Screening for cancer makes so much sense. Find the cancer early -- before symptoms show and tumors have grown and cancer has spread -- and have better chance of survival. However, in practice this is not always so. I wrote about an 18-year study in nearly 80,000 women found no benefit of screening for ovarian cancer for the Los Angeles Times. The lack of benefit couldn't have been more clear: no reductions in deaths, no finding cancers at earlier stages.