An investigation of the sudden increase in breast cancer deaths in the Northern Territory in 1999

In 1999 there were 25 deaths from breast cancer in the Northern Territory (NT), approximately three times as many deaths as occurred in each of the several preceding years, and more than would have been expected due to random variation in the number of breast cancer deaths in any one year. The high number of breast cancer deaths in 1999 appears to be at least partially explained by an increase in the incidence of breast cancer in Aboriginal women (who have, on average, very short survival time) in the preceding three years, and ‘delayed’ deaths of non-Aboriginal women in the three years before 1999 which resulted in a larger number of deaths in 1999. A clinical audit of breast cancer treatment for women who died during 1999 did not reveal any pattern of cancer occurrence or treatment, which could explain the high number of deaths in that year.