When they were growing up, the sisters figured they would have breast cancer one day.
That's what happened to women in their family. Their grandmother got it. Three great-aunts. Two aunts. And, eventually, their mother.
Four years ago, their mom, Palm Harbor resident Martha Buis, got breast cancer again. And she found out something else: She had BRCA-1, a gene that puts women at high risk for breast and ovarian cancer.
Now the sisters, Amy Charles and Tina Shaw, had a choice to make. Should they get tested too?
The sisters are best friends. While they are 10 years apart, they live a few minutes from each other and have sons the same age.
But on this, they had different feelings.
"We went back and forth," said little sister Charles, who was then 33. "I knew immediately that I wanted to be tested. … My sister just didn't want to know."
As science improves, it's a question more of us will face, more often, about more health conditions. Do we want to take the test? Will it help if we know? If we find out, could insurance companies or prospective employers use a positive test against us?
Last week, a national task force said men over 75 shouldn't bother taking the PSA test, a blood test that can indicate prostate cancer. It gave less guidance to younger men, saying that there's not enough evidence to say whether the widely used test helps save lives.
So they're left to wonder: Do they want to take the test? Will it help if they know?
It's not just cancer. Genetic testing means that science can find out beforehand if babies will be born with birth defects or if we're destined to get such conditions as Huntington's Disease or if we carry the gene for sickle cell anemia.
Some tests are clearly helpful. If a pregnant woman tests positive for HIV, doctors can almost always keep her baby from becoming infected. And, of course, people who know they're HIV-positive can take drugs to stay healthy, as well as practice safer sex to keep from spreading it.
Even so, researchers estimate that one-quarter of the people who are HIV-positive haven't been tested. They'd rather not know.
How much harder is it, then, when there's a test where the benefits of knowledge are less clear? Would you want to know that you had an incurable disease — especially one that you saw kill your mother or father? Or would you rather live with uncertainty?
"A lot of people say they'd rather not know," said Dr. Juan Sanchez-Ramos, the Helen Ellis neurology professor at the University of South Florida. "They say it's fate, and if it's going to happen, it's going to happen."
Sanchez-Ramos sees patients and families confronting that choice all the time, because he's the director of USF's Huntington's Disease Center of Excellence.
He thinks it's better to know. People who have a parent with the disease have a 50-50 chance of carrying the gene and getting the disease itself.
"I think knowledge by itself is empowering," Sanchez-Ramos said. "It's not like it's a death sentence. We all have a death sentence from the day we're born."
Symptoms usually appear in middle age, when nerve cells in the brain begin to die. Over the years, people gradually lose the ability to walk, talk and swallow. Eventually, they die.
Sometimes, children of Huntington's patients have practical reasons for wanting to know, Sanchez-Ramos said. It might influence their career decisions or help them make financial and long-term plans. The biggest question: whether they should have children.
Fortunately, Huntington's is rare. The decision that people face far more often: whether to get genetic testing done on their fetus. As science advances, the tests available to check for Down syndrome and other birth defects have increased and become more accurate. But it's still an intensely personal — and often emotional — decision.
"Often patients don't want any prenatal screening at all," said Dr. Victoria Belogolovkin, a USF assistant professor of maternal-fetal medicine. "Then there are patients who want everything."
Some women feel they shouldn't get testing, because they wouldn't end the pregnancy if there were a problem. Others want to know. But it's a time when a positive test leads to more difficult decisions. If the first test is positive, do you take the small risk to the fetus in order to do invasive testing and know for sure? If those tests are positive, do you end the pregnancy?
For Amy Charles and her family, the BRCA1 test led to more hard decisions. Charles took the test — and came back negative. She doesn't carry the gene. But her big sister, Tina Shaw, still hesitated.
"It took me asking every day for a month and a half before she did it," Charles said.
The girls' mother, Martha Buis, also had difficulty deciding to take the test. Genetic counselors often find that for parents, taking such a test can be especially hard. They feel tremendous guilt at the thought that they've somehow hurt their children by passing flawed genes on to them.
Because their mother carries the gene, Shaw's odds were 50-50. But her test result was different than her sister's: positive. Doctors gave her an 80 percent chance of one day getting breast cancer.
In the end, Shaw decided, as some women do, to have a double mastectomy and a hysterectomy to keep from getting breast or ovarian cancer. Charles became a member of the local board of the American Cancer Society and chairs a fundraising walk. Her mother and sister helped with the walk as well.
"My sister and my mother are the bravest people I know," Charles said. In the end, none of them regret taking the test. Charles says that her mother's decision to find out about the gene, by setting in motion the events that led to Shaw's surgery, may ultimately have saved Shaw's life.
"For me, I had to know. If we know about it, we can fix it. If we don't know, we can't fix it," Charles said. "But every woman has to make that decision on her own."
Lisa Greene can be reached at firstname.lastname@example.org or (813) 226-3322.