The INTEROCC case-control study: risk of meningioma and occupational exposure to selected combustion products, dusts and other chemical agents

The Carcinogenic Effects of Formaldehyde Occupational Exposure: A Systematic Review

BACKGROUND

Formaldehyde, classified as a carcinogen in 2004, as of today is widely used in many work activities. From its classification, further studies were performed to evaluate its carcinogenicity. The aim of the systematic review is to update the evidence on occupational exposure to formaldehyde and cancer onset.

METHODS

The review, in accordance with the PRISMA statement, includes articles in English reporting original results of studies conducted on workers exposed to formaldehyde, considering all types of cancer, published from 1 January 2000 to 30 July 2021 and selected from the Pubmed and Scopus databases. The studies' quality was assessed by the Newcastle-Ottawa Scale.

RESULTS

A total of 21 articles were included, conducted in different European, American, and Asian countries. The most investigated occupational areas are those characterized by a deliberate use of formaldehyde. Some studies evaluated all types of cancer, whereas others focused on specific sites such as thyroid and respiratory, lymphohematopoietic, or central nervous systems. The results showed weak associations with lung cancer, nasopharyngeal cancer, leukemia, and non-Hodgkin's lymphoma.

CONCLUSIONS

The results demonstrate the need for further original studies carried out on representative samples of workers exposed to measured levels of FA. These studies should be designed to reduce the bias due to co-exposure to other carcinogens.

Demographic and socioeconomic disparities of benign and malignant spinal meningiomas in the United States

INTRODUCTION

Spinal meningiomas constitute the majority of primary spinal neoplasms, yet their pathogenesis remains elusive. By investigating the distribution of these tumors across sociodemographic variables can provide direction in etiology elucidation and healthcare disparity identification.

METHODS

To investigate benign and malignant spinal meningioma incidences (per 100,000) with respect to sex, age, income, residence, and race/ethnicity, we queried the largest American administrative dataset (1997-2016), the National (Nationwide) Inpatient Sample (NIS), which surveys 20% of United States (US) discharges.

RESULTS

Annual national incidence was 0.62 for benign tumors and 0.056 for malignant. For benign meningiomas, females had an incidence of 0.81, larger (P=0.000004) than males at 0.40; yet for malignant meningiomas, males had a larger (P=0.006) incidence at 0.062 than females at 0.053. Amongst age groups, peak incidence was largest for those 65-84 years old (2.03) in the benign group, but 45-64 years old (0.083) for the malignant group. For benign and malignant meningiomas respectively, individuals with middle/high income had an incidence of 0.67 and 0.060, larger (P=0.000008; P=0.04) than the 0.48 and 0.046 of low income patients. Incidences were statistically similar (P=0.2) across patient residence communities. Examining race/ethnicity (P=0.000003) for benign meningiomas, incidences for Whites, Asian/Pacific Islanders, Hispanics, and Blacks were as follows, respectively: 0.83, 0.42, 0.28, 0.15.

CONCLUSIONS

Across sociodemographic strata, healthcare inequalities were identified with regards to spinal meningiomas. For benign spinal meningiomas, incidence was greatest for patients who were female, 65-84 years old, middle/high income, living in rural communities, White, and Asian/Pacific Islander. Meanwhile, for malignant spinal meningiomas incidence was greatest for males, those 45-65 years old, and middle/high income.

Lifetime occupational exposure to metals and welding fumes, and risk of glioma: a 7-country population-based case-control study

BACKGROUND

Brain tumor etiology is poorly understood. Based on their ability to pass through the blood-brain barrier, it has been hypothesized that exposure to metals may increase the risk of brain cancer. Results from the few epidemiological studies on this issue are limited and inconsistent.

METHODS

We investigated the relationship between glioma risk and occupational exposure to five metals - lead, cadmium, nickel, chromium and iron- as well as to welding fumes, using data from the seven-country INTEROCC study. A total of 1800 incident glioma cases and 5160 controls aged 30-69 years were included in the analysis. Lifetime occupational exposure to the agents was assessed using the INTEROCC JEM, a modified version of the Finnish job exposure matrix FINJEM.

RESULTS

In general, cases had a slightly higher prevalence of exposure to the various metals and welding fumes than did controls, with the prevalence among ever exposed ranging between 1.7 and 2.2% for cadmium to 10.2 and 13.6% for iron among controls and cases, respectively. However, in multivariable logistic regression analyses, there was no association between ever exposure to any of the agents and risk of glioma with odds ratios (95% confidence intervals) ranging from 0.8 (0.7-1.0) for lead to 1.1 (0.7-1.6) for cadmium. Results were consistent across models considering cumulative exposure or duration, as well as in all sensitivity analyses conducted.

CONCLUSIONS

Findings from this large-scale international study provide no evidence for an association between occupational exposure to any of the metals under scrutiny or welding fumes, and risk of glioma.