Although "[m]ost people believe that finding cancer early is a certain way to save lives," the "reality of cancer screening is far more complicated," New York Times columnist Tara Parker-Pope writes.

"Studies suggest that some patients are enduring aggressive treatments for cancers that could have gone undetected for a lifetime without hurting them," while "[a]t the same time, some cancers found through screening and treated in the earliest stages still end up being deadly," according to Parker-Pope. "It is estimated that for every 100 women who are told they have breast cancer, as many as 30 have cancers that are so slow-growing they are unlikely to be life-threatening," she adds. Figures like these and other studies have prompted the American Cancer Society to say that some benefits of early detection have been overstated. The group issued a press release Wednesday standing by its current recommendations of mammograms for women ages 40 and older. However, ACS also says that women should be aware of the limitations of screenings, and it "will continue to revise its public messages about cancer screening as new information becomes available," Parker-Pope says.