The results from genetic testing are returned from the laboratory to the patient’s physician. The physician and or/genetic counselor will schedule a meeting with the patient to discuss the findings and any follow-up steps, if necessary. Depending on the nature of the testing, patients may have to wait several weeks to several months for results.

When genetic tests are analyzed, three primary factors are considered:

• Analytical validity. How well the test measures the property or characteristic it is supposed to measure.
  
  
• Clinical validity. The likelihood that a cancer, or other disease, will develop in someone with a positive test result.
  
  
• Clinical utility. The likelihood a test will result in an improved health outcome by prompting an intervention.

A positive genetic test result means the patient is more likely than the average person to develop the cancer associated with the mutation. However, it does not mean the patient or that individual's children will definitely get the disease. The likelihood of developing the cancer is based on the genetic mutation and its link to the specific cancer.

If an individual tests positive for a gene mutation, there are several approaches that may be considered. There is limited data available for the effectiveness of these approaches in preventing cancer. Patients should discuss their options with their physicians and genetic counselors. These approaches include:

• Surveillance. Careful monitor by the patients themselves and appropriate physicians may help detect the cancer at an earlier stage. For example, individuals who test positive for BRCA1/2 alterations may undergo mammograms more frequently or at an earlier age. They also may be monitored with transvaginal ultrasounds and CA-125 testing for ovarian cancer prevention.
  
  
• Prophylactic surgery. This type of preventive surgery involves removing at-risk tissue to reduce the risk of developing cancer. These types of surgeries include preventive mastectomy (removal of healthy breasts) or oophorectomy (removal of healthy ovaries). Not all at-risk tissue can be removed and patients can still develop associated cancers (e.g. breast or ovarian cancer).
  
  
• Risk avoidance. Individuals may change lifestyle habits to reduce the risk of their cancer. Those who have mutations associated with breast cancer may increase their physical activity and maintain a healthy weight. Individuals who test positive for colorectal cancer gene mutations may choose to reduce red meat in their diets and eat more grains and fiber.
  
  
• Chemoprevention.  This approach uses natural or synthetic substances to lower the risk of developing cancer or help prevent its recurrence. Some studies have found that certain hormone-blocking drugs can reduce the risk of invasive breast cancer in women at higher risk for developing the disease. However, there have been limited studies on the use of chemoprevention in women with BRCA1/2 mutations. Additional studies are being considered for the use of hormone-blocking drugs for individuals with these altered genes.

A negative genetic test result does not mean the individual will not develop the cancer, but simply indicates that the patient may be no more likely to develop the disease than the average person with no inherited risk. However, it is possible that the patient may have another family mutation that has gone undetected. In addition, genetic tests do not detect all mutations that can cause a disease and some mutations are still being investigated for their connection to cancer.