Exposure to animals and increased risk of marginal zone B-cell lymphomas of the ocular adnexae

Epidemiology of Marginal Zone Lymphoma

In 2016 there were an estimated 7,460 newly diagnosed patients with marginal zone lymphoma (MZL) in the US, which comprised 7% of all mature non-Hodgkin lymphomas (NHL). Based on data from the US SEER-18 program from 2001-2017, the age-standardized incidence rate for MZL was 19.6 per 1,000,000 person-years; 9% of MZL cases were splenic MZL (SMZL), 30% nodal MZL (NMZL), and 61% extranodal MZL (EMZL) of mucusa-associated lymphoid tissue (MALT). Incidence rates were slightly higher in men for SMZL and NMZL, but similar for EMZL, and increased steeply with age for all MZL subtypes. The incidence (age-standardized per 1,000,000) of MZL was highest among non-Hispanic whites (20.7), followed by Hispanics of all races (17.6), non-Hispanic blacks (15.4), and Asian/Pacific islanders (15.0). The incidence of MZL increased +1.0% per year in the US from 2001-2017, with increases reported in other countries during this timeframe. The 5-year relative survival rate for MZL in the US was 89.8% and was similar across racial/ethnic groups and by sex; survival rates have been increasing in the US and other countries. Established risk factors for MZL (or MZL subtypes) include family history of NHL, genetic loci in the HLA region, Helicobacter pylori infection (gastric MALT lymphoma), and several autoimmune diseases (Sjögren syndrome, systemic lupus erythematosus and Hashimoto thyroiditis), with strong (but not definitive) evidence for Chlamydia psittaci (ocular adnexal MALT lymphoma), Borrelia burgdorferi (cutaneous MZL), hepatitis C virus, human immunodeficiency virus, and solid organ transplantation. Promising risk factors that require additional study include other infections, other autoimmune conditions, trichloroethylene exposure, certain occupations, hair dye, cigarette smoking, sun exposure (protective), and alcohol use (protective). MZL is a model of an antigen-driven malignancy, where epidemiologic risk factors, tissue-specific factors, and host immune response (including the impact of chronic inflammation and immunosuppression) drive lymphomagenesis with implications for prevention.

Bacterial infection and non-Hodgkin's lymphoma

One quarter of all cancers are linked to infectious diseases. The link between viral infection and cancer has been widely studied, but few reports have focused on the carcinogenic role of bacterial infection. Nonetheless, Helicobacter pylori, Chlamydia psittaci, Coxiella burnetii, Borrelia burgdorferi and Campylobacter jejuni are bacteria that can be associated with non-Hodgkin's lymphoma (NHL), the most common haematologic malignancy. Here, we review the evidence in favour of a link between these bacterial infections and NHL. Sero-epidemiological observation makes it possible to identify a link between H. pylori, C. burnetii, B. burgdorferi infection and NHL. Helicobacter pylori, Chlamydia psittaci, Coxiella burnetii, Borrelia burgdorferi and Campylobacter jejuni could be identified in NHL tissue samples at the site of chronic inflammation, where B and T lymphocytes are attracted to participate in follicle formation. Lymphoma remissions have been observed under antimicrobial therapies supporting the carcinogenic contribution of bacteria. If the theory of causality is characterized by the lack of universal criteria for establishing a causal link between two diseases, infection and lymphoma, epidemiological, clinical, and histological evidences reported here, should lead clinicians to pay attention to these infectious agents, to detect early lymphoma transformation.

The aetiology of B-cell lymphoid malignancies with a focus on chronic inflammation and infections

B-cell malignancies are a heterogeneous group of lymphoproliferative disorders with different molecular characteristics and clinical course. It is increasingly recognized that the group displays considerable heterogeneity also regarding aetiologic factors. Here, we summarize the latest developments in the aetiology of B-cell lymphoid malignancy subtypes focusing on immune perturbation. Severe immune suppression constitutes a strong and well-established risk factor for aggressive subtypes (e.g. diffuse large B-cell and Burkitt lymphoma), but appears unrelated to risk of common low-grade subtypes (e.g. follicular and mantle cell lymphoma). Inflammation and infections are known co-factors amongst the immunosuppressed; however, immune stimulation is now recognized as a crucial determinant of lymphomagenesis also amongst immunocompetent individuals. This is best exemplified in marginal zone lymphomas where local chronic inflammation and infection in the stomach, ocular adnexa and salivary glands have been directly linked with the development of oligoclonal and monoclonal malignant B-cell populations. Aggressive subtypes (e.g. diffuse large B-cell lymphoma) are increasingly linked with features of systemic immune stimulation including autoimmune/inflammatory disease and subclinical cytokine elevations. Lifestyle factors (e.g. high body mass index, cigarette smoking) are associated with risk of diffuse large B-cell and follicular lymphoma, respectively, possibly mediated through inflammation. Recent genome-wide association studies further underline the importance of immune function by linking several subtypes to variations in the human leucocyte antigen (HLA) class genes. In the future, improved knowledge of mechanistic pathways of inflammation/infections in lymphoma development may translate to active measures of prevention or treatment, as is already the case for some low-grade lymphoma subtypes.

Ocular adnexal marginal zone lymphoma: Clinical presentation, pathogenesis, diagnosis, prognosis, and treatment

Ocular adnexal marginal zone lymphoma (OAML) represents 1-2% of all non Hodgkin lymphomas. In the last few years many advances in understanding the pathogenesis and the molecular basis involved in its development have been done. Many potential risk factors have been proposed; a dysregulation of immune response in association with a chronic antigenic stimulation, have been hypothesized as possible pathogenic mechanism. In particular, Chlamydia psittaci infection has been related to OAML arising, and eradicating antibiotic therapy has been addressed as a safe and cost-effective approach. Management of OAML is still heterogeneous and matter of debate. There is no consensus about the best upfront treatment and therapeutic decision should take into account several patient-, lymphoma- and treatment-related factors. Novel agents and chemotherapy-free strategies are being investigated to reduce side effects and improve tumor control. This review is focused in recent knowledge improvements in this lymphoma.

Clinicopathologic characteristics and treatment of marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) accounts for 7% to 8% of newly diagnosed lymphomas. Because of its association with infectious causes, such as Helicobacter pylori (HP) or Chlamydophila psittaci (CP), and autoimmune diseases, it has become the paradigm of an antigen-driven malignancy. MALT lymphoma usually displays an indolent course, and watch-and-wait strategies are justified initially in a certain percentage of patients. In patients with gastric MALT lymphoma or ocular adnexal MALT lymphoma, antibiotic therapy against HP or CP, respectively, is the first-line management of choice, resulting in lymphoma response rates from 75% to 80% after HP eradication and from 33% to 65% after antibiotic therapy for CP. In patients who have localized disease that is refractory to antibiotics, radiation is widely applied in various centers with excellent local control, whereas systemic therapies are increasingly being applied, at least in Europe, because of the potentially systemic nature of the disease. Therefore, the objective of this review is to briefly summarize the clinicopathologic characteristics of this distinct type of lymphoma along with current data on management strategies.

Medical history, lifestyle, family history, and occupational risk factors for marginal zone lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Marginal zone lymphoma (MZL), comprised of nodal, extranodal, and splenic subtypes, accounts for 5%-10% of non-Hodgkin lymphoma cases. A detailed evaluation of the independent effects of risk factors for MZL and its subtypes has not been conducted.

METHODS

Data were pooled from 1052 MZL cases (extranodal [EMZL] = 633, nodal [NMZL] = 157, splenic [SMZL] = 140) and 13766 controls from 12 case-control studies. Adjusted unconditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Novel findings for MZL subtypes include increased risk for B-cell activating autoimmune conditions (EMZL OR = 6.40, 95% CI = 4.24 to 9.68; NMZL OR = 7.80, 95% CI = 3.32 to 18.33; SMZL OR = 4.25, 95% CI = 1.49 to 12.14), hepatitis C virus seropositivity (EMZL OR = 5.29, 95% CI = 2.48 to 11.28), self-reported peptic ulcers (EMZL OR = 1.83, 95% CI = 1.35 to 2.49), asthma without other atopy (SMZL OR = 2.28, 95% CI = 1.23 to 4.23), family history of hematologic cancer (EMZL OR = 1.90, 95% CI = 1.37 to 2.62) and of non-Hodgkin lymphoma (NMZL OR = 2.82, 95% CI = 1.33 to 5.98), permanent hairdye use (SMZL OR = 6.59, 95% CI = 1.54 to 28.17), and occupation as a metalworker (NMZL OR = 3.56, 95% CI = 1.67 to 7.58). Reduced risks were observed with consumption of any alcohol (EMZL fourth quartile OR = 0.48, 95% CI = 0.28 to 0.82) and lower consumption of wine (NMZL first to third quartile ORs < 0.45) compared with nondrinkers, and occupation as a teacher (EMZL OR = 0.58, 95% CI = 0.37 to 0.88).

CONCLUSION

Our results provide new data suggesting etiologic heterogeneity across MZL subtypes although a common risk of MZL associated with B-cell activating autoimmune conditions was found.

[Exposure to animals and non-Hodgkin lymphomas: pilot analysis about 261 cases]

This study investigated a possible link between the occupational or domestic exposure to animals and a histological subgroup of non-Hodgkin lymphomas (LNH) (diffuse large B-cell lymphomas [LDGCB], follicular lymphomas [LF], indolent non-follicular LNH [LNHINF] and T-cell LNH). This retrospective, descriptive study was carried out over one year in a regional cancer research center. Data on occupational and domestic exposures to animals, from patients treated for a LNH, was collected via a questionnaire. Among the 261 participants, 73.9% reported they had been exposed to animals, 5% were exposed at work, whereas 72.4% were exposed in a domestic setting. The occupational exposure tended to be more frequent in the subgroup of patients with a LF (P = 0.06). The domestic exposure was less frequent (P = 0.04) in patients with LDGCB (63.0%) than in patients with a small cell LNH B (LF and LNHINF) (76.0%). Although there was no obvious link between occupational or domestic exposure to animals and one of the four histological subgroups of LNH, domestic exposure seemed less common among LDGCB patients. These results need to be confirmed by further studies.

Marginal zone lymphomas and infectious agents

A link with infectious agents, bacteria and viruses in particular, has been reported for many lymphoma entities. Marginal zone lymphomas (extranodal, nodal and splenic forms) are frequently associated with chronic infections, with important clinical, molecular, biological, and therapeutic implications. The well-known correlation between Helicobacter pylori and gastric MALT-lymphoma, the recently reported links between Chlamydophila psittaci and ocular adnexal MALT-lymphoma and Borrelia burgdorferi and cutaneous MALT lymphoma constitute the best studied examples of lymphomagenic activity of bacteria, while the hepatitis C virus represents the most extensively investigated virus associated with marginal zone lymphomas. Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review.

Central nervous system lymphoma newly developed 12 years after remission of an ocular adnexal lymphoma

Recurrence of non-Hodgkin's lymphoma more than 5 years after the initial diagnosis is rare. When late relapse occurs, it is difficult to determine whether it is a true recurrence or a new lesion. We experienced a case of an 81-year-old woman who developed central nervous system (CNS) lymphoma 12 years after remission of ocular adnexal lymphoma. Both showed the histology of diffuse large B-cell lymphoma. To elucidate whether the CNS lymphoma was clonally related to the first lymphoma, rearrangement of the immunoglobulin heavy chain genes of each lymphoma was studied using a polymerase chain reaction-based method. The results revealed that the sizes of the amplified products of the rearranged regions from the two lymphomas were different. This suggested different clonal origins of the lymphomas. It is clinically important to determine the origin of a second neoplasm because patients with a clonally related second lymphoma are usually treated with more intensive regimens, while those with a clonally unrelated lymphoma receive standard first-line therapy. The present case shows that, in the case of recurrent non-Hodgkin's lymphoma, not only histological confirmation but also genetic assessment is important to clarify the origin of the second lymphoma.