Exposure to UV radiation and risk of Hodgkin lymphoma: a pooled analysis

A Systematic Review Assessing the Impact of Vitamin D Levels on Adult Patients with Lymphoid Malignancies

Vitamin D deficiency has been correlated with various conditions, including the risk of developing lymphoid malignancies. This systematic review aimed to assess the association between vitamin D levels at diagnosis of lymphoid malignancies, patient outcomes, and survival. A systematic review was conducted, encompassing 15 studies published until January 2023, involving 4503 patients, examining the relationship between vitamin D and lymphoid cancers. The median age of the patients was 56.5 years, with a median follow-up duration of approximately 36 months across studies. The overall median vitamin D level at initial measurement was 20.4 ng/mL, while a <20 ng/mL threshold was used to define vitamin D insufficiency. The results demonstrated significant associations between vitamin D levels and patient outcomes in several lymphoid malignancies, with a pooled risk in disease progression of 1.93 and a pooled hazard ratio of 2.06 for overall survival in patients with 25-(OH)D levels below the normal threshold of 20 ng/mL. Among findings, it was demonstrated that supplemental vitamin D improves the chemosensitivity of tumors by reducing the rate of tumor growth compared with vitamin D or chemotherapy alone. Vitamin D had a protective effect for patients with DLBCL under R-CHOP treatment, while vitamin D insufficiency was associated with the impairment of rituximab treatment and showed worse clinical outcomes in chimeric antigen receptor T-cell (CAR-T) recipients. Although one study found no association between vitamin D deficiency and the cause of death, most associated vitamin D insufficiency with early clinical failure and lower survival probability. In conclusion, his systematic review highlights the importance of vitamin D levels in the prognosis and survival of patients with lymphoid malignancies. Further research is needed to better understand the underlying mechanisms and explore the potential benefits of vitamin D supplementation in managing these cancers.

Solar UVR and Variations in Systemic Immune and Inflammation Markers

The characterization of the effects of solar UVR on a broad set of circulating markers in systemic immunity and inflammation may provide insight into the mechanisms responsible for the UVR associations observed for several benign and malignant diseases. We examined the associations between exposure to solar UVR and circulating levels of 78 markers among 1,819 individuals aged 55–74 years who participated in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial using multiplex assays. Solar UVR was derived by linking the geocoded locations of 10 screening centers across the continental United States and the date of blood draw to the National Solar Radiation Database from 1993 to 2005. We assessed associations between ambient solar UVR and dichotomized marker levels using adjusted weighted logistic regression models and applied a 5% false discovery rate criterion to P-values. UVR exposure was associated (P < 0.05) with 9 of the 78 markers. CCL27, CCL4, FGF2, GM-CSF, IFN-γ, soluble IL4R, IL-7, and IL-11 levels were lower with increasing UVR tertile, with adjusted ORs ranging from 0.66 to 0.80, and the significant association for CCL27 withstood multiple comparison correction. In contrast, CRP levels were elevated with increasing UVR. Solar UVR was associated with alterations in systemic immune and inflammation marker levels.

Low sun exposure acts synergistically with high Epstein-Barr nuclear antigen 1 (EBNA-1) antibody levels in multiple sclerosis etiology

BACKGROUND

Among multiple sclerosis (MS) patients, an association has been observed between low levels of vitamin D and high Epstein-Barr nuclear antigen 1 (EBNA-1) antibody levels. However, whether sun exposure/vitamin D moderates the role of Epstein-Barr virus (EBV) infection in MS etiology is unclear. We aimed to investigate potential synergistic effects between low sun exposure and elevated EBNA-1 antibody levels regarding MS risk.

METHODS

We used a population-based case-control study involving 2017 incident cases of MS and 2443 matched controls. We used logistic regression models to calculate the odds ratios of MS with 95% confidence intervals (CIs) in subjects with different sun exposure habits and EBNA-1 status. Potential interaction on the additive scale was evaluated by calculating the attributable proportion due to interaction (AP).

RESULTS

Low sun exposure acted synergistically with high EBNA-1 antibody levels (AP 0.2, 95% CI 0.03-0.3) in its association to increased MS risk. The interaction was present regardless of HLA-DRB1*15:01 status.

CONCLUSIONS

Low sun exposure may either directly, or indirectly by affecting vitamin D levels, synergistically reinforce pathogenic mechanisms, such as aspects of the adaptive immune response, related to MS risk conveyed by EBV infection.

Significant current epidemiological trend: Haematological malignancies as subsequent primary tumours in cancer patients

BACKGROUND

Numbers of patients who develop subsequent primary tumours have markedly increased recently. This study aimed to carry out a comprehensive analysis documenting the risk of incidence of subsequent haematological malignancies.

METHODS

The Czech National Cancer Registry was the main data source, containing records of 126,822 haematological malignancies diagnosed in the period 1977-2016. Subsequent haematological malignancies were identified according to IACR rules. Joinpoint regression was employed to assess the time trends. The risk of development of subsequent haematological malignancy was evaluated by the standardised incidence ratio. The Kaplan-Meier curves were used to assess the differences in survival.

RESULTS

Age-standardised incidence of subsequent haematological malignancies increased from 0.5 in 1977 to 9.1 in 2016. In 1992, there was a significant change in the trend: a sharp increase by 7.7 % annually was revealed thereafter. The risk of development of a haematological malignancy was approximately 1.5 times higher in persons with history of any cancer than in the general Czech population. Patients with haematological malignancies - mainly myelodysplastic syndromes, polycythaemia vera and non-Hodgkin lymphoma - were shown to be at the highest risk of developing a subsequent haematological malignancy. While the median survival following a first haematological malignancy was 2.3 years, it was only 1.1 years for subsequent haematological malignancies (p < 0.001).

CONCLUSIONS

Our study identified the highest-risk diagnoses in terms of development of subsequent haematological malignancy. The results might be useful to set up correctly follow-up procedures from which cancer patients could benefit.

Sunlight exposure in association with risk of lymphoid malignancy: a meta-analysis of observational studies

PURPOSE

Several observational studies have shown contradictory results regarding the association between sunlight exposure and the risk of malignant lymphoma. Thus, we aimed to systematically determine the association between sunlight exposure and lymphoid malignancy risk through a meta-analysis.

METHODS

A thorough search of four electronic databases (PubMed, Embase, Web of Science, and Scopus) was performed to identify eligible studies until 13 August 2020. A random-effects model was used to calculate risk estimates of sunlight exposure. The main outcome measure was the risk of lymphoid malignancy subtypes with odds ratios (ORs) and 95% confidence intervals (CIs) according to various forms of solar ultraviolet radiation.

RESULTS

In total, 17 case-control studies and 9 cohort studies including 216,285 non-Hodgkin lymphoma (NHL) and 23,017 Hodgkin's lymphoma (HL) patients were included in the final analysis. Personal sunlight exposure was significantly associated with a decreased risk of HL (OR 0.77; 95% CI 0.68-0.87) and NHL (OR 0.81; 95% CI 0.71-0.92), including all subtypes except T-cell lymphoma. Ambient sunlight exposure at residence was associated with a reduced risk of HL (OR 0.88; 95% CI 0.81-0.95) and all NHL subtypes (OR 0.84; 95% CI 0.73-0.96), except for chronic lymphocytic leukemia/small lymphocytic lymphoma. As the number of sunburns and sunbaths increased, the risk of NHL tended to decrease.

CONCLUSION

While there was an observed protective effect both from case-control and prospective studies, substantial heterogeneity was found in the current study. Thus, more evidence is required to confirm that promoting sunlight exposure can prevent the development of lymphoid neoplasia.

Environmental Risk Factors and Health: An Umbrella Review of Meta-Analyses

Background: Environmental health is a growing area of knowledge, continually increasing and updating the body of evidence linking the environment to human health. Aim: This study summarizes the epidemiological evidence on environmental risk factors from meta-analyses through an umbrella review. Methods: An umbrella review was conducted on meta-analyses of cohort, case-control, case-crossover, and time-series studies that evaluated the associations between environmental risk factors and health outcomes defined as incidence, prevalence, and mortality. The specific search strategy was designed in PubMed using free text and Medical Subject Headings (MeSH) terms related to risk factors, environment, health outcomes, observational studies, and meta-analysis. The search was limited to English, Spanish, and French published articles and studies on humans. The search was conducted on September 20, 2020. Risk factors were defined as any attribute, characteristic, or exposure of an individual that increases the likelihood of developing a disease or death. The environment was defined as the external elements and conditions that surround, influence, and affect a human organism or population’s life and development. The environment definition included the physical environment such as nature, built environment, or pollution, but not the social environment. We excluded occupational exposures, microorganisms, water, sanitation and hygiene (WASH), behavioral risk factors, and no-natural disasters. Results: This umbrella review found 197 associations among 69 environmental exposures and 83 diseases and death causes reported in 103 publications. The environmental factors found in this review were air pollution, environmental tobacco smoke, heavy metals, chemicals, ambient temperature, noise, radiation, and urban residential surroundings. Among these, we identified 65 environmental exposures defined as risk factors and 4 environmental protective factors. In terms of study design, 57 included cohort and/or case-control studies, and 46 included time-series and/or case-crossover studies. In terms of the study population, 21 included children, and the rest included adult population and both sexes. In this review, the largest body of evidence was found in air pollution (91 associations among 14 air pollution definitions and 34 diseases and mortality diagnoses), followed by environmental tobacco smoke with 24 associations. Chemicals (including pesticides) were the third larger group of environmental exposures found among the meta-analyses included, with 19 associations. Conclusion: Environmental exposures are an important health determinant. This review provides an overview of an evolving research area and should be used as a complementary tool to understand the connections between the environment and human health. The evidence presented by this review should help to design public health interventions and the implementation of health in all policies approach aiming to improve populational health.

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.

Mutual Risks of Cutaneous Melanoma and Specific Lymphoid Neoplasms: Second Cancer Occurrence and Survival

Background

It is unclear whether the established association between cutaneous melanoma (CM) and lymphoid neoplasms (LNs) differs across LN subtypes. This study quantifies risk for developing CM after specific LNs and, conversely, for developing specific LNs after CM, as well as assessing clinical impact.

Methods

We identified a cohort of Caucasian adults (age 20-83 years) initially diagnosed with CM or LN, as reported to 17 US population-based cancer registries, 2000-2014. Standardized incidence ratios (SIRs) quantified second cancer risk. We assessed impact of second cancer development on risk of all-cause mortality using Cox regression.

Results

Among 151 949 one-or-more-year survivors of first primary LN, second primary CM risk was statistically significantly elevated after chronic lymphocytic leukemia/small lymphocytic lymphoma (SIR = 1.96, 95% confidence interval [CI] = 1.74 to 2.21), follicular lymphoma (SIR = 1.32, 95% CI = 1.09 to 1.58), and plasma cell neoplasms (SIR = 1.33, 95% CI = 1.07 to 1.63). Risks for these same subtypes were statistically significantly elevated among 148 336 survivors of first primary CM (SIR = 1.44, 95% CI = 1.25 to 1.66; SIR = 1.47, 95% CI = 1.21 to 1.77; SIR = 1.25, 95% CI = 1.06 to 1.47; respectively). Risk for CM was statistically significantly elevated after diffuse large B-cell lymphoma (SIR = 1.22, 95% CI = 1.02 to 1.45) and Hodgkin lymphoma (SIR = 1.75, 95% CI = 1.33 to 2.26), but the reciprocal relationship was not observed. There were no statistically significant associations between marginal zone lymphoma and CM. Among survivors of most LN subtypes, CM statistically significantly increased risk of death (hazard ratio [HR] range = 1.52, 95% CI = 1.25 to 1.85, to 2.46, 95% CI = 1.45 to 4.16). Among survivors of CM, LN statistically significantly increased risk of death (HR range = 1.75, 95% CI = 1.15 to 2.65, to 6.28, 95% CI = 5.00 to 7.88), with the highest risks observed for the most aggressive LN subtypes.

Conclusions

Heterogeneous associations between CM and specific LN subtypes provide novel insights into the etiology of these malignancies, with the mutual association between CM and certain LN suggesting shared etiology. Development of second primary CM or LN substantially reduces overall survival.

Does hypothyroidism augment sun-induced skin damage?

OBJECTIVES

We investigated the mutual effects of overt hypothyroidism and prolonged sunlight exposure on free radical accumulation and oxidative skin damage.

METHODS

Free radical accumulation was evaluated by monitoring the transformation of 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) into MTT-formazan. The pro-oxidant enzymes xanthine oxidase (XO) and NADPH-diaphorase were measured in the skin. XO activity was estimated based on the yield of uric acid, while NADPH-diaphorase reactivity was monitored histochemically as an indirect marker of nitric oxide synthase and nitric oxide activity. Cellular damage was determined by malondialdehyde formation, a marker for lipid peroxidation.

RESULTS

In the skin of both euthyroid and hypothyroid animals, solar simulated ultraviolet irradiance increased the activity of XO and the NADPHdiaphorase reactivity as a protective response to formation of free radicals, such as reactive oxygen or nitrogen species. These pro-oxidant enzymes diminished in hypothyroid rats. Accumulation of the same amount of free radicals led to similar peroxidation in both hypothyroid and irradiated euthyroid rats. Hypothyroid skin after UV-exposure showed even greater lipid peroxidation.

DISCUSSION

The hypothyroid state could be a risk factor for enhanced oxidative skin damage in chronic photo-exposed skin due to oxidative stress. The lipid peroxidation is one of the major pathways by which photo-oxidative stress promotes photocarcinogenesis and photo-aging.

Does sunlight protect us from cancer?

The Ultraviolet (UV) radiation contained in sunlight is a powerful mutagen and immune suppressant which partly explains why exposure to solar UV is the biggest risk factor for the development of cutaneous tumours. Evidence is building that sunlight may be protective against some internal malignancies. Because patients with these tumours are often vitamin D deficient, this has led some to propose that vitamin D supplementation will be beneficial in the treatment of these cancers. However, the results from already completed trials have been disappointing which has given weight to the argument that there must be something else about sunlight that explains its cancer-protecting properties.

Hodgkin Lymphoma has a seasonal pattern of incidence and mortality that depends on latitude

Seasonal variations in incidence and mortality after a Hodgkin lymphoma (HL) diagnosis have been previously described with partly conflicting results. The goal of this analysis is to provide a comprehensive analysis of these seasonal variations. In total, 41,405 HL cases diagnosed between 1973 and 2012 in the 18 Surveillance, Epidemiology, and End Results registries were included. Cosinor analysis and Cox proportional-hazards models were employed to analyze seasonality of incidence and mortality, respectively. HL shows a sinusoid seasonal incidence pattern (p < 0.001). Estimated incidence in March is 15.4% [95%-CI: 10.8-20.0] higher than in September. This sinusoid pattern is more pronounced at higher latitudes (p = 0.023). The risk of dying within the first three years after a HL diagnosis in winter is significantly increased compared to a HL diagnosis in summer at higher latitudes (HR = 1.082 [95%-CI: 1.009-1.161], p = 0.027). Furthermore, increasing northern latitude increases the additional mortality risk conferred by a diagnosis in winter (pinteraction0.033). The seasonality patterns presented here provide epidemiological evidence that Vitamin D might play a protective role in HL. Further evidence on the direct association between Vitamin D levels and the clinical course of HL needs to be collected to advance the understanding of the role of Vitamin D in HL.

Meta-analysis of genome-wide association studies reveals genetic overlap between Hodgkin lymphoma and multiple sclerosis

BACKGROUND

Based on epidemiological commonalities, multiple sclerosis (MS) and Hodgkin lymphoma (HL), two clinically distinct conditions, have long been suspected to be aetiologically related. MS and HL occur in roughly the same age groups, both are associated with Epstein-Barr virus infection and ultraviolet (UV) light exposure, and they cluster mutually in families (though not in individuals). We speculated if in addition to sharing environmental risk factors, MS and HL were also genetically related. Using data from genome-wide association studies (GWAS) of 1816 HL patients, 9772 MS patients and 25 255 controls, we therefore investigated the genetic overlap between the two diseases.

METHODS

From among a common denominator of 404 K single nucleotide polymorphisms (SNPs) studied, we identified SNPs and human leukocyte antigen (HLA) alleles independently associated with both diseases. Next, we assessed the cumulative genome-wide effect of MS-associated SNPs on HL and of HL-associated SNPs on MS. To provide an interpretational frame of reference, we used data from published GWAS to create a genetic network of diseases within which we analysed proximity of HL and MS to autoimmune diseases and haematological and non-haematological malignancies.

RESULTS

SNP analyses revealed genome-wide overlap between HL and MS, most prominently in the HLA region. Polygenic HL risk scores explained 4.44% of HL risk (Nagelkerke R(2)), but also 2.36% of MS risk. Conversely, polygenic MS risk scores explained 8.08% of MS risk and 1.94% of HL risk. In the genetic disease network, HL was closer to autoimmune diseases than to solid cancers.

CONCLUSIONS

HL displays considerable genetic overlap with MS and other autoimmune diseases.

Relationship between ambient ultraviolet radiation and Hodgkin lymphoma subtypes in the United States

Background:

There are few modifiable risk factors for Hodgkin lymphoma (HL), the most common cancer among young adults in Western populations. Some studies have found a reduced risk with exposure to ultraviolet radiation (UVR), but findings have been inconsistent and limited to HL as a group or the most common subtypes.

Methods:

We evaluated UVR and incidence of HL subtypes using data from 15 population-based cancer registries in the United States from 2001 to 2010 (n=20 021). Ground-based ambient UVR estimates were linked to county of diagnosis. Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated for UVR quintiles using Poisson regression models adjusted for age, sex, race/ethnicity, diagnosis year, and registry.

Results:

Hodgkin lymphoma incidence was lower in the highest UVR quintile for nodular sclerosis (IRR=0.84, 95% CI=0.75–0.96, P-trend<0.01), mixed cellularity/lymphocyte-depleted (IRR=0.66, 95% CI=0.51–0.86, P-trend=0.11), lymphocyte-rich (IRR=0.71, 95% CI=0.57–0.88, P-trend<0.01), and nodular lymphocyte predominant HL (IRR=0.74, 95% CI=0.56–0.97, P-trend<0.01), but ‘not otherwise specified' HL (IRR=1.19, 95% CI=0.96–1.47, P-trend=0.11).

Conclusions:

This is the largest study of UVR and HL subtypes covering a wide range of UVR levels; however, we lack information on personal UVR and other individual risk factors. These findings support an inverse association between UVR and HL.

Hepatitis B seropositivity and risk of developing multiple myeloma or Hodgkin lymphoma: A meta-analysis of observational studies

Multiple myeloma (MM) and Hodgkin lymphoma (HL) are common hematological malignancies. There is conflicting data on the potential role of hepatitis B virus (HBV) infection and developing MM or HL. The main aim of this study is to evaluate the association of HBV seropositivity and HL or MM through a meta-analysis of epidemiological studies A literature search through March 2015 found 10 studies that evaluated the association between HBV and MM or HL. Meta-analysis was calculated as an odds ratio (OR). Our analysis showed an OR of developing MM of 1.41 (P=0.03) and an OR of developing HL of 1.54 (P=0.03) in patients with HBV seropositivity. Our results did not change based on study design, quality of studies and use of HBV seropositivity to determine HBV status. Our results suggest that HBV seropositivity increases the risk of developing MM and HL. Further research is needed to confirm these findings.

Childhood determination of Hodgkin lymphoma among U.S. servicemen

BACKGROUND

Hodgkin lymphoma in young adults is inexplicably linked to economic development.

METHODS

We conducted a nested case-control study of the 656 servicemen with Hodgkin lymphoma diagnosed between ages 17 to 32 while on active duty in the U.S. military during 1950-68. Controls, chosen randomly from the servicemen on duty at the time, were matched on service, birth year, and induction date. Information came from preinduction records and military records for the period ending at onset or the equivalent date.

RESULTS

Risk was independently increased with small sib-ship size [OR, 2.3; confidence interval (CI), 1.6-3.5], low birth order (OR, 1.9; CI, 1.4-2.6), and an interval of at least 5 years between birth and that of a previous or subsequent sibling (OR, 2.1; CI, 1.5-3.1). Other factors independently and significantly associated with elevated risk of Hodgkin lymphoma were: tallness, high body mass index, more education (but not higher income) in the county of birth, BB or AB blood type, and past infectious mononucleosis (but a deficit of other childhood viral infections). Early fatherhood conveyed high risk (OR, 2.6; CI, 1.4-4.8), especially if with a high-risk sibling configuration. Factors unrelated to risk included personal education, preinduction or military occupation, induction test score, and rank. Findings were similar for nodular sclerosis and mixed cell histologic subtypes.

CONCLUSIONS

Protection from the environment in childhood, but not in adulthood, increases the likelihood of young adult Hodgkin lymphoma, which may result from nonspecific isolation from early infections and/or exposure to late infection by a specific but unidentified ubiquitous childhood virus.

IMPACT

Events in childhood protect against later Hodgkin lymphoma.

Residential exposure to solar ultraviolet radiation and incidence of childhood hematological malignancies in France

PURPOSE

Few studies have investigated the relationship between solar ultraviolet radiation (UV) and childhood hematological malignancies (CHM). This study addresses the associations between residential UV exposure at diagnosis and the incidence of types and subtypes of CHM, by age and gender, in France, over a long period, on the fine scale of the 36,326 Communes that constitute mainland France.

METHODS

The 9,082 cases of acute leukemia and 3,563 cases of lymphoma diagnosed before the age of 15 years from 1990 to 2009 were provided by the French National Registry of Childhood Hematological Malignancies. The incidence of CHM was calculated by Commune, year, age and gender and expressed as the standardized incidence ratio (SIR). UV data from 1988 to 2007 were extracted from the EUROSUN database.

RESULTS

The annual daily average UV exposure of the children ranged from 85.5 to 137.8 J/cm(2). For each additional 25 J/cm(2), there was a significant increase in precursor B-cell acute lymphoblastic leukemia (PBC-ALL) in children aged less than 5 years (SIR 1.18; 95% CI 1.10-1.27). Further analysis of PBC-ALL in the young children suggested a better fit of models with a threshold, with the risk increasing above 100 J/cm(2), for which the SIR was 1.24 (95% CI 1.14-1.36) for a 25 J/cm(2) increase. The results remained stable in analyses stratifying by deprivation index or degree of urbanization of the Communes.

CONCLUSION

The study suggests that higher residential UV exposure may be positively associated with a higher incidence of PBC-ALL in early childhood.

Shedding light on UVR and Hodgkin lymphoma

In this issue of Blood, Monnereau and colleagues pool 4 retrospective (case-control), observational epidemiologic studies to demonstrate an inverse association between UV radiation (UVR) exposure and risk of developing Hodgkin lymphoma (HL).