FRIDAY, March 15, 2002 (HealthDayNews) -- Evidence continues to mount that mammography does, indeed, save women's lives.
In an article in tomorrow's issue of the journal The Lancet, Swedish researchers report that a reexamination of 247,000 women found that mammography can reduce the risk of death from breast cancer beginning in those as young as age 50, with the greatest risk reduction -- up to 33 percent -- seen in women between the ages of 60 and 69.
The new research re-analyzed a number of Swedish breast-cancer screening trials conducted during the 1980s, all of which originally found that mammography had lifesaving benefits.
The reason for the reanalysis stemmed, in part, from a report published in The Lancet last October by researchers Drs. Ole Olsen and Peter Gotzsche. They looked at a number of breast-cancer screening trials -- including the so-called Swedish Malmo trial -- and concluded that, contrary to popular belief, mammography did not save lives.
Their claim generated a fierce controversy that moved U.S. Secretary of Health and Human Services Tommy G. Thompson to announce last month the government's continued backing of regular screening mammography as a lifesaving tool.
The debate also prompted the start of the study being reported tomorrow.
In this new analysis, the Swedish researchers added a nearly 16-year follow-up to four previously conducted breast-cancer screening studies, including the Malmo trial. They found that not only did the original lifesaving benefits of mammography cited in the earlier research still hold up, but the evidence is now stronger than ever that mammography saves lives.
For breast cancer expert Dr. Clifford Hudis, the new finding isn't surprising. But, he says, there's value in this report.
"For those of us who never doubted mammography, this re-analysis is not news. But it is important because it helps to confirm that what we knew all along to be true is true -- mammography saves lives," says Hudis, chief of breast cancer medicine service at Memorial Sloan-Kettering Cancer Center in New York City.
To help validate the integrity of the earlier studies, the Swedish researchers turned to the national Swedish Cancer and Cause of Death Registry. There, they pinpointed mortality data on 247,000 women, almost 130,000 of whom had mammography screenings.
Then, going back to the original mammography studies from the '80s, they tracked the women for almost 16 years following the conclusion of the earlier research, including their rate of death. Then the researchers used the national registry to calculate how many deaths were due to breast cancer, in both the women who had mammography and those who did not.
Their finding: Combining the results of all four studies, 584 women who didn't have regular mammography died of breast cancer, compared to 511 breast-cancer deaths among those who did have regular breast screenings. That's a 21 percent difference, the researchers say.
Using further analysis that divided the women by age groups, the benefits of breast screening became even clearer, with 33 percent fewer deaths in women who were between the ages of 60 and 69 when the trials started.
Statistically significant lifesaving benefits were also seen when the women were divided still further, into age groups of 55 to 59, 60 to 64, and 65 to 69. Even in the youngest group -- 50 to 54 -- there was a reduction of 5 percent in mortality rates from breast cancer in those that had the mammograms, the researchers say.
The researchers add that the benefits of mammography only began to emerge after approximately four years of follow-up and didn't become truly obvious until year 10.
Dr. Claudia Henschke, of New York Weill Cornell Medical College, had reported in the Jan. 31 issue of The Lancet that the Olsen-Gotzsche analysis of the Malmo trial was flawed because it didn't track the women far enough into the future to see the benefits of mammography.
The study in tomorrow's Lancet reaffirms Henschke's analysis. It also offers new support to those who, like Hudis, continue to believe in the lifesaving strengths of mammography screening.
"The big picture is simply this: Since the advent of mammography screening, the rate of death from breast cancer has gone down," Hudis says. "And that is all we really need to look at or recognize to know that it works."
What To Do
The National Cancer Institute continues to recommend that:
- Women in their 40s should be screened every one to two years with mammography;
- Women age 50 and older should be screened every one to two years;
- Women who are at higher-than-average risk of breast cancer should seek expert medical advice about whether they should begin screening before age 40 and the frequency of screening.
For more information on breast cancer and mammography, visit The National Cancer Institute.
To find an accredited mammogram facility in your area, check this U.S. Food and Drug Administration site.
