Night‐time work predisposes to non‐Hodgkin lymphoma

• Published in: International journal of cancer Vol. 123; no. 9; pp. 2148 - 2151
• Main Authors: Lahti, Tuuli A., Partonen, Timo, Kyyrönen, Pentti, Kauppinen, Timo, Pukkala, Eero
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-11-2008; Wiley-Liss
• Subjects: Aged; Biological and medical sciences; circadian clock; Circadian Rhythm - physiology; Female; Hematologic and hematopoietic diseases; Humans; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Lymphoma, Non-Hodgkin - epidemiology; Lymphoma, Non-Hodgkin - etiology; Male; Medical sciences; Middle Aged; night‐time shift work; non‐Hodgkin lymphoma; Personnel Staffing and Scheduling; Risk; Sex Characteristics; Time Factors; Tumors; Work Schedule Tolerance; Europe; Finland; Human; Night; Malignant hemopathy; Biological rhythm; non-Hodgkin lymphoma; Circadian rhythm; Occupational exposure; Non Hodgkin lymphoma; Epidemiology; circadian clock; Biological clock; Cancerology; Lymphoproliferative syndrome; Cohort study; Risk factor; night-time shift work; Occupational medicine; Public health; Cancer
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.23566

Our aim was to find out whether non‐Hodgkin lymphoma (NHL) was more common than expected among night‐time shift workers. The Finnish job‐exposure matrix (FINJEM) provided estimates of the proportion of exposed persons and the mean level of exposure among the exposed in each occupation. The probability of night‐time work in each occupation was assessed, the observed and expected numbers of cancer cases in a cohort of persons born in 1906–1945 during the years of 1971–1995 were calculated, and the cumulative index of night‐time work was scored. The cohort compromised of 1,669,272 persons of whom 6,307 (3,813 men and 2,494 women) had NHL during the follow‐up. Night‐time work increased significantly (p = 0.01) the risk of NHL in men, the overall relative risk being 1.10 (95% confidence interval of 1.03–1.19). Using the lag period of 10 years, the risk ratio was 1.28 (1.03–1.59) for men who worked in night‐time shifts to a high degree as compared with those who had not been exposed to night‐time work. Night‐time workers are cancer prone and have a greater risk of NHL than population on average. © 2008 Wiley‐Liss, Inc.