Expert Advice

Screening safety

How effective are cancer screenings at early detection?

For certain types of cancer, screenings can be effective with early-stage identification or with cancer prevention by identifying precancerous lesions that can be removed. Estimates of how many premature deaths cancer screenings can prevent in general range from 3 percent to 35 percent, according to the National Institutes of Health. The reason for such a wide range is due to the variety of assumptions that researchers must make when estimating. Early detection reduces the risk of death of the following cancers: colorectal, breast, uterine cervix and lung cancer.

For example, the American Cancer Society (ACS) estimates that of the more than 250,000 cases of breast cancer that will likely be diagnosed in 2017, about 16 percent will be fatal. For those cases that are caught early through cancer screening, the survival rate is 99 percent. The ACS estimates that about 60 percent, or 6 out of every 10 cases, will be caught at this early stage in 2017.

While colorectal cancers have a similarly high survival rate of 90 percent survival when caught at an early stage, only 39 percent, or about 4 out of every 10 cases, are caught at this stage. However, even with that lower rate of early detection, the ACS notes that overall incidences of colorectal cancer have declined sharply in recent years due to increased awareness around cancer screenings.

Although not every type of cancer can be effectively screened for and detected early, for those cancers that can be caught, early detection almost always improves odds of survival. For people who are at high risk for colorectal, breast and other cancers, being screened can mean the difference between life and death. Ask your doctor if you are at risk for any common types of cancer for which you can be screened. If you are, try to have yourself screened.