Controversies in Cancer Screening in the General Population*
| Test | To Detect | Discussion |
|---|---|---|
| Breast self-examination | Breast cancer | Monthly self-examination by women is a noninvasive way to screen for changes in the breast. This method detects many benign and cancerous lumps, but its ability to prolong life is still debated. |
| Mammography | Breast cancer | Mammography is clearly effective screening in women over 50. Most mammograms are obtained by women in their 40s. The incidence of cancer is higher in later life, when mammography use tends to decline. |
| Digital rectal examination (DRE) | Colorectal cancer, prostate cancer | DRE is easy to perform and inexpensive but its cancer screening value is unproven; and , when it detects cancers, there is no proof that the test results in better patient outcomes. In addition, DRE detects a very small number of cancers, only those within the reach of the examiner. |
| Fecal occult blood test | Colorectal cancer | In people over 50, testing stool specimens for hidden bleeding detects many cancers; this detection results in earlier treatment and prolongation of life. The accuracy and value of the test relative to sigmoidoscopy and colonoscopy are uncertain. |
| Chest x-ray, sputum cytology, CT of the chest | Lung cancer | Prospective studies have yielded conflicting results for any method of screening for lung cancer in smokers, and the costs of screening, e.g., with CT of the chest, may be prohibitive. The tests are of no value to nonsmokers. |
| Prostate specific antigen (PSA) | Prostate cancer | PSA testing detects many previously undetected prostate cancers but may result in increased death and disease due to complications from subsequent surgery. Refinements in its application may improve its usefulness as a screening tool. |
| Genetic testing | For predisposition to a variety of cancers | The predictive value of genetic testing for cancer is very small. Experts are debating the emotional and ethical consequences of genetic cancer screening tests. |
*Note: Cancer screening tests are most likely to be useful when: (1) the cancer is common and deadly; (2) the test reliably distinguishes between healthy and diseased people; (3) early detection of the disease leads to improved treatments; (4) treatments are safe and well-tolerated; (5) the psychological effects of test results are addressed sensitively and carefully; (6) the tests are applied to people who will truly benefit from them.