 R-CHOP. High-dose chemotherapy (HDCT) followed by autologous hematopoietic stem cell transplantation in the first remission (upfront auto-HSCT) can serve as an option to improve a prognosis in these patients.

AIMS

This trial aimed to improve prognosis in DLBCL by upfront auto-HSCT.

METHODS AND RESULTS

A group of 105 patients: DLBCL NOS, age 18-65, stage IV, IPI ≥2, CR/PR after x6 R-CHOP/DA-EPOCH-R from 2010 to 2019 at NMRC of Oncology named after N.N.Petrov of MoH of Russia was retrospectively analyzed. The HSCT group included patients with upfront HDCT followed by auto-HSCT (n = 35). The control group included patients with non-invasive follow-up after induction (n = 70). Primary endpoint was progression-free survival (PFS). Secondary endpoints were overall survival (OS), response rate and relapse rate. The 3-year OS (p = .013) and 3-year PFS (p = .033) were significantly higher in the HSCT group. The 3-year OS was decreased by the occurrence of relapse (p ≤ .001) and weight loss (B-symptom) (p = .04). DEL was the negative prognostic factor for 3-year PFS in all patients (p = .001) and control group (p = .001). DA-EPOCH-R significantly increased the 3-year PFS (p = .041).

CONCLUSION

Upfront HDCT followed by auto-HSCT can increase 3-year OS and PFS and improve prognosis in DLBCL NOS, age 18-65, stage IV, IPI ≥2 patients.

[Clinical features and prognosis of 166 cases of MYC/BCL2 double-expression diffuse large B-cell lymphoma]

Objective: To investigate the clinical features and prognosis of MYC/BCL2 double-expression diffuse large B-cell lymphoma (DEL) . Methods: The clinical data, including clinical characteristics, survival, and prognostic factors, of 166 patients with DEL treated at Peking University Third Hospital from January 2016 to December 2020 were retrospectively analyzed. Results: A total of 410 patients with diffuse large B-cell lymphoma were collected, including 166 cases (40.5%) of DEL. There were 82 males and 84 females with a median age of 63.5 (21-95) years at diagnosis. A total of 110 patients (66.3%) were aged over 60 years at initial diagnosis, 106 patients (106/163, 65.0%) had elevated lactate dehydrogenase (LDH) at diagnosis, 74 patients (74/160, 46.2%) had β(2) microglobulin level over 3 mg/L at diagnosis, and 107 patients (107/163, 65.6%) had≥2 extranodal involvement. Sixty-five patients (65/166, 39.2%) had B symptoms, 131 patients (131/165, 79.4%) had stage Ⅲ and Ⅳ disease at initial diagnosis, 41 patients (41/161, 25.5%) had an International Prognostic Index (IPI) score of 0-2 at initial diagnosis, and 38 patients (38/161, 23.6%) had an IPI score of 3 at initial diagnosis. Eighty-two patients (82/161, 50.9%) had an IPI score of 4-5 at initial diagnosis. Nine (9/56, 16.1%) patients with DEL had MYD88 and CD79B mutations. Univariate analysis showed that age over 60 years (P=0.004) , increased β(2) microglobulin level (P=0.002) , and high IPI score (P=0.003) were associated with poor overall survival (OS) . Increased β(2) microglobulin level (P=0.031) , LDH level (P=0.017) , stage Ⅲ-Ⅳ (P=0.001) , high IPI score (P=0.013) , immunohistochemical p53 mutation (P=0.049) , and PIM1 mutation (P=0.039) were associated with poor progression-free survival (PFS) . Multivariate analysis showed that IPI score of 4-5 was an independent risk factor for the prognosis of DEL (HR=2.622, 95% CI 1.398-4.917, P=0.003) . Survival analysis showed that there was a significant difference in the PFS between patients with DEL and those without DEL (65.6% vs 75.1%, P=0.002) . However, there was no significant difference in the OS (81.8% vs 83.6%, P=0.226) . In patients with DEL, the overall response rate of R-EPOCH regimen was higher than that of RCHOP or RCHOP-like regimen (81.5% vs 63.4%, P=0.004) . Conclusion: DEL is a group of aggressive lymphomas with relatively poor PFS. The R-EPOCH regimen may improve the overall prognosis of patients.

Ki67 Proliferation Index in Germinal and Non-Germinal Subtypes of Diffuse Large B-Cell Lymphoma

Introduction

Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma. The 2016 World Health Organization (WHO) update on hematopoietic tumors suggested that all DLBCL cases should be subtyped into germinal and non-germinal center phenotypes. Ki67 immunohistochemistry is a maker of cell proliferation and thus is used as a prognostic and predictive marker in various tumors of human body. Only a few studies evaluated the proliferative index of DLBCL subtypes in our population. Therefore, in this study, we evaluated the frequency of subtypes of DLBCL in our population and K67 index in each subtype.

Methods

A retrospective observational study was conducted in the Department of Histopathology, Liaquat National Hospital and Medical College, from January 2018 till December 2020, over a period of three years. A total of 101 cases with a histopathological diagnosis consistent DLBCL were included in the study. Immunohistochemical (IHC) stains CD10, B-cell lymphoma 6 (Bcl-6), and multiple myeloma oncogene 1 (MUM1) were applied for the further sub-categorization of DLBCL into germinal center B-cell-like (GCB) and non-GCB subtypes according to the Hans algorithm. The Ki67 index was interpreted in hot spots of the tumor and reported as an average percentage.

Results

Out of 101 DLBCL cases, 47.5% of DLBCL were GCB, while 52.5% were non-GCB subtypes. Bcl-2, Bcl-6, MUM1, c-Myc, CD10, and CD30 expression were noted in 62.4%, 45.5%, 42.6%, 44.6%, 39.6%, and 7.9% cases, respectively. The mean Ki67 index was 72.94±16.69%. The mean Ki67 index in non-GCB-type DLBCL was 77.67±14.80%, which was significantly higher than the mean Ki67 index in GCB-type DLBCL (67.70±17.22%) with a significant p-value (p=0.002). Cervical lymph node was the most common site of DLBCL, while the stomach was the most common extra-nodal site. A significant association of Ki67 index was noted with subtypes of DLBCL. A higher proportion of non-GCB-type DLBCL exhibited greater than 80% Ki67 index than GCB subtype DLBCL. Moreover, a significant association Ki67 index was noted with c-Myc positivity. A higher proportion of c-Myc-positive DLBCL had greater than 80% Ki67 index.

Conclusion

We found that non-GCB-type DLBCL had a higher Ki67 index than GCB subtype DLBCL, portending a poor prognostic significance of non-GCB subtype of DLBCL. Moreover, c-Myc expression was associated with a higher Ki67 index.