Women who never got mammograms are far more likely to die of
breast cancer than women who are regularly screened, US researchers
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 Center and Harvard Medical School in
Massachusetts told reporters in a telephone briefing.
"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.
"We didn't pretend to understand the reasons for not getting
mammograms," he said.
People who are ill, who do not speak English or who are poor could
all be among those not getting regular medical care and thus not
getting mammograms, which in the United States are recommended for
all women over the age of 50.
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.
