Cancer screening in older adults: What to do when we don't know

More than one-half of new cancers and over 70% of cancer deaths in industrialized nations occur in adults age 65 or older. Systematic screening has been associated with reductions in cancer-related mortality for a variety of cancers, including breast, cervical, and colorectal cancer. Prostate cancer screening remains more controversial despite the recent publication of two large randomized trials of screening. Although guidelines are beginning to address cancer screening specifically among the growing group of seniors age 70 or older, guidance on estimating remaining life expectancy by explicitly considering competing causes of mortality (e.g. comorbid medical illness) and functional status in this age group is limited. In this article, key evidence-based guidelines are reviewed for cancer screening in adults and limitations of screening studies with respect to older adults are discussed. A framework is reviewed for deciding how long to continue cancer screening in older adults, which incorporates age and health status to provide quantitative estimates of remaining life expectancy.