History of infections and vaccinations and risk of lymphoid neoplasms: does influenza immunization reduce the risk?

Vaccination History and Risk of Lymphoma and Its Major Subtypes

BACKGROUND

Vaccinations have been hypothesized to play a role in lymphoma etiology, but there are few studies, mixed results, and limited data on lymphoma subtypes. Herein, we investigate the association of vaccinations with risk of major lymphoma subtypes.

METHODS

We studied 2,461 lymphoma cases and 2,253 controls enrolled from 2002 to 2014. Participants self-reported history of vaccinations against hepatitis A, hepatitis B, yellow fever, and influenza. Polytomous logistic regression was used to estimate OR and 95% confidence intervals (CI), adjusting for potential confounders.

RESULTS

After multivariable adjustment, vaccination against influenza was inversely associated with lymphoma (OR = 0.82; 95% CI, 0.66-1.02), which was stronger for last vaccination 1+ years before enrollment (OR = 0.71; 95% CI, 0.56-0.91) and for >5 influenza vaccinations (OR = 0.56; 95% CI, 0.46-0.68). Ever vaccination against hepatitis A (OR = 0.81; 95% CI, 0.66-1.00) but not hepatitis B (OR = 0.97; 95% CI, 0.81-1.18) was associated with lymphoma risk, although more recent vaccinations were inversely associated with lymphoma risk for both hepatitis A (<6 years before enrollment, OR = 0.56; 95% CI, 0.40-0.77) and hepatitis B (<9 years before enrollment, OR = 0.72; 95% CI, 0.55-0.93). Ever vaccination against yellow fever was inversely associated with risk (OR = 0.73; 95% CI, 0.55-0.96), and this did not vary by time since last vaccination. Although there was no overall statistical evidence for heterogeneity of vaccination history by lymphoma subtype, the only statistically significant inverse associations were observed for influenza and yellow fever vaccinations with diffuse large B-cell and follicular lymphoma.

CONCLUSIONS

Selected vaccinations were inversely associated with lymphoma risk, with time since last vaccination relevant for some of these vaccines.

IMPACT

Vaccinations against hepatitis A, hepatitis B, yellow fever, and influenza are unlikely to increase lymphoma risk.

Association between Bacillus Calmette-Guerin (BCG) vaccination and lymphoma risk: A systematic review and meta-analysis

Lymphoma etiology remains ill-defined, but immune factors seem to play a major role. The Bacillus Calmette-Guérin (BCG) vaccine, a non-specific stimulator of the cellular immune response, could influence lymphoma risk. Previous studies addressing this issue showed conflicting results. In this study, we performed a systematic review and meta-analysis to synthesize the epidemiological evidence. We conducted a systematic search of all relevant articles in PubMed, Embase, Library and Archives Canada, and Cochrane databases, up to November 1^st 2018. A total of 11 studies were included. Each study was summarized, methodological quality was assessed by independent evaluators, and a consensus score was generated. Heterogeneity and publication bias were evaluated. Summary odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated separately for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL) by either a fixed effect (FE) or a random effect (RE) model depending on heterogeneity. In this meta-analysis, BCG vaccination was not associated with HL (FE summary OR = 1.10; 95 % CI 0.93-1.30), but positively associated with NHL (RE summary OR = 1.20; 95 % CI 1.01-1.43). However, when restricting to higher quality studies, no association was found between BCG vaccination and either HL (RE summary OR = 0.97; 95 % CI 0.67-1.43) or NHL (RE summary OR = 1.15; 95 % CI 0.84-1.59). Overall, our findings do not support that BCG vaccination is associated with lymphoma risk. Yet, lack of statistical power and relatively high heterogeneity among studies prevent us from making definitive conclusions. Future studies investigating this issue are needed, using robust methodology.

Association between Bacillus Calmette-Guérin vaccination and lymphoma: a population-based birth cohort study

BACKGROUND

Most risk factors for lymphoma identified so far relate to immunosuppression, but its aetiology remains unclear.

OBJECTIVES

We investigated whether Bacillus Calmette-Guérin (BCG) vaccination is associated with lymphoma, overall and separately for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL).

METHODS

A cohort of 400 611 subjects born in the province of Québec, Canada, between 1970 and 1974 was used. Information on BCG vaccination was extracted from the Quebec BCG Vaccination Registry. Lymphomas cases were individuals who had ≥2 health encounters, medical visits or hospitalizations, for lymphoma within 2 months or who were identified through the Quebec Tumor Registry. Cox proportional hazard regression was used to estimate hazard ratios (HRs) and 95% confidence interval (CI), adjusting for potential confounders.

RESULTS

A total of 178 335 (46.0%) subjects were BCG-vaccinated, and 1478 (0.38%) cases of lymphomas were ascertained. Amongst them, 922 were identified as NHL and 421 as HL. After adjustment, no association was observed between BCG vaccination and either lymphoma (any type) (HR = 1.03, 95% CI: 0.96-1.11) or NHL (HR = 0.99, 95% CI: 0.86-1.13). For HL, nonproportional hazards were observed. Before the age of 18, the risk of HL was elevated amongst vaccinated individuals (HR = 2.26, 95% CI: 1.39-3.69). However after 18 years of age, no association was found (HR = 0.93, 95% CI: 0.75-1.15).

CONCLUSION

Bacillus Calmette-Guérin vaccination may increase the risk of HL before 18 years of age, but residual confounding cannot entirely be excluded. Given the benefits of BCG vaccination, these results need to be reproduced in other populations before firm conclusions can be drawn.

Childhood use of antimicrobials and risk of Hodgkin lymphoma: a Danish register-based cohort study

The peculiar bimodal age distribution of Hodgkin lymphoma (HL), together with other epidemiological findings, inspired the so-called "late infection hypothesis" in the 1970s. Under this model, HL in young adults is caused by delayed infection with a relatively common agent, with HL risk increasing with age at infection. We time-dependently tallied prescriptions filled, for a broad spectrum of antimicrobials, at age 0 to 9 years for all Danish HL patients diagnosed in 1997 to 2015 at age 10 to 25 years (n = 296) and up to 10 controls for each of these, individually matched for sex and birthdate (n = 2688). Antimicrobial use was taken as a proxy for general infectious disease pressure. Analyses were also stratified by the 2 main histological subtypes: nodular sclerosis HL (NSHL) (n = 206) and mixed cellularity HL (MCHL) (n = 47). We compared antimicrobial use at ages 0 to 9 years between cases and comparators using stratified Cox regressions with repeated follow-up for a next prescription, to produce hazard ratios (HRs) of antimicrobial use according to (future) HL status. Reverse causation was mitigated by disregarding risk time <2 years before HL (pseudo)diagnosis. Analyses were adjusted for number of older and younger siblings. NSHL patients had received statistically significantly fewer antimicrobials than comparators early in life (HR_{0-2 years}, 0.79; 95% confidence interval, 0.66-0.95), whereas patients with MCHL had received statistically significantly more antimicrobials than comparators throughout the first 10 years of life (HR_{0-9 years}, 1.53; 95% confidence interval, 1.33-1.76). The late infection hypothesis was supported in NSHL, whereas immune dysfunction seemed more prominent in MCHL etiology.

Lack of evidence for post-vaccine onset of autoimmune/lymphoproliferative disorders, during a nine-month follow-up in multiply vaccinated Italian military personnel

Anecdotal case reports, amplified by mass media and internet-based opinion groups, have recently indicated vaccinations as possibly responsible for autoimmunity/lymphoproliferation development. Multiply vaccinated Italian military personnel (group 1, operating in Italy, group 2, operating in Lebanon) were followed-up for nine months to monitor possible post-vaccine autoimmunity/lymphoproliferation onset. No serious adverse event was noticed in both groups. Multivariate analysis of intergroup differences only showed a significant association between lymphocyte increase and tetanus/diphtheria vaccine administration. A significant post-vaccine decrease in autoantibody positivity was observed. Autoantibodies were also studied by microarray analysis of self-proteins in subjects exposed to ≥4 concurrent vaccinations, without observing significant difference among baseline and one and nine months post-vaccine. Moreover, HLA-A2 subjects have been analyzed for the possible CD8T-cell response to apoptotic self-epitopes, without observing significant difference between baseline and one month post-vaccine. Multiple vaccinations in young adults are safe and not associated to autoimmunity/lymphoproliferation onset during a nine-month-long follow-up.

Medical history, lifestyle, family history, and occupational risk factors for lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/WM), a rare non-Hodgkin lymphoma subtype, shows strong familial aggregation and a positive association with chronic immune stimulation, but evidence regarding other risk factors is very limited.

METHODS

The International Lymphoma Epidemiology Consortium (InterLymph) pooled data from 11 predominantly population-based case-control studies from North America, Europe, and Australia to examine medical history, lifestyle, family history, and occupational risk factors for LPL/WM. Age-, sex-, race/ethnicity-, and study-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression for a total of 374 LPL/WM cases and 23 096 controls.

RESULTS

In multivariate analysis including all putative risk factors, LPL/WM risk was associated with history of Sjögren's syndrome (OR = 14.0, 95% CI = 3.60 to 54.6), systemic lupus erythematosus (OR = 8.23, 95% CI = 2.69 to 25.2), hay fever (OR = 0.73, 95% CI = 0.54 to 0.99), positive hepatitis C serology (OR = 2.51, 95% CI = 1.03 to 6.17), hematologic malignancy in a first-degree relative (OR = 1.64, 95% CI = 1.02 to 2.64), adult weight (OR = 0.61, 95% CI = 0.44 to 0.85 for highest vs. lowest quartile), duration of cigarette smoking (OR = 1.46, 95% CI = 1.04 to 2.05 for ≥ 40 years vs. nonsmokers), and occupation as a medical doctor (OR = 5.54, 95% CI = 2.19 to 14.0). There was no association with other medical conditions, lifestyle factors, or occupations.

CONCLUSIONS

This pooled analysis confirmed associations with immune conditions and family history of hematologic malignancy, and identified new associations with hay fever, weight, smoking, and occupation, and no association with other lifestyle factors. These findings offer clues to LPL/WM biology and prevention.

Rationale and Design of the International Lymphoma Epidemiology Consortium (InterLymph) Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Non-Hodgkin lymphoma (NHL), the most common hematologic malignancy, consists of numerous subtypes. The etiology of NHL is incompletely understood, and increasing evidence suggests that risk factors may vary by NHL subtype. However, small numbers of cases have made investigation of subtype-specific risks challenging. The International Lymphoma Epidemiology Consortium therefore undertook the NHL Subtypes Project, an international collaborative effort to investigate the etiologies of NHL subtypes. This article describes in detail the project rationale and design.

METHODS

We pooled individual-level data from 20 case-control studies (17471 NHL cases, 23096 controls) from North America, Europe, and Australia. Centralized data harmonization and analysis ensured standardized definitions and approaches, with rigorous quality control.

RESULTS

The pooled study population included 11 specified NHL subtypes with more than 100 cases: diffuse large B-cell lymphoma (N = 4667), follicular lymphoma (N = 3530), chronic lymphocytic leukemia/small lymphocytic lymphoma (N = 2440), marginal zone lymphoma (N = 1052), peripheral T-cell lymphoma (N = 584), mantle cell lymphoma (N = 557), lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (N = 374), mycosis fungoides/Sézary syndrome (N = 324), Burkitt/Burkitt-like lymphoma/leukemia (N = 295), hairy cell leukemia (N = 154), and acute lymphoblastic leukemia/lymphoma (N = 152). Associations with medical history, family history, lifestyle factors, and occupation for each of these 11 subtypes are presented in separate articles in this issue, with a final article quantitatively comparing risk factor patterns among subtypes.

CONCLUSIONS

The International Lymphoma Epidemiology Consortium NHL Subtypes Project provides the largest and most comprehensive investigation of potential risk factors for a broad range of common and rare NHL subtypes to date. The analyses contribute to our understanding of the multifactorial nature of NHL subtype etiologies, motivate hypothesis-driven prospective investigations, provide clues for prevention, and exemplify the benefits of international consortial collaboration in cancer epidemiology.

Occupational exposure to pesticides and lymphoid neoplasms among men: results of a French case-control study

OBJECTIVES

Investigating the relationship between occupational exposure to pesticides and the risk of lymphoid neoplasms (LNs) in men.

METHODS

A hospital-based case-control study was conducted in six centres in France between 2000 and 2004. The cases were incident cases with a diagnosis of LN aged 18-75 years. During the same period, controls of the same age and sex as the cases were recruited in the same hospital, mainly in the orthopaedic and rheumatological departments. Exposures to pesticides were evaluated through specific interviews and case-by-case expert reviews. Four hundred and ninety-one cases (244 cases of non-Hodgkin's lymphoma (NHL), 87 of Hodgkin's lymphoma (HL), 104 of lymphoproliferative syndromes (LPSs) and 56 of multiple myeloma (MM) cases) and 456 controls were included in the analyses. The odds ratios (ORs) and 95% CI were estimated using unconditional logistic regressions.

RESULTS

Positive associations between HL and occupational exposure to triazole fungicides and urea herbicides were observed (OR = 8.4 (2.2 to 32.4), 10.8 (2.4 to 48.1), respectively). Exposure to insecticides, fungicides and herbicides were linked to a threefold increase in MM risk (OR = 2.8 (1.2 to 6.5), 3.2 (1.4 to 7.2), 2.9 (1.3 to 6.5)). For LPS subtypes, associations restricted to hairy-cell leukaemia (HCL) were evidenced for exposure to organochlorine insecticides, phenoxy herbicides and triazine herbicides (OR = 4.9 (1.1 to 21.2), 4.1 (1.1 to 15.5), 5.1 (1.4 to 19.3)), although based on small numbers. Lastly, despite the increased ORs for organochlorine and organophosphate insecticides, carbamate fungicides and triazine herbicides, no significant associations were evidenced for NHL.

CONCLUSIONS

The results, based on case-by-case expert review of occupation-specific questionnaires, support the hypothesis that occupational pesticide exposures may be involved in HL, MM and HCL and do not rule out a role in NHL. The analyses identified specific pesticides that deserve further investigation and the findings were consistent with those of previous studies.

UV radiation exposure, skin type and lymphoid malignancies: results of a French case-control study

OBJECTIVES

Investigating the relationship between skin type, UV exposure, and lymphoid malignancies (LM).

METHODS

We conducted a hospital-based case-control study in France, including 813 incident cases of non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HL), lymphoproliferative syndrome (LPS) or multiple myeloma and 748 controls.

RESULTS

Positive associations between HL and blond/red hair (OR = 1.8 [0.8-3.8]), very fair/fair skin (OR = 1.6 [1.0-2.5]) were observed. High propensity to burn was associated with HL (OR = 1.5 [1.0-2.2]) and LPS (OR = 1.4 [1.0-2.1]). Poor ability to tan was significantly associated with HL (OR = 1.7 [1.0-2.8]). Having light hair with high propensity to burn was associated with NHL (OR = 1.5 [0.9-2.5]) and significantly with HL (OR = 3.4 [1.4-8.4]). Having dark hair with high propensity to burn was significantly associated with LPS (OR = 1.5 [1.0-2.2]). The associations with HL and NHL were significant for men only, with significant interactions. Outdoors activities since leaving school or in the last decade were not related to LM. Only an almost negative trend was observed. Prior exposure to artificial UV was not associated with LM.

CONCLUSION

These results suggest a positive association between the most reactive and palest skin types and NHL or HL in men and do not rule out a slight negative relationship between UV exposure and LM.