TP53 mutation and survival in aggressive B cell lymphoma

TP53 is mutated in 20–25% of aggressive B‐cell lymphoma (B‐NHL). To date, no studies have addressed the impact of TP53 mutations in prospective clinical trial cohorts. To evaluate the impact of TP53 mutation to current risk models in aggressive B‐NHL, we investigated TP53 gene mutations within the RICOVER‐60 trial. Of 1,222 elderly patients (aged 61–80 years) enrolled in the study and randomized to six or eight cycles of CHOP‐14 with or without Rituximab (NCT00052936), 265 patients were analyzed for TP53 mutations. TP53 mutations were demonstrated in 63 of 265 patients (23.8%). TP53 mutation was associated with higher LDH (65% vs. 37%; p < 0.001), higher international prognostic index‐Scores (IPI 4/5 27% vs. 12%; p = 0.025) and B‐symptoms (41% vs. 24%; p = 0.011). Patients with TP53 mutation were less likely to obtain a complete remission CR/CRu (CR unconfirmed) 61.9% (mut) vs. 79.7% (wt) (p = 0.007). TP53 mutations were associated with decreased event‐free (EFS), progression‐free (PFS) and overall survival (OS) (median observation time of 40.2 months): the 3 year EFS, PFS and OS were 42% (vs. 60%; p = 0.012), 42% (vs. 67.5%; p < 0.001) and 50% (vs. 76%; p < 0.001) for the TP53 mutation group. In a Cox proportional hazard analysis adjusting for IPI‐factors and treatment arms, TP53 mutation was shown to be an independent predictor of EFS (HR 1.5), PFS (HR 2.0) and OS (HR 2.3; p < 0.001). TP53 mutations are independent predictors of survival in untreated patients with aggressive CD20+ lymphoma. TP53 mutations should be considered for risk models in DLBCL and strategies to improve outcome for patients with mutant TP53 must be developed.     

弥漫性大B细胞淋巴瘤中MYD88基因突变及其临床病理相关性分析

背景与目的：MYD88基因在弥漫性大B细胞淋巴瘤（diffuse large B-cell lymphoma,DLBCL）中有一定突变率,但其临床病理相关性目前研究报道甚少。该研究旨在分析DLBCL中MYD88基因突变的发生率及与临床病理参数的相关性。方法：收集121例DLBCL患者的临床病理资料,采用免疫组织化学法分析其免疫表型,采用PCR扩增及直接测序法检测MYD88 L265P位点突变情况,采用统计学方法分析MYD88突变与各临床病理参数的相关性。结果：121例DLBCL患者中,38例（31.4%）检测到MYD88 L265P突变。其中男性50例,女性71例,患者性别与该基因突变没有相关性（P=0.609）。年龄≥60岁组MYD88突变率为40.3%（25/62）,显著高于<60岁组（13/59,22.0%）（P=0.030）。MYD88突变主要发生在结外部位,其中最常见的是乳腺（12/13,92.3%）、男性生殖系统（10/11,90.9%）、女性生殖系统（5/6,83.3%）及中枢神经系统（4/6,66.7%）;结外DLBCL中的MYD88突变率（35/98,35.7%）显著高于结内者（2/20,10%）（P=0.024）。Non-GCB型DLBCL中MYD88突变率为39.7%（25/63）,显著高于GCB亚型（10/55,18.2%）（P=0.010）;结外DLBCL组中MYD88突变与免疫分型的相关性更加显著（P=0.003）,而结内组中两者无相关性（P=0.776）。Bcl-2蛋白阳性组（30/77,39.0%）及MYC/Bcl-2蛋白双表达组（19/46,41.3%）中MYD88突变率分别高于Bcl-2阴性组（5/40,12.5%）及非双表达组（16/70,22.9%）（P=0.003和0.034）。Ki-67增殖活性与MYD88基因突变显著相关［高增殖活性组为38.8%（33/85）,低增殖活性组为6.3%（2/32）］（P<0.001）。该基因突变与MYC蛋白及CD5表达均无相关性（P=0.581和0.759）。结论：MYD88 L265P突变好发于年龄≥60岁、non-GCB起源及特殊结外部位（如乳腺、中枢神经系统及生殖系统等）的DLBCL中,且具有较高增殖指数及MYC/Bcl-2蛋白双表达率;其预后相关性有待积累更多病例进一步分析。MYD88基因突变有望为揭示DLBCL发病机制及靶向治疗提供新的理论依据。     

Molecular and genetic biomarkers implemented from next-generation sequencing provide treatment insights in clinical practice for Waldenström macroglobulinemia

Waldenström macroglobulinemia (WM) is a distinct type of indolent lymphoplasmacytic lymphoma (LPL) with a high frequency of MYD88^L265P mutation. Treatment for WM/LPL is highly variable in clinic and ibrutinib (a Bruton tyrosine kinase inhibitor, BTKi) has become a new treatment option for WM. To investigate the clinical impact of genetic alterations in WM, we assembled a large cohort of 219 WMs and 12 LPLs dividing into two subcohorts: a training cohort, patients sequenced by a same targeted 29-gene next-generation sequencing (NGS) panel, and a validation cohort, patients sequenced by allele specific-PCR or other targeted NGS panels. In both training and validation subcohorts, MYD88^L265P and TP53 mutations showed favorable and adverse prognostic effects, respectively. CXCR4 nonsense/missense mutations (CXCR4^NS/MS), cytogenetic complex karyotypes, and a family history of lymphoma/leukemia in first-degree relatives were associated with significantly worse clinical outcomes only or more in the validation subcohort. We further investigated the efficacy of various treatments and interaction with genetic factors in the entire cohort. Upfront dexamethasone usage was associated with poorer clinical outcomes in patients who received non-proteasome-containing chemotherapy as first-line treatment independent of genetic factors. Maintenance rituximab was associated with better survival. Ibrutinib/BTKi showed potential benefit in relapsed/refractory patients and patients without CXCR4^NS/MS including those with TP53 mutations. In conclusion, genetic testing for MYD88^L265P, TP53, and CXCR4 mutations and cytogenetic analysis provide important information for prognosis prediction and therapy selection. The findings in these study are valuable for improving treatment decisions on therapies available for WM/LPL patients with integration of NGS in clinic.     

Mutations found in cell‐free DNAs of patients with malignant lymphoma at remission can derive from clonal hematopoiesis

Cell‐free DNA (cfDNA) analysis to detect circulating tumor DNA has been focused on monitoring malignant lymphomas. However, clonal hematopoiesis of indeterminate potential (CHIP)‐associated mutations can also be detected by cfDNA analysis. Our aim is to investigate the origin of mutations detected in cfDNA among B‐cell lymphoma patients. MYD88/CD79B, DNMT3A, and TP53 were chosen as genes of interest, representing each of the following categories: lymphoma driver genes, CHIP‐related genes, and genes shared between lymphoma and CHIP. Seventy‐five B‐cell lymphoma patients were included in this retrospective study. Serum cfDNAs at time of complete metabolic response (CMR) were sequenced for TP53 (N = 75) and DNMT3A (N = 49). MYD88 p.L265P and CD79B p.Y196C/H mutations were analyzed in diffuse large B‐cell lymphoma (DLBCL) patients whose tumor samples were available (N = 29). Two and seven mutations in TP53 and DNMT3A, respectively, were detected in cfDNA at CMR. These mutations were detected in either bone marrow mononuclear cells (BMMC) or PBMC. Although four DNMT3A mutations were also detected in tumors, median variant allele frequencies in the tumors (<1.0%) were significantly lower than those in both BMMC (6.1%) and serum (5.2%) obtained before the therapy. Conversely, five MYD88 and three CD79B mutations detected in tumors were confirmed in cfDNA before therapy, but not in BMMC nor in cfDNA at CMR. Thus, all TP53 and DNMT3A mutations detected in cfDNA at remission seemed to originate from CHIP rather than from residual disease. Results of liquid biopsy should be carefully interpreted, especially in genes shared between lymphomas and CHIP.     

Effect of Coexisting KRAS and TP53 Mutations in Patients Treated With Chemotherapy for Non–small-cell Lung Cancer

BackgroundKRAS and TP53 are common mutations in non–small-cell lung cancer (NSCLC). The Lung Adjuvant Cisplatin Evaluation Biological Program group found adjuvant chemotherapy to be deleterious in patients with coexisting KRAS/TP53 mutations.Patients and MethodsTo validate these results, patients with NSCLC tested for KRAS and TP53 mutations and receiving chemotherapy for any stage NSCLC were selected. Mutation status was analyzed using next generation sequencing (Illumina) or multiplex recurrent mutation detection (MassARRAY, Agena Biosciences) assays, and was correlated with clinical and demographic data. Disease-free (DFS) or progression-free survival (PFS) was the main endpoint, and overall survival (OS) was the secondary endpoint.ResultsAmong 218 patients, 28 had coexisting KRAS/TP53 mutations, 77 TP53, 37 KRAS, 76 had neither KRAS nor TP53 mutation (WT/WT). There was no DFS/PFS difference for the KRAS/TP53 group versus all others among 99 patients who received adjuvant chemotherapy (hazard ratio [HR], 1.22; 95% confidence interval [CI], 0.61-2.44; P = .57), 27 stage III patients who received chemo-radiation (HR, 0.87; 95% CI, 0.32-2.38; P = .8), and 63 patients who received palliative chemotherapy (HR, 0.68; 95% CI, 0.31-1.48; P = .33). OS was longer in the WT/WT group compared with any other group (KRAS: HR, 1.87; 95% CI, 1.02-3.43; P = .043; TP53: HR, 2.17; 95% CI, 1.3-3.61; P = .0028; KRAS/TP53: HR, 2.06; 95% CI, 1.09-3.88; P = .026). No OS difference was seen for KRAS/TP53 compared with the other groups (HR, 1.26; 95% CI, 0.75-2.13; P = .38).ConclusionsThere was no significant difference in DFS/PFS between the 4 groups. However, OS was longer for patients with TP53 and KRAS wild-type NSCLC who received chemotherapy for any stage compared with patients with KRAS, TP53 mutation, or double mutant tumors.     

Clinical significance of disease‐specific MYD88 mutations in circulating DNA in primary central nervous system lymphoma

Recent sequencing studies demonstrated the MYD88 L265P mutation in more than 70% of primary central nervous system lymphomas (PCNSL), and the clinical significance of this mutation has been proposed as diagnostic and prognostic markers in PCNSL. In contrast, mutational analyses using cell‐free DNAs have been reported in a variety of systemic lymphomas. To investigate how sensitively the MYD88 L265P mutation can be identified in cell‐free DNA from PCNSL patients, we carried out droplet digital PCR (ddPCR) and targeted deep sequencing (TDS) in 14 consecutive PCNSL patients from whom paired tumor‐derived DNA and cell‐free DNA was available at diagnosis. The MYD88 L265P mutation was found in tumor‐derived DNA from all 14 patients (14/14, 100%). In contrast, among 14 cell‐free DNAs evaluated by ddPCR (14/14) and TDS (13/14), the MYD88 L265P mutation was detected in eight out of 14 (ddPCR) and in 0 out of 13 (TDS) samples, implying dependence on the detection method. After chemotherapy, the MYD88 L265P mutation in cell‐free DNAs was traced in five patients; unexpectedly, the mutations disappeared after chemotherapy was given, and they remained undetectable in all patients. These observations suggest that ddPCR can sensitively detect the MYD88 L265P mutation in cell‐free DNA and could be used as non‐invasive diagnostics, but may not be applicable for monitoring minimal residual diseases in PCNSL.     

Characteristics of Waldenström Macroglobulinemia in Korean Patients According to Mutational Status of MYD88 and CXCR4: Analysis Using Ultra-Deep Sequencing

BackgroundLittle is known about the mutational frequency of myeloid differentiation factor 88 (MYD88) and C-X-C chemokine receptor type 4 (CXCR4) and the corresponding characteristics in Asian individuals afflicted with Waldenström macroglobulinemia (WM). We investigated the characteristics of WM according to mutational status of MYD88/CXCR4, and attempted to determine the lineage commitment among hematopoietic cells by MYD88^L265P single-cell sequencing on bone marrow (BM) smear slides.Materials and MethodsCXCR4 mutations (muts) were detected using ultra-deep sequencing using target capture. Mutational burden of MYD88 was assessed using real-time polymerase chain reaction. Single-cell sequencing for MYD88 was performed on lymphocytes, plasmacytoid lymphocytes, plasma cells, and neutrophils using laser microdissection.ResultsAmong 31 patients, the frequencies of MYD88/CXCR4 muts were as follows: MYD88 wild type (WT) CXCR4^WT (6 patients, 19.4%), MYD88^L265PCXCR4^WT (19 patients, 61.4%), MYD88^L265PCXCR4^mut (6 patients, 19.4%; 1 frameshift and 5 nonsense muts). Immunoglobulin M levels of MYD88^L265CXCR4^WT patients were significantly higher than those of MYD88^WTCXCR4^WT patients (P = .024). Tumor burden in BM was highest in patients with MYD88^L265PCXCR4^mut (82.0%), followed by MYD88^L265PCXCR4^WT (52.8%) and MYD88^WTCXCR4^WT (14.2%) (P < .001). The quantity of MYD88-mutated DNA tended to correlate with tumor burden in BM (correlation coefficient 0.647; P = .009). MYD88^L265P was detected in plasma cells, plasmacytoid lymphocytes, and lymphocytes but not neutrophils.ConclusionThe frequency of MYD88/CXCR4 muts in Korean and Caucasian patients with WM was similar, however 5 of the 6 CXCR4 muts were nonsense—a proportion higher than reported frequencies in Caucasian individuals. Ultra-deep sequencing was capable of detecting CXCR4 muts not detectable using Sanger sequencing, suggesting a possible replacement of the B-cell sorting.     

初治弥漫大B细胞淋巴瘤患者MYD88基因突变的临床特征及预后分析

目的:探讨MYD88基因突变对初治弥漫大B细胞淋巴瘤（diffuse large B-cell lymphoma,DLBCL）的临床特征及预后的影响。方法:收集2013年1月至2015年1月空军军医大学第二附属医院血液科的74例初治DLBCL患者,回顾分析MYD88突变组（MYD88mut）和MYD88野生组（MYD88wt）患者的临床特征及治疗效果。结果:74例DLBCL患者中,MYD88mut组和MYD88wt组患者性别、年龄、ECOG评分、LDH、Ann Arbor分期、结外侵犯及IPI评分比较差异无统计学意义。MYD88mut组主要为ABC亚型（75.00%）。12例MYD88mut突变均为错义突变,其中8例氨基酸改变为L265P。MYD88mut组2周期R-CHOP方案完全缓解率（complete remission,CR）为41.67%,部分缓解率(partial remission,PR)为33.33%,客观有效率(objective effective,OR)为75.00%。MYD88wt组分别为77.42%、11.29%和88.71%。2组比较,2周期CR率具有统计学差异（P=0.030 4）。生存分析结果显示,MYD88mut组及MYD88wt组患者5年OS分别为54.98%与73.53%,PFS分别为48.61%与66.54%,2组比较,OS及PFS均具有统计学差异（P=0.003 4,P=0.031 9）。结论:MYD88突变主要存在于DLBCL的ABC亚型,且MYD88突变提示其预后不良。     

Detection of L265P MYD‐88 mutation in a series of clonal B‐cell lymphocytosis of marginal zone origin (CBL‐MZ)

Clonal B‐cell lymphocytosis of marginal zone origin (CBL‐MZ) is a recently described entity characterized by the presence of clonal B cells in the blood and/or bone marrow (BM) with morphologic and immunophenotypic features consistent with marginal zone derivation in otherwise healthy individuals. CBL‐MZ is commonly associated with paraproteinemia, usually immunoglobulin M (IgM), raising diagnostic difficulties from Waldenstrom macroglobulinemia (WM). The aim of the present study was to determine the presence of MYD‐88 L265P mutation in a well‐characterized series of CBL‐MZ to identify cases that may in fact represent WM. Fifty‐three CBL‐MZ cases were retrospectively evaluated. MYD‐88 L265P mutation was determined by allele‐specific polymerase chain reaction in blood and/or BM mononuclear cells. Almost half of the CBL‐MZ cases (49%) were associated with paraproteinemia mainly of the IgM type (65%). MYD‐88 L265P mutation was identified in 10 cases (19%). These cases may truly represent WM, whereas 43 cases (81%) are still classified as CBL‐MZ. Mutated cases were all associated with paraproteinemia compared with 37% of the nonmutated ones (P < .0001). In addition, mutated cases displayed more frequently CD38 and CD25 positivity (P = .002 and P = .005, respectively). Moreover, cases without paraproteinemia presented more frequently with lymphocytosis, irrespective of the presence of the MYD‐88 mutation (P = .02). The present study demonstrates that MYD‐88 L265P mutation may represent the only sensitive marker for the differentiation of CBL‐MZ from probable WM. However, further studies are warranted to better define the biological significance of MYD‐88 L265P mutation and to clarify whether the presence of the mutation establishes WM diagnosis or that it can also be present in borderline cases associated with paraproteinemia.     

Liquid biopsy of cerebrospinal fluid for MYD88 L265P mutation is useful for diagnosis of central nervous system lymphoma

The current standard of diagnosing central nervous system (CNS) lymphoma is stereotactic biopsy, however the procedure has a risk of surgical complication. Liquid biopsy of the CSF is a less invasive, non-surgical method that can be used for diagnosing CNS lymphoma. In this study, we established a clinically applicable protocol for determining mutations in MYD88 in the CSF of patients with CNS lymphoma. CSF was collected prior to the start of chemotherapy from 42 patients with CNS lymphoma and matched tumor specimens. Mutations in MYD88 in 33 tumor samples were identified using pyrosequencing. Using 10 ng each of cellular DNA and cell-free DNA (cfDNA) extracted from the CSF, the MYD88 L265P mutation was detected using digital PCR. The conditions to judge mutation were rigorously determined. The median Target/Total value of cases with MYD88 mutations in the tumors was 5.1% in cellular DNA and 22.0% in cfDNA. The criteria to judge mutation were then determined, with a Target/Total value of 0.25% as the cutoff. When MYD88 mutations were determined based on these criteria, the sensitivity and specificity were 92.2% and 100%, respectively, with cellular DNA; and the sensitivity and specificity were 100% with cfDNA. Therefore, the DNA yield, mutated allele fraction, and accuracy were significantly higher in cfDNA compared with that in cellular DNA. Taken together, this study highlights the importance of detecting the MYD88 L265P mutation in cfDNA of the CSF for diagnosing CNS lymphoma using digital PCR, a highly accurate and clinically applicable method.     

Activation of TAK1 by MYD88 L265P drives malignant B-cell Growth in non-Hodgkin lymphoma

Massively parallel sequencing analyses have revealed a common mutation within the MYD88 gene (MYD88_L265P) occurring at high frequencies in many non-Hodgkin lymphomas (NHLs) including the rare lymphoplasmacytic lymphoma, Waldenström''s macroglobulinemia (WM). Using whole-exome sequencing, Sanger sequencing and allele-specific PCR, we validate the initial studies and detect the MYD88_L265P mutation in the tumor genome of 97% of WM patients analyzed (n=39). Due to the high frequency of MYD88 mutation in WM and other NHL, and its known effects on malignant B-cell survival, therapeutic targeting of MYD88 signaling pathways may be clinically useful. However, we are lacking a thorough characterization of the role of intermediary signaling proteins on the biology of MYD88_L265P-expressing B cells. We report here that MYD88_L265P signaling is constitutively active in both WM and diffuse large B-cell lymphoma cells leading to heightened MYD88_L265P, IRAK and TRAF6 oligomerization and NF-κB activation. Furthermore, we have identified the signaling protein, TAK1, to be an essential mediator of MYD88_L265P-driven signaling, cellular proliferation and cytokine secretion in malignant B cells. Our studies highlight the biological significance of MYD88_L265P in NHL and reveal TAK1 inhibition to be a potential therapeutic strategy for the treatment of WM and other diseases characterized by MYD88_L265P.     

Prognostic value of TP53 gene mutation in adjuvant treated breast cancer patients

We investigated the prognostic significance of mutation to the TP53 tumor suppressor gene in a series of 908 breast cancer patients treated with or without adjuvant therapies. The frequency of TP53 mutation detected by single strand conformation polymorphism (SSCP) was 19.4% (176/908) in the overall tumor series. In multivariate analysis, TP53 mutation was independently associated with worse survival in the overall (HR=2.1, 95% CI [1.5–3.1], P<0.0001), non-adjuvant treated (HR=2.2, 95% CI [1.2–4.2], P=0.017) and adjuvant treated (HR=2.0, 95% CI [1.3–3.1], P=0.0009) patients.     

Prevalence and clinical impact of TP53 germline mutations in Chinese women with breast cancer

The prevalence and clinical relevance of TP53 germline mutations in a large unselected breast cancer series are largely unknown. Here, we determined TP53 germline mutations in a large cohort of 10,053 unselected breast cancer patients through multigene panel-based next-generation and/or Sanger sequencing assays. We found that 0.5% of patients (50 cases) carried a pathogenic TP53 germline mutation in this large series of 10,053 unselected breast cancer patients, and the prevalence of TP53 germline mutation was 3.8% in very early onset breast cancer (age ≤30 years) in this large cohort. TP53 mutation carriers were significantly more likely to have early onset cancer (p < 0.001) and bilateral breast cancer (p = 0.03), they and were significantly more likely to respond to carboplatin-based neoadjuvant chemotherapy compared to anthracycline- or taxane-based regimen in terms of pathologic complete response (50% vs. 0%, p = 0.006). At the median follow-up of 54 months, TP53 mutation was an independent unfavorable factor for recurrence-free survival (RFS), distant recurrence-free survival (DRFS), and overall survival (OS) (RFS, adjusted hazard ratio [HR]: 2.24, 95% confidence interval [CI]: 1.15–4.33, p = 0.02; DRFS, adjusted HR: 2.73, 95% CI: 1.41–5.30, p = 0.003; OS, adjusted HR: 4.60, 95% CI: 2.26–9.41, p < 0.001) in multivariate analyses. Our study suggested that TP53 germline mutations occur more frequently in very early onset unselected breast cancer patients; and TP53 germline mutation carriers have a very poor survival and may benefit from carboplatin-based neoadjuvant chemotherapy in unselected breast cancer patients.     

Rapid detection of the MYD88 L265P mutation for pre- and intra-operative diagnosis of primary central nervous system lymphoma

The myeloid differentiation primary response gene 88 (MYD88) L265P mutation is a disease-specific mutation of primary central nervous system lymphoma (PCNSL) among the central nervous system tumors. Accordingly, this mutation is considered a reliable diagnostic molecular marker of PCNSL. As the intra-operative diagnosis of PCNSL is sometimes difficult to achieve using histological examinations alone, intra-operative detection of the MYD88 L265P mutation could be effective for the accurate diagnosis of PCNSL. Herein, we aimed to develop a novel rapid genotyping system (GeneSoC) using real-time polymerase chain reaction (PCR) based on microfluidic thermal cycling technology. This real-time PCR system shortened the analysis time, which enabled the detection of the MYD88 L265P mutation within 15 min. Rapid detection of the MYD88 L265P mutation was performed intra-operatively using GeneSoC in 24 consecutive cases with suspected malignant brain tumors, including 10 cases with suspected PCNSL before surgery. The MYD88 L265P mutation was detected in eight cases in which tumors were pathologically diagnosed as PCNSL after the operation, while wild-type MYD88 was detected in 16 cases. Although two of the 16 cases with wild-type MYD88 were pathologically diagnosed as PCNSL after the operation, MYD88 L265P could be detected in all eight PCNSL cases harboring MYD88 L265P. The MYD88 L265P mutation could also be detected using cell-free DNA derived from the cerebrospinal fluid of two PCNSL cases. Detection of the MYD88 L265P mutation using GeneSoC might not only improve the accuracy of intra-operative diagnosis of PCNSL but also help the future pre-operative diagnosis through liquid biopsy of cerebrospinal fluid.     

成人弥漫大B细胞淋巴瘤二代测序结果分析（附21例）

目的:利用二代测序方法分析弥漫性大B细胞淋巴瘤（DLBCL）患者的基因突变情况，探讨基因突变与其危险因素分组、疗效及生存的关系。方法:回顾性分析21例DLBCL患者的临床资料，分析21例患者的基因突变情况与性别、年龄、危险因素分组、疗效及生存的关系，并分析突变组及未突变组患者的细胞免疫分型结果。结果:根据国际预后指数（international prognostic index,IPI）积分将患者分为低危组（0~1分）6例，中低危组（2分）6例，中高危组（3分）5例，高危组（4~5分）4例，基因突变情况与性别、年龄无显著相关性。在不同的危险因素分组中，低危组的基因突变率明显低于高危组，其差异有统计学意义（P=0.02<0.05）；中低危组、中高危组、高危组三组间差异无统计学意义。分析细胞免疫表型时发现，CD5作为潜在的预后不良因素，突变组CD5阳性率高于未突变组（P=0.03<0.05）。在应用R-CHOP方案化疗的12例中，发现突变组的CR率（42.86%）低于未突变组的CR率（60.00%），但差异无统计学意义（P=0.38＞0.05）。TP53+组6个月OS为67%，TP53-组为80%，MYD88+组为50%，MYD88-组为70%，差异均无统计学意义。结论:基因突变与患者的危险分组相关，且与CD5阳性相关，但突变组及未突变组间的CR率及6个月OS无显著性差异。     

Gene expression profiling of primary vitreoretinal lymphoma

The characteristics of tumor cells of primary vitreoretinal lymphoma (PVRL) have not been defined, although researches have shown that most cases are of diffuse large B‐cell lymphoma (DLBCL). To determine the subtype and biological characteristics of tumor cells of PVRL, we performed a gene expression profiling analysis. RNA was extracted from the vitreous fluid of 7 PVRL patients and from nodal samples of 10 DLBCL patients: 6 of germinal center B‐cell (GCB) type and 4 of activated B‐cell (ABC) type determined by Hans’ criteria. Six PVRL samples showed gene expression profiles that were similar to each other. The patterns were different from those of the ABC‐type nodular DLBCL but relatively close to those of the GCB‐type nodular DLBCL. Interestingly, all of the 6 examined PVRL samples had either MYD88^L265P or mutation in the immunoreceptor tyrosine‐based activation motif (ITAM) region of CD79B. Five PVRL patients with similar gene expression profiles were treated with a standardized regimen: intravitreal administration of methotrexate (MTX) followed by six courses of systemic high doses of MTX. As a result, 2 patients had CD79B mutations and showed early central nervous system (CNS) progression. Patients without CNS progression did not have this mutation. In conclusion, PVRL had unique genetic features: an expression pattern different from ABC‐type and relatively close to GCB‐type DLBCL. CD79B mutations showed potential to serve as prognostic markers for CNS progression.     

TP53 mutations are associated with higher rates of pathologic complete response to anthracycline/cyclophosphamide‐based neoadjuvant chemotherapy in operable primary breast cancer

The role of TP53 mutations in predicting response to neoadjuvant chemotherapy in breast cancer remains controversial. The aims of this study were to investigate whether TP53 mutations were associated with response and survival in breast cancer patients who received neoadjuvant chemotherapy. Therefore, we identified TP53 mutations in the core‐needle biopsy tumor samples obtained before the neoadjuvant chemotherapy from 351 operable primary breast cancer patients who either received anthracycline/cyclophosphamide‐based (n = 252) or paclitaxel (n = 99) neoadjuvant chemotherapy. We found that 41.0% (144 of 351) of patients harbored TP53 mutations, and 14.8% of patients achieved a pCR (pathologic complete response) after neoadjuvant chemotherapy. Among patients treated with anthracycline/cyclophosphamide (n = 252), patients with TP53 mutations had a significantly higher pCR rate than those with wild‐type (28.6 vs.7.1%; p < 0.001), and TP53 mutation was an independent favorable predictor of pCR [odds ratio (OR) = 3.41; 95% confidence interval (CI) 1.50–7.77; p = 0.003] in this group; moreover, patients with TP53 mutation had a better distant recurrence‐free survival (DRFS) than those with wild‐type [unadjusted hazard ratio (HR) = 0.43; 95% CI 0.20–0.94; p = 0.030] in this group. Among patients treated with paclitaxel (n = 99), no significant difference in pCR rates was observed between patients with or without TP53 mutations (15.2 vs. 11.3%; p = 0.57). Our results suggested that patients with TP53 mutations are more likely to respond to anthracycline/ cyclophosphamide‐based neoadjuvant chemotherapy and have a favorable survival.     

Low incidence of BCL-6 gene alterations for diffuse large B-cell lymphomas in Taiwan Chinese

BACKGROUND: In Western populations, rearrangement of the BCL-6 gene can be identified in 20-40% of patients with diffuse large B-cell lymphoma (DLBCL). Analysis of the BCL-6 gene has revealed the presence of point mutations or small deletions in 70% of DLBCL tumors; however, few studies have investigated BCL-6 gene alteration in patients with non-Hodgkins lymphoma (NHL) of Chinese descent. METHODS: Samples from 135 Taiwanese patients with NHL were examined (28 samples of T-cell NHL and 107 samples of B-cell NHL; 59 samples from patients with DLBCL) for gene rearrangement and mutation of the BCL-6 proto-oncogene using Southern blot analysis and single-strand conformation polymorphism (SSCP) followed by sequence analysis. RESULTS: BCL-6 rearrangement and point mutations were found in 14.8% of patients (n = 20) and in 7.4% of patients (n = 10), respectively. All BCL-6 gene alterations occurred in patients with B-cell NHL, and none occurred in patients with T-cell NHL. Among the 59 patients with DLBCL, BCL-6 gene rearrangements were identified in 10 patients (16.9%), and mutations were identified in 8 patients (13.6%), with the BCL-6 mutation occurring independent of the BCL-6 rearrangement. The incidence of BCL-6 gene rearrangement and mutations in patients with extranodal DLBCL was 9.5% (2 of 21 patients) and 23.8% (5 of 21 patients), respectively. Univariate analysis and multivariate logistic regression found no association between BCL-6 gene alternations and clinical characteristics, including extranodal tumors in patients with DLBCL, and no association between the BCL-6 alterations and prognosis was found. CONCLUSIONS: The incidence of BCL-6 alterations was lower in Taiwanese patients with DLBCL compared with Western populations, and BCL-6 gene alterations showed no prognostic significance in patients with DLBCL.     

Genetic evidence implies that primary and relapsed tumors arise from common precursor cells in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare subtype of lymphoma that arises within the brain or the eyes. PCNSL recurs within the central nervous system (CNS) in most relapsed cases, whereas extra‐CNS relapse is experienced in rare cases. The present study aimed at identifying the presence of common precursor cells (CPC) for primary intra‐ and relapsed extra‐CNS tumors, and further assessing the initiating events in bone marrow (BM). Targeted deep sequencing was carried out for five paired primary intra‐ and relapsed extra‐CNS tumors of PCNSL. Two to five mutations were shared by each pair of intra‐ and extra‐CNS tumors. In particular, MYD88 mutations, L265P in three and P258L in one, were shared by four pairs. Unique somatic mutations were observed in all five intra‐CNS tumors and in four out of five extra‐CNS tumors. Remarkably, IgH clones in the intra‐ and the extra‐CNS tumors in two pairs were distinct from each other, whereas one pair of tumors shared identical monoclonal IgH rearrangement. In a cohort of 23 PCNSL patients, L265P MYD88 mutations were examined in tumor‐free BM mononuclear cells (MNC) in which the PCNSL tumors had L265P MYD88 mutations. L265P MYD88 mutations were detected by a droplet digital PCR method in nine out of 23 bone marrow mononuclear cells. These results suggest that intra‐ and extra‐tumors are derived from CPC with MYD88 mutations in most PCNSL, arising either before or after IgH rearrangement. The initiating MYD88 mutations may occur during B‐cell differentiation in BM.     

Development and Validation of a Novel TP53 Mutation Signature That Predicts Risk of Metastasis in Primary Prostate Cancer

IntroductionProstate tumors with TP53 gene mutations are molecularly heterogenous, and the presence of TP53 gene mutations has been linked to inferior outcomes. We developed an RNA-based gene signature that detects underlying TP53 gene mutations and identifies wild-type prostate tumors that are analogous to TP53-mutant tumors.Materials and MethodsUsing genomic expression profiles from The Cancer Genome Atlas, we developed a mutation signature score to predict prostatic tumors with a molecular fingerprint similar to tumors with TP53 mutations. Area under the receiver operating characteristic curve assessed model accuracy in predicting TP53 mutations, and Cox regression models measured association between the signature and progression-free survival and metastasis-free survival (MFS).ResultsThe TP53 signature score achieved an area under the receiver operating characteristic curve of 0.84 in the training and 0.82 in the validation cohorts for predicting an underlying mutation. In three retrospective cohorts, a high score was prognostic for poor 5-year MFS: 46% versus 81% (hazard ratio [HR], 3.05; P < .0001; Johns Hopkins University cohort), 64% versus 83% (HR, 2.77; P < .0001; Mayo Clinic cohort), and 71% versus 97% (HR, 6.8; P = .0001; Brigham and Women’s Hospital cohort). The signature also identified TP53 wild-type tumors molecularly analogous to TP53 mutant tumors, wherein high signature score correlated with worse 5-year MFS (50% vs. 82%; HR, 3.05; P < .0001).ConclusionsThis novel mutational signature predicted tumors with TP53 mutations, identified TP53 wild-type tumors analogous to mutant tumors, and was independently associated with poor MFS. This signature can therefore be used to strengthen existing clinical risk-stratification tools.