Risk of breast cancer is also increased among Danish female airline cabin attendants

EDITOR,—Eero Pukkala and colleagues report the incidence of cancer among a cohort of Finnish airline cabin attendants.1 Women made up the overwhelming majority of the cohort, and they were found to have an excess risk of cancer of the breast (number of cases observed, 20; standardised incidence ratio 1.87 (95% confidence interval 1.15 to 2.23)). Excess risks were also found for cancer of the bone and leukaemia, on the basis of only two cases of each of these diseases.

In Denmark the incidence of cancer has been monitored for 17 years for the cohort of participants in the 1970 census.2 The standardised incidence ratio was calculated for each occupational group on the basis of the incidence for all economically active people. In 1970, 915 women were registered as airline cabin attendants in Denmark, while 362 men were registered as cabin attendants and 620 men as pilots. Table I shows the Danish data for the three types of cancer found in excess among the Finnish workers. The standardised incidence ratio for breast cancer in the Danish female cabin attendants is 1.61 (0.9 to 2.7), while that in all women in social class I is 1.40. The Danish data thus support the Finnish observation that the risk of breast cancer in female airline cabin attendants is higher than that for their social class.