Arguments Against Mammograms for Age 40-49 Refuted

PHILADELPHIA—The American Cancer Society was on the right track in their March 1997 recommendation that women in their 40s have screening mammograms for detection of breast cancer, Thomas Jefferson University’s Stephen Feig, MD, said at a breast cancer symposium at Fox Chase Cancer Center. At the same time, he took to task the NIH consensus panel, which looked at the same data and did not recommend mam-mography screening for this age group.

A metaanalysis of seven population-based trials demonstrated a 26% decrease in mortality in this age group in mam-mography screened women versus controls. “That’s why there was so much surprise when the consensus panel did not recommend screening for women in their 40s,” Dr. Feig said. Two trials have shown significant breast cancer mortality reductions of 35% and 45%, respectively, for screening women aged 40 to 49, he said.

One of the principal rationales of the panel was that no statistically significant difference in breast cancer mortality is seen within 7 years. But this is because the curves don’t diverge in that limited time period. “It’s saying that benefit that occurs later is not beneficial,” he said.

Another argument against screening in the 40s is that 2,500 women must undergo mammography just to extend one life. However, for women in their 50s, some 1,500 women must be screened per life extended, not an overwhelming difference, he said.

Then there is the anxiety issue. About 10% of mammograms are read as abnormal and require follow-up studies, usually more mammo-grams or ultrasound, not biopsies. “Additional tests may cause slight anxiety, but this is far preferable to the anxiety of dying of breast cancer,” he argued.

The risk/benefit ratio is very favorable for mammography, Dr. Feig said. For every 100,000 women in their 40s, 292 lives would be saved with annual mammo-grams versus a worst-case theoretical risk of just two lives lost to radiation-induced cancer. And it must be remembered that given the 10-year latency of radiation-induced cancers, they would be occurring in women in their 50s, resulting in fewer years of life lost, compared to the years of life saved for women in their 40s.

Total Number of Years Lost

The total number of years of life lost is an important factor, he said. Although 20% of all breast cancer deaths are due to breast cancers found in women below age 50, these cancers account for 34% of all the years of life lost to the disease.

As for the cost argument, his view is that “cost is really a political matter. It’s a matter of deciding whether you’re going to spend your money on other government programs, say, or for screening.”

Clearly you get more bang for the buck by screening women age 50 and up, he said. The cost per year of life saved for biennial mammography screening in women 50 to 59 is $3,325, which rises to $5,664 for annual screening. The cost per year of life saved rises sharply in the 40- to 49-year-old group to $6,360 for biennial and $8,899 for annual mammograms.

But Dr. Feig had an answer to this argument, too. “I don’t think anyone in this room would decide not to extend their life for 1 year at a cost of $9,000.”