No abstract

Objective To assess the incidence of cancer among male airline pilots in the Nordic countries, with special reference to risk related to cosmic radiation. Design Retrospective cohort study, with follow up of cancer incidence through the national cancer registries. Setting Denmark, Finland, Iceland, Norway, and Sweden. Participants 10 032 male airline pilots, with an average follow up of 17 years. Main outcome measures Standardised incidence ratios, with expected numbers based on national cancer incidence rates; dose-response analysis using Poisson regression. Results 466 cases of cancer were diagnosed compared with 456 expected. The only significantly increased standardised incidence ratios were for skin cancer: melanoma 2.3 (95% confidence interval 1.7 to 3.0), non-melanoma 2.1 (1.7 to 2.8), basal cell carcinoma 2.5 (1.9 to 3.2). The relative risk of skin cancers increased with the estimated radiation dose. The relative risk of prostate cancer increased with increasing number of flight hours in long distance aircraft. Conclusions This study does not indicate a marked increase in cancer risk attributable to cosmic radiation, although some influence of cosmic radiation on skin cancer cannot be entirely excluded. The suggestion of an association between number of long distance flights (possibly related to circadian hormonal disturbances) and prostate cancer needs to be confirmed.

The hormonal background of endometrial cancer is insufficiently characterised. We investigated the significance of parity, age at first birth, intensity between births, length of time from the first to the last birth and length of delivery-free premenopausal period in a cohort of grand multiparous (GM) women, i.e., women with at least 5 births. Data of the Population Register of Finland (86,978 GM-women) and the population-based Finnish Cancer Registry were combined. Standardised incidence ratios (SIRs) were calculated by dividing the number of observed cancer cases by the expected number based on the national incidence rates. Key words: endometrial cancer; age at first birth; parity; grand multiparity; birth periodEndometrial cancer is a hormone-dependent malignancy. Unopposed estrogen promotes malignant transformation of the endometrium, an action that is counteracted by progesterone. 1 Pregnancy is characterised by continuous progesterone production from the early weeks of gestation until delivery. 2 Possibly for this reason, at least partly, parous women have a markedly lower risk of endometrial cancer than nulliparous women. [3][4][5][6][7][8] The term grand multiparity (GM) defines women who have undergone at least 5 full-term pregnancies. 9 The Population Register of Finland contains detailed information on the births and children of all GM mothers. Using this national population register of GM-women and data of Finnish Cancer Registry, we studied the significance of parity, age at first birth, average intensity between births, birth period and premenopausal delivery-free period as risk determinants of endometrial cancer. MATERIAL AND METHODS Population-based registersThe computerised files of the Finnish Population Register, which includes links between parents and their children who were living at the same address in 1974 or later, revealed 86,978 GMwomen during the period 1974 until the end of 1997. Follow-up for endometrial cancer was done automatically through the files of the national, population-based Finnish Cancer Registry with personal identifiers. Follow-up for cancer started on 1 January 1974 or at the birth of the fifth child, whichever was later, and ended at death, emigration or on 31 December 1997, whichever was first. There were 1.68 million person-years in the study. The mean length of follow-up was 19.3 years.The cancer registry data also included information about the histopathologic diagnosis made by local pathologists and clinical stage at diagnosis. Statistical methodsCases of endometrial cancer and person-years at risk were counted by 5-year age groups and separately for 4 parity categories (5, 6, 7 and 8ϩ children), 4 categories by age at first birth (Ͻ20, 20 -24, 25-29 and 30ϩ years) and 3 birth-intensity categories (average interval between the first 5 deliveries Ͻ2.0, 2.0 -3.0 and Ͼ3.0 years). Age at follow up of cancer was categorised into 3 groups, Ͻ50 years ("premenopausal" women), 50 -64 years ("postmenopausal" women) and 65ϩ years. For women 50 years or older, most of who...

(2007) Nordic biological specimen banks as basis for studies of cancer causes and control -more than 2 million sample donors, 25 million person years and 100 000 prospective cancers, Acta Oncologica, 46:3,

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 nighttime 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 5 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.