The life-saving value of mammograms has been debated a lot, causing some women to question recommendations for annual exams.
NIH via Wikimedia Commons
The white arrow points out cancer in this mammogram.
Skeptics might consider data researchers are presenting in San Francisco today showing higher breast cancer mortality in women who didn't have mammograms compared with those who did.
Dr. Blake Cady and his coworkers looked at nearly 7,000 Massachusetts women diagnosed with invasive breast cancer in the 1990s.
Thirteen years after diagnosis, 461 women had died of breast cancer. And this is where it gets interesting. Three-quarters of the deaths occurred among women who didn't get regular screening mammograms, the kinds of scans done to detect a cancer early. Among those who got the tests, only one in four died.
Cady, an emeritus professor of surgery at Harvard and Brown, is presenting the results at a breast cancer symposium in San Francisco sponsored by the American College of Clinical Oncology.
Applying these results to the 193,000 American women who get diagnosed with breast cancer each year, the researchers say fewer than five percent of those who got regular mammograms would be expected to die of their breast cancer within 13 years. But more than half of those who didn't get regular mammograms would die in that time period.
That's a mortality rate comparable to the 1970s, before the advent of mammography.
This isn't a perfect study. It's retrospective and un-randomized. But it's a strong signal of the likely impact of mammography in large populations. So it complements earlier randomized studies that have shown 25 to 50 percent fewer deaths among women offered regular mammograms.
Because mammograms can find some cancers early, women over 50 are urged to get them regularly. In Massachusetts about 80 percent of these women get mammograms at least every two years. The other 20 percent are more likely to be poor, less well-educated, and lacking health insurance.
Where doubts remain about the worth of mammography is as a screening tool for younger women not at special risk for breast cancer.