Doǧan, Ahmet

Abstract Angioimmunoblastic T-cell Lymphoma (AITL) is a rare Peripheral T-cell lymphoma that primarily affects the elderly, presenting as advanced disease characterized by aggressive behaviour and very poor outcome. Despite the unfavourable prognosis, the best approach for treating patients with AITL is still unknown. We report a retrospective multicentre study of 64 AITL patients (37 male, 27 female) who were diagnosed as AITL in our institution based on typical histology and molecular clonality analysis between 1995 and 2004. The median age at diagnosis was 60 years (range 25 to 87). Fifty-two patients (81%) presented with advanced stage III–IV disease, 41 (64%) had B symptoms and 49 (76%) elevated LDH. ECOG performance status was 1 for 40%, 2 for 53% and 3 for 9% of the patients. Based on IPI risk factors 12% of the patients were classified as low risk, 17% low intermediate, 29% high intermediate and 42% as high risk. Six patients developed autoimmune haemolytic anaemia. Therapeutic approach varied from no treatment to high dose therapy (HDT). The majority of the patients had received CHOP chemotherapy. Overall 19 patients (30%) had received 1 treatment line, 20 (31%) had 2, 19 (30%) 3, 4 patients (6%) were treated with ≥4 and 2 (3%) were not eligible for any treatment. Twenty patients (31%) proceeded to an autologous and 2 to allogeneic transplantation after achieving CR (n=12), PR (n=7) while 3 had progressive disease. Following first line therapy 37 patients (58%) achieved CR, 15 (23%) PR and 10 (16%) had primary refractory disease. Median time to relapse or progression was 6 months (1 to 89). Interestingly three patients relapsed as EBV driven DLBCL, 1as DLBCL and 2 as EBV driven Hodgkin’s lymphoma. With a median follow-up of 19 months (1 to 119) twenty-six patients (41%) were alive. Eighteen (28%) of these patients were in CR, and 8 in PR (13%). Thirty-seven patients (58%) died, 29 (45%) from disease progression. Twelve patients developed toxic complications -infectious complications (n=8), haemorrhage (n=1), thrombosis (n=1) myocardial infarction (n=2). The estimated PFS rates at 1 and 2 years were 33% and 27% respectively. Overall survival rates were estimated at 55% and 28% at 2 and 4 years. By univariate and multivariate analyses, no response to first line therapy (p=0.035) and male sex (p=0.0161), were significantly associated with higher relapse rate. Application of HDT resulted to significantly superior PFS (p=0.002). Poor performance status at presentation was the only factor found to be significant for the OS (p= 0.0317). In conclusion analysis of the results of this large cohort of AITL patients showed that although the initial overall response rate was 73% this was short lived. It is estimated that less than 30% of the patients will survive and remain disease free at 4 years. Considering the dismal outcome with current therapeutic approaches, new strategies using novel agents to improve further and most importantly maintain initial response are needed. The role of frontline HDT either autologous or allogeneic for eligible AITL patients is worth exploring in prospective collaborative studies.

Abstract Intravascular lymphoma is a rare subtype of extranodal DLBCL characterized by the proliferation of malignant B-cells within the lumina of blood vessels. Organ involvement is variable and diffuse. Making the diagnosis can be challenging with symptoms persisting for months prior to definitive diagnosis. Treatment to date with standard anthracycline containing chemotherapy regimens has been disappointing with variable response rates, high relapse rates, and median survival times typically measured in months. We report diagnostic, treatment, and follow-up information regarding a group of patients with intravascular lymphoma evaluated at the Mayo Clinic with special attention to those receiving rituximab and/or high dose chemotherapy with or without peripheral blood autologous stem cell rescue. Methods: The medical records of patients with intravascular lymphoma seen at the Mayo Clinic between January 1970 and May 2005 were reviewed. Patients were included if they had evidence of intravascular lymphoma at the time of diagnosis of lymphoma. Pathologic specimens were reviewed for confirmation of diagnosis. Results: Twenty patients with a diagnosis of intravascular lymphoma were identified. Their median age was 66.5 years. Thirteen (65%) had B symptoms at the time of diagnosis and 13 had a performance status ≥ 3. Nine (45%) had an IPI ≥ 4. The median time to diagnosis from the onset of symptoms was 5.5 months. All had stage IV disease with biopsy proven involvement of at least one organ. The sites of disease involvement were CNS (10), marrow (7), lung (5), adrenal (3), kidney (2), lymph node, seminal vesicle, and skin (1). Two patients had involvement of three organs, six had involvement of two organs, and twelve had involvement of one organ. Nineteen patients received chemotherapy: ProMACE/CytaBOM (3), CHOP (6), RCHOP (6), DHAP (1), high dose methotrexate (1), methylprednisolone, nitrogen mustard, rituximab (1), and hyperCVAD (1). Three patients underwent peripheral blood autologous stem cell rescue after conditioning with BEAM. With a median follow-up of 60 months for all patients, the median overall survival was 8 months. No difference in outcome was seen with regard to site of organ involvement, number of organs involved, presence of B symptoms, or IPI. With a median follow-up for those receiving rituximab of 26 months, the median survival has not yet been reached while the median survival for those receiving non-rituximab containing regimens was 6.5 months. Similarly, with a median follow-up for those receiving high dose chemotherapy (hyperCVAD or BEAM) of 9.3 months, the median survival has not yet been reached while the median survival for those not receiving high dose therapy was 7 months. Conclusion: Intravascular lymphoma is a unique and aggressive subtype of DLBCL. The clinical presentation and sites of organ involvement are variable and the time from onset of symptoms to diagnosis can be prolonged. Standard chemotherapeutic treatment leads to poor outcomes. However, survival may be improved upon with newer strategies such as the use of rituximab and/or high dose chemotherapy with or without peripheral blood autologous stem cell rescue.

Abstract Purpose: In a previous retrospective study, we have shown that 75% of gastric MALT lymphomas that did not respond to H. pylori eradication could be identified by detection of t(11;18)(q21;q21). The present study examined the value of t(1;14)(p22;q32) in prediction of the response of gastric MALT lymphomas to H. pylori eradication. Patients and Methods: A total of 111 patients with H. pylori-positive gastric MALT lymphoma, who were treated by H. pylori eradication, were screened for BCL10 involved chromosome translocation by BCL10 immunohistochemistry, followed by interphase FISH and real-time quantitative reverse transcription PCR (qRT-PCR). The clinical presentation of 11 cases of MALT lymphoma including 6 from the stomach with known BCL10 involved chromosome translocation was reviewed. Results: Of the 111 cases of gastric MALT lymphoma treated by H. pylori eradication, 75 including 35 from the complete regression group and 40 from the non-responsive group, had adequate specimens for BCL10 immunohistochemistry. Two cases showed strong BCL10 nuclear staining in virtually all tumor cells, similar to that seen in those with t(1;14)(p22;q32). Both were from the H. pylori eradication non-responsive group. Although interphase FISH failed to show evidence of BCL10 gene break or amplification, one case showed an IGH break. This case also showed a high level of BCL10 mRNA expression, compatible to that seen in MALT lymphoma with t(1;14)(p22;q32). 9 of the 11 cases with known BCL10 involved translocation were at stage IIE or above, with three showing agressive clinical presentations. Conclusion: Gastric MALT lymphomas with strong BCL10 nuclear expression or t(1;14)(p22;q32) are mostly likely resistant to H. pylori eradication.

Abstract Background: Castleman Disease (angiofollicular hyperplasia) is a rare, lymphoproliferative disease. There has been no large study describing the natural history of this disease. Hypothesis: A retrospective analysis of clinical, pathologic, and laboratory factors predictive of outcome should be identifiable. Methods: During the period from 3/30/48 to 6/18/2002, 114 patients with Castleman Disease were seen at the Mayo Clinic (Rochester, 56; Jacksonville, 19; Arizona, 13) and at the University of Nebraska (26). Pathology, laboratory and clinical characteristics analyzed included: the presence of unicentric or multicentric disease, the pathologic variant (hyaline vascular versus plasma cell variant), co-existing POEMS syndrome, age, serum albumin, alkaline phosphatase, AST, sedimentation rate, the presence of cytopenias, organomegaly (hepatomegaly or splenomegaly), papilledema, peripheral neuropathy, sclerotic bone lesions, renal disease, B-symptoms or respiratory symptoms. The impact of these variables on overall survival from time of diagnosis was evaluated using univariate analyses, where their significance was determined based on the logrank statistic. To derive the multivariable model, the score-based model-building method was used. Based on this approach, a 3-variable model was designed, adjusting for age at diagnosis. Patients were then assigned a risk score corresponding to how many of these risk factors they possessed. A final proportional hazards model was constructed based on this risk score. Results: The median age at diagnosis was 43 (range: 5 – 78), and 48% of patients were male. Fifty-five patients had multicentric disease. Median follow-up of living patients was 5.8 years (range: 0.02 – 27). On univariate analysis, factors that predicted for overall survival included: age at diagnosis, presence of multicentric disease, presence of a monoclonal protein in the urine, co-existing POEMS syndrome, serum albumin, presence of cytopenias, organomegaly, neuropathy, thrombocytosis, and respiratory symptoms. The final multivariable model included 98 patients. Adjusting for age, the model included organomegaly, respiratory symptoms, and thrombocytosis. Patients were assigned 1 point for each risk factor they possessed based on clinical relevance and similarity of the hazard ratios for each of these 3 variables (ranging from 3.1 to 4). A final prognostic survival model was constructed using this assigned risk score. These scores were collapsed further based on observed similarities (0 factors vs. 1 or more factors). This final model yielded a hazards ratio of 5.5 (95% CI 2.3–13.4). The 10 year survival rates were 80% (95% CI: 65–98%) and 41% (95% CI: 28–59%) for the 0 factor and 1+ factor groups, respectively. The 20 year survival rates were 71% (95% CI: 52–87%) and 31% (95% CI: 19–51%), respectively. Conclusion: The most distinguishing prognostic clinical, laboratory, and pathological characteristics of Castleman’s Disease are orgnaomegaly, respiratory symptoms, and thrombocytosis. This prognostic scoring system should aid in individual cases and in assessing results of therapeutic interventions.

Abstract Waldenström’s macroglobulinemia (WM) is an incurable low-grade lymphoproliferative disorder characterized by bone marrow (BM) infiltration of a clonal population of small B-lymphocytes, plasmacytoid lymphocytes and plasma cells that secrete monoclonal IgM antibody. Because it is difficult to obtain tumor metaphases for karyotype studies, few recurrent chromosomal abnormalities have been reported and the genetic basis of the disease remains poorly defined. Therefore, we performed a comprehensive high-resolution study to identify genomic abnormalities involved in WM pathogenesis. Fifty-seven WM patients were analyzed using a combination of array-based comparative genomic hybridization (aCGH)(N=42); gene expression profiling (GEP)(N=22), DNA sequencing (N=24) and cIgM-FISH (N=57). Agilent 244A and Affymetrix U133 platforms were used in the aCGH and GEP experiments, respectively. An NF-κB index was calculated from GEP data, as a surrogate marker of NF-κB transcription activity. NFKB2 sub cellular localization was determined by immunofluorescence staining. Overall, 83% of samples have aCGH defined chromosomal abnormalities, with a median of 3 abnormalities per patient (range 0 to 27). We identified 16 recurrent regions of copy number change found in >5% (3 or more patients); 10 deleted and 6 amplified regions. The most common abnormality was the entire or partial deletion of 6q, identified in 40% of cases. Four nonoverlapped minimal deleted regions were identified on 6q (MDR1 to MDR4), each of them being present in at least 14 of 17 patients with the abnormality. Gain of 6p was the second most common abnormality (17%) and its presence was always concomitant with 6q loss. Other recurrent deletions were 13q14 (10%) and 7q22, 8p, 11q22-q23, 11q23-q24 and 17p11-p13 (7% each). Copy gains were identified as partial or entire gains of chromosomes 18 (17%), 4 (12%) and 3 (10%), 8q (10%) and Xq27.1-q28 (10%). Three patients had either homozygous deletions or LOH with mutations affecting both alleles of TRAF3 on 14q32. TRAF3 inactivation was correlated with an increased NF-kB transcriptional signature and it was associated with activation of the non-canonical NFkB pathway. Additionally, we identified the inactivation of TNFAIP3, another negative regulator of the NF-kB pathways, in one of 24 patients. Finally, interstitial deletions identified in 4 patients at 13q14 identified a 1.1 Mb MDR, including MIRN15A and MIRN16-1. These findings confirm that focal 13q14 deletion is not restrict to B-CLL and that the MIRN15A/MIRN16-1 abnormalities might be common to several indolent B-cell diseases. Overall, we identified TRAF3 and TNFAIP3 inactivation in 5.3% and 2.4%, respectively. To our knowledge, this is the first study showing the inactivation of bona fide tumor suppressor genes in WM patients. Furthermore, these genes are negative regulators of NF-kB signaling pathway, highlighting its biologic importance in sustaining and limiting growth in WM. Mutational activation of this pathway, which is normally activated by ligand-receptor interactions within the BM microenvironment, suggest a therapeutic role for inhibitors of NF-KB pathway activation in the treatment of WM.

Abstract Marginal zone B-cell lymphomas (MZL) represent a sub-group of indolent B-cell lymphomas, normally localized in the “marginal zone” of the secondary lymphoid follicles. Depending on the site of involvement, three distinct sub-types have been identified: extra nodal MZL of MALT type, splenic MZL (SMZL), and nodal MZL (NMZL). MALT lymphoma is the most frequent of the MZL subtypes, representing 70% of MZL and 7% to 8% of non-Hodgkin lymphomas. SMZL and NMZL comprise the remaining 20% and 10% of MZL, respectively, and account for less than 1% of NHL. The relative rarity of these lymphomas and difficulty in distinguishing them from other low-grade B-cell lymphoma subtypes like lymphoplasmacytic lymphomas (LPL), making therapeutic decisions difficult. The aim of this study was to perform a comprehensive high-resolution study to identify distinctive molecular markers in MZL and LPL, which would help to better define these lymphomas at genomic level and distinguish them from other types of low-grade B-cell lymphoma. We analyzed 119 patients, including 22 pulmonary MALT (pMALT), 20 non-pulmonary MALT (npMALT), 34 SMZL, 21 NMZL and 22 LPL (8 Waldenström’s Macroglobulinemia and 14 non-WM) cases. Human Agilent 244A platform was used by array-based comparative genomic hybridization (aCGH) analysis. Overall, 93% of patients have an altered genome. LPL had the highest amount of copy number abnormalities (median of 7.5 per patient; average of 11.7; range: 0–44), followed by npMALT (6.5; 7.6; 0–33), NMZL (5; 8.3; 0–31), SMZL (4; 7.1; 0–56) and pMALT (3.5; 4.3; 1–11). When the overall size of the abnormalities was considered, LPL was also the most affected disease with an average size of 245.15Mb included in copy number changes per patient, followed by NMZL (188.6Mb), npMALT (187.2Mb), SMZL (126.4Mb) and pMALT (109Mb). Deletions were more commonly observed than amplifications but the affected area was significantly smaller (average of 55.2Mb and 118.6Mb included in deletions and amplifications per genome, respectively). Partial or total gains of chromosome 3 and 18 were recurrently identified in all the entities, being the most common abnormalities in npMALT (60% and 50%, respectively) and pMALT (27% each). Trisomy 12 was also ubiquitously observed, ranging from 24% of NMZL to 9% of pMALT. Deletions in 6q were commonly identified in LPL (55%), npMALT (35%) and, in a less extent, in SMZL (12%) and NMZL (5%), but not in pMALT. Biallelic and focal monoallelic deletions at 6q23 clearly delineate a minimal deleted region (MDR) that includes TNFAIP3 as being the target gene of the abnormality. Deletions on 7q were found in SMZL and npMALT, thus delineating two MDR. Interstitial 11q deletions were found in LPL, NMZL and SMZL, but not in MALT. Chromosome 13 abnormalities were monosomies in NMZL and interstitial 13q14 deletions in LPL and SMZL, comprising MIRN15A and MIRN16-1 in the MDR. Partial X chromosome gains were common to all the entities but involving different areas: Xq27.3–q28 gains were recurrent events in LPL and NMZL, but not in SMZL and MALT, which were characterized by p arm gains or trisomies. Finally, some recurrent abnormalities were exclusive of specific entities: 1p deletions and 1q gains were only common in NMZL; a focal 2p gain including BCL11A and REL was found in npMALT and partial 8q gains were only identified in LPL. Trisomy 4 was only identified in the subgroup of LPL with WM, but not in the remaining LPL cases or in the remaining diseases. In this study we made a compendium of chromosomal abnormalities present in a group of related diseases, in which the molecular basis remains poorly defined. Using this high-resolution approach we were able to establish recurrent and disease-specific patterns of abnormalities and minimal deleted/amplified regions were redefined. Furthermore, TNFAIP3, a negative regulator of the NF-kB pathway, has been identified as being a commonly affected gene in MALT, LPL and NMZL, highlighting its potential role in pathogenesis.

Abstract Abdominal subcutaneous fat aspiration is one of the most practical, sensitive and specific methods for the diagnosis of systemic amyloidosis. One limitation of this method, compared to more invasive tissue biopsy based approaches, remains the technical difficulties in further classification of the amyloidosis as commonly used methods, such as immunohistochemistry, are not readily applicable to fat aspiration specimens. To overcome these difficulties we developed a method using nano-flow liquid chromatography electrospray tandem mass spectrometry (LC-MS/MS) that could identify amyloid subtypes in freshly obtained Congo Red positive fat aspirate specimens with great accuracy. Abdominal subcutaneous fat aspirate specimens were obtained from 73 patients with clinical suspicion for systemic amyloidosis. One half of the specimen was stained with Congo red and used for diagnosis of amyloidosis and the other half was processed and enzyme digested for LC-MS/MS analysis. The resulting LC-MS/MS data was correlated to theoretical fragmentation patterns of tryptic peptide sequences from the Swissprot database using Scaffold (Mascot, Sequest, and X!Tandem search algorithms). Peptide identifications were accepted if they could be established at greater than 90.0% probability and protein identifications were accepted if they could be established at greater than 90.0% probability and contain at least 2 identified spectra. The identified proteins were subsequently examined for the presence or absence of amyloid related peptides. Of the 73 cases studied, 41 were positive for Congo red consistent with systemic amyloidosis. In Congo red positive cases, LC-MS/MS peptide profiles consistent with AL-lambda (28/31), AL-kappa (6/7), and ATTR (2/3) were observed. Only one case in the Congo red negative control group (31/32) gave a kappa light chain profile which was attributed to a high level of kappa in the serum (285 mg/dL). Of the 35 out of 41 cases of systemic amyloidosis successfully classified by LC-MS/MS, additional clinical and pathology data validating the amyloid type was available. In each of these cases the MS/MS results accurately predicted the amyloid type. In conclusion, LC-MS/MS proteomic analysis of abdominal subcutaneous fat aspiration specimens involved by amyloidosis provides a highly specific (97% specificity) and sensitive (>85% sensitivity) method for diagnosis and classification of amyloidosis. The method is rapid and readily applicable in a clinical setting and will greatly improve the clinical management of amyloidosis patients.

Abstract Although classified as marginal zone lymphomas under the WHO classification, the molecular relationship between splenic marginal zone lymphoma (SMZL), extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), and nodal marginal zone lymphoma (NMZL) has not been clarified. Furthermore, lymphoplasmacytic lymphoma (LPL) can show clinical morphologic and immunophenotypic overlap with these entities and may present a diagnostic challenge. In this analysis of gene expression data generated using the Affymetrix U133plus 2.0 chip from 32 SMZL, 25 MALTs (GI, salivary gland and lung), 23 NMZL and 25 LPL, we aim to identify the molecular relationship between these pathological entities using unsupervised methods, identify disease specific signatures and markers using supervised methods and also the functional implications of these signatures using a modified gene-set enrichment analysis. Using hierarchical clustering, MALT lymphoma forms a tight cluster regardless of tumor site. In addition, SMZL and NMZL form another large cluster. LPLs are divided into 2 main clusters with occasional samples interspersed amongst the SMZL and NMZL. There is no correlation between the percentage of CD20-positive B-cells, CD3-positive T-cells or CD138- positive plasma cells or tissue origin of the tumor and the way the samples are clustered. However, the separation of the LPLs into 2 major cluster correspond to the presence and absence of underlying Waldenstrom Macroglobulinaemia (WM), suggesting that the genes distinguishing the 2 clusters are potential markers for differentiating WM LPL from non-WM LPL. Next, using supervised analysis we identified a cluster of genes including MMP7, LTF and SFRP2 with high signals specific to MALTs, while other genes including PRDM1 (BLIMP1), XBP1 and TNFRSF17 (BCMA) were specifically over-expressed in LPL. These may therefore represent novel diagnostic marker differentiating these entities. Several of these are further validated at the protein level using immunohistochemistry on a tissue microarray. Consistent with the unsupervised analysis, SMZL and NMZL have little difference and share the over-expression of CD22 and WNT3 among other genes. Clustering of these samples based on the pathways and genesets that are enriched in the individual tumors as compared to their normal tissue counterpart showed a mutually exclusive pattern with significant enrichment of NFKB-related genesets and genes in LPL and MALT, and significant enrichment of B-cell receptor signaling genesets and genes in SMZL and NMZL. Our analysis, for the first time, describes the molecular relationship between these closely related lymphomas. In the process, we identified novel diagnostic markers that may differentiate these conditions and also new insights into molecular pathways that are differentially activated in the different conditions. These may represent potential therapeutic targets

Abstract Background: Amyloidosis caused by immunoglobulin light chain (IGLC) deposition, so-called AL-type or primary amyloidosis, is the most common type of amyloidosis. It has been long believed that IGLC variable regions form the core of the AL-type amyloid deposits and peptides derived from IGLC constant region peptides are only occasionally integrated into this core. For this reason, the scientific effort to identify thge risk factors for development of AL amyloidosis and the biochemical characteristics amyloid deposits has focused on IGLC variable region derived proteins. To understand the peptide constituents of AL amyloidosis better, we undertook a comprehensive study of AL amyloidosis using a novel mass spectrometry based proteomic analysis approach. Methods: Paraffin embedded tissue from 100 cases of AL amyloidosis was studied. In each case amyloid type was previously established by clinical and pathological examination. Congo red stained paraffin sections were prepared and amyloid deposits were microdissected by laser microdissection microscopy. The microdissected tissue fragments were processed and trypsin digested into peptides. The peptides were analyzed by nano-flow liquid chromatography electrospray tandem mass spectrometry (LC-MS/MS). The resulting LC-MS/MS data were correlated to theoretical fragmentation patterns of tryptic peptide sequences from the Swissprot database using Scaffold (Mascot, Sequest, and X!Tandem search algorithms). Peptide identifications were accepted if they could be established at greater than 90.0% probability and protein identifications were accepted if they could be established at greater than 90.0% probability and contain at least 2 identified spectra. The identified proteins were subsequently examined for the presence or absence of amyloid related peptides. Results and Discussion: LC-MS/MS gave peptide profiles consistent with AL amyloidosis in each case. The analysis showed IGLC-lambda deposition in 66 cases and IGLC-kappa deposition in 34 of cases. In each case, LC MS/MS confirmed the previous clinicopathological diagnosis. Interestingly peptides representing IGLC constant region were present in each case. Using this LC-MS/MS methodology, theoretically it is possible to cover 78% of the IGLC-lambda and 87% IGLC-kappa constant regions. In our samples, the average coverage of the IGLC-lambda and IGLC-kappa constant regions were 40% (range 14–78%)and 55% (range 16–87%) respectively. Additionally, the distribution of the peptides suggested that in the majority of the cases whole of the IGLC constant region was deposited. LC MS/MS also identified IGLC-lambda variable region peptides in 37 of 66 cases and IGLC-kappa variable region peptides in 29 of 34 cases studied. The variable region coverage was more restricted and the peptides identified were frequently within the framework segments. It is likely that the peptides derived from CDR segments were present but not detected by the methodology as somatic hypermutation randomly alters the amino acid sequence in the CDR segments and such new sequences are not available in public databases used by algorithms for peptide identification. In the cases with the IGLC variable region hits, it was also possible to assign variable region family usage. IGLC-lambda cases frequently used IGLC-lambda variable region I, II and III families whereas, in IGLC-kappa cases, IGLC-kappa variable region I and III families dominated. Conclusions: AL amyloidosis can be accurately diagnosed using laser microdissection and LC-MS/MS based proteomic analysis in routine clinical specimens. AL amyloidosis invariably contains IGLC constant region peptides and, frequently, the whole of the constant region is deposited. This finding suggests that studies on molecular pathogenesis of amyloidosis should not only consider the IGLC-variable region but also the constant region. It is possible to identify IGLC variable region family usage in AL amyloidosis using LC MS/MS based proteomic analysis. In the clinical setting, this information may be helpful in predicting organ distribution and clinical outcome.

Abstract Background: Inhibitors of HMG-CoA reductase (“statins”) are effective in reducing the risk of cardiovascular disease. Preclinical data from rodents suggested that they may increase the incidence of some cancers, including lymphoma. However, monitoring of randomized trials in humans have generally found decreased cancer risks, and these findings have been supported by a growing number of observational studies, including three recent reports of a protective association in NHL. The suggested anti-carcinogenic mechanisms for statins include their impact on inflammatory (including a shift from a Th1 to Th2 profile) and angiogenesis pathways, as well as the induction of apoptosis by modulation of signaling pathways, all of which are of biologic relevance in NHL. Methods: We evaluated the history of statin use and risk of NHL in a clinic-based study of 243 newly diagnosed NHL cases and 499 frequency matched controls enrolled at the Mayo Clinic from 2002-2005. Risk factor data were collected using self-administered questionnaires, and included history of use of cholesterol lowering drugs two or more years before diagnosis (for cases) or enrollment (for controls); specific drug names were not available. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI), adjusting for age, gender, and residence. NHL subtypes were centrally reviewed, and subtype-specific risks were estimated using polychotomous logistic regression. Results. The mean age at diagnosis was 59.5 years for cases and 55% were men; among controls, the mean age at enrollment was 61.8 years and 54% were men. Twenty-one percent of the cases reported ever using statins compared to 30% of the controls, supporting a lower risk of NHL for ever users (OR=0.69; 95% CI 0.47–1.00). The lowest risk was seen for the longest users; i.e., compared to never users, person who had 10 or more years of use had the greatest reduction in risk (OR=0.52; 95% CI 0.24–1.10). A history of high cholesterol was also inversely associated with risk of NHL (OR=0.72; 95% CI 0.55–0.93). However, the association for the type of treatment for cholesterol lowering varied. Those who were medically treated had inverse association with risk of NHL (OR=0.63; 95% CI 0.46–0.86), while the no treatment and dietary change only groups were found to have no association with risk. The reduction in NHL risk with medical treatment was specific to statin use, as the use of other cholesterol lowering drugs was not associated with risk (OR=1.13; 95% CI 0.50–2.57). These results were not confounded by education, family history of NHL, body mass index, cigarette smoking or alcohol use. In subtype analysis, the inverse association was seen for diffuse large B-cell lymphoma (OR=0.27; 95% CI 0.08–0.90), but not for CLL/SLL or follicular NHL. Conclusions. Statin use was associated with a lower risk of developing NHL, particular diffuse large B-Cell lymphoma.