Screening for Cancer
Human genome research is creating new opportunities for discovery of noninvasive methods to detect and reduce the risk of cancer. As an example, strategies for early detection of colorectal cancer include colonoscopy, sigmoidoscopy, and barium enemas. However, these are invasive procedures, and have been limited by patient compliance issues.[11,12] Testing of stool samples for occult blood is a noninvasive method to screen for colorectal cancer; however, it has not been shown to be sensitive or specific enough for early detection. Furthermore, patients need to change their diet before testing is performed, or they must undergo multiple fecal occult blood tests to increase the sensitivity and specificity of the tests.
Noninvasive methods to detect colorectal tumors are being researched, and have the potential to reduce the morbidity and mortality associated with colorectal cancer. Traverso et al. sought to determine the efficacy of detecting APC mutations (adenomatous polyposis coli gene) in DNA from stool samples using a newly developed method called digital protein truncation. Using this technique, researchers hypothesized that they would be able to identify many different mutations involved in colon carcinogenesis in a sensitive and specific way. Stool samples were collected and analyzed from 74 patients; some of these patients had nonmetastatic colorectal cancer and some did not have neoplastic disease.
Results showed that 57% of the patients with neoplasia had identifiable APC mutations. No APC mutations were identified in the control group. The researchers concluded that APC mutations can be identified in DNA collected from a stool sample in patients with relatively early stage colorectal tumors. Their early feasibility study shows a new, noninvasive way to detect colorectal neoplasms, which has evolved to include more genes and is a clinically available test. Oncology nurses will be involved increasingly in this type of noninvasive cancer screening, and as noted in the Essentials of Genetic and Genomic Nursing, will be using new genetic- and genomic-based information and interventions to improve their patients' health outcomes.
In recognition of the importance of screening and prevention of common diseases, the Agency for Healthcare Research and Quality (AHRQ) created a Guide to Clinical Preventive Services. This includes the US Preventive Services Task Force (USPSTF) recommendations on screening; counseling; and preventive medication topics, with clinical considerations for each topic. The Guide provides healthcare practitioners including nurses and nurse practitioners with an authoritative source for making decisions about risk-management services.