Mammogram study 'definitely flawed,' says Kingman doctor
KINGMAN - Christopher Johansen doesn't mince words when it comes to a 25-year Canadian study that has recently revived debate about the value of mammograms.
"This study is definitely flawed, and there are literally hundreds of other good studies out there that conclusively prove the value of mammograms," said Johansen, a doctor and the director of breast imaging at Kingman Regional Medical Center.
"This is a classic example of what not to do in a study and how it can go awry. There is no doubt in my mind that mammograms lead to early detection of cancer and less-invasive treatment."
Johansen, who also served as chief resident at Mayo Clinic in Rochester, Minn., has been familiar with the study for years. When it began, he was spending a year in a fellowship at Massachusetts General Hospital, where he and the other doctors discussed the study they believe was skewed from the start because of how participants were grouped.
The study, which was published last week in The British Medical Journal and has drawn criticism from around the world, casts doubts on the value of the screening test for all women. It involved 90,000 women, finding that death rates from breast cancer were the same in those who got mammograms and those who did not.
The study randomly assigned Canadian women to have regular mammograms and breast exams by trained nurses or to have breast exams alone.
It also found that one in five cancers discovered with mammography and treated was not a threat to the woman's health and did not need chemotherapy, radiation or surgery.
But Johansen, who followed the study closely, said there was no random assignment of participants. The women were given physical breast exams first, he said, and if a lump was noticed, they were placed in the group that also received the mammograms.
Johansen said that because that group was loaded with participants who already had lumps, more of them died and the study results were compromised. All the study's impartial reviewers quit, he added.
"It was a laudable goal to try to help these women who had lumps by getting them mammograms," said Johansen. "But we watched this study as it progressed and thought it was so bizarre that these people in the mammogram group were dying. No wonder. It was improperly randomized. And when you start doing that, you skew the results. We're still dealing with it years later."
The American Cancer Society recommends yearly mammograms starting at age 40 and continuing for as long as a woman is in good health.