[Survival of patients with primary central nervous system diffuse large B-cell lymphoma: impact of gene aberrations and protein overexpression of bcl-2 and C-MYC, and selection of chemotherapy regimens].

Objective: To investigate the impact of clinicopathological features, gene rearrangements and protein expression of bcl-6, bcl-2, C-MYC and chemotherapy regime on the prognosis of patients with primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: Thirty-three cases of PCNS-DLBCL diagnosed from January 2006 to December 2016 at Zhejiang Cancer Hospital were collected. The expression of CD10, bcl-6, bcl-2, MUM1 and MYC were detected by immunohistochemical staining (IHC). The presence of EB virus was detected by in situ hybridization(EBER). Copy number variation (ICN) and translocation status of bcl-6, bcl-2 and C-MYC genes were detected by fluorescence in situ hybridization (FISH). The relationship between the above indexes and the prognosis was analyzed by univariate, bivariate survival analysis and multiple Cox hazard regression analysis. Results: The study included 33 patients of PCNS-DLBCL, without evidence of primary or secondary immunodeficient disease. Male to female ratio was 1.36∶1.00, and the average age was 56 years. Twenty cases had single lesion while 13 had multiple lesions. Deep brain involvement was seen in 12 cases. All patients underwent partial or total tumor resection. Five patients received whole brain post-surgery radiotherapy, nine patients received high-dose methotrexate (HD-MTX) based chemotherapy, and 12 patients received whole-brain radiotherapy combined with HD-MTX based chemotherapy. Severn patients received no further treatment and rituximab was used in 8 patients. According to the Hans model, 27 cases were classified as non-GCB subtypes (81.8%). Bcl-2 was positive in 25 cases (75.8%, 25/33) and highly expressed in 8 (24.2%). MYC was positive in 12 cases (36.4%) and double expression of bcl-2 and MYC was seen in 6 cases. EBER positive rate was 10.0%(3/30), all of which had multiple lesions. Two bcl-6 gene translocations and 3 amplifications were found in 28 patients. Two translocations, 3 ICN or with both bcl-2 gene translocation and ICN were found in 30 patients. Four ICNs of C-MYC gene were found in 28 patients. Elevated protein in cerebrospinal fluid (CSF) was found in 13 patients. LDH increased in 10 cases. Follow-up period was 2-90 months with the average survival time of (23.0±3.7) months and two-year survival rate of 39.0%. Univariate survival analysis showed that overexpression of bcl-2 protein (≥70%) and MYC protein (≥40%), bcl-2 gene abnormality (including copy number increase and translocation), C-MYC gene copy number increased were adverse factors for survival. C-MYC/ bcl-2 gene double hit was seen in 2 cases. Bivariate survival analysis found that of bcl-2/MYC protein double expression and bcl-2 and C-MYC genes double aberration were significantly associated with adverse outcomes. Cox multivariate risk regression analysis found that gender, cerebrospinal fluid protein increasing, and ICN of C-MYC gene were independent poor prognostic factors. DH-MTX based comprehensive chemotherapy was associated with better prognosis. Conclusions: Double hit at genomic level (copy number variations and gene rearrangements) and double protein expression of bcl-2 and C-MYC in PCNS-DLBCL are significantly associated with an adverse outcome. DH-MTX based comprehensive treatment may prolong the patient survival.目的： 探讨原发中枢神经系统(PCNS)弥漫性大B细胞淋巴瘤(DLBCL)临床病理学特点，分析其中bcl-6、bcl-2、C-MYC基因异常、蛋白表达及治疗方案选择对患者预后的影响。 方法： 收集浙江省肿瘤医院2007年1月至2016年12月收治的33例PCNS-DLBCL患者资料，对33例患者样本进行免疫组织化学(IHC)染色以检测CD10、bcl-2、bcl-6、MUM1、MYC蛋白表达；原位杂交检测肿瘤组织中EB病毒编码的小RNA(EBER)；荧光原位杂交(FISH)检测bcl-6、bcl-2、C-MYC基因扩增及易位情况；利用单、双因素生存分析及Cox风险回归模型分析上述指标改变与预后的关系。 结果： 33例患者，男女比为1.36∶1.00，平均年龄56岁。20例为单发病灶，13例为多发病灶；12例累犯深部脑组织。所有患者接受部分或全部肿瘤切除，5例术后接受全脑放疗，9例接受高剂量甲氨蝶呤为基础的化疗，12例接受全脑放疗联合高剂量甲氨蝶呤为基础的化疗，7例未进一步治疗，8例患者在化疗时联合使用利妥昔单抗。按照Hans模型分类非生发中心型(non-GCB)27例(81.8%，27/33)。25例(75.8%，25/33)bcl-2蛋白表达阳性，其中8例(24.2%)为高表达(≥70%)，12例(36.4%)C-MYC蛋白表达阳性(≥40%)，C-MYC和bcl-2蛋白双表达者有6例(18.2%，6/33)。EBER阳性率为10.0%(3/30)。28例患者中检测到5例bcl-6基因异常；7例bcl-2基因异常；4例C-MYC基因异常，bcl-2、C-MYC基因同时发生异常("双打击")者2例(7.4%)。13例患者发现脑脊液中蛋白升高，10例血中乳酸脱氢酶升高。随访时间2～90个月，平均生存时间(23.0±3.7)个月，2年生存率为39.0%。单因素分析发现bcl-2蛋白高表达、MYC蛋白阳性、bcl-2基因异常是PCNS-DLBCL的不良预后指标，以高剂量甲氨蝶呤为基础的化疗、利妥昔单抗的应用为良性预后因素，双因素分析发现bcl-2、MYC蛋白双表达及bcl-2、C-MYC基因双打击为PCNS-DLBCL的不良预后因素。Cox多因素风险回归分析发现男性、脑脊液中蛋白升高、C-MYC基因拷贝数增加为不良预后因素，高剂量甲氨蝶呤为基础的联合化疗为良性风险因素。 结论： PCNS-DLBCL中bcl-2、C-MYC基因双打击及蛋白双表达均和不良预后明显相关，高剂量甲氨蝶呤为基础的联合化疗可明显延长患者生存期，利妥昔单抗可使PCNS-DLBCL患者生存获益。.