A comment of the chief medical officer of the American Cancer Society that the benefits of cancer screening, especially for breast and prostate cancer, have been overstated received widespread media coverage. The basic problem is not that the cancers can be detected, but that there has been very little improvement in overall survival rate between screened and unscreened populations.

The Quandary of Interpreting the Results of Cancer Screening

Cancer screening has a clear-cut objective: to detect a deadly cancer while it is still small and can be treated. When small tumors are found, however, it does not necessarily mean that they will grow and metastasize into an untreatable cancer. Many tumors found during screening turn out to be benign upon biopsy. A study reported in the Journal of the American Medical Association found that many small tumors found in breast and prostate cancer screening turn out to stop growing on their own and even disappear.

Cancer screening has many risks, including the stress of receiving a cancer diagnosis, biopsies and other tests, and unnecessary operations and treatments.