Women who never get mammograms are far more likely to die of breast cancer than women who are regularly screened, US researchers recently reported.
They said 75% of the women they studied who died of breast cancer had never had a mammogram, or were diagnosed after their very first mammogram. Only 25% of the women they studied who died of breast cancer had received more than one mammogram.
"The most effective method for women to avoid death from breast cancer is to have regular mammographic screening," Dr Blake Cady of Cambridge Hospital Breast Centre and Harvard Medical School in the US told reporters.
Low mortality with screening programmes
"Women who are in screening programs have only a 4.7% mortality. Women who are not screened have a 56% mortality," added Cady, who will present his findings later this week to a meeting of the American Society of Clinical Oncology.
"That is the same as the overall mortality we used to see in breast cancer up to 1970, prior to the onset of wide mammography screening."
A mammogram is an X-ray of the breast that can spot tumours before they are large enough to feel, and potentially before they spread.
Cady and colleagues examined 6,997 Massachusetts breast cancer patients, some who got regular mammograms and some who did not, between 1990 and 1999. The patients were followed through 2007.
After about 12.5 years of follow-up, 461 of the women died of their breast cancer. Nearly 75% of these were women who had not had regular mammograms. Cady said it is not clear why some women did not get mammograms, and said it is possible these women got less medical care in general.
Value of mammograms
There has been some debate about the value of mammograms.
Most cancer societies and many governments recommend that women be screened regularly but a few studies have shown that mammograms may detect many false positives - meaning a woman does not have a tumour but may undergo more testing, involving worry and perhaps a biopsy.
Breast cancer kills more than 400,000 women a year globally. - (Maggie Fox/Reuters Health, October 2009)
Reasons to go for a mammogram
Know your breast status