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October 22, 2010
Finally, there’s good news!
New research offers hope for women with ovarian cancer.
CYNTHIA RAMSAY
Recent research by the Ovarian Cancer Research Program at Vancouver General Hospital and the B.C. Cancer Agency offers the opportunity to reduce ovarian cancer deaths by as much as 50 percent over 20 years.
This good news was shared at an Oct. 13 forum entitled Ovarian Cancer Prevention: New Developments Women Need to Know. Presented by Ovarian Cancer Canada, the Jewish Independent and the Jewish Community Centre of Greater Vancouver, the event featured three experts: Dr. Mark Rosengarten, an obstetrician gynecologist at St. Paul’s Hospital and associate professor of obstetrics and gynecology at the University of British Columbia; Dr. Sarah Finlayson, a gynecologist oncologist at VGH and BCCA and assistant professor in the division of gynecologic oncology at UBC; and Mary McCullum, an oncology nurse with BCCA’s Hereditary Cancer Program.
“As we know, ovarian cancer is the ‘silent killer,’” said Rosengarten in his opening remarks. “It is the leading cause of cancer-related deaths of women in North America. Breast cancer affects more women, but ovarian cancer kills more. It affects about one in 70 women overall, with the Ashkenazi Jewish population having a much higher incidence.”
He noted that, until recently, there had been no good news on the prevention of ovarian cancer. He explained that, because of its vague symptoms, the cancer is often not detected until an advanced stage and the treatment options are limited and harsh. He said the removal of the ovaries has been an accepted practice and, while it’s a simple surgery to do, for the patient, “it really destroys her quality of life, it often leaves her as a shell of her former self.”
But, he concluded, “For once, we have options to offer you to prevent ovarian cancer.” Finlayson, who, with the belief that “knowledge is power,” urged audience members to each “tell three people what you’ve heard tonight, what you’ve learned tonight,” went on to describe some of those options. First, however, she provided some background on the current state of research.
One reason that ovarian cancer is diagnosed at an advanced stage in 70-80 percent of cases is that there is no screening test for it, she said. CA125 (cancer antigen-125, a protein found at elevated levels in ovarian cancer cells compared to normal cells), ultrasound and pap tests are not effective tests, she stressed. Later, in response to a question, she explained that a pelvirectal exam, though “an embarrassing and uncomfortable exam,” is the only way doctors can feel cancerous lesions in the pelvis. She said, “You have a physical exam or an ultrasound, that’s typically how these things are picked up and ... unfortunately, by the time they’re creating symptoms, they’re fairly advanced.”
In her talk, however, Finlayson pointed to the great progress that has been made recently. Up to three years ago, she said, ovarian cancer was thought to be one disease with a single treatment approach and no screening options. In 2010, “we’re now talking about five different subtypes of ovarian cancer, we’re embarking on amazing research looking at screening tests, we’re being able to individualize treatment and we’re now finally able to talk about prevention.”
Finlayson focused her remarks on high-grade serous cancer because, she said, it represents easily 70 percent of the ovarian cancers and is the subtype associated to mutations in the BRCA1 and BRCA2 genes, which affect Ashkenazi women disproportionately. BRCA1 mutations increase the lifetime risk of breast cancer to up to about 80 percent and ovarian cancer to 25-50 percent, compared to one to two percent for women without those mutations, she explained, adding that one in 40 women with eastern European ancestry will carry the mutation.
“In the past 20 years, if a woman was known to have a mutation in BRCA, she was offered risk-reducing surgery, and that risk-reducing surgery was to remove the ovaries and fallopian tubes before cancer started,” said Finlayson. Sometimes, the ovaries would be removed when the woman was in her forties and, while this procedure reduces the risk of cancer really well, it can be devastating for the patient, she said, echoing Rosengarten’s comments. “It wasn’t until some of the oncologists started to look carefully through the fallopian tube that we suddenly started to have our ah-ha moment in ovarian cancer,” she said.
It turns out that ovarian cancer actually originates in the fallopian tubes, not the ovaries. In the question-and-answer period, Finlayson expanded on the possible reason for this. Menstrual blood flowing into the fallopian tube instead of through the cervix – with the blood carrying inflammatory and possibly infectious things – can set the tube up for cancer, she explained. This is why ovarian cancer risks are reduced for women who have been pregnant, have breastfed, been on the pill or had tubal ligation – because these things reduce the number of periods in a woman’s lifespan.
“That’s what we’ve learned about women with BRCA mutation and that represents about 20 percent of these high-grade serous cancers,” said Finlayson in her presentation. “So what about the other 80 percent that have nothing to do with having a mutation in BRCA? Are those fallopian tube cancers, too? The answer is, yes.”
Armed with this new knowledge, Finlayson, who heads the education outreach program at VGH’s Ovarian Cancer Research Program (OvCaRe) and BCCA, said the challenge is to change surgical practice. The goal is to have the fallopian tube removed when a hysterectomy or tubal ligation is performed – the current conventional practice being to leave the fallopian tubes in place – and to have physicians send every single woman with a high-grade serous cancer for genetic testing. Over the next 20 years, she said, such changes could reduce the number of ovarian cancer deaths by up to 50 percent.
In addition, said Finlayson, now that it’s known that the fallopian tube is the culprit, researchers can investigate screening options related to the tubes, and they can better focus their research, knowing that there is not just one type of ovarian cancer, but at least five different subtypes.
McCullum concluded the presentations with a discussion of the Hereditary Cancer Program, what it does and who should be referred to the program.
“We know that cancer is very common,” she said. “If we put all cancers together, one in three people will have some kind of cancer at some point in their lifetime, which means everybody in this room, unless you’re extremely unusual, will probably have some family history of cancer, but most of those family histories would be considered average.” However, she continued, between five to 10 percent of cancers are hereditary, and this suggests that people who have that sort of family history might need extra screening.
Referring to the risk of ovarian cancers in particular, McCullum said, “about 10 percent of them are related to having been born with an abnormal copy of a specific gene that increases the risk for specific kinds of cancer. Of that 10 percent, as we’ve already heard, most of those are related to the BRCA1 [about 75 percent] and BRCA2 [about 15 percent] genes.”
The criteria used in British Columbia to identify people who might be eligible for BRCA1 and BRCA2 genetic testing, explained McCullum, include, but are not limited to, having had ovarian cancer, having had breast cancer before age 35, and a history of breast and ovarian cancer in the family.
If you think you’re at a greater risk of ovarian cancer, the first thing to do is talk with your doctor, she said, and to collect as much information as you can; from family members who have had and from those who haven’t had cancer, and from both the maternal and paternal sides, three generations back, if possible. If you and your doctor decide that your family has some of the red flags, she said, you can be referred to the Hereditary Cancer Program.
McCullum explained that hereditary cancer genetic counseling includes education about genes, a review of medical and family history and a discussion of the likelihood of specific cancers, the benefits/drawbacks of genetic testing, strategies for screening and risk reduction, psychosocial issues and communication with family members. She said that genetic testing should be considered when a person has a high chance of carrying a cancer susceptibility gene mutation, there is a genetic test that can be adequately interpreted, the results will influence medical management and a person wants the information. She pointed out that some of the possible risks and limitations of genetic testing are uninformative results, a false sense of security, unacceptable prevention options, stress on relationships, anxiety and discrimination.
The question-and-answer period lasted about a half hour, at the end of which Rosengarten concluded by reminding the audience, “Cancer is big, but we are bigger. We will beat this. We will beat the disease.”
For more information, visit ovariancanada.org, ovcare.ca and bccancer.bc.ca.
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