Is cancer inherited? Should I be worried if my family has a history of cancer? These are questions that may have crossed your mind when loved family members suffered the torment of cancer. It is well-acknowledged that environmental factors such as smoking, diet, and infections contribute significantly to the risk of developing cancer.
Nonetheless, the importance of an individual’s genetic makeup should not be neglected. The heritability of cancer fluctuates, depending on the type of cancer. To decode the contribution of genetics to cancer development, research scientists cleverly monitored ~134,000 pairs of identical twins and fraternal twins to examine the frequency at which the same type of cancer developed in each twin pair . After an average of 40+ years of careful monitoring and combining data from earlier findings published in 2000, they have provided an updated estimate in which prostate, testicular and breast cancer have the highest probability of being hereditary cancers at 58%, 36%, and 28%, respectively (See Table 1).
Table 1. Probability of cancer being hereditary
|Cancer Type||Heritability Estimate|
Benefits of genetic test for prostate cancer
1. Understanding your prostate cancer risk
At 58%, prostate cancer is the most heritable form of cancer. Emphasis has been placed on identifying variations in human DNA that lead to an increase in prostate cancer risk. Currently, there are 77 sets of susceptible genetic variations that can be collectively screened via genetic test to evaluate the risk of developing prostate cancer. However, it is important to understand that information from genetic tests do not provide a firm YES or NO to an individual developing prostate cancer in their lifetime but rather, estimates the RISK that prostate cancer could occur. By reducing the environmental factors through proper life style management and routine monitoring, prostate cancer risk can be controlled.
2. Improving prostate cancer diagnosis
Early detection is the key to combat cancer of all types. For prostate cancer, physicians rely on prostate specific antigen (PSA) screen from blood samples as the biomarker. Although commonly used, this method lacks sensitivity and specificity. Moreover, there is no standardized threshold level of PSA in the blood to definitively confirm the necessity of a follow-up prostate biopsy exam, which creates the burden of unnecessary procedures and anxiety. Part of the low sensitivity and specificity comes from genetic variations among individuals. Genetic test can easily detect these variations and serve as a genetic correction factor to reflect a more accurate measurement of PSA. This could significantly prevent 15-20% of unnecessary prostatic biopsies, which will reduce complications, costs, and enhance quality of life for patients.
3. Enhancing the effectiveness of prostate cancer therapy
Steroid hormone androgen is the culprit leading to the development of metastatic prostate cancer. In treating this aggressive form of prostate cancer, androgen deprivation therapy is considered the first-line therapeutic option. However, a patient’s response to this therapy varies greatly and there is a lack of guidelines to identify which sub-population of patients will benefit most from the treatment. New insights from genetic studies have revealed that genetic variance could be utilized as a marker for responsiveness to androgen deprivation therapy . In other words, genetic tests can improve the prognosis of therapy for genetically favourable individuals and allow early identification of patients with poor response so that alternative treatment is provided to reduce delay in prostate cancer management.
4. Economical in the long term
Although the up-front cost of genetic test might be slightly higher than the fees associated with current prostate cancer screens such as PSA, the economic benefit is realized in the long run. First of all, a genetic test is not age-dependent. Once you are tested, your genetic information does not change, which means it is not necessary to repeat tests. Although prostate cancer screens such as PSA is relatively cheaper than a genetic test, its low detection limit, poor specificity, age-dependent, and individual variations require at-risk groups to undergo repeated tests to ensure correct interpretation of the results. Such an effort is time-consuming and expensive. As the genetic information can be used to validate your risk of prostate cancer, responsiveness to PSA screens, and prostate cancer treatment, it can greatly improve the effectiveness of each step while avoiding unnecessary costs associated with continuous poorly responsive therapeutic options.
Genetic tests for prostate cancer can be a significant step towards managing your risk and treatment options. If you are interested in knowing more, please read about how genetic test can help colon cancer treatment or contact us for more information about the available genetic test options for you.
- American Society of Human Genetics (ASHG) 63rd Annual Meeting: Abstract 43. Presented October 23, 2013.
- The Role of Single Nucleotide Polymorphisms in Predicting Prostate Cancer Risk and Therapeutic Decision Making. BioMed Research International. 2014.