Genetic testing can keep cancer at bay

Published Jun 11, 2013


Pretoria - Breast cancer is one of South Africa’s leading killers of women, and although it has been associated with older women for many years, more women under the age of 25 are being diagnosed with it.

Dubbed “killers on the prowl”, breast and ovarian cancer have replaced pregnancy and childbirth as the leading causes of death in women below the age 50 in developing nations, studies have shown.

The development of cancer in 90 percent of reported cases has been attributed to lifestyle and the environment.

It has been reported as being unfortunate that a lot of sufferers get detected at late stages when they can only be offered palliative care instead of treatment.

Although the real causes of breast cancer have not been found yet, obesity, generally being overweight, age, excessive alcohol consumption and unhealthy diets have been fingered.

Preventive measures and risk lowering measures include advice on food to eat and not to eat, maintaining a certain body weight and being physically active.

Doctors say early detection can save cancer sufferers fromdeath.

Mastectomy has caused quite an uproar since sex symbol and actress Angelina Jolie announced that she had had a double mastectomy to prevent breast cancer.

She had learnt that she carried a mutated BRCA1 (breast cancer 1) gene, which sharply increased her chances of developing breast and ovarian cancer. She lost her mother and aunt to cancer.

However, arguments arose on the preventive method she used.

Some argued that they would have their breasts removed at the first sign of risk, others said it was too drastic and other avenues needed to be explored first.

The realities of this preventive measure are genuine and can reduce the chances of developing breast cancer by about 90 percent, University of Pretoria geneticist, Professor Lizzie van Rensburg said.

At the Department for Human Genetics, the professor and her colleagues have been studying breast genetics, both the inherited disorder and the somatic cell disease, for more than 20 years.

The study has seen hundreds of South African women submit themselves for profiling and tests to determine the existence of the mutant genes and their susceptibility to the disease.

“Evidence that both the BRCA1 and BRCA2 genes exist in our community was found between 1994 and 1995, and they exist in all population groups and in both men and women,” Van Rensberg told the Pretoria News.

The genes are human caretaker genes and they help repair damaged DNA or destroy cells if DNA cannot be repaired.

If the genes themselves are damaged they cannot perform this function and this increases the risk of cancer.

Both men and women carry the mutant genes and can pass them on to their children.

The process to determine candidacy for genetic testing was a long and thorough one: “We first study family history to determine if three or more people in the same family line had been affected by breast or ovarian cancer and if they were diagnosed premenopausal.”

From there, tests for the faulty gene take place, with changes in their performance being monitored.

“If the changes are consistent with high risk options, including mastectomy, are considered.”

One option was screening on a regular basis to pick up the rate of change.

“The second option is preventive surgery, the prophylaxis mastectomy,” said Van Rensburg.

But even it did not provide 100 percent protection from cancer: “…because not all breast tissues get removed.”

If double mastectomy was the option of choice, genetic counsellors were brought in and families spoken to.

Plastic surgeons are also brought into the picture to speak about the reconstruction process and possibility of reconstruction.

“Families normally take time to discuss it among themselves because it is not an easy decision to make.”


Cancer facts:

One in every 31 women in South Africa is diagnosed with breast cancer.

Breast cancer is the second most common cancer in South Africa.

Approximately 5 percent of women diagnosed in South Africa are under 35.

There has been an alarming increase in women under the age of 25 being diagnosed with breast cancer.

If breast cancer is detected early enough, there is a survival rate of more than 95 percent. - Pretoria News

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