It isn’t everyday that scientists thank Hollywood for helping science.
However, Professor of Genome Sciences at Washington University Mary-Claire King, who identified a suit of genes that can help ascertain one’s likelihood of breast and ovarian cancer, said in a lecture here that actor Angelina Jolie had contributed immensely towards raising awareness about how an early genetic test can help some women avoid cancer.
Faulty gene
Ms. Jolie had revealed in a New York Times article in 2013 that she’d undergone prophylactic mastectomy (elective removal of breasts) after being told that she had an 87% chance of getting breast cancer.
Ms. Jolie carried a faulty version of a set of genes called BRCA genes (breast cancer 1 and 2 genes). Her mother had died due to breast cancer at 56. Ms. Jolie later had her ovaries excised as well.
Cancer mutation
Dr. King was speaking at the All India Institute of Medical Sciences (AIIMS) as part of a multi-city tour for the Cell Press-TNQ India Distinguished Lectureship Series, 2017.
She said the global phenomena of women increasingly hitting puberty early (on account of improved access to nutrition) and delaying pregnancy meant they were at an increased risk of cancer mutation.
Dr. King is one of the pioneers in arguing for a genetic link to cancer. Early in her career, she found that chimpanzees and humans shared 99% of their genes and the differences between them lay in the manner and sequence in which they were expressed.
BRCA genes
When working well, the BRCA 1 and 2 genes help repair damaged DNA. However, if someone inherits the faulty versions of these genes, the protective shield is dented and the woman is highly likely to get breast or ovarian cancer, sometimes even both, Dr. King said, citing work from “thousands of studies” beginning from 1990s.
Only 15% to 20% of women with ovarian or breast cancer have BRCA and other mutations that are definitely known to cause cancer, said Dr. King. While several genes are suspected to be linked to cancer, the BRCA family is but one of them.
‘Undertake study’
Dr. King added that it would be well worth a national effort in India to undertake a study of women afflicted by breast and ovarian cancers and see how many of them have the mutated dangerous versions of the BRCA genes.
The genetic test to determine the presence of BR CA genes costs about ₹15,000 in India. Were women to take the test in their 30s, it would help them with decisions such as mastectomy in case they possess the errant genes. Family history would also help determine the risk to one’s sisters and daughters.
Cost of tests
“I’m sure that ingenuity, efficiency and ability to reduce the cost of tests exists in India,” she added.
Her hour-long talk invited several questions from students, physicians and veteran scientists ranging from whether women in a largely poor country such as India could afford such a test and the extent to which physicians ought to trust test results before recommending surgical removal of breasts and the ovarian tubes.
“Matter of time”
Dr. King said making women more aware of the necessity for such a test and getting them to be comfortable with the idea was a “matter of time”.
She gave the example of one her friends who died from ovarian cancer but could’ve possibly been saved had she known about the risk.
It’s not only women who must be wary of BRCA genes. A notable but still small percentage of men with mutations in these genes are known to have an increased risk of prostate cancer.
