The epidemiology of non-Hodgkin's lymphoma

Identification of proteins released by follicular lymphoma-derived cells using a mass spectrometry-based approach

The recent advent of mass spectrometry-based methodologies for the analysis of complex protein mixtures opens new opportunities for the discovery of biomarkers that may aid in the diagnostic work-up of cancer. Follicular lymphoma (FL) is the most common form of low-grade non-Hodgkin lymphoma in the Western Hemisphere. Identification of tumor markers that facilitate early disease detection would be a significant advance in the management of FL. We have employed a strategy that entailed propagation of a follicular-derived cell line in serum-free media, protein extraction, and reverse-phase liquid chromatography, with subsequent electrospray ionization and tandem mass spectrometry analysis for the identification of proteins that are released by FL. Using a two-peptide minimum per protein and standard criteria, 209 proteins (5.6% maximum predicted error rate) released from the FL cells were identified. The released proteins included several growth factors, cytokines, acute phase reactants and cellular components previously known to be present in FL cells. Importantly, a greater proportion of proteins previously unassociated with FL were identified with high statistical confidence. Our studies provide a list of proteins, which may be candidates for early screening, diagnosis and therapeutic monitoring of patients with a suspected or biopsy-confirmed diagnosis of FL.

The Relationship Between HLA Class II Polymorphisms and Somatic Deletions in Testicular B Cell Lymphomas of Dutch Patients

Several risk factors including immune deficiencies, infections, and autoimmune diseases have been established for non-Hodgkin's lymphoma (NHL). For diffuse large B cell lymphoma (DLBCL), the most common type of lymphoma, no risk factors have been described, which may be due to the intrinsic heterogeneity of this disorder. Previously we reported that, in contrast to nodal DLBCLs, the majority of testicular DLBCLs manifested complete loss of HLA-DR and -DQ expression associated with homozygous deletions of the corresponding genes. To determine the correlation between HLA class II polymorphisms and these lymphomas, we applied DNA typing for HLA-DRB1 and HLA-DQB1 on 50 Dutch patients with testicular and 48 with nodal DLBCL and compared the frequencies with a cohort of healthy Dutch controls. Both the patients with nodal and those with testicular DLBCL manifested significantly higher frequencies of HLA-DRB1*15 than the controls (p < 0.018, odds ratio 2.09 and p < 0.013, odds ratio 2.12, respectively). Moreover, a positive association was seen with HLA-DRB1*12 (p = 0.043, odds ratio 4.17) in the patients with testicular DLBCL, and a negative association was seen with HLA-DRB1*07 (p = 0.022, odds ratio 0.13) in the patients with nodal DLBCL. Homozygous deletions of the HLA-DR/DQ region, evaluated by interphase fluorescence in situ hybridization were seen in 20 of 48 testicular tumors. No preferential loss or retention of a particular HLA-DR or -DQ allele was seen because all alleles were at least once retained or involved in a homozygous deletion.

Anthropometrics, physical activity, related medical conditions, and the risk of non-hodgkin lymphoma

BACKGROUND

Recent reports suggest that obesity, or conditions associated with obesity, might be risk factors for non-Hodgkin lymphoma (NHL), a cancer with dramatically increasing incidence in western countries over the last several decades. Physical inactivity increases the risk of obesity and of type 2 diabetes, but there are few data on the association of physical activity with risk of NHL.

METHODS

We evaluated these factors in a population-based case-control study conducted in Detroit, Iowa, Los Angeles, and Seattle from 1998 to 2000. Incident HIV-negative NHL cases aged 20-74 years were rapidly reported in each area (n = 1321). Controls were identified through random digit dialing and Medicare files, and were frequency matched to cases on sex, age, race, and study site (n = 1057). Risk factor data were collected by in-person interviews and self-administered questionnaires. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI), adjusted for age, sex, race and study center.

RESULTS

High body mass index (OR = 1.73 for 35+ versus <25 kg/m2; 95% CI 1.15-2.59) and history of gallstones (OR = 1.95, 95% CI 1.11-3.40) were positively associated with diffuse NHL, but were not associated with follicular or all NHL combined. Height was positively associated with risk of all NHL combined (OR = 1.38 for >70 versus <65 inches; 95% CI 0.98-1.94), and positive associations were apparent for both diffuse and follicular NHL. Non-occupational physical activity was inversely associated with risk of all NHL combined (ORs with increasing level: 1, 0.75, 0.71, 0.55, 0.68; p-trend = 0.04) and for diffuse and follicular NHL. We observed no association of total energy intake, type 2 diabetes, or hypertension with risk of NHL. In a multivariable model to predict risk of diffuse NHL, BMI (OR = 2.15 for 35+ versus <25 kg/m2; 95% CI 1.09-4.25) and height (OR = 1.63 for 71+ versus <65 inches; 95% CI 0.75-3.57) were positively associated with risk while physical activity was weakly and inversely associated risk (ORs with increasing level: 1, 0.76, 0.72, 0.78, 0.82; p-trend = 0.9).

CONCLUSION

BMI and history of gallstones were positively associated with risk of diffuse NHL, supporting a role for obesity in this NHL subtype. Height was positively associated with NHL risk across subtypes, and suggests a role for early life nutrition in NHL risk. Non-occupational physical activity was only weakly and inversely associated with NHL risk after adjustment for obesity, height and alcohol use.

Subsequent therapy can be administered after tositumomab and iodine I-131 tositumomab for non-Hodgkin lymphoma

BACKGROUND

Iodine I-131 tositumomab is a well tolerated and effective therapy for recurrent low-grade and transformed low-grade non-Hodgkin lymphoma (NHL). Hematologic reserve after radioimmunotherapy (RIT) is an important consideration when subsequent therapy is required.

METHODS

One hundred fifty-five patients who received treatment with I-131 tositumomab were assessed, and 68 patients had progressive disease after RIT. The median age (n=68 patients) was 59 years (range,18-82 yrs), and patients received a median of 2 pre-RIT regimens (range,1-8 regimens), including 66% who received anthracycline, 19% who received platinum, and 50% who received fludarabine.

RESULTS

The median time to disease progression (among progressors) was 168 days (range, 19-771 days). At the time they developed recurrent disease, patients had median white blood cell count (WBC) of 4.9 K cells/microL (range, 1.1-21.4 K cells/microL), a median absolute neutrophil count (ANC) of 3.25 K cells/microL (range, 0.59-8.20 K cells/microL), a median platelet count of 130 K cells/microL (range, 9-440 K cells/microL), and there was no significant difference between pre-RIT and recurrence values except for the platelet count (P<0.05). No patient demonstrated a WBC<1.0 K cells/microL or an ANC<0.5 K cells/microL, although 1 patient had a platelet count<10 K cells/microL. Twenty-four patients subsequently received no further chemotherapy; and, in 21 patients (88%), hematologic parameters appeared to allow subsequent chemotherapy if necessary (blood counts: National Cancer Institute Grade 0-2). Among 44 patients (65%) who received further chemotherapy (median, 2 regimens; range, 1-4 regimens), 19 patients (43%) were treated with anthracyclines, 17 patients (39%) were treated with platinum, 10 patients (23%) were treated with fludarabine, and 13 patients (30%) underwent stem cell transplantation. Disease improvement occurred in most patients, although 18 patients died (40%) after further chemotherapy, predominantly from refractory lymphoma.

CONCLUSIONS

Most patients with progressive disease after treatment with iodine I-131 tositumomab were able to receive subsequent therapy, including cytotoxic chemotherapy and stem cell transplantation.

A past history of gastric ulcers and Helicobacter pylori infection increase the risk of gastric malignant lymphoma

Helicobacter pylori (H. pylori) is a causative agent for peptic ulcers as well as some types of gastric lymphoma; however, the relationship between a peptic ulcer history in combination with H. pylori infection and the risk of gastric lymphoma has not been fully evaluated. To examine this point, we conducted a case-control study with 645 patients histologically diagnosed as having malignant lymphomas and 3225 non-cancer controls. Plasma H. pylori IgG status was assessed for subgroups for which blood samples were available (116 cases and 114 controls). An association with a history of gastric, but not duodenal ulcers was found for gastric lymphoma [odds ratio (OR) = 5.41, 95% confidence interval (CI): 3.12-9.39]. In the examination according to histological subtype, the OR was high for both gastric mucous-associated lymphoid tissue (MALT) lymphoma (OR = 5.54, 95% CI: 2.56-12.01) and diffuse large B-cell lymphoma (DLBCL) (OR = 7.23, 95% CI: 2.62-19.90). In the analysis of H. pylori antibody, the risk of total gastric lymphoma was associated with H. pylori infection (OR = 5.34, 95% CI: 1.42-20.05). A high prevalence of H. pylori infection was also found for both gastric MALT lymphoma (8 out of 10: 80.0%) and DLBCL (8 out of 9: 88.9%). Further, in subgroup analysis of subjects with H. pylori infection, gastric ulcer history, but not duodenal ulcer history was associated with the risk of gastric lymphoma (OR = 4.15, 95% CI: 1.02-16.89). In conclusion, we found a positive association with a past history of gastric ulcer and H. pylori infection for gastric lymphoma, while duodenal ulcer history was no association. These results suggested the risk of gastric lymphoma increased by interaction between H. pylori infection and gastric ulcer history. Further studies are warranted.

A past history of gastric ulcers and Helicobacter pylori infection increase the risk of gastric malignant lymphoma

Helicobacter pylori (H. pylori) is a causative agent for peptic ulcers as well as some types of gastric lymphoma; however, the relationship between a peptic ulcer history in combination with H. pylori infection and the risk of gastric lymphoma has not been fully evaluated. To examine this point, we conducted a case-control study with 645 patients histologically diagnosed as having malignant lymphomas and 3225 non-cancer controls. Plasma H. pylori IgG status was assessed for subgroups for which blood samples were available (116 cases and 114 controls). An association with a history of gastric, but not duodenal ulcers was found for gastric lymphoma [odds ratio (OR) = 5.41, 95% confidence interval (CI): 3.12-9.39]. In the examination according to histological subtype, the OR was high for both gastric mucous-associated lymphoid tissue (MALT) lymphoma (OR = 5.54, 95% CI: 2.56-12.01) and diffuse large B-cell lymphoma (DLBCL) (OR = 7.23, 95% CI: 2.62-19.90). In the analysis of H. pylori antibody, the risk of total gastric lymphoma was associated with H. pylori infection (OR = 5.34, 95% CI: 1.42-20.05). A high prevalence of H. pylori infection was also found for both gastric MALT lymphoma (8 out of 10: 80.0%) and DLBCL (8 out of 9: 88.9%). Further, in subgroup analysis of subjects with H. pylori infection, gastric ulcer history, but not duodenal ulcer history was associated with the risk of gastric lymphoma (OR = 4.15, 95% CI: 1.02-16.89). In conclusion, we found a positive association with a past history of gastric ulcer and H. pylori infection for gastric lymphoma, while duodenal ulcer history was no association. These results suggested the risk of gastric lymphoma increased by interaction between H. pylori infection and gastric ulcer history. Further studies are warranted.

Cancer risk among patients with condylomata acuminata

Condylomata acuminata have been shown to increase the risk of anogenital cancers. However, previous studies have been of limited sample size and/or short follow-up duration, which prevent precise estimates of long-term excess risk, especially for specific cancer sites. We estimated the risk of specific cancers in a large cohort of hospitalized patients with condylomata acuminata, as recorded in the Swedish Inpatient Register between 1965 and 1999. Altogether, 10,971 patients (1,685 men and 9,286 women) were followed through 1999 for a median of 13 years. The standardized incidence ratio (SIR)--the ratio of the observed number of cancers to the number expected on the basis of the incidence in the Swedish population at large--was used as a measure of relative risk. After excluding the first-year of follow-up, we observed 43 cases of anogenital cancer in women, and 7 cases in men. Risks were elevated for cancers of the vulva (N = 13, SIR = 10.2, 95% confidence interval (CI) = 5.4-17.4), vagina (N = 4, SIR = 12.0, 95% CI = 3.3-30.7) and penis (N = 5, SIR = 21.9, 95% CI = 7.1-51.2). There was a moderate excess risk of cervical cancer in situ (N = 259, SIR = 1.9, 95% CI = 1.7-2.1), but not invasive cervical cancer. Excess risks of esophageal, buccal cavity, nonmelanoma skin, lung and bladder cancers, and Hodgkin and non-Hodgkin lymphoma, were also observed in both men and women. In conclusion, condylomata acuminata are strongly associated with increased risk of cancers of the vulva, vagina, penis and anus, as well as some nonanogenital malignancies, but not invasive cervical cancer.

Lymphoma incidence patterns by WHO subtype in the United States, 1992-2001

Because the causes of most lymphoid neoplasms remain unknown, comparison of incidence patterns by disease subtype may provide critical clues for future etiologic investigations. We therefore conducted a comprehensive assessment of 114,548 lymphoid neoplasms diagnosed during 1992-2001 in 12 Surveillance, Epidemiology, and End Results (SEER) registries according to the internationally recognized World Health Organization (WHO) lymphoma classification introduced in 2001. Cases coded in International Classification of Diseases for Oncology, Second Edition (ICD-O-2), were converted to ICD-O-3 for WHO subtype assignment. Age-specific and age-adjusted rates were compared by sex and race (white, black, Asian). Age-adjusted trends in incidence were estimated by sex and race using weighted least squares log-linear regression. Diverse incidence patterns and trends were observed by lymphoid neoplasm subtype and population. In the elderly (75 years or older), rates of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma increased 1.4% and 1.8% per year, respectively, whereas rates of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) declined 2.1% per year. Although whites bear the highest incidence burden for most lymphoid neoplasm subtypes, most notably for hairy cell leukemia and follicular lymphoma, black predominance was observed for plasma cell and T-cell neoplasms. Asians have considerably lower rates than whites and blacks for CLL/SLL and Hodgkin lymphoma. We conclude that the striking differences in incidence patterns by histologic subtype strongly suggest that there is etiologic heterogeneity among lymphoid neoplasms and support the pursuit of epidemiologic analysis by subtype.

Is there an association between SV40 contaminated polio vaccine and lymphoproliferative disorders? An age-period-cohort analysis on Norwegian data from 1953 to 1997

Between 1955 and 1963, an estimated number of 150 million people in various parts of the world, including Norway, received poliomyelitis vaccine possibly contaminated with infectious simian virus 40 (SV40). Human studies have investigated the hypothesised association between SV40 and various cancers, but the results have so far been contradicting. The aim of the present study was to examine Norwegian cancer incidence data to assess a possible association between birth cohorts assumed to have been subjected to the vaccine and the incidence rate of lymphoproliferative disorders (excluding Hodgkin's lymphoma), further subdivided into non-Hodgkin's lymphoma (NHL), lymphocytic leukemia and plasma cell neoplasms. Between 1953 and 1997, the incidence rate of lymphoproliferative diseases combined increased about 3-fold in both males and females. Subgroup analysis showed that this increase was largely attributable to NHL. Age-period-cohort modelling of the subgroups, as well as of all groups combined, showed that the cohort effect was more prominent than the period effect. However, the variations in incidence patterns across the birth cohorts did not fit with the trends that would be expected if a SV40 contaminated vaccine did play a causative role. Thus, our data do not support the hypothesis of an association between the vaccine and any subgroup of lymphoproliferative diseases.

Cancer incidence in the south Asian population of California, 1988-2000

BACKGROUND

Although South Asians (SA) form a large majority of the Asian population of U.S., very little is known about cancer in this immigrant population. SAs comprise people having origins mainly in India, Pakistan, Bangladesh and Sri Lanka. We calculated age-adjusted incidence and time trends of cancer in the SA population of California (state with the largest concentration of SAs) between 1988-2000 and compared these rates to rates in native Asian Indians as well as to those experienced by the Asian/Pacific Islander (API) and White, non-Hispanic population (NHW) population of California.

METHODS

Age adjusted incidence rates observed among the SA population of California during the time period 1988-2000 were calculated. To correctly identify the ethnicity of cancer cases, 'Nam Pehchan' (British developed software) was used to identify numerator cases of SA origin from the population-based cancer registry in California (CCR). Denominators were obtained from the U.S. Census Bureau. Incidence rates in SAs were calculated and a time trend analysis was also performed. Comparison data on the API and the NHW population of California were also obtained from CCR and rates from Globocan 2002 were used to determine rates in India.

RESULTS

Between 1988-2000, 5192 cancers were diagnosed in SAs of California. Compared to rates in native Asian Indians, rates of cancer in SAs in California were higher for all sites except oropharyngeal, oesophageal and cervical cancers. Compared to APIs of California, SA population experienced more cancers of oesophagus, gall bladder, prostate, breast, ovary and uterus, as well as lymphomas, leukemias and multiple myelomas. Compared to NHW population of California, SAs experienced more cancers of the stomach, liver and bile duct, gall bladder, cervix and multiple myelomas. Significantly increasing time trends were observed in colon and breast cancer incidence.

CONCLUSION

SA population of California experiences unique patterns of cancer incidence most likely associated with acculturation, screening and tobacco habits. There is need for early diagnosis of leading cancers in SA. If necessary steps are not taken to curb the growth of breast, colon and lung cancer, rates in SA will soon approximate those of the NHW population of California.

Simultaneous presentation of acute monoblastic leukemia and mantle cell lymphoma: case report and review of the literature

This paper reports a 73-year old woman with simultaneous presentation of acute monoblastic leukemia (acute myeloid leukemia (AML), French-American-British (FAB) type M5a) and mantle cell lymphoma. The patient presented with wasting, generalized lymphadenopathy, an extensive infiltrative rash and pancytopenia. Bone marrow and lymph node histopatholology showed extensive infiltration by leukemic monoblasts. Marrow cytogenetics revealed a complex karyotype, including t(8;16)(p11;p13). Flow cytometric immunophenotyping of peripheral blood, lymph node and bone marrow demonstrated two populations, expressing CD5, CD19, CD20 and CD22 and CD45, HLA-DR, CD13, CD33, CD14 and CD38, respectively. A focus of abnormal lymphocytes in the lymph node biopsy demonstrated BCL1 expression and t(11;14)(p11;p13) by fluorescence in situ hybridization and immunoglobulin heavy chain gene rearrangement by the polymerase chain reaction. The patient received infusional cytarabine, daunorubicin and etoposide chemotherapy, with complete remission of both the AML and the mantle cell leukemia. To the authors' knowledge, this is the first report of simultaneous presentations of AML, FAB M5a and mantle cell lymphoma. The case is discussed and the literature is reviewed.

Simian virus 40 tumor antigen expression and immunophenotypic profile of AIDS-related non-Hodgkin's lymphoma

Simian virus 40 (SV40) is associated with some systemic non-Hodgkin's lymphomas (NHL) among HIV-positive patients, based on assays for viral DNA sequences. To investigate the possible production of the viral transforming protein, we examined age-matched case-control specimens from patients with HIV/AIDS for the expression of SV40 large tumor antigen (T-ag). Masked specimens initially examined by polymerase chain reaction (PCR) for polyomavirus and herpesvirus DNA sequences were assessed for the expression of SV40 T-ag and phenotypic lymphocyte markers by immunohistochemistry (IHC). Fifty-five systemic NHL and 25 nonmalignant lymphoid and malignant nonlymphoid tissue control cases from two HIV community programs in Texas and New Jersey were scored for IHC positivity without knowledge of the PCR results. IHC showed expression of SV40 T-ag among B-cell lymphomas, whereas none of the control tissue samples were positive for T-ag (12/55, 22% vs. 0/25, 0%; P = 0.01). SV40 T-ag expression was detected only in B-cell lymphoma specimens that contained SV40 DNA sequences. Not all lymphoma cells in a positive specimen stained for T-ag, and the reaction was lower intensity than observed in SV40 hamster tumors. SV40 T-ag was demonstrated in both primary and recurrent tumors from one patient. A germinal center B-cell-like (GCB) profile was more frequently expressed by SV40-positive tumors than in Epstein-Barr virus (EBV)-related lymphomas (10/12, 83% vs. 6/13, 46%; P = 0.05), whereas a non-GCB phenotype was more frequent in EBV-positive than in SV40-positive lymphomas (7/13, 54% vs. 2/12, 17%; P = 0.05). This study shows that SV40 gene expression occurs in a fraction of cells in some B-cell lymphomas among patients with HIV/AIDS.

Occupational exposure to pesticides and risk of non-Hodgkin's lymphoma

Pesticide exposure may be a risk factor for non-Hodgkin's lymphoma, but it is not certain which types of pesticides are involved. A population-based case-control study was undertaken in 2000-2001 using detailed methods of assessing occupational pesticide exposure. Cases with incident non-Hodgkin's lymphoma in two Australian states (n = 694) and controls (n = 694) were chosen from Australian electoral rolls. Logistic regression was used to estimate the risks of non-Hodgkin's lymphoma associated with exposure to subgroups of pesticides after adjustment for age, sex, ethnic origin, and residence. Approximately 10% of cases and controls had incurred pesticide exposure. Substantial exposure to any pesticide was associated with a trebling of the risk of non-Hodgkin's lymphoma (odds ratio = 3.09, 95% confidence interval: 1.42, 6.70). Subjects with substantial exposure to organochlorines, organophosphates, and "other pesticides" (all other pesticides excluding herbicides) and herbicides other than phenoxy herbicides had similarly increased risks, although the increase was statistically significant only for "other pesticides." None of the exposure metrics (probability, level, frequency, duration, or years of exposure) were associated with non-Hodgkin's lymphoma. Analyses of the major World Health Organization subtypes of non-Hodgkin's lymphoma suggested a stronger effect for follicular lymphoma. These increases in risk of non-Hodgkin's lymphoma with substantial occupational pesticide exposure are consistent with previous work.

Adult lymphomas in Edo state, Niger Delta region of Nigeria - clinicopathological profile of 205 cases

The clinicopathologic features of malignant lymphomas had not been documented in the Niger Delta region of Nigeria, which is known for its petrochemical industries and gas flare sites. Cases of lymphomas that presented to the University of Benin Teaching Hospital (UBTH), a major referral centre in the region, from January 1990 to December 2003 were reviewed. Demographic and clinical information were obtained from the case files. Diagnosis was established based on the histological examination of an accessible biopsy lymph node and classified according to the Working Formulation (WF). Haematological parameters were done using an automated Coulter counter. Non-Hodgkin's lymphoma (NHL) occurred predominantly in young adults (20-39 years). A majority of the patients presented in the advanced stage of the disease (Stages III-IV) according to the Ann Arbor system and a performance status (PS) scale of 2-4. The intermediate grade NHL (41.2%) formed the largest group of which diffuse large cell lymphoma (DLCL) was the most commonly observed histopathologic type followed by the large cell immunoblastic type.

Two cases of non-Hodgkin's lymphoma presenting as primary gynecologic malignancies

BACKGROUND

Non-Hodgkin's lymphoma (NHL) presenting as a gynecologic malignancy is exceedingly rare. We present two cases of NHL presenting as primary ovarian and cervical cancer, respectively.

CASE

A 66-year-old female presented with abdominal bloating and increased abdominal girth. She underwent a supracervical hysterectomy, bilateral salpingo-oophorectomy, and omentectomy for a large pelvic mass. Immunophenotyping/flow cytometry revealed monoclonal B-cells positive for the CD 20 marker, consistent with NHL. A 47-year-old female presented with persistent vaginal discharge and an ulcerative lesion of the cervix. Cervical biopsies were non-diagnostic for carcinoma but immunophenotyping demonstrated CD 20 positive B-cells, consistent with NHL.

CONCLUSION

Although uncommon, lymphoma should be included in the differential diagnosis of gynecologic malignancies because of a favorable outcome when properly diagnosed and treated.

Single nucleotide polymorphism in 5'-flanking region of BCL6 is not associated with increased risk of non-Hodgkin's lymphoma

Mutations in the 5'-regulatory region of BCL6 were suggested to play a role in non-Hodgkin's lymphoma (NHL) progression and in the transformation of follicular lymphoma to more aggressive diffuse large B-cell type. The aim of this study was to explore association between polymorphism G397C in the 5'-region of BCL6 and both incidence and progression of NHL in 154 NHL cases and 362 controls. Neither frequencies of the rare BCL6 allele 397C nor particular genotypes differed significantly between NHL cases and controls. There was no significant association of histological type of NHL and clinical characteristics with this polymorphism.

The role of pixantrone in the treatment of non-Hodgkin’s lymphoma

Pixantrone is an anthraquinone-based inhibitor of topoisomerase II. It is similar to both the anthracycline doxorubicin and the anthracenedione mitoxantrone, but lacks the 5,8-dihydroxy substitution pattern of mitoxantrone, and has a tricyclic system unlike the tetracyclic structure seen with anthracyclines. Anthracyclines are the most active drugs in lymphoma therapy, but their use is limited by their cumulative and irreversible cardiotoxicity. Pixantrone was developed to improve the toxicity profile of the current anthracyclines and anthracenediones while maintaining their activity. Interestingly, pixantrone showed no measurable cardiotoxicity compared with its parent compound mitoxantrone or other anthracyclines at equi-effective doses in several animal models. Together with its superior cytotoxic activity in leukaemia and lymphoma models, these features render the drug a promising candidate for clinical development in indolent and aggressive non-Hodgkin's lymphoma. In this review, the latest results of the use of pixantrone in indolen-t and aggressive non-Hodgkin's lymphomas are summarised.

Genetic analysis of the 2q33 region containing CD28-CTLA4-ICOS genes: association with non-Hodgkin's lymphoma

There is strong evidence that altered immunological function entails an increased risk of lymphoma, although the current knowledge of aetiological factors for lymphomas is limited. The CTLA4 gene encodes a receptor that provides a negative signal to the T-cell once an immune response is initiated and completed. We analysed the 2q33 chromosomal region harbouring CD28, CTLA4 and ICOS genes, which are closely linked and have related functions in immune regulation, for association in 100 non-Hodgkin's lymphoma (NHL) patients and in 128 healthy controls; both groups originated from Sardinia. There was a strong association of the CTLA4 49A and the 3'-untranslated region (AT)(82) alleles with NHL [odds ratio (OR) = 2, 95% confidence interval (CI) = 1.2-3.2, and OR = 1.6, 95% CI = 1.1-2.4 respectively]. CTLA4-318C:49A:(AT)(82) was the most represented haplotype in the studied population and was associated with NHL (P = 0.0029, OR = 1.76, 95% CI = 1.2-2.5). Strong linkage disequilibrium was detected between CD28, CTLA4 and ICOS and a 'common' haplotype was found very frequently among NHLs. However, no independent association between CD28, ICOS, D2S72 markers and NHL was observed. Our findings enable CTLA4 from adjacent functionally related genes as the true causative risk gene for NHL susceptibility at least in Sardinian patients.

Mechanisms of B-cell lymphoma pathogenesis

Chromosomal translocations involving the immunoglobulin loci are a hallmark of many types of B-cell lymphoma. Other factors, however, also have important roles in the pathogenesis of B-cell malignancies. Most B-cell lymphomas depend on the expression of a B-cell receptor (BCR) for survival, and in several B-cell malignancies antigen activation of lymphoma cells through BCR signalling seems to be an important factor for lymphoma pathogenesis. Recent insights into the lymphomagenic role of factors supplied by the microenvironment also offer new therapeutic strategies.

Immunopathogenesis and therapy of cutaneous T cell lymphoma

Cutaneous T cell lymphomas (CTCLs) are a heterogenous group of lymphoproliferative disorders caused by clonally derived, skin-invasive T cells. Mycosis fungoides (MF) and Sezary syndrome (SS) are the most common types of CTCLs and are characterized by malignant CD4(+)/CLA(+)/CCR4(+) T cells that also lack the usual T cell surface markers CD7 and/or CD26. As MF/SS advances, the clonal dominance of the malignant cells results in the expression of predominantly Th2 cytokines, progressive immune dysregulation in patients, and further tumor cell growth. This review summarizes recent insights into the pathogenesis and immunobiology of MF/SS and how these have shaped current therapeutic approaches, in particular the growing emphasis on enhancement of host antitumor immune responses as the key to successful therapy.