Night Shift Work, Chronotype, Sleep Duration, and Prostate Cancer Risk: CAPLIFE Study.

Macarena Lozano-Lorca,María-José Sánchez,Inmaculada Salcedo-Bellido,María-Victoria Vega-Galindo,Rocío Olmedo-Requena,José-Juan Jiménez-Moleón,Fernando Vázquez-Alonso,Antonio Jiménez-Pacheco

doi:10.3390/ijerph17176300

Abstract

To analyze the association between prostate cancer (PCa) risk and night shift work, chronotype, and sleep duration in the context of a population-based case-control study of incident prostate cancer in Spain, a total of 465 PCa cases and 410 controls were analyzed. Selection criteria were: (i) age 40–80 years, and (ii) residence in the coverage area of the reference hospitals for ≥6 months before recruitment. Exposure variables were: (i) night shift work (permanent or rotating); (ii) chronotype: morning, neither, or evening (Munich ChronoType Questionnaire) and (iii) sleep duration according to the recommendations of the American National Sleep Foundation. PCa aggressiveness was determined according to the International Society of Urology Pathology classification. Adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) were estimated using logistic regression models. Night shift work was associated with PCa, aOR = 1.47 (95% CI 1.02–2.11), especially for rotating night shifts, aOR = 1.73 (95% CI 1.09–2.75). The magnitude of the association between ever night work and PCa was higher in evening subjects with aOR = 3.14 (95% CI 0.91–10.76) than in morning chronotypes with an aOR = 1.25 (95% CI 0.78–2.00). Working night shifts, especially rotating night shifts, could increase PCa risk. This risk may be higher in people with an evening chronotype.

Highlights

Prostate cancer (PCa) is the most frequent cancer in males and has the third-highest mortality in Europe [1]
We observed a risk association between ever night work and prostate cancer (PCa) with an adjusted Odds Ratio = 1.47
The probable carcinogenicity of night shift work is still not a major concern in Spain, and men were informed about the objectives of the CAPLIFE study—to analyze the association between lifestyles and PCa—but not the effects of night shift work. In this Spanish population-based case-control study, an association was observed between night shift work and PCa risk, for rotating night shift work

Summary

Introduction

Prostate cancer (PCa) is the most frequent cancer in males and has the third-highest mortality in Europe [1]. PCa incidence has increased in all countries in recent years, with high variations geographically [2,3]. In Spain, it is estimated that 35,126 new cases of PCa are diagnosed, according to the latest estimates from the Spanish Cancer Registry Network, this being the most frequent cancer in men [4]. By 2040, more than 2 million men are estimated to be affected [1]. Despite its considerable impact, the etiology of PCa is still unknown. Established risk factors include older age, race/ethnicity, and family history, all nonmodifiable risk factors [5,6,7,8].

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Discussion

Conclusion