37,460 research outputs found
Semi-Supervised Methods to Predict Patient Survival from Gene Expression Data
An important goal of DNA microarray research is to develop tools to diagnose cancer more accurately based on the genetic profile of a tumor. There are several existing techniques in the literature for performing this type of diagnosis. Unfortunately, most of these techniques assume that different subtypes of cancer are already known to exist. Their utility is limited when such subtypes have not been previously identified. Although methods for identifying such subtypes exist, these methods do not work well for all datasets. It would be desirable to develop a procedure to find such subtypes that is applicable in a wide variety of circumstances. Even if no information is known about possible subtypes of a certain form of cancer, clinical information about the patients, such as their survival time, is often available. In this study, we develop some procedures that utilize both the gene expression data and the clinical data to identify subtypes of cancer and use this knowledge to diagnose future patients. These procedures were successfully applied to several publicly available datasets. We present diagnostic procedures that accurately predict the survival of future patients based on the gene expression profile and survival times of previous patients. This has the potential to be a powerful tool for diagnosing and treating cancer
Primary cutaneous B-cell lymphoblastic lymphoma in an elderly man
Precursor B-cell lymphoblastic lymphoma (B-LBL) is an uncommon high-grade neoplasm of immature B cells. It occurs predominantly in childhood with extranodal involvement such as skin and bone. Therefore, primary cutaneous involvement in elderly adults is a very rare manifestation of B-LBL. Here, we report a 78-year-old man with B-LBL presenting as a single cutaneous lesion which was immunohistochemically positive for leukocyte common antigen (LCA), CD79a, paired box 5 (PAX5), B cell lymphoma-2 (bcl-2), and terminal deoxynucleotidyl transferase (TdT) staining, but was without systemic involvement. The patient was treated using cyclophosphamide, adriamycin, vincristine, and prednisolone (CHOP), and achieved complete response (CR) at the first response assessment conducted after 3 CHOP cycles. After an additional cycle of CHOP treatment, radiotherapy was administered at a total dose of 3,600 cGy over 4 weeks. At the 21-month follow-up, he had maintained CR
Possible role of GADD45Îł methylation in diffuse large B-cell Lymphoma: Does it affect the progression and tissue involvement?
Objective: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma among adults and is characterized by heterogeneous clinical, immunophenotypic, and genetic features. Different mechanisms deregulating cell cycle and apoptosis play a role in the pathogenesis of DLBCL. Growth arrest DNA damage-inducible 45 (GADD45γ) is an important gene family involved in these mechanisms. The aims of this study are to determine the frequency of GADD45γ methylation, to evaluate the correlation between GADD45γ methylation and protein expression, and to investigate the relation between methylation status and clinicopathologic parameters in DLBCL tissues and reactive lymphoid node tissues from patients with reactive lymphoid hyperplasia. Materials and Methods: Thirty-six tissue samples of DLBCL and 40 nonmalignant reactive lymphoid node tissues were analyzed in this study. Methylation-sensitive high-resolution melting analysis was used for the determination of GADD45γ methylation status. The GADD45γ protein expression was determined by immunohistochemistry. Results: GADD45γ methylation was frequent (50.0%) in DLBCL. It was also significantly higher in advanced-stage tumors compared with early-stage (p=0.041). In contrast, unmethylated GADD45γ was associated with nodal involvement as the primary anatomical site (p=0.040). Conclusion: The results of this study show that, in contrast to solid tumors, the frequency of GADD45γ methylation is higher and this epigenetic alteration of GADD45γ may be associated with progression in DLBCL. In addition, nodal involvement is more likely to be present in patients with unmethylated GADD45γ. © 2015 Turkish Society of Hematology. All rights reserved
Characterization and outcomes of 414 patients with primary SS who developed haematological malignancies
Objective To characterize 414 patients with primary SS who developed haematological malignancies and to analyse how the main SS- and lymphoma-related features can modify the presentation patterns and outcomes. Methods By January 2021, the Big Data Sjögren Project Consortium database included 11¿966 patients fulfilling the 2002/2016 classification criteria. Haematological malignancies diagnosed according to the World Health Organization (WHO) classification were retrospectively identified. Results There were 414 patients (355 women, mean age 57¿years) with haematological malignancies (in 43, malignancy preceded at least one year the SS diagnosis). A total of 376 (91%) patients had mature B-cell malignancy, nearly half had extranodal marginal zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT lymphoma) (n¿=¿197), followed by diffuse large B-cell lymphoma (DLBCL) (n¿=¿67), nodal MZL lymphoma (n¿=¿29), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (n¿=¿19) and follicular lymphoma (FL) (n¿=¿17). Rates of complete response, relapses and death were 80%, 34% and 13%, respectively, with a 5-year survival rate of 86.5% after a mean follow-up of 8¿years. There were significant differences in age at diagnosis (younger in MALT, older in CLL/SLL), predominant clinical presentation (glandular enlargement in MALT lymphoma, peripheral lymphadenopathy in nodal MZL and FL, constitutional symptoms in DLBCL, incidental diagnosis in CLL/SLL), therapeutic response (higher in MALT lymphoma, lower in DLBCL) and survival (better in MALT, nodal MZL and FL, worse in DLBCL). Conclusion In the largest reported study of haematological malignancies complicating primary SS, we confirm the overwhelming predominance of B-cell lymphomas, especially MALT, with the salivary glands being the primary site of involvement. This highly-specific histopathological scenario is linked with the overall good prognosis with a 5-year survival rate of nearly 90%.Peer ReviewedPostprint (published version
Human leukocyte antigens and genetic susceptibility to lymphoma
Familial aggregation, coupled with ethnic variation in incidence, suggests that inherited susceptibility plays a role in the development of lymphoma, and the search for genetic risk factors has highlighted the contribution of the human leukocyte antigen (HLA) complex. In a landmark study published almost 50 years ago, Hodgkin lymphoma (HL) was the first disease to be associated with HLA variation. It is now clear that Epstein-Barr virus (EBV)-positive and -negative HL are strongly associated with specific HLA polymorphisms but these differ by EBV status of the tumours. HLA class I alleles are consistently associated with EBV-positive HL while a polymorphism in HLA class II is the strongest predictor of risk of EBV-negative HL. Recent investigations, particularly genome-wide association studies (GWAS), have also revealed associations between HLA and common types of non-Hodgkin lymphoma (NHL). Follicular lymphoma is strongly associated with two distinct haplotypes in HLA class II whereas diffuse large B-cell lymphoma is most strongly associated with HLA-B*08. Although chronic lymphocytic leukaemia is associated with variation in HLA class II, the strongest signals in GWAS are from non-HLA polymorphisms, suggesting that inherited susceptibility is explained by co-inheritance of multiple low risk variants. Associations between B-cell derived lymphoma and HLA variation suggest that antigen presentation, or lack of, plays an important role in disease pathogenesis but the precise mechanisms have yet to be elucidated
Characterization and outcomes of 414 patients with primary SS who developed haematological malignancies
Objective: To characterize 414 patients with primary SS who developed haematological malignancies and to analyse how the main SS- and lymphoma-related features can modify the presentation patterns and outcomes. Methods: By January 2021, the Big Data Sjögren Project Consortium database included 11â966 patients fulfilling the 2002/2016 classification criteria. Haematological malignancies diagnosed according to the World Health Organization (WHO) classification were retrospectively identified. Results: There were 414 patients (355 women, mean age 57âyears) with haematological malignancies (in 43, malignancy preceded at least one year the SS diagnosis). A total of 376 (91%) patients had mature B-cell malignancy, nearly half had extranodal marginal zone lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT lymphoma) (nâ=â197), followed by diffuse large B-cell lymphoma (DLBCL) (nâ=â67), nodal MZL lymphoma (nâ=â29), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) (nâ=â19) and follicular lymphoma (FL) (nâ=â17). Rates of complete response, relapses and death were 80%, 34% and 13%, respectively, with a 5-year survival rate of 86.5% after a mean follow-up of 8âyears. There were significant differences in age at diagnosis (younger in MALT, older in CLL/SLL), predominant clinical presentation (glandular enlargement in MALT lymphoma, peripheral lymphadenopathy in nodal MZL and FL, constitutional symptoms in DLBCL, incidental diagnosis in CLL/SLL), therapeutic response (higher in MALT lymphoma, lower in DLBCL) and survival (better in MALT, nodal MZL and FL, worse in DLBCL). Conclusion: In the largest reported study of haematological malignancies complicating primary SS, we confirm the overwhelming predominance of B-cell lymphomas, especially MALT, with the salivary glands being the primary site of involvement. This highly-specific histopathological scenario is linked with the overall good prognosis with a 5-year survival rate of nearly 90%
Deciphering the role of Epstein-Barr virus in the pathogenesis of T and NK cell lymphoproliferations
Epstein-Barr virus (EBV) is a highly successful herpesvirus, colonizing more than 90% of the adult human population worldwide, although it is also associated with various malignant diseases. Primary infection is usually clinically silent, and subsequent establishment of latency in the memory B lymphocyte compartment allows persistence of the virus in the infected host for life. EBV is so markedly B-lymphotropic when exposed to human lymphocytes in vitro that the association of EBV with rare but distinct types of T and NK cell lymphoproliferations was quite unexpected. Whilst relatively rare, these EBV-associated T and NK lymphoproliferations can be therapeutically challenging and prognosis for the majority of patients is dismal. In this review, we summarize the current knowledge on the role of EBV in the pathogenesis of these tumours, and the implications for treatment. \ud
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