In some cases, however, screening might pick up cancers that would not end up cutting a woman’s life short, especially if she was at risk of dying from another condition, such as heart disease. In that sense, a woman is at risk of being treated with invasive procedures unnecessarily since they would not extend her expected lifespan.

“I suspect that a lot of these cancers are cancers that never would have affected someone’s life expectancy” had they not been caught, Schonberg told Reuters Health. However, she said, it’s very hard to know which cancers are going to progress and which are not likely to cause a woman’s death.

“This is the fundamental problem in screening for cancer in general,” Elkin added. She said that each woman’s decision about whether or not to get screened should depend on how much she would benefit from doctors catching an early-stage cancer. Every older woman “should not just get a mammogram routinely, but have a discussion with her doctor,” she said.

The main message is that “screening can be effective even in older women,” Elkin said. “What’s important is not necessarily a woman’s age but her general health and her life expectancy ... and that’s true for any age.”

SOURCE: Journal of Clinical Oncology, online March 14, 2011.