- Numerous genes have been identified to increase the risk of cancer; however, not everyone who has the mutation develops cancer.
- The relative risk of 25 cancer genes identified by Stanford scientists will help in determining individual risk of developing cancer among individuals who carry the gene mutation.
- Risk assessment can be used to provide personalized care for high-risk patients and to determine the type of care.
Genome wide association
studies were used to identify gene mutations that are known to increase the
risk of cancer. However, patients who find out that they have the mutation may
not want to know that they have an increased risk of cancer. Moreover, it is
difficult to identify which patient will actually develop the disease
condition, which raises the anxiety level of individuals and affects their
ability to choose their treatment. A research team from Stanford University School of Medicine along with Fox Chase Center
studied 95,561 women to help
interpret the results of genetic testing.
Interpreting the Genetic Test ResultsThe scientists involved in the study analyzed the family history, genetic test results and the presence of disease among the study participants who underwent genetic testing. The genetic tests were conducted to identify the presence of 25 mutations that are found to lead to the development of breast and ovarian cancer. Some of the study participants had cancer while others did not.
The study found that
- 7% of the women
- Providing the degree of risk which will help women and their physicians assess the risk of cancer.
- Preventing confusion regarding the prospect of developing cancer.
- Providing clarity to regulatory bodies like the American Cancer Society who recommend when further tests should be taken, or how frequently.
Cancer Management Based On Risk
Cancer management is a combination of various therapeutic strategies that include chemotherapy, radiation therapy as well as hormone treatment. An example stated by Dr. Kurian was that women at high risk would prefer mastectomy while women at low risk would prefer frequent intensive screening procedures like breast magnetic resonance imaging.
Relevance of a Mutation
Genetic testing is now accessible for many women and, most often, women are tested for a number of gene variations or mutations that are known to increase the risk for cancer. However, there is little understanding about the exact effect of these gene variations.
Certain well-known genes like BRCA1 and BRCA2 are known to increase the risk of cancer, while there are numerous other genes that have been implicated in the condition but have not yet been substantiated with large scale studies to understand the extent of their risk.
Testing 25 Cancer Associated Mutations
95,561 cancer patients and healthy women who were matched according to their age and ethnicity were included in the study, and their genetic results assessed. A total of 25 cancer-associated genes formed the panel of gene variations that were tested. The family history of cancer was gathered to determine the relative risk of developing the disease condition based on the presence of the mutation.
The study was published in the journal JCO Precision Oncology and detailed the relevance of a mutation and the risk of cancer.The study results showed that
- 8 genes
A number of small case-control studies have been carried out to identify genes that are associated with cancer risk; however, this is one of the largest studies conducted till date, and the results will help in improving personalized care for cancer patients.
Based on the relevance to smaller studies, this comprehensive study
- Substantiated the results of smaller studies
Precision Medicine in Cancer Care
Precision medicine plays an important role in cancer diagnosis, treatment and care. There are specific gene mutations that are known to increase the risk of cancer and analyzing these genes will help determine the level of risk.
Apart from the risk of developing the disease condition, they can also be used for determine the type of treatment, constituting precision medicine, for example
- Patients with chronic myelogenous leukemia who have a variant enzyme produced by a fused variant of 2 genes can be treated using the drug Imatinib (Gleevec), which blocks the enzyme production.
- Breast cancer patients who have a genetic profile known as HER-2 positive can be treated with the breast cancer drug Trastuzumab (Herceptin).
- Lung cancer patients with certain EGFR mutations respond to the drugs Erlotinib (Tarceva) and Gefitinib (Iressa).
- Impact of Cancer Genomics on Precision Medicine for the Treatment of Cancer - (https://cancergenome.nih.gov/cancergenomics/impact)