MORTALITY IN A COHORT OF WOMEN GIVEN X-RAY THERAPY FOR METROPATHIA HAEMORRHAGICA

Mortality to January 1, 1991, has been studied in 2,067 women in Scotland given X-ray therapy for metropathia haemorrhagica during the period 1940-1960. Average follow-up was 28 years. Overall, 1,313 deaths were observed compared with 1,297.01 expected from Scottish rates [standardized mortality ratio (SMR): 1.01]. Mortality was increased for cancers of heavily irradiated pelvic sites (SMR 5+ years after irradiation: 1.46) following mean doses to organs in the vicinity of the pelvis in the range 2.6-5.3 Gy. For these cancers the SMR was higher 30+ years after irradiation than at 5-29 years, indicating that the effects of exposure last for over 30 years, and in this period bladder cancer mortality was exceptionally high (SMR = 4.91). Mortality was also raised for leukaemia (SMR 2+ years after irradiation: 2.05), following a mean bone-marrow dose of 1.3 Gy, and for multiple myeloma (SMR 5+ years after irradiation: 2.59). For leukaemia the SMR was lower 30+ years after irradiation than at earlier periods, but remained greater than unity. For other cancers mortality was similar to Scottish rates, except for breast cancer for which mortality was low (SMR 5+ years after irradiation: 0.53), even in women aged over 50 at irradiation (SMR 5+ years after irradiation: 0.14). The deficit was principally due to a large deficit of breast cancer in women with ovarian doses of at least 5 Gy. (C) 1994 Wiley-Liss, Inc.