Mammography screening for breast cancer offers only minimal gains in life expectancy for women beyond the age of 69, a factor that should be taken into consideration when elderly women are deciding about breast cancer screening. Mammography offers the greatest potential benefit for women between 50 and 69 years old. Beyond that, the benefits are pretty small
Kerlikowske and colleagues compared three different breast cancer screening strategies for women over age 65: mammography every 2 years between ages 65 and 69; mammography every 2 years from age 65 to 69, followed by continued mammography only for women who have higher levels of bone density; and mammography every 2 years between ages 65 and 79. Their results are published in the December 8th issue of The Journal of the American Medical Association.
The second strategy, basing mammography decisions on the results of bone density testing, would add an average of only 2 days of life per woman screened, compared to mammography only through age 69, the authors report. In other words, more than 1,000 women would have to be enrolled in this strategy to save one death from breast cancer, at an additional cost of nearly $67,000 per year of life saved.
Continuing biennial mammography through age 79 would save only an additional three-tenths of a day per woman, compared to the second strategy, the report indicates, requiring nearly 10,000 mammograms to prevent one breast cancer death. The additional cost to save one year of life would exceed $117,000.
"Based on these results, one could justify using mammography to screen healthy, elderly women with the highest bone mineral density levels as a general policy," said Kerlikowske. "Even then, though, simply using a clinical breast exam may be more appropriate."
All things considered, the authors suggest that elderly women might reasonably decide to forego mammography screening for breast cancer. "Women's preferences for a small gain in life expectancy and the potential harms of screening should play an important role when elderly women are deciding about screening," they conclude.
The Journal of the American Medical Association December 8, 1999;282:2156-2163.