Autoimmune and Atopic Disorders and Risk of Classical Hodgkin Lymphoma

Classic Hodgkin lymphoma in young people

Classic Hodgkin lymphoma (CHL) is a unique form of lymphoid cancer featuring a heterogeneous tumor microenvironment and a relative paucity of malignant Hodgkin and Reed-Sternberg (HRS) cells with characteristic phenotype. Younger individuals (children, adolescents and young adults) are affected as often as the elderly, producing a peculiar bimodal age-incidence profile that has generated immense interest in this disease and its origins. Decades of epidemiological investigations have documented the populations most susceptible and identified multiple risk factors that can be broadly categorized as either biological or environmental in nature. Most risk factors result in overt immunodeficiency or confer more subtle alterations to baseline health, physiology or immune function. Epstein Barr virus, however, is both a risk factor and well-established driver of lymphomagenesis in a significant subset of cases. Epigenetic changes, along with the accumulation of somatic driver mutations and cytogenetic abnormalities are required for the malignant transformation of germinal center-experienced HRS cell precursors. Chromosomal instability and the influence of endogenous mutational processes are critical in this regard, by impacting genes involved in key signaling pathways that promote the survival and proliferation of HRS cells and their escape from immune destruction. Here we review the principal features, known risk factors and lymphomagenic mechanisms relevant to newly diagnosed CHL, with an emphasis on those most applicable to young people.

Inflammatory marker testing in primary care in the year before Hodgkin lymphoma diagnosis: a UK population-based case-control study in patients aged ≤50 years

BACKGROUND

Proinflammatory conditions are associated with increased risk of Hodgkin lymphoma, although the neoplastic process per se often induces an inflammatory response.

AIM

To examine pre-diagnostic inflammatory marker test use to identify changes that may define a 'diagnostic window' for potential earlier diagnosis.

DESIGN AND SETTING

This was a matched case-control study in UK primary care using Clinical Practice Research Datalink data (2002-2016).

METHOD

Primary care inflammatory marker test use and related findings were analysed in 839 Hodgkin lymphoma patients and 5035 controls in the year pre-diagnosis. Poisson regression models were used to calculate monthly testing rates to examine changes over time in test use. Longitudinal trends in test results and the presence/absence of 'red-flag' symptoms were examined.

RESULTS

In patients with Hodgkin lymphoma, 70.8% (594/839) had an inflammatory marker test in the year pre-diagnosis versus 16.2% (816/5035) of controls (odds ratio 13.7, 95% CI = 11.4 to 16.5, P<0.001). The rate of inflammatory marker testing and mean levels of certain inflammatory marker results increased progressively during the year pre-diagnosis in Hodgkin lymphoma patients while remaining stable in controls. Among patients with Hodgkin lymphoma with a pre-diagnostic test, two-thirds (69.5%, 413/594) had an abnormal result and, among these, 42.6% (176/413) had no other 'red-flag' presenting symptom/sign.

CONCLUSION

Increases in inflammatory marker requests and abnormal results occur in many patients with Hodgkin lymphoma several months pre-diagnosis, suggesting this period should be excluded in aetiological studies examining inflammation in Hodgkin lymphoma development, and that a diagnostic time window of appreciable length exists in many patients with Hodgkin lymphoma, many of whom have no other red-flag features.

Antibodies as biomarkers for cancer risk: a systematic review

Increasing evidence has linked the humoral immune response with the development of various cancers. Therefore, there is growing interest in investigating the predictive value of antibodies to assess overall and tissue site-specific cancer risk. Given the large amount of antibody types and the broad scope of the search (i.e. cancer risk), the primary aim of this systematic review was to present an overview of the most researched antibodies (i.e. immunoglobulin (Ig) isotypes (IgG, IgM, IgA, and IgE), tumour and self-antigen-reactive antibodies, infection-related antibodies) in relation to overall and site-specific cancer risk. We identified various antibody types that have been associated with the risk of cancer. While no significant associations were found for IgM serum levels, studies found an inconsistent association among IgE, IgA, and IgG serum levels in relation to cancer risk. When evaluating antibodies against infectious agents, most studies reported a positive link with specific cancers known to be associated with the specific agent recognized by serum antibodies (i.e. helicobacter pylori and gastric cancer, hepatitis B virus and hepatocellular carcinoma, and human papillomavirus and cervical cancer). Several reports identified autoantibodies, as single biomarkers (e.g. anti-p53, anti-MUC1, and anti-CA125) but especially in panels of multiple autoantibodies, to have potential as diagnostic biomarkers for specific cancer types. Overall, there is emerging evidence associating certain antibodies to cancer risk, especially immunoglobulin isotypes, tumour-associated antigen-specific, and self-reactive antibodies. Further experimental studies are necessary to assess the efficacy of specific antibodies as markers for the early diagnosis of cancer.

Patients with autoimmune diseases have an altered activity of the PD-1 pathway and proportions of Epstein-Barr virus infected cells in benign lymphadenopathies

Patients with autoimmune diseases (AD) have an increased risk to develop benign lymphadenopathies compared to patients without AD. The aim with this study was to determine the role of the PD-1 pathway and the number of cells harboring Epstein-Barr virus (EBV) in benign lymphadenopathies in patients with AD (cases) compared to patients without AD (controls). Pathology registries were screened to identify patients with biopsies diagnosed as benign lymphadenopathy and medical journals were reviewed for information on AD. Immunohistochemical stainings (PD-1 and PD-L1) and EBER in situ hybridization for EBV were applied on lymph node biopsies in patients with AD (n = 22) and patients without AD (n = 57). The case group was compared with the control group with Wilcoxon-signed rank, chi-square and Fischeŕs exact test. There was a statistically significantly higher proportion of PD-1+ cells and a tendency for a lower prevalence of PD-L1+ and EBV+ cells in cases compared to controls. Apparently, patients with AD have an altered immune response as revealed in benign lymphadenopathies compared to patients without AD. If this association might be a piece of the puzzle for the increased risk of development of lymphomas in patients with AD remains to be determined.

Risk factors for Epstein Barr virus-associated cancers: a systematic review, critical appraisal, and mapping of the epidemiological evidence

BACKGROUND

Epstein Barr Virus (EBV) infects 90%-95% of all adults globally and causes ~ 1% of all cancers. Differing proportions of Burkitt's lymphoma (BL), gastric carcinoma (GC), Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC) are associated with EBV. We sought to systematically review the global epidemiological evidence for risk factors that (in addition to EBV) contribute to the development of the EBV-associated forms of these cancers, assess the quality of the evidence, and compare and contrast the cancers.

METHODS

MEDLINE, Embase and Web of Science were searched for studies of risk factors for EBV-associated BL, GC, HL and NPC without language or temporal restrictions. Studies were excluded if there was no cancer-free comparator group or where analyses of risk factors were inadequately documented. After screening and reference list searching, data were extracted into standardised spreadsheets and quality assessed. Due to heterogeneity, a narrative synthesis was undertaken.

RESULTS

9916 hits were retrieved. 271 papers were retained: two BL, 24 HL, one GC and 244 NPC. The majority of studies were from China, North America and Western Europe. Risk factors were categorised as dietary, environmental/non-dietary, human genetic, and infection and clinical. Anti-EBV antibody load was associated with EBV-associated GC and BL. Although the evidence could be inconsistent, HLA-A alleles, smoking, infectious mononucleosis and potentially other infections were risk factors for EBV-associated HL. Rancid dairy products; anti-EBV antibody and EBV DNA load; history of chronic ear, nose and/or throat conditions; herbal medicine use; family history; and human genetics were risk factors for NPC. Fresh fruit and vegetable and tea consumption may be protective against NPC.

CONCLUSIONS

Many epidemiological studies of risk factors in addition to EBV for the EBV-associated forms of BL, GC, HL and NPC have been undertaken, but there is a dearth of evidence for GC and BL. Available evidence is of variable quality. The aetiology of EBV-associated cancers likely results from a complex intersection of genetic, clinical, environmental and dietary factors, which is difficult to assess with observational studies. Large, carefully designed, studies need to be strategically undertaken to harmonise and clarify the evidence.

REGISTRATION

PROSPERO CRD42017059806.

Epidemiology and Etiology of Leukemia and Lymphoma

Available evidence suggests that the incidence of leukemia and lymphoma tends to be higher in highly developed regions of the world and among Whites in the United States. Temporal trends in incidence are dynamic and multifactorial; for instance, the incidence of non-Hodgkin's lymphoma increased around the turn of the century, in part because of the acquired immune deficiency syndrome (AIDS) epidemic. Most leukemias and lymphomas are sporadic and the specific etiology remains elusive. Still, research shows that these malignancies often develop in the context of genetic abnormalities, immunosuppression, and exposure to risk factors like ionizing radiation, carcinogenic chemicals, and oncogenic viruses. The prognosis varies by subtype, with poorer survival outcomes for acute leukemias among adults, and more favorable outcomes for Hodgkin's lymphoma. At a time when specific prevention efforts targeting these malignancies are nonexistent, there is a great need to ensure equitable access to diagnostic services and treatments worldwide.

Current status and perspectives regarding the association between allergic disorders and cancer

While activation of immune system may lead to a lower risk of some diseases, it has been shown that a history of atopic allergic disorders such as asthma, hay fever, eczema, and food allergies could be related to several types of cancer. However, the evidence is not entirely conclusive. Two proposals suggest a possible mechanism for the association between allergic disorders and cancers: immune surveillance and the antigenic stimulation. The association of allergy and cancer may vary by cancer site and the type of exposure. The aim of current review was to summarize the current knowledge of the association between allergic diseases and the risk of cancers with particular emphasis on case-controls and cohort studies to estimate the cancer risk associated with allergy.

Population-based study of patients with primary Sjögren's syndrome and lymphoma: lymphoma subtypes, clinical characteristics, and gender differences

Objective: To examine lymphoma subtypes, clinical characteristics, and gender differences in patients with primary Sjögren's syndrome (pSS) and lymphoma in a population-based setting.Method: Patients with Sjögren's syndrome and lymphoma diagnoses were identified by linkage of the Swedish Patient Register 1964-2007 with the Cancer Register 1990-2007. Clinical data were collected from medical records and lymphoma tissues were re-examined. The lymphoma subtype distribution was compared with the Swedish Lymphoma Register.Results: We identified 105 pSS patients with lymphoma. Diffuse large B-cell lymphoma (DLBCL) (32%) and marginal zone lymphoma [MZL including mucosa-associated lymphoid tissue (MALT) lymphoma] (31%) were the most common lymphoma subtypes. The proportion of DLBCL was not increased compared to the general population reference (32%, p = 1), in contrast to MZL (general population 5%, p < 0.0001). Compared to DLBCL, MALT lymphoma was diagnosed at a younger age (55 vs 67 years, p = 0.0001), and earlier after patient-reported sicca onset (7 vs 18 years, p = 0.0001) and pSS diagnosis (2 vs 9 years, p = 0.0005). Sixteen of the pSS-lymphoma cases were men (15%), twice the proportion in general pSS populations. Compared to women, men had a shorter median time from pSS diagnosis to lymphoma diagnosis (1 vs 8 years, p = 0.0003) and more often had lymphoma in the salivary glands (56% vs 29%, p = 0.04).Conclusion: DLBCL and MZL are common in pSS patients, but only MZL/MALT lymphoma occurs at an increased relative frequency in pSS compared to the general population. The study supports increased awareness of signs of lymphoma in men in the first years after pSS diagnosis.

Allergic disease, corticosteroid use, and risk of Hodgkin lymphoma: A United Kingdom nationwide case-control study

BACKGROUND

Immunodeficiency syndromes (acquired/congenital/iatrogenic) are known to increase Hodgkin lymphoma (HL) risk, but the effects of allergic immune dysregulation and corticosteroids are poorly understood.

OBJECTIVE

We sought to assess the risk of HL associated with allergic disease (asthma, eczema, and allergic rhinitis) and corticosteroid use.

METHODS

We conducted a case-control study using the United Kingdom Clinical Practice Research Datalink (CPRD) linked to hospital data. Multivariable logistic regression investigated associations between allergic diseases and HL after adjusting for established risk factors. Potential confounding or effect modification by steroid treatment were examined.

RESULTS

One thousand two hundred thirty-six patients with HL were matched to 7416 control subjects. Immunosuppression was associated with 6-fold greater odds of HL (adjusted odds ratio [aOR], 6.18; 95% CI, 3.04-12.57), with minimal change after adjusting for steroids. Any prior allergic disease or eczema alone was associated with 1.4-fold increased odds of HL (aOR, 1.41 [95% CI, 1.24-1.60] and 1.41 [95% CI, 1.20-1.65], respectively). These associations decreased but remained significant after adjustment for steroids (aOR, 1.25 [95% CI, 1.09-1.43] and 1.27 [95% CI, 1.08-1.49], respectively). There was no effect modification by steroid use. Previous steroid treatment was associated with 1.4-fold greater HL odds (aOR, 1.38; 95% CI, 1.20-1.59).

CONCLUSIONS

In addition to established risk factors (immunosuppression and infectious mononucleosis), allergic disease and eczema are risk factors for HL. This association is only partially explained by steroids, which are associated with increased HL risk. These findings add to the growing evidence that immune system malfunction after allergic disease or immunosuppression is central to HL development.

Brentuximab Vedotin: A Nursing Perspective on Best Practices and Management of Associated Adverse Events

BACKGROUND

Brentuximab vedotin (BV) is an antibody-drug conjugate that targets CD30-expressing cells.

OBJECTIVES

This article assesses the occurrence and management of the most frequent and clinically relevant BV-associated adverse events (AEs), with a focus on Hodgkin lymphoma and systemic anaplastic large cell lymphoma trials, and shares practical tips that may help decrease occurrence and severity.

METHODS

Peer-reviewed literature was surveyed to collect safety data from sponsored clinical trials of BV and to compile associated management guidelines.

FINDINGS

Peripheral neuropathy was the most common BV-associated AE across clinical trials. Other clinically relevant AEs included neutropenia, infection, and infusion-related reactions. Awareness of and preparedness for these common BV-associated AEs and other less common but significant AEs will help nurse clinicians and patients maximize the clinical benefit for patients receiving BV.

Other immunomodulatory agent-related lymphoproliferative diseases: a single-center series of 72 biopsy-confirmed cases

Ongoing development of new drugs, as well as novel indications in the treatment of autoimmune diseases leads to the increasing use of immunomodulatory and immunosuppressive drugs. Immunomodulatory agent-related lymphoproliferative disorders are a known and potentially life threatening complication of chronic administration of these drugs, but are less well characterized compared with post-transplant lymphoproliferative disorders. The heterogeneous drug targets, various underlying disease indications, different drug combinations used and relatively low incidence render data collection and interpretation difficult. In this retrospective paper, we describe the clinicopathological characteristics of a larger single-center series of 72 immunomodulatory agent-related lymphoproliferative disorder cases. We divided the cases according to the therapy, administered in the year preceding diagnosis of a lymphoproliferative disorder, in an immunosuppressive drug, an immunomodulatory drug and a combination of immunosuppressive and immunomodulatory drugs group. We observed differences in "time to lymphoproliferative disorder development" with a shorter time for all the immunomodulatory drug-related cases combined (immunomodulatory and immunomodulatory + immunosuppressive = immunomodulatory-all) vs immunosuppressive-only (p = 0.0031). The proportion of malignant cases in patients receiving immunomodulatory therapy was, however, also significantly lower when compared with the immunosuppressive treated cases (43 vs 88%; p = 0.0184). The immunomodulatory/suppressive agent-related lymphoproliferative disorders were less often associated with the Epstein-Barr virus (EBV) (31 vs 66%; p = 1.829e-05) and the lymphoproliferative disorders incidence in the first year after immunomodulatory/immunosuppressive therapy initiation was lower (18 vs 41%; p = 0.04151)-compared with a published series of 140 post-transplant lymphoproliferative disorder cases from the same center. However, a similar histopathological spectrum from nondestructive, to polymorphic and monomorphic lesions as in post-transplant lymphoproliferative disorders is observed. With increasing use of immunosuppressive and especially immunomodulatory therapy, a higher incidence of immunomodulatory/suppressive agent-related lymphoproliferative disorders is to be expected. Life-long awareness for development of immunomodulatory/suppressive agent-related lymphoproliferative disorders with clinical follow-up and timely biopsies of suspicious lesions is required since these lymphoproliferative disorders arise both early after therapy initiation and many years later. Histopathological confirmation and correct classification is necessary to guide therapy and EBV ISH should be a part of routine pathological diagnostics.

Description of Malignancy Rates in Childhood- and Adult-Onset Systemic Lupus Erythematous by Proportional Meta-analysis

OBJECTIVE

Describe malignancy rates in childhood onset and adult onset systemic lupus erythematous (SLE) by proportional meta-analysis.

METHODS

Two reviewers screened data from PubMed (1966-2015), EMBASE (1980-2015), and LILACS (1982-2015) for SLE-associated malignancy. Proportional meta-analysis with a random-effects model and 95% confidence intervals (CIs) were calculated according to SLE onset age and mean follow-up time. Statistical difference was defined by 95% CI overlap.

RESULTS

Overall the malignancy rate reported in 30 case series with 96,578 subjects was 3.4% (95% CI, 0.0260-0.0442; I = 97.6%; P < 0.0001). The malignancy rate was 4.2% (95% CI, 0.0318-0.0531; I = 98%; P < 0.0001) in 25 adult-onset SLE series, compared with 0.5% (95% CI, 0.0003-0.0154; I = 62.6%; P = 0.03) in 5 childhood-onset SLE series. Overall, in those with less than 5 years' follow-up, the malignancy rate was 2.8% (95% CI, 0.013-0.047; I = 91%; P < 0.0001) compared with 3.6% (95% CI, 0.0226-0.0531; I = 98.3%; P < 0.0001) in those with more than 5 years' follow-up, which was not significant, with 95% CI overlap.

CONCLUSIONS

The meta-analysis indicated lower malignancy rates in pediatric-onset SLE compared with adult-onset SLE, but accrued data from childhood-onset SLE are still needed.

Spectrum of lymphomas across different drug treatment groups in rheumatoid arthritis: a European registries collaborative project

BACKGROUND

Lymphomas comprise a heterogeneous group of malignant diseases with highly variable prognosis. Rheumatoid arthritis (RA) is associated with a twofold increased risk of both Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). It is unknown whether treatment with biologic disease-modifying antirheumatic drugs (bDMARDs) affect the risk of specific lymphoma subtypes.

METHODS

Patients never exposed to (bionaïve) or ever treated with bDMARDs from 12 European biologic registers were followed prospectively for the occurrence of first ever histologically confirmed lymphoma. Patients were considered exposed to a bDMARD after having received the first dose. Lymphomas were attributed to the most recently received bDMARD.

RESULTS

Among 124 997 patients (mean age 59 years; 73.7% female), 533 lymphomas were reported. Of these, 9.5% were HL, 83.8% B-cell NHL and 6.8% T-cell NHL. No cases of hepatosplenic T-cell lymphoma were observed. Diffuse large B-cell lymphoma (DLBCL) was the most frequent B-cell NHL subtype (55.8% of all B-cell NHLs). The subtype distributions were similar between bionaïve patients and those treated with tumour necrosis factor inhibitors (TNFi). For other bDMARDs, the numbers of cases were too small to draw any conclusions. Patients with RA developed more DLBCLs and less chronic lymphocytic leukaemia compared with the general population.

CONCLUSION

This large collaborative analysis of European registries has successfully collated subtype information on 533 lymphomas. While the subtype distribution differs between RA and the general population, there was no evidence of any modification of the distribution of lymphoma subtypes in patients with RA treated with TNFi compared with bionaïve patients.

Allergic conditions are not associated with the risk of non-Hodgkin's lymphoma or Hodgkin's lymphoma: a systematic review and meta-analysis

We aimed to systematically evaluate the association between allergic conditions and the risk of Hodgkin’s lymphoma (HL) and non-HL (NHL). Systematic literature searches in PubMed and Embase were conducted up to October 2015 to identify eligible studies. Either a fixed-effects model or a random-effects model was adopted to estimate overall odds ratios (ORs) according to heterogeneity across studies. Subgroup and publication bias analyses were applied. A total of 24 case–control studies and 13 cohort studies (conducted from 1987 to 2015) were included in the analysis of the risk of NHL. History of any allergic condition was inversely associated with the risk of NHL in case–control studies (OR =0.83, 95% CI 0.76–0.91), while the reduction in the risk of NHL was not observed in cohort studies (OR =1.18, 95% CI 0.98–1.42). Significant association with the risk of NHL was found for asthma, hay fever, food allergy, allergic rhinitis, and hives. In the pooled analysis of the risk of HL, 12 studies (two were cohort studies) were included. The pooled OR was 0.96 (95% CI 0.84–1.09) for case–control studies and 1.46 (95% CI 0.63–3.38) for cohort studies. For specific allergic condition, we observed a reduced risk of HL in individuals with hay fever and food allergy. In conclusion, history of any allergic condition was not significantly associated with the risk of NHL or HL. Several specific allergic conditions, including asthma, hay fever, food allergy, and allergic rhinitis, might be associated with a reduced risk of NHL, while individuals with hay fever or food allergy may have a reduced risk of HL.

Elevated Serum Levels of sCD30 and IL6 and Detectable IL10 Precede Classical Hodgkin Lymphoma Diagnosis

Background: We investigated whether an immune system environment characterized by elevated serum levels of B-cell activation molecules was associated with the subsequent development of classical Hodgkin lymphoma (cHL).Methods: We measured serum levels of B-cell-stimulatory cytokines, IL6 and IL10, soluble CD30 (sCD30), and total IgE prior to cHL diagnosis in 103 cases and 206 matched controls with archived specimens in the DoD Serum Repository.Results: Prediagnosis serum sCD30 and IL6 levels had strong positive associations with risk of a cHL diagnosis 0 to 1 year prior to diagnosis [sCD30 OR = 5.5; 95% confidence interval (CI), 3.4-9.0; IL6 OR = 4.6; 95% CI, 2.9-7.5] and >1 year to 2 years pre-cHL diagnosis (sCD30 OR = 3.3; 95% CI, 1.6-6.7; IL6 OR = 2.9; 95% CI, 1.3-6.5). We observed similar, albeit not consistently significant positive associations, over 4 or more years preceding diagnosis. We did not observe a clear association with IgE levels. Of note, detectable IL10 levels were significantly associated with Epstein-Barr virus (EBV)-positive cHL cases compared with EBV-negative cases.Conclusion: In this prospective analysis, elevated sCD30 and IL6 levels and detectable IL10 preceded cHL diagnosis.Impact: The associations of these cytokines with cHL risk may reflect the production of these molecules by proliferating nascent cHL tumor cells, or by immune cells responding to their presence, prior to clinical detection. The stable elevation in cHL risk, 4 or more years prediagnosis, also suggests that a B-cell-stimulatory immune system milieu precedes, and may promote, lymphomagenesis. Cancer Epidemiol Biomarkers Prev; 26(7); 1114-23. ©2017 AACR.

Increased healthcare use up to 10 years among relapse-free Hodgkin lymphoma survivors in the era of intensified chemotherapy and limited radiotherapy

With today's excellent cure rates for Hodgkin lymphoma (HL), the number of long-term survivors is increasing. This study aims to provide a global assessment of late adverse effects for working-age HL survivors treated with contemporary protocols (combination chemotherapy and limited radiotherapy). From Swedish nationwide registers we identified 1017 HL survivors diagnosed in 2000-2009, aged 18-60 years (median 32) and surviving at least one year post-diagnosis, and 4031 age-, sex-, and calendar-year-matched population comparators. Incidence rate ratios (IRR) and 95% confidence intervals (95%CI) for outpatient visits and inpatient bed-days after the first year up to 14 years post-diagnosis (through 2013) were estimated across treatment subgroups, considering relapse-free time and using negative binomial regression. Scheduled outpatient visits for HL were excluded. The rate of outpatient visits was nearly double (IRR = 1.8, 95%CI: 1.6-2.0) that among comparators and higher rates persisted up to 10 years post-diagnosis. The rate of inpatient bed-days among relapse-free survivors was more than three-fold (IRR = 3.6, 95%CI: 2.7-4.7) that of comparators and the increase persisted up to four years post-diagnosis. Patients requiring 6-8 chemotherapy courses had higher rates of outpatient visits (IRR = 1.4, 95%CI: 1.1-1.7) and bed-days (IRR = 4.7, 95%CI: 2.9-7.8) than patients treated with 2-4 courses + radiotherapy. Previously seldom reported reasons for the excess healthcare use included chest pain, keratitis, asthma, diabetes mellitus, and depression. Contemporary treatment, chemotherapy in particular, was associated with excess healthcare use among HL survivors during the first decade postdiagnosis. The reasons for healthcare visits reflected a wide range of disorders, indicating the need of broad individualized care in addition to specific screening programs.

Risk of lymphoid neoplasms in a Swedish population-based cohort of 337,437 patients undergoing appendectomy

OBJECTIVE

Appendectomy remains one of the most common surgical procedures, but possible long-term consequences for health and disease are incompletely investigated. The appendix forms part of the secondary lymphoid system and appendectomy has been associated with increased risks of hematolymphoproliferative malignancies in some studies.

MATERIALS AND METHODS

We examined the risk of lymphoid neoplasms in a large cohort of 337,437 appendectomised patients <60 years of age in Sweden 1975-2009. We estimated relative risks of non-Hodgkin lymphoma (NHL) and major subtypes, Hodgkin lymphoma (HL), chronic lymphocytic leukaemia (CLL), myeloma, and acute lymphoblastic leukaemia (ALL) versus the general population using standardised incidence ratios (SIRs) with 95% confidence intervals (CIs).

RESULTS

There was no increased risk of NHL (SIR = 0.97, 95%CI 0.88-1.06), major NHL subtypes, CLL (SIR = 0.87, 95%CI 0.70-1.06), myeloma (SIR = 1.14, 95%CI 0.96-1.33) or ALL (SIR = 1.10, 95%CI 0.80-1.47) following appendectomy. An increased risk of HL was observed among patients diagnosed with appendicitis (SIR = 1.29, 95%CI 1.07-1.54, p=0.007), especially individuals aged <20 years at surgery (SIR = 1.43, 95%CI 1.11-1.82), and for the nodular sclerosis subtype of HL (SIR = 1.55, 95%CI 1.01-2.27). A marginally increased risk of myeloma was noted among men, but the association was limited to the first few years of follow-up.

CONCLUSION

Appendectomy is not associated with any notable increase in risk of lymphoid neoplasms. A small increased risk of HL following appendicitis (rather than appendectomy per se) could reflect a true association, or shared susceptibility to infection/inflammation among individuals prone to develop HL. The association observed for myeloma may be explained by chance or surveillance bias.