In modern times, with the best medical care, most breast cancer patients survive the first years after diagnosis and look forward in anticipation that they are cured. Certainly, as time goes on without any signs of recurrence, the chance of winning this battle becomes higher. However, can we really talk about cure from breast cancer?

 

The recent study by Woods and colleagues [1] was very simple: they followed 80,313 women from the UK and Australia who were diagnosed with invasive breast cancer, for a period of up to 23 years. They used a statistical model that calculated relative survival and excess hazard rates. For women diagnosed from 1980 to 1987, the excess mortality rate between the 15th and 23rd anniversaries of diagnosis was greater than zero for all extent-of-disease groups and for all women diagnosed before their 65th birthday. This suggests that these groups of women continued to die as a consequence of their malignancy during the 16th to 23rd years of follow-up and thus that they could not be considered cured of cancer within 23 years of their diagnosis. Similarly, the excess mortality rate for women diagnosed from 1988 to 1995 between the 10th and 15th anniversaries of diagnosis was greater than zero for all extent-of-disease groups and for women less than 80 years old at diagnosis. However, some groups of women who were diagnosed at an older age could be considered cured after their 80th birthday. The modeling analyses suggested that about half of the women diagnosed in Australia in the period 1980–1987, aged either 65–69 or 70–79 years, could be considered as cured, depending on the model applied. Similarly, around 70% of 70–79-year olds diagnosed in Australia during the period 1988–1995 and 65% of women aged 80–99 years at diagnosis could be considered as cured. However, the estimate of the time taken for cure to be reached exceeded 10 years for the youngest group and 8 years for the oldest, implying that cure was not achieved before 75 years of age. In the UK, the relative survival rates predicted by the models were very different from the rates observed. This suggests that, although excess mortality was substantially reduced 10 or 15 years after diagnosis, the overall pattern of survival was not consistent with the presence of a cured subpopulation. In conclusion, young and middle-aged women diagnosed up to 1995 with breast cancer experienced continuous excess mortality attributable to their disease up to 23 years after diagnosis. This was the case in both populations examined. However, some evidence of cure was found among older women diagnosed in Australia, but not in the UK.