Socioeconomic status and risk of lung cancer by histological subtype in the Nordic countries

Abstract

Background While the excess in lung cancer risk among lower socioeconomic status individuals has been widely described, the magnitude of this association across lung cancer subtypes, as well as histotype‐related long‐term incidence trends, are inconclusively reported. Aims We explored the variation in the incidence of the three main lung cancer histotypes (i.e. squamous cell carcinoma, small cell carcinoma and adenocarcinoma) by socioeconomic status (SES, i.e. upper and lower white collar, upper and lower blue collar, and farming/forestry/fishing) in the adult population of four Nordic countries (i.e. Sweden, Norway, Finland and Denmark). Materials & Methods We have used data from the Nordic Occupational Cancer Study (NOCCA), computing age‐standardized incidence rates per 100,000 person‐years truncated at ages 50–69 years, by sex, histotype, country and SES, for the period 1971–2005. We estimated relative risks and the corresponding 95% confidence intervals through Poisson regression models, including terms for SES, age, sex and country, as indicated. Results A clear socioeconomic gradient, with a progressive increase in lung cancer risk as SES level decreases, was observed in all subtypes and in both sexes. Favourable lung cancer incidence trends were seen among men for squamous cell and small cell carcinomas, although for adenocarcinomas rates were increasing everywhere except for Finland. Among women, upward temporal trends were seen in all SES groups and for all subtypes, although rates increased to a greater extent for low, compared to high, SES, especially in Denmark and Norway. Farmers showed comparatively lower risks compared to other SES categories. Discussion This prospective cohort study shows that substantial socioeconomic inequalities in the incidence of the most important lung cancer histotypes exist in the Nordic Countries, and that these inequalities are on the rise, especially among women. Conclusion Smoking habits are likely to largely explain the observed social gradient for lung cancer histotypes in both sexes.

Decreasing COPD-related incidences and hospital admissions in a German health insurance population

“…COPD-rates also turned out to increase with decreasing income level. So far, our findings on social inequalities in COPD are in line with findings pertaining to other smoking-related diseases with the most prominent example being lung cancer 9 , 12 , 28 , 29 . Separate analyses by income level revealed that in the highest income group no or only minor decreases in individual rates occurred.…”

Long-term mortality among adults diagnosed with cancer during three decades in Finland

“…In our study, increased all-cause SMRs were observed among lung cancer patients in both sexes and all age groups. Although the overall prevalence of smoking has declined over time in Finland, the decline started much later and was slower among people in lower socio-economic groups as compared to higher socio-economic groups which caused higher overall all-cause SMR among lung cancer patients who more and more represent lowest socioeconomic groups (27,28). The excess overall mortality also markedly increased in female lung cancer patients in the most recent period in our study.…”

Estimating 10-year risk of lung and breast cancer by occupation in Switzerland

“…Studies on socioeconomic status and cancer show similar results as our findings. Risk of lung cancer has been shown to be higher among lower socioeconomic status individuals (29)(30)(31)(32). This socioeconomic gradient is likely due to differences in risk factors and exposures related to lung cancer, such as smoking, diet and occupational exposures (33)(34)(35).…”