Night-time work predisposes to non-Hodgkin lymphoma

Int J Cancer. 2008 Nov 1;123(9):2148-51. 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Circadian Rhythm / physiology*
  • Female
  • Humans
  • Lymphoma, Non-Hodgkin / epidemiology
  • Lymphoma, Non-Hodgkin / etiology*
  • Male
  • Middle Aged
  • Personnel Staffing and Scheduling
  • Risk
  • Sex Characteristics
  • Time Factors
  • Work Schedule Tolerance*