The Yomiuri Shimbun This is the fourth installment of a series on cancer genomics to see what the present and future of the field look like.
“Sure enough, our family lineage is one of cancer.”
The extended family all gather for the Bon Festival holiday in summer and the New Year’s break. When everyone is together after not seeing each other for some time, at some point the conversation turns to the same topic.
“Mom had breast cancer, and grandma had colon cancer.”
“We should also get checked properly.”
For one member of the family, a woman in her early 40s who lives in Saitama Prefecture, cancer was more or less always on her mind. She became acutely aware of it three years ago, when her sister, who was three years older, discovered she had ovarian cancer.
Her sister’s words stayed with her: “I thought I needed an examination, but I was too busy to go [to the hospital]. That was my mistake.”
The woman accompanied her sister to the hospital, where a doctor confirmed her worries. “You may also have hereditary breast cancer and ovarian cancer syndrome,” the doctor said.
A person with a mutation in their BRCA1 or BRCA2 gene is six to 12 times more likely to get breast cancer than a person who does not have it. The risk of ovarian cancer is eight to 60 times greater.
Four years ago, American actress Angelina Jolie was found to have a mutation in the BRCA1 gene and to be genetically predisposed to breast cancer. She had both breasts removed before she could develop cancer.
There is a 50 percent probability that this genetic mutation is transmitted from parent to child. The woman in Saitama Prefecture went to the Saitama Cancer Center to get a genetic test, and, as expected, it was found that she had a mutation in the BRCA2 gene.
“I want to do anything I can to reduce the risk,” she thought.
The woman had her ovaries removed at a hospital in Tokyo. The fact that she already had two children helped her make the decision.
“Seeing my mother and older sister struggle [with cancer], I was scared of getting it,” she said. “The risk of me getting cancer is not zero, but now my family and I can live with peace of mind.” She said she will recommend her children get checked when they are adults.
Kiwamu Akagi, the doctor who was in charge of her examination, emphasized the benefits of genetic testing. “If you know your genetic makeup, you consciously get medical exams,” Akagi said. “Even if you develop cancer, it can be detected early.”
However, the perception of genetic testing differs among people, with some worried about things like the fear of being devastated at learning the truth or being discriminated against because of their genes. If a person is found to have cancer, care must be taken in how they are told.
A consultation room for genetic outpatients at the Shizuoka Cancer Center in Shizuoka Prefecture has landscape paintings on wood-grained walls and plants in the corner. This warm, friendly space is separate from the medical exam rooms.
“How many siblings do you have?”
“When did your aunt get cancer?”
The counselor asks questions, carefully listens to the answers and writes down the family tree of the visitor. Knowing who their blood relatives are and when they got cancer is used as a basis to search for possible genetic cancer. It is also possible to determine which relatives might be susceptible to cancer.
Patients who are worried about their “family lineage of cancer” have gone to the cancer center for consultations. Specialized genetic counselors sit close to people to explain genetics in simple terms.
“It’s important to understand genetics and choose whether you and your family will consent to being examined. The use of genetic information for cancer treatment has only just begun, so I want people to understand it correctly,” genetic counselor Yasue Horiuchi said.