Researchers from Chicago have shown that a gene present in almost 10 percent of the population is the “most commonly inherited cancer susceptibility” gene identified so far, and increases cancer risk by 26 percent.
The gene, transforming growth factor beta receptor 1*6A, which is more common than the BRCA gene mutations, may increase the risk of breast cancer by 48 percent, ovarian cancer by 53 percent, and colon cancer by 38 percent, the researchers have found.
“This is an exciting finding because TGFBR1*6A is a common gene that may cause a large number of cancers,” said Boris Pasche, director of the newly created cancer genetics program at Chicago’s Northwestern Memorial Hospital. His group’s findings “should put TGFBR1*6A on the map with better known cancer susceptibility genes such as BRCA1 and BRCA2 that have been implicated in an estimated 5 to 10 percent of all breast and ovarian cancers,” he said.
Pasche and his team analyzed combined results from seven studies and showed that the TGFRB1*6A gene may be responsible for around 7 percent of all breast cancers, nearly 11 percent of all ovarian cancers, and 5.5 percent of all colon cancers across “a variety” of ethnic groups.
According to the researchers, Northwestern offers TGFBR1*6A testing only as part of the research conducted at the cancer genetics program. However, Pasche said he predicts that testing for the gene “will enter the mainstream … in the near future.”
“The results of this study will certainly spark interest in genetic testing and counseling for TGFBR1*6A,” he said in a statement. Results of his group’s study appear in the current Journal of Clinical Oncology.
To be sure, there is a long road ahead for researchers eager to begin using the TGFBR1*6A gene as a predictive marker. These tests are “not ready for prime time yet,” cautioned Virginia Kaklamani, an oncologist at Northwestern Memorial Hospital and assistant professor of medicine at the Feinberg School of Medicine. “We still have to understand its role in relation with other genes that we commonly test for, such as BRCA1 and BRCA2.”
She added, though, that “in the foreseeable future, we may be able to identify high-risk women more precisely because of the TGFBR1*6A mutation and prevent many cases of breast and ovarian cancer.”