Breast cancer can hide away for 15 years

BREAST CANCER can resurface after remaining dormant for 15 years following successful treatment, research has found.

The study shows patients who appear cancer free when they stop therapy may relapse many years later with tumours spreading through their body.

Scientists analysed data from 88 clinical trials involving 62,923 women, all of whom had the most common form of breast cancer fuelled by the hormone oestrogen. Every patient received pill treatments such as tamoxifen or aromatase inhibitors which block the effects of oestrogen or shut off the hormone’s supply.

After five years of therapy, their cancers had gone. But monitoring the women’s progress revealed recurrences of the disease up to 15 years later – 20 years after initial diagnosis.

Lead researcher Dr Hongchao Pan, from Oxford University, said: “It is remarkable that breast cancer can remain dormant for so long and then spread many years later, with this risk remaining the same year after year and still strongly related to the size of the original cancer and whether it had spread to the (lymph) nodes.”

Women who started off with large tumours and cancer that spread to four or more lymph nodes faced the highest risk of recurrence. They had a 40 per cent risk of cancer returning in a different part of the body over a period of 15 years after stopping treatment. The research is published today in the New England Journal of Medicine.