Sun sensitivity, indoor tanning and B-cell non-Hodgkin lymphoma risk among Caucasian women in Los Angeles County

Physical activity and the risk of non-Hodgkin lymphoma subtypes: A pooled analysis

Non-Hodgkin lymphoma (NHL) is composed of a heterogeneous collection of subtypes with considerable differences in genetics, biology and aetiology. Studies to date on physical activity and NHL risk have not had sufficient sample size to evaluate whether associations differ by subtype. We pooled data from nine case-control studies to examine the association between moderate-to-vigorous intensity physical activity (MVPA) and risk of NHL overall and by subtype (diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukaemia/small lymphocytic lymphoma, marginal zone lymphoma and mature T-cell lymphoma). A total of 5653 cases and 9115 controls were included in the pooled analysis. Physical activity was harmonised across nine studies and modelled as study-specific tertiles. Multinomial logistic regression was used to estimate the association between physical activity and NHL, adjusting for confounders. The overall odds of NHL was 13% lower among participants in the most active tertile of MVPA compared to the least active tertile (adjusted odds ratio = 0.87, 95% CI = 0.80, 0.95). Similar decreases were observed across NHL subtypes. In summary, in this pooled analysis of case-control studies, physical activity was associated with a modest risk reduction for each NHL subtype examined and with overall NHL.

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.

Assessing Cancer Treatment Information Using Medicare and Hospital Discharge Data among Women with Non-Hodgkin Lymphoma in a Los Angeles County Case-Control Study

BACKGROUND

We assessed the ability to supplement existing epidemiologic/etiologic studies with data on treatment and clinical outcomes by linking to publicly available cancer registry and administrative databases.

METHODS

Medical records were retrieved and abstracted for cases enrolled in a Los Angeles County case-control study of non-Hodgkin lymphoma (NHL). Cases were linked to the Los Angeles County cancer registry (CSP), the California state hospitalization discharge database (OSHPD), and the SEER-Medicare database. We assessed sensitivity, specificity, and positive predictive value (PPV) of cancer treatment in linked databases, compared with medical record abstraction.

RESULTS

We successfully retrieved medical records for 918 of 1,004 participating NHL cases and abstracted treatment for 698. We linked 59% of cases (96% of cases >65 years old) to SEER-Medicare and 96% to OSHPD. Chemotherapy was the most common treatment and best captured, with the highest sensitivity in SEER-Medicare (80%) and CSP (74%); combining all three data sources together increased sensitivity (92%), at reduced specificity (56%). Sensitivity for radiotherapy was moderate: 77% with aggregated data. Sensitivity of BMT was low in the CSP (42%), but high for the administrative databases, especially OSHPD (98%). Sensitivity for surgery reached 83% when considering all three datasets in aggregate, but PPV was 60%. In general, sensitivity and PPV for chronic lymphocytic leukemia/small lymphocytic lymphoma were low.

CONCLUSIONS

Chemotherapy was accurately captured by all data sources. Hospitalization data yielded the highest performance values for BMTs. Performance measures for radiotherapy and surgery were moderate.

IMPACT

Various administrative databases can supplement epidemiologic studies, depending on treatment type and NHL subtype of interest.

Follicular lymphoma polygenic risk score is associated with increased disease risk but improved overall survival among women in a population based case-control in Los Angeles County California

INTRODUCTION

Although clinical prognostic indicators exist for follicular lymphoma(FL), patient outcomes remain heterogeneous.

MATERIAL AND METHODS

We evaluated the association between survival and a polygenic risk score(PRS) composed of five previously identified FL susceptibility loci(rs12195582, rs13254990, rs17749561, rs4245081, rs4938573) among women who participated in a case-control study of non-Hodgkin lymphoma in Los Angeles County between 2004-2008. Risk associations were estimated through logistic regression, calculating the odds ratios(OR) and 95 % confidence intervals(95 % CI). Survival was estimated under a Cox proportional hazards model and hazard ratios(HR) and 95 % CI were calculated.

RESULTS

Among 437 non-Hispanic White controls and 100 non-Hispanic White FL patients, we confirmed a 2.6-fold increased risk of FL associated with the highest PRS tertile (95 % CI:1.35-4.86). After accounting for clinical indicators, the PRS was associated with improved overall survival in non-Hispanic women (HR:0.31; 95 % CI:0.10-0.96).

CONCLUSION

PRS was associated with increased risk of FL, but improved overall survival.

Vitamin D status and risk of non-Hodgkin lymphoma: An updated meta-analysis

Purpose

This meta-analysis aimed to extensively investigate the association between various measures of vitamin D status and non-Hodgkin lymphoma (NHL) and its subtypes.

Methods

We searched MEDLINE (PubMed), Embase, and the Cochrane Library in February 2018. Two authors independently reviewed and selected articles based on predetermined criteria.

Results

A total of 30 studies with 56,458 NHL cases were finally selected, with 24, 9, and 3 studies on sunlight/ultraviolet radiation (UVR) exposure, dietary intake, and serum/plasma 25-hydroxyvitamin D levels, respectively. Significant protective effects of overall sunlight/UVR exposure on NHL and subtypes were observed, with summary relative risks (RRs) ranging from 0.67–0.80 (RR for NHL = 0.80; 95% confidence interval [CI]: 0.71–0.90) among subjects with high exposure compared to those with low exposure. The results were consistent with various classifications of sunlight/UVR exposure. In contrast, when exposure measures of dietary vitamin D intake (RR for NHL = 1.03; 95% CI: 0.90–1.19) and serum/plasma 25-hydroxyvitamin D levels (RR for NHL = 0.97; 95% CI: 0.82–1.15) were used, risk estimates were inconsistent or non-significant for NHL and the subtypes.

Conclusion

While risk estimates varied by different measures of vitamin D status, a protective effect of sunlight/UVR exposure on NHL incidence was verified, across most of the tested subtypes as well as exposure categories.

Evaluating the use of friend or family controls in epidemiologic case-control studies

BACKGROUND

Traditional methodologies for identifying and recruiting controls in epidemiologic case-control studies, such as random digit dialing or neighborhood walk, suffer from declining response rates. Here, we revisit the feasibility and comparability of using alternative sources of controls, specifically friend and family controls.

METHODS

We recruited from a recently completed case-control study of non-Hodgkin lymphoma (NHL) among women in Los Angeles County where controls from the parent study were ascertained by neighborhood walk. We calculated participation rates and compared questionnaire responses between the friend/family controls and the original matched controls from the parent study.

RESULTS

Of the 182 NHL case patients contacted, 111 (61%) agreed to participate in our feasibility study. 70 (63%) provided contact information for potential friend and/or family member controls. We were able to successfully contact and recruit a friend/family member for 92% of the case patients. This represented 46 friend controls and 54 family controls. Family controls significantly differed from original matched controls by sex and household income. Other characteristics were similar between friend controls and the original study's neighborhood controls.

CONCLUSION

The apparent comparability of neighborhood controls to friend and family controls among respondents in this study suggests that these alternative methods of control identification can serve as a complementary source of eligible controls in epidemiologic case-control studies.