As the debate over the value of mammography continues, a new study has surfaced in favour of regular screening: Mammograms not only find tumours earlier, they can also increase the chance for breast-conserving treatment.
Reporting in the September issue of Cancer, researchers from the Fox Chase Cancer Center in Philadelphia offer new evidence that regular mammogram screening lets breast cancers be discovered at an earlier, and smaller, stage - even in women as young as 40. And doing so appears to impact treatment, helping women avoid mastectomy and keep their breast.
Goal of research
Because there continues to be much controversy over the older, mostly European mammography studies, the goal of our research was to confirm findings about mammography in a modern population in a modern hospital setting, using modern equipment, says study author Dr Gary Freedman, a radiation oncologist at the Fox Chase Cancer Center.
While in the past some mammography studies have shown regular screening could lead to early tumour detection, Freedman says the new study goes one step further in two different areas.
First, we showed that this is true in women aged 40 to 49. And second, we were able to show that in the event a breast cancer was discovered, women who had frequent mammograms were far more likely to undergo breast-conservation therapy - something other studies have not documented, Freedman says.
Doctors have intuitively known
For breast surgeon Dr Kimberly van Zee, the study gives scientific credence to what she says doctors have intuitively known for a long time.
Many of us always believed that regular mammograms help find cancers earlier and at a smaller size, and that doing so results in not only saving a woman's life, but saving her breast, says Van Zee, of Memorial Sloan-Kettering Cancer Center in New York City. This study is important, she says, because it backs up intuitive thinking with hard science.
If offers immediate results and immediate conclusions - women who underwent regular mammogram screening were more likely to have a lumpectomy [instead of mastectomy]. And that is an important scientific validation, Van Zee says.
What's more, she says, because finding tumours early is more likely to increase survival rates, this study helps draw the connecting line between regular mammograms and surviving cancer.
It doesn't prove that, but it implies that, and this is an important point in this research, Van Zee says.
The research study
The study involved 1 591 women, aged 40 to 92, diagnosed with breast cancer between 1995 and 2001. After diagnosis, the women were divided into three groups: one had no previous mammogram (192 women); one had a mammogram less than every year (695 women); and one had a mammogram at least once a year or more (704 women).
Doctors then examined the medical charts drawn up at the time of diagnosis. They noted specific information on tumour size and classification (indicating the severity of the cancer), as well as whether any lymph nodes were involved in the disease process. In addition, the researchers also noted how many women had breast-conservation therapy (a lumpectomy) and how many had a mastectomy.
The final step was cross-referencing these findings with the earlier information on the frequency of mammography.
What the researchers found
The end result: Including women from all age groups, those who had mammograms most frequently (yearly or more often) had tumours under one centimetre in size 23 percent of the time, while those who never had a mammogram had small tumours only eight percent of the time. Those who had mammograms yearly or less often had small tumours 20 percent of the time.
In addition, 56 percent of the patients who had frequent mammograms had tumours classified as early cancers, compared to just 32 percent of the women who never had a mammogram.
Finally, 61 percent of women who received frequent, regular mammograms received a lumpectomy, with 28 percent requiring mastectomy (11 percent had other treatments, including chemotherapy, radiation or no treatment). In the group that had no previous mammograms, lumpectomy was performed in 41 percent of patients, while 41 percent had mastectomy and the rest, other treatment combinations.
Trend toward breast-conservation therapy
While most of the statistical data also held true for women between 40 and 49, there was less of a difference in their lumpectomy versus mastectomy rates. Instead of a statistically significant difference, the study showed only a trend toward breast-conservation therapy in this group.
Freedman says several reasons may be behind this portion of the finding, including a much smaller group of women with cancer in this age category. - (HealthDayNews)