There is some evidence that mammograms may decrease
deaths from breast cancer in women in their seventies. In studies
involving thousands of women, there were fewer cases of metastatic
breast cancer in those who got routine mammograms than in those who
did not. Metastatic breast cancer is the spread of cancer, through
the bloodstream or the lymphatic system, from one part of the body
to another. Metastatic breast cancer is almost always fatal.
Among 10,000 women 70 years old, if all 10,000 women get routine
mammograms over the next 10 years, 10 breast cancer deaths may be
prevented. This means for women in their seventies, mammograms may
avert one breast cancer death for every 1,000 women screened regularly
for 10 years.
As for women of all ages, there are potential harms (see
question 12 part 4) to performing mammograms after age
69 including further test(s) to determine whether or not
you have cancer. In addition, women undergoing screening
mammography are more likely than unscreened women to have
DCIS detected (see
question 19) and the value of treating DCIS in older
women, who are more likely to die before DCIS progresses
to invasive cancer, is not known.