CANCER RISK AND PROGNOSIS IN NORWAY - COMPARING WOMEN IN THEIR FIRST MARRIAGE WITH WOMEN WHO HAVE NEVER MARRIED

Study objective - The difference in risk of cancer between never marri ed women and married women in their first marriage and whether surviva l from cancer was the two groups were different studied. Design - This was a population based, nested case-control study of cancer in Norweg ian women diagnosed between 1966 and 1990, and followed up with regard to overall survival until the end of 1991. Setting - Norway. Particip ants - These were Norwegian women born between 1935 and 1954. The case -control study included 12 237 married and 1466 unmarried cases, and 2 6 075 married and 2768 unmarried controls. In the survival analysis, 1 1 943 married and 1473 unmarried cases were included. Main results - U nmarried women had an overall increased cancer risk (OR-1.13, 95% CI 1 .05, 1.21), which could be attributed to cancer of the ovaries, uterus , brain and haematological malignancies. For cervical and thyroid canc er, the risk was lower than for married women. In the survival analysi s, unmarried cases had an overall 26% increased risk of dying (HR = 1. 26, 95% CI 1.15, 1.39), after adjustment for age and stage at diagnosi s. The increased death rate was seen for cancer of the cervix, lung, a nd thyroid. Conclusions - Since most unmarried women were nulliparous, this might explain their increased risk of ovarian and uterine cancer . The increased risk ofbrain tumours and haematological malignancies m ay result from selection bias, since disease among unmarried women may cause a large proportion to remain unmarried. The lower survival in u nmarried cases may support the hypothesis that psychosocial factors pl ay a role in the prognosis of cancer patients.