Breast cancer tumours grow faster in younger women, a new Norwegian study says.
A research team from the Cancer Registry of Norway analyzed data from almost 400,000 female breast cancer patients between the ages of 50 and 69. They found that tumours in women aged 50 to 59 took an average of 1.4 years to grow from 10 mm to 20 mm in diameter. In women aged 60 to 69 years of age, tumours took an average of 2.1 years to grow the same amount.
Overall, the researchers found that tumour growth varied greatly among the study's subjects. About one in 20 tumours doubled in size, from 10 mm to 20 mm, in about a month. Another one in 20 tumours took more than six years to grow the same size.
At the same time, researchers used mammography to evaluate the efficacy of mammograms to detect tumours.
They found that tumours were easier to detect the larger they got. Only 26 per cent of tumours that measured 5 mm were found by mammogram, while 91 per cent of tumours 10 mm in size were detected this way.
The researchers said that studying tumour growth will allow health-care professionals to determine at what age and how often women should have mammograms. As well, scientists will be better able to design breast-cancer studies and clinical trials.
The study is published in BioMed Central's open-access journal Breast Cancer Research.
