Other than the BRCA1 and BRCA2 gene mutation test for breast and ovarian cancer, there are other gene-related tests available for cancer.
As an example, one such test that is available is for Lynch syndrome, a hereditary condition which comes with a family history of colon cancer and other types of cancer at a younger age. Those with the syndrome have a higher risk of colorectal and uterine (womb) cancers.
Like BRCA screening, the genetic screening test for Lynch is expensive and is recommended only for high-risk individuals with a strong family history of such cancers.
Trying to find the Lynch syndrome in the general population would be rather costly and not necessarily helpful, said Dr Lim Sheow Lei, a senior consultant at the department of gynaecological oncology at KK Women’s and Children’s Hospital.
The field of cancer genetics is a rapidly evolving area. But things are changing quickly. As genomic technology advances, the cost of sequencing the human genome is plunging, said Dr Lim. Just two weeks ago, a US company announced it was offering a much cheaper and easier way for women to get tested for the BRCA1 and BRCA2 genetic mutations.
Color Genomics* has begun selling a test (USD $249) that it said could accurately analyze a saliva sample for the mutations, as well as check for 17 other genetic variants that have been associated with a somewhat increased risk for cancer of the breast or ovaries.
Cancer can sometimes appear to “run in families” even if it is not caused by an inherited mutation. Acquired mutations are the most common cause of cancer. These mutations occur from genes damaged during a person’s life. Smoking, viruses, and aging can damage genes and cause these mutations.
One such cancer caused by an acquired mutation is cervical cancer, which stem from the human papilloma virus (HPV). Last year, the US Food and Drug Administration approved the HPV DNA test, manufactured by Roche, as a first-line primary screening test in women 25 and older. The geno-typing test detects DNA from 14 high-risk HPV types and specifically identifies HPV 16 and HPV 18, which carry the highest risk of cervical cancer. It can be used to help a healthcare professional assess the need for the woman to undergo additional diagnostic testing for cervical cancer. The test can also provide information about the patient’s risk for developing cervical cancer in the future.
Women who test positive for HPV 16 or HPV 18 should have a colposcopy, an examination using a device that illuminates and magnifies the cervix so a doctor can directly observe the cervical cells. Those who test positive for one or more of the 12 other high-risk HPV types should have a PAP smear to determine the need for a colposcopy. In a United States study of more than 47,000 women that compared HPV DNA tests with PAP smear tests, up to one in three women with cervical cancer had a normal PAP smear result.
Scientists and researchers are uncovering more genetic markers for other cancers. The challenge is to know what to do with these pieces of information, how to interpret the multitude of newly uncovered mutations, work out the associated cancer risks and to manage the risks, said Dr Lim.
Got Questions? We have Answers! Contact us at CriteriumBlog@criteriuminc.com