Background and purpose: Primary central nervous system lymphoma (PCNSL) is a rare aggressive type of non-Hodgkin's lymphoma that occurs in the brain

spinal cord

meninges or eyes

without parts outside of central nervous system (CNS) involvement. Compared with other types of lymphoma

PCNSL has shorter survival time

poor prognosis and high recurrence rate. The median survival time of untreated patients is only 3 months. In recent years

studies have found that C-MYC

BCL-2

BCL-6

Ki-67 and other indicators affect the prognosis of PCNSL patients to a certain extent. Therefore

this study analyzed the effects of PCNSL-related protein expression

treatment methods and other clinical factors on the prognosis of patients

hoping to accumulate data for the clinical treatment and prognosis evaluation of the disease. Methods: In this study

we performed a retrospective analysis of the clinical data of 42 patients with primary central nervous system diffuse large B-cell lymphoma treated in the Second Affiliated Hospital of Dalian Medical University from June 2013 to May 2021

including gender

age

number of lesions

Eastern Cooperative Oncology Group (ECOG) score

serum lactate dehydrogenase (LDH)

whether the lesion involves deep brain tissue

treatment plan

pathological Hans classification and C-MYC

BCL-2

BCL-6

Ki-67 and other biomarkers

combined with follow- up investigation

to understand the survival time and survival status of patients. Kaplan-Meier method and log-rank test were used to analyze the prognostic factors affecting progression-free survival (PFS) and overall survival (OS). COX regression model was used in multivariate analysis. Results: The median age of onset in 42 patients with PCNSL was 61 years

and the male to female ratio was 1.33:1.00. Most of the brain-enhanced magnetic resonance imaging (MRI) lesions showed homogeneous and obvious enhancement. All patients received chemotherapy with high-dose methotrexate (HD-MTX) regimen. After treatment

there were 20 cases of complete response (CR)

5 cases of partial remission (PR)

11 cases of stable disease (SD) and 6 cases of progressive disease (PD). The median PFS was 21 months

the median OS was 34 months

the 1-year PFS rate was 63.7%

the 2-year PFS rate was 47.0%

the 1-year OS rate was 70.8%

and the 2-year OS rate was 55.6%. Univariate analysis showed that the factors affecting PFS were HD-MTX multidrug combination chemotherapy

intrathecal chemotherapy and combined rituximab. The factors affecting OS were ECOG score ≥2

C-MYC (+)

BCL-2 and C-MYC double expression

HD-MTX multidrug combination chemotherapy

intrathecal chemotherapy and combined rituximab. Multivariate analysis showed that rituximab treatment was an independent prognostic factor for PFS (P=0.020)

while ECOG score and rituximab were independent prognostic factors for OS (P=0.007

P=0.046). The median PFS and OS of patients receiving consolidation therapy were higher than those of patients without consolidation therapy

and further subgroup analysis showed that the median PFS and OS of autologous stem cell transplantation (ASCT) group were higher than those of whole brain radiotherapy (WBRT) group

however there was no significant statistical difference. Conclusion: PCNSL occurs mostly in middle-aged and elderly people

more men than women without specific imaging characteristics. ECOG score ≥2 is associated with poorer OS in PCNSL patients. C-MYC (+) and dual expression of BCL-2 and C-MYC can be used as prognostic markers to guide risk stratification. HD-MTX-based multidrug combination chemotherapy has become the first choice for the treatment of PCNSL

and the application of rituximab can prolong survival. Systemic chemotherapy combined with local intrathecal chemotherapy can improve the prognosis. Further consolidation treatments mainly include ASCT and WBRT

which can prolong PFS and OS. ASCT can achieve similar curative effects as WBRT and avoid the late neurotoxicity of WBRT. However

due to the limitations of sample size and follow-up time

no clear statistical results have been obtained in this study.