I think you do a nice job of highlighting some of the shortcomings of cancer screening, even as we acknowledge that screening still saves lives. As I recall, the colon cancer screening test mailed invitations for screening, and even if the person did not get screened, the intent to treat analysis counted them as screened. The moral? If you don't get screened, screening has not shot at working. Alas, the majority of cancers are not detected by screening. As you remind us, we have much work to do in determining risk (genetics, etc.) and risk reduction (physical activity, diet, tobacco avoidance, no more moderate alcohol consumption, a good weight, etc.). Vaccines such as HPV are reducing cervix and other cancers. Screening has value, but the tools remain quite suboptimal. We have much work to do. Thank you for taking the time to highlight some of the promises and perils of screening.

Warm regards,

Michael