Occupational Heat Exposure and Breast Cancer Risk in the MCC-Spain Study

Global epidemiology of breast cancer based on risk factors: a systematic review

Background

Numerous reviews of the epidemiology and risk factors for breast cancer have been published previously which heighted different directions of breast cancer.

Aim

The present review examined the likelihood that incidence, prevalence, and particular risk factors might vary by geographic region and possibly by food and cultural practices as well.

Methods

A systematic review (2017-2022) was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, reporting on epidemiological and risk factor reports from different world regions. Medical Subject Heading (MeSH) terms: "Breast neoplasm" "AND" country terms such as "Pakistan/epidemiology", "India/epidemiology", "North America/epidemiology", "South Africa/epidemiology" were used to retrieve 2068 articles from PubMed. After applying inclusion and exclusion terms, 49 papers were selected for systematic review.

Results

Results of selected articles were summarized based on risk factors, world regions and study type. Risk factors were classified into five categories: demographic, genetic and lifestyle risk factors varied among countries. This review article covers a variety of topics, including regions, main findings, and associated risk factors such as genetic factors, and lifestyle. Several studies revealed that lifestyle choices including diet and exercise could affect a person's chance of developing breast cancer. Breast cancer risk has also been linked to genetic variables, including DNA repair gene polymorphisms and mutations in the breast cancer gene (BRCA). It has been found that most of the genetic variability links to the population of Asia while the cause of breast cancer due to lifestyle modifications has been found in American and British people, indicating that demographic, genetic, and, lifestyle risk factors varied among countries.

Conclusion

There are many risk factors for breast cancer, which vary in their importance depending on the world region. However, further investigation is required to better comprehend the particular causes of breast cancer in these areas as well as to create efficient prevention and treatment plans that cater to the local population.

Sociodemographic profile and description of the presenting symptom in women with breast cancer in a population-based study: Implications and role for nurses

OBJECTIVE

To describe the frequency and typology of the presenting symptom of women diagnosed of breast cancer in Spain and their socio-demographic profile.

METHODS

Descriptive study nested in a population epidemiological study (MCC-SPAIN) in 10 Spanish provinces. Between 2008 and 2012, 836 histologically confirmed incident cases of breast cancer were recruited who reported some symptom prior to diagnosis in a direct computerized interview. For the comparison of 2 discrete variables, the Pearson Chi square test was used.

RESULTS

The most frequent presenting symptom among women who reported at least one symptom was noticing a "lump in the breast" (73%), followed far behind by noticing "changes in the breast" (11%). Geographic heterogeneity was observed in the frequency of the presenting symptom, as well as with menopausal status. No association was observed between the type of presenting symptom and the rest of the sociodemographic variables explored, except for the educational level in which women with a higher educational level tended to proportionally report other symptoms different from the "lump in the breast" more frequently than less educated. Postmenopausal women reported noticing changes in the breast (13%) more frequently than premenopausal women (8%), although without reaching statistical significance (P = .056).

CONCLUSIONS

The most frequent presenting symptom is "breast lump", followed by "breast changes". There could be sociodemographic heterogeneity in the type of presenting symptom to be taken into account by nurses in their socio-sanitary interventions.

Occupational heat exposure and prostate cancer risk: A pooled analysis of case-control studies

BACKGROUND

Heat exposures occur in many occupations. Heat has been linked to key carcinogenic processes, however, evidence for associations with cancer risk is sparse. We examined potential associations between occupational heat exposure and prostate cancer risk in a multi-country study.

METHODS

We analysed a large, pooled dataset of 3142 histologically confirmed prostate cancer cases and 3512 frequency-matched controls from three countries: Canada, France, and Spain. Three exposure indices: ever exposure, lifetime cumulative exposure and duration of exposure, were developed using the Finnish Job-Exposure Matrix, FINJEM, applied to the lifetime occupational history of participants. We estimated odds ratios (ORs) and 95% confidence intervals (CIs), using conditional logistic regression models stratified by 5-year age groups and study, adjusting for potential confounders. Potential interactions with exposure to other occupational agents were also explored.

RESULTS

Overall, we found no association for ever occupational heat exposure (OR 0.97; 95% CI 0.87, 1.09), nor in the highest categories of lifetime cumulative exposure (OR 1.04; 95% CI 0.89, 1.23) or duration (OR 1.03; 95% CI 0.88, 1.22). When using only the Spanish case-control study and a Spanish Job Exposure Matrix (JEM), some weakly elevated ORs were observed.

CONCLUSIONS

Findings from this study provide no clear evidence for an association between occupational heat exposure and prostate cancer risk.

Cancer and Ongoing Climate Change: Who Are the Most Affected?

Cancer has become the leading cause of premature death in many counties in recent decades. Previous studies showed plenty of evidence that control of modifiable risk factors would reduce the cancer burden. Since modifiable risk factors could be eliminated by changing the lifestyles of individuals, a greater uptake of modifiable risk factors is critical to reducing cancer burden and inequality in cancer survival. However, climate change will widen cancer inequities through its complex connections with modifiable risk factors. In this perspective, complex connections between climate change and cancer risks via modifiable risk factors, including abnormal temperature, UV, air pollution, natural disasters, food (diet), water, infections, and inefficient physical activities, have been summarized. The associations between climate change and modifiable risk factors have no doubt expanded the inequities. People who face overlapping modifiable risk factors, but who are unable to change or adapt, are at the highest risk in the climate change-cancer linkage. Though individual actions to avoid exposure to modifiable risk factors have been recommended, limited benefits would be achieved unless the nations strive to ensure the basic needs of the people. No choice makes avoiding exposure to risk factors an empty phrase. Thus, government actions should be taken to reduce the expanded inequities in cancer risks.

Impact of Variability in Job Coding on Reliability in Exposure Estimates Obtained via a Job-Exposure Matrix

OBJECTIVES

The use of a job-exposure matrix (JEM) to assess exposure to potential health hazards in occupational epidemiological studies requires coding each participant's job history to a standard occupation and/or industry classification system recognized by the JEM. The objectives of this study were to assess the impact of inter-coder variability in job coding on reliability in exposure estimates derived from linking the job codes to the Canadian job-exposure matrix (CANJEM) and to identify influent parameters.

METHOD

Two trained coders independently coded 1000 jobs sampled from a population-based case-control study to the ISCO-1968 occupation classification at the five-digit resolution level, of which 859 could be linked to CANJEM using both assigned codes. Each of the two sets of codes was separately linked to CANJEM and thereby generated, for each of the 258 occupational agents available in CANJEM, two exposure estimates: exposure status (yes/no) and intensity of exposure (low, medium, and high) for exposed jobs only. Then, inter-rater reliability (IRR) was computed (i) after stratifying agents in 4 classes depending, for each, on the proportion of occupation codes in CANJEM defined as 'exposed' and (ii) for two additional scenarios restricted to jobs coded differently: the first one using experts' codes, the other one using codes randomly selected. IRR was computed using Cohen's kappa, PABAK and Gwet's AC1 index for exposure status, and weighted kappa and Gwet's AC2 for exposure intensity.

RESULTS

Across all agents and based on all jobs, median (Q1, Q3; Nagents) values were 0.68 (0.59, 0.75; 220) for kappa, 0.99 (0.95, 1.00; 258) for PABAK, and 0.99 (0.97, 1.00; 258) for AC1. For the additional scenarios, median kappa was 0.28 (0.00, 0.45; 209) and -0.01 (-0.02, 00; 233) restricted to jobs coded differently using experts' and random codes, respectively. A similar decreasing pattern was observed for PABAK and AC1 albeit with higher absolute values. Median kappa remained stable across exposure prevalence classes but was more variable for low prevalent agents. PABAK and AC1 decreased with increasing prevalence. Considering exposure intensity and all exposed jobs, median values were 0.79 (0.68, 0.91; 96) for weighted kappa, and 0.95 (0.89, 0.99; 102) for AC2. For the additional scenarios, median kappa was, respectively, 0.28 (-0.04, 0.42) and -0.05 (-0.18, 0.09) restricted to jobs coded differently using experts' and random codes, with a similar though attenuated pattern for AC2.

CONCLUSION

Despite reassuring overall reliability results, our study clearly demonstrated the loss of information associated with jobs coded differently. Especially, in cases of low exposure prevalence, efforts should be made to reliably code potentially exposed jobs.