Danish researcher Dr. Peter Gotzsche first made this claim in a study published in "The Lancet" in October 2006. Gotzsche had re-analyzed the studies originally done on the benefits of mammograms and found them unconvincing.
Since then, other doctors have begun to assert that in addition to failing to offer protection, mammograms — which involve exposing patients to radiation —may actually increase women's risk of cancer.
"The latest evidence shifts the balance towards harm and away from benefits," said Dr. Michael Baum of University College in London.
According to Canadian columnist Dr. W. Gifford -Jones, women between the ages of 40 and 49 who have regular mammograms are twice as likely to die from breast cancer as women who are not screened.
"Experts say you have to screen 2,000 women for 10 years for one benefit," he wrote recently.
Gifford-Jones also points to other risks, from the physical to the psychological. According to some authorities, the squeezing of women's breasts during mammograms may rupture blood vessels, causing cancer to spread to other parts of the body and actually increasing a patient's risk of death.
He also pointed to the trauma suffered by women who receive false positives from their mammograms, and to the dangerous sense of security felt by those who receive false negatives.
Studies show that mammograms fail to detect cancer 30 percent of the time in women aged 40 to 49. In addition, it can take eight years before a breast tumor is large enough to detect, by which time the cancer could have spread to other parts of the body.
"Mammograms actually harm far more women than they help," said Mike Adams, author of "The Healing Power of Sunlight and Vitamin D," a free report that teaches prevention strategies for breast and prostate cancer. "They are used more as a recruiting tool to ensnare women into a system of medical control based on false diagnosis and fear tactics. Most women then give in to chemotherapy, surgery or radiation treatments that may ultimately harm them or even kill them."