Genetic Test

‘Yet you do not know what tomorrow will bring. What is your life? For you are a mist that appears for a little time and then vanishes.’ (James 4:14)

Genetic test Genetic test becomes a talking point recently when Angelina Jolie, 37, had a double mastectomy after learning from the genetic test that she carried a faulty BRCA1 gene which gives her an 87% chance of getting breast cancer and 50% chance for ovarian cancer. Her mother died of ovarian cancer at the age of 56. She will also go for oophorectomy in future.

This type of surgery involves removing as much of the ‘at-risk’ tissue as possible. But since it is not possible to do it completely, the doctor may prescribe natural or synthetic substances such as the drug, Tamoxifen, to further reduce the cancer risk. Genetic test for breast and ovarian cancer is the most sought after as compared to other types of cancer (such as pancreatic) as a woman can surgically remove her breasts and the whole reproductive system, and still functions normally notwithstanding having to bear some side-effects.

BRCA1 and BRCA2 (*) are human genes known as tumor suppressors. Mutation of these genes has been linked to hereditary breast and ovarian cancer. If a harmful BRCA1 or BRCA2 mutation is found, several options are available to help a person manage her cancer risk. Some hints of the existence of hereditary factors:

1. Cancers occurring at younger ages than usual

2. More than one type of cancer in a single person

3. Cancers occurring in both of a pair of organs (e.g. both breasts)

4. Similar cancer in a set of siblings

The test normally begins with a family member who has breast or ovarian cancer. If that person is found to have a harmful BRCA1 or BRCA2 mutation, then other family members can be tested to see if they also have the mutation. A positive test result provides information only about a person’s risk of developing cancer. It cannot tell whether that person will actually develop cancer or when. On the other hand, having a negative test result does not mean that a person will not develop cancer. It just means that the person’s risk of cancer is probably the same as that of people in the general population. It is possible for a person to have a mutation in a gene other than BRCA1 or BRCA2 that increases her cancer risk but is not detectable by the tests used.

Frankly speaking, my medical oncologist has never mentioned such test during consultations and I do not know much about it till recently. May be I shall ask her the next time when I see her. A positive test result may have an effect on one’s emotions, relationships, finances, and medical choices etc. It may even have bearing on one’s insurance policies, employment. Anyway, it is not cheap to do such test over here. I read from newspapers that it is somewhere between S$ 2500-3500.

Currently, hereditary cancers are still not common in this country. Older generations (our parents) are healthier and have long life-span but I am not so sure of my generation, worst, the younger generation, giving the deteriorating physical environment and the lifestyles we are in. May be more people will  go for such test in future.

(*) BRCA1: breast cancer susceptibility gene 1 /BRCA2 : breast cancer susceptibility gene 2