WEDNESDAY, Feb. 27, 2002 (HealthDayNews) -- Advances in genetic testing for life-threatening diseases such as cancer have also triggered an ethical dilemma: Doctors have debated whether knowing you're genetically susceptible to a serious health threat would have any real benefit.
In a report published today in the Journal of Clinical Oncology, researchers from Memorial Sloan-Kettering Cancer Center reveal that if you're a woman and your genetic susceptibility is for breast or ovarian cancer, knowing you're at risk just might save your life.
"It's been shown to make a difference in how frequently people screen for both ovarian and breast cancer," says lead study author Lauren Scheuer, a senior geneticist at Memorial Sloan-Kettering Cancer Center. "And certainly, one would expect that the more frequent screening allows us to detect earlier-stage cancers than we would have if they were followed less closely."
This is the first prospective study to show that genetic testing can lead to interventions that result in the diagnosis of earlier-stage breast and ovarian tumors. That, experts say, can translate into saving more lives.
"This was an interesting study and an important study because it clarifies the benefit of genetic testing and shows that the interventions -- surgery and screening -- that were done most likely would not have been done had these patients not been shown to be gene positive," says Dr. Karen Green, assistant professor of medicine at New York Weill Cornell Medical College and an oncologist at the Weill Cornell Breast Center.
Indeed, says Green, the study showed that information from genetic testing lets women make what could be life-saving decisions, particularly concerning "risk-reduction surgery." In these procedures, women elect to have organs or tissue removed that may be likely to become cancerous, including breasts, ovaries and fallopian tubes.
"Without the genetic testing, I don't think many of these women [in the study] would have been able to make that decision, or at least not as easily," Green says.
The new study focused on the genes known as BRCA1 and BRCA2. Although everyone carries these genes, for women who have a mutation in either one, the risk of breast and ovarian cancer can increase dramatically.
Often, says Scheuer, one sign that you may have the mutation is a strong family history of either breast or ovarian cancer, particularly if either disease occurred in relatives at a young age.
However, even if you're identified as "gene positive" -- carrying the genetic defect that increases your risk for cancer -- genetic testing can play an important role in helping you understand your total cancer risk profile.
"A lot of women come to see us with a strong family history of breast cancer, which is their primary focus and reason for wanting genetic testing," Scheuer says. What they usually don't realize is that they also carry an equally high risk for ovarian cancer because it's linked to the same genetic mutation.
So, while knowing your family history of breast cancer might make you more likely to have more frequent breast exams, Scheuer says knowing you are at risk for both diseases would allow you to also increase surveillance and screening for both cancers. In some cases, this might help you make important decisions concerning risk-reduction surgery.
Scheuer's study, conducted at Memorial Sloan-Kettering Cancer Center between 1995 and 2000, used genetic testing to identify 251 patients with BRCA mutations, including 233 women. All were given uniform recommendations for stepped-up screening practices and advised about risk-reducing surgery. They were followed for an average of two years. During that time, each person responded to questionnaires, and their medical records were reviewed. They also maintained a dialogue with their primary care physicians.
By the end of the study, researchers concluded the women did have more frequent physical exams and cancer screenings, resulting in the diagnosis of 21 cases of breast, ovarian, primary peritoneal or fallopian tube cancers.
Additionally, of 29 women who chose to have risk-reducing breast surgery after screenings, two were found to have undetected breast cancer. Among the 90 who chose risk-reducing ovarian and fallopian tube surgery after screenings, two early-stage cases of cancer were found.
The study also confirmed that radiology screening was able to detect six breast cancers, five of which were very early stage, as well as one early-stage primary peritoneal cancer, and three early-stage ovarian cancers.
Six more women had breast cancers diagnosed via a physical exam performed between mammography exams, and four of the six tumors found were stage 1 -- considered a very early cancer.
The really good news: There were no advanced malignancies detected in those patients who underwent genetic testing.
The take-home message, Scheuer says, is simple: "To increase the likelihood that breast and ovarian cancer could be detected early, women should learn their family medical history, including any incidence of breast or ovarian cancer in female relatives of both their mother and their father."
With that information in hand, she says, speak to your physician or a genetic counselor to determine whether genetic testing should be considered.
What To Do: For more information on genetic testing and counseling for breast and ovarian cancer, visit The National Institutes of Health. To learn more about genetic testing for all diseases, visit The National Library of Medicine.
