Like any other of her contemporaries, skepticism from fellow researchers and other challenges also greeted American geneticist Mary-Claire King when she set out to establish a genetic link to breast cancer more than four decades ago. However, this did not stop her from pursuing her goals.
According to South China Morning Post, Mary-Claire King, 72, won this year's Shaw Prize for life science and medicine for mapping the first breast cancer gene, BRCA1. "The major challenge was that the technology at that time did not exist," she said of her long road.
When King, who earned her bachelor's degree in mathematics from Carleton College in Minnesota before receiving her Ph.D. in genetics from the University of California, Berkeley, began her research in 1974, most in the field believed cancer was viral.
"It was caused by viruses. That's true," she added. "But not all cancers are caused by viruses, and some cancers as we now know are in part a consequence of inherited mutation."
King persisted because a significant amount of statistical data generated around the world from the 1920s indicated that daughters of women who died of breast cancer were more likely to develop and die from the disease themselves. The groundbreaking researcher used mathematics to see if there was a genetic model to test her hypothesis.
King studied more than 1,500 families in which multiple members were affected by breast cancer. Using a mathematical approach, she predicted that clusters of cases could be best explained by the presence of a disease-linked gene in about 4 percent of families, Topix reports.
She also predicted that among women carrying gene mutations, the risk of breast cancer was about 80 percent by age 70 whereas the risk fell to 8 percent among women without them.
But still there was skepticism about her mathematical model, so King set out to show the existence of a breast cancer gene by locating it using linkage analysis. In 1990, she mapped the gene to human chromosome 17.
Now the American Cancer Society professor in the departments of medicine and genome sciences at the University of Washington, King has a straightforward explanation for focusing on breast cancer: she described the disease as one of the easiest cancers to diagnose and a common cause of death.
In the absence of genomic tools for human genetic analysis, she explained: "it was therefore necessary to develop the technology - that is, to sequence the genomic regions - to learn the sequence of BRCA1."
