What's Being Evaluated Now?
The focus of the EGAPP project in 2006 and 2007 will be model evaluations of selected genetic tests. Tests are chosen based on their potential for broad application and public health impact. Outcomes to be considered will include benefits and harms to the patient and family, as well as societal and public health issues (e.g., availability or access to testing, adequacy of consumer and provider education, resources and infrastructure).
Several tests are currently under review. These include tests related to colorectal, breast, and ovarian cancer, and depression.
Colorectal Cancer
This review concerned the effectiveness of tests for hereditary nonpolyposis colorectal cancer (HNPCC) in improving outcomes of patients with newly diagnosed colorectal cancer (including prognosis and treatment) and their families (e.g., prevention and early detection). HNPCC testing is currently in use and helpful because not all colorectal cancer is of the hereditary nonpolyposis variety. However, this test is relatively expensive, so it is not feasible for all newly diagnosed colorectal cancer cases. The HNPCC review also assesses the other tests used to identify colorectal cancer patients who are at risk for HNPCC and might be offered testing for associated gene variations.
An evidence-based report on Hereditary Nonpolyposis Colorectal Cancer: Diagnostic Strategies and Their Implications has been released by the Agency for Healthcare Research & Quality (AHRQ).
Ovarian Cancer
The EGAPP working group collaborated with the CDC's Division of Cancer Prevention and Control on a review of current and emerging genetic tests related to ovarian cancer. The panel is reviewing evidence on tests used to detect ovarian cancer, predict the risk of the disease in apparently healthy women, and help tailor treatment.
An evidence-based report on Genomic Tests for Ovarian Cancer Detection and Management has been released by the Agency for Healthcare Research & Quality (AHRQ).
Breast Cancer
This review assessed the evidence that three marketed gene expression-based assays (Oncotype DXTM, MammaPrint® and the Breast Cancer Profiling (BCP or H/I ratio) test) improve prognostic accuracy, treatment choice, and health outcomes in women diagnosed with early stage breast cancer.
An evidence-based report on the Impact of Gene Expression Profiling Tests on Breast Cancer Outcomes has been released by the Agency for Healthcare Research & Quality (AHRQ).
Depression
This review focused on tests for common variations in enzymes that metabolize drugs commonly prescribed for people with depression. These tests detect genetic variations that could affect how well a patient with depression responds to treatment with selective serotonin reuptake inhibitors (SSRIs). SSRIs include some of the most common antidepressants on the market: Prozac, Zoloft, and Paxil. Testing for variations in the cytochrome P450 enzyme is currently being marketed to physicians and has a huge potential impact because of the large number of patients taking drugs metabolized by these enzymes. EGAPP intentionally chose this test as it concerns a common disorder and for which there is a commonly prescribed treatment.
An evidence-based report on Testing for CYP450 Polymorphisms in Adults With Non-Psychotic Depression Treated With SSRIs has been released by the Agency for Healthcare Research & Quality (AHRQ).
In addition, EGAPP has released a recommendation statement.
Colorectal Cancer and Chemotherapy
The test being evaluated has the potential to show when a specific form of chemotherapy (irinotecan) could be potentially toxic for a cancer patient. Irinotecan is often used to slow the advance of late-stage colorectal cancer. The UDP-glucuronosyltransferase 1A1 (UGT1A1) gene helps metabolize irinotecan. This genetic test tracks common variations of the gene, which limit its ability to metabolize irinotecan and can lead to a toxic buildup of the chemical in the blood.