Researchers link types of cancer

Scientists at USC’s Keck School of Medicine have discovered that faults in the same genetic region can contribute to the causes of both ovarian and breast cancer, suggesting a link between the developments of the two diseases.

Published online Sept. 19 in the journal Nature Genetics, the study looked at the “genetic basis of cancer causation,” said Jonathan Samet, chair of the Department of Preventive Medicine at Keck.

“This involved looking at the genes in people with cancer in comparison to the genes in people without [it],” Samet said.

Simon Gayther, who joined USC in early September and spearheaded the study, worked with colleagues from Keck’s Department of Preventive Medicine, including Susan Ramus, Anna Wu and Celeste Leigh Pearce, among others.

They looked at the genetic information of roughly 13,000 subjects, seeking to find common genetic factors within the population that could be responsible for causing ovarian cancer. The intent was to find a link between a genetic factor that appears more in a cancer patient, which would be less common in a healthy patient, Gayther said.

They discovered five new genetic factors that increase a woman’s chance of developing ovarian cancer.

Since the mid-1990s, scientists have understood that some cancers travel together. In other words, a woman may develop ovarian cancer and breast cancer in quick succession, Gayther said.

What his study now suggests is that some common genetic variants interact with one another in patients at high risk for cancer.

“If you take the woman who has a fault in one gene and on top of that has a fault in another region of the gene [that causes] ovarian cancer, that woman has a much higher risk of getting breast cancer,” Gayther said.

Women who have variations of these gene patterns in their DNA could thus benefit from being screened for both types of cancer simultaneously, which could lead to better forms of cancer prevention.

Gayther has worked on ovarian cancer research throughout his career. He described the disease as a particularly aggressive one that has lacked sufficient scientific research and awareness.

“It is a particularly nasty disease that is very hard to detect, especially early on,” Gayther said.

The positive impacts that research and medical advances have had on understanding breast cancer during the past 20 years are what inspired Gayther’s pursuit to study ovarian cancer, which he said has not benefited from the same improvements.

“When a woman gets a diagnosis, she is almost given a long-term death sentence,” Gayther said. “Seventy percent [of diagnosed women] will be dead within five years. It’s not the most common cancer in the world, but the fact that very few survive means it causes a lot of deaths.”

Samet said he was pleased with the research conducted by Gayther and his colleagues, saying it represents much of the breakthrough work typical of Keck faculty.

“The research has received some publicity. What’s important are the next steps,” Samet said. “[Future breakthroughs] bring the possibility of early detection and possibly therapeutic approaches.”

Gayther said he has essentially moved his entire ovarian cancer program that he started in London to USC, and will soon begin teaching classes in genetics and public health.

“My main interest will be trying to develop young people [by bringing them] into the lab and turning them into really good scientists,” he said.

Both Gayther and Samet emphasized the significant role this research will play in the lives of USC students. Although this research is time-consuming, the benefits are bound to influence the way society understands cancer and the resources it will have to combat it, they said.

Gayther remained optimistic about future developments and encouraged the university to continue supporting research that will enhance the ability to fight and eliminate diseases such as cancer.

“Until we get to a stage where we are able to [better] understand and cure diseases and there isn’t this big fear that we could one day be sick,” he said, “we have to keep motivating ourselves to solve these problems.”