Genetic testing for cancer susceptibility: challenges for creators of practice guidelines.

The science of cancer is being revolutionized by the collaboration of cancer-afflicted families and determined scientists. The result has been an explosion of knowledge about inherited susceptibilities to particular types of cancer and the possibilities of testing for those susceptibilities. Susceptibility tests are becoming available for breast cancer, ovarian cancer, prostate cancer, colon cancer, retinoblastoma, and hereditary medullary thyroid cancer--cancers both common and rare. Now, cancer patients, cancer families, and cancer physicians face the challenge of determining how--and whether--such tests can be put to good use.