With any serious disease, it's
obviously a good idea to find the best doctor - and
the best hospital - you can.
But with ovarian cancer, a rare
disease that strikes 25,000 women a year, kills
nearly 15,000, and is almost impossible to detect
early - it's absolutely essential.
That's because there are often no
symptoms in the early stages. In three-quarters of
cases, by the time ovarian cancer is diagnosed, it's
already spread. Currently, only half of women
diagnosed with it are alive five years later.
All of this means it's crucial to
get state-of-the-art chemotherapy and specialized
surgery, not from a general surgeon or gynecologist,
but from a gynecological cancer surgeon who knows
how to probe every inch of the abdominal cavity for
tiny tumors.
In ovarian cancer, the primary
tumor usually, though not always, begins in the
ovary itself. It then spreads quickly throughout the
abdomen, scattering mini-tumors all over - on the
colon, the spleen, the gallbladder, the diaphragm.
Even the walls of the peritoneum - the Saran-wrap
like tissue that covers all the internal organs -
are studded with sprouting tumors.
"When we see inside the abdomen,
it's like DOTS candies," says Dr. Linda Duska, a
gynecologic cancer surgeon at Massachusetts General
Hospital. "It's not just a mass in the ovary, it's
diffuse miliary cancer - little, teeny things
everywhere." Research shows that the more thorough
this initial surgery - which involves a long,
vertical incision and can take several hours - the
better a woman's chances of survival.
Historically, those odds have been
grim. If the cancer is caught early, while the tumor
is confined to the ovary, the 5-year survival rate
is more than 90 percent. But few cases are caught
early because there's still no good screening test.
Researchers are working on new tests, including a
blood test called LPA.
There is already a blood test for
a protein called CA125 that can detect some tumors,
but it's notoriously unreliable. It misses some
cases and suggests cancer is present when it's not.
Ultrasound can spot some cancers, but it, too,
raises many false alarms. Even when these two tests
are combined with a standard pelvic exam, ovarian
cancer is so hard to differentiate from benign cysts
on the ovary that 30 women with suspicious findings
may be sent to the operating room for every cancer
found.
Barbara O'Brien, 54, an Arlington
woman, is one of the lucky ones. She was diagnosed
three years ago when her cancer was in the earliest
stage. But she says she's "one of the few in my
support group" whose cancers were caught this early.
If cancer isn't caught until after
it has spread to the fallopian tubes, the 5-year
survival rate drops from 90 percent to 80 percent.
If it has spread to the lymph nodes and abdomen, it
drops to 30 percent. Even when symptoms - abdominal
swelling, bloating, vague abdominal and pelvic pain,
gas - are present, they are so non-specific, a
doctor may not suspect ovarian cancer.
Better chemotherapy drugs,
however, and equally important, a much better
understanding of how best to combine and administer
them, are beginning to make a dent in those numbers.
There's no data yet showing that
bone marrow transplantion is more effective than
standard chemotherapy. But there are several studies
showing that giving chemotherapy intraperitoneally -
through a tube into the abdomen, instead of through
intravenous injections into the bloodstream - may
yield some improvement in survival.
The advantage is that the drugs
get directly to the tumor, cause less nerve and
marrow damage, and trigger fewer side effects. The
downside is this treatment can cause severe
abdominal pain and may not work against tiny tumors
that travel through the circulation to other areas
of the body.
Another emerging strategy is to
try new drugs early, instead of waiting until a
relapse, as is traditionally done. "The hope is that
by utilizing more of the new, active agents in
ovarian cancer right at the beginning, it may result
in more effective killing of tumors and potentially
prolong survival," says Dr. Ross Berkowitz,
co-director of the Gillette Center for Women's
Cancers at Dana-Farber Cancer Institute.
Doctors are also finding new ways
to combine drugs so that they attack the tumor
through different biochemical pathways and don't
exacerbate each other's side effects. "The concept
of chemotherapy that works in different ways is
critically important," says Dr. Stephen A.
Cannistra, program director of gynecological medical
oncology at Beth Israel Deaconess Medical Center in
Boston.
For instance, platinum-based drugs
- either cisplatin or carboplatin - have long been
the mainstay of treatment. The drugs insert
themselves into DNA and interfere with its
replication. Seven out of 10 tumors can be shrunk
this way, but the drugs kill only tumor cells that
are sensitive to them, and many aren't.
Adding Taxol to platinum drugs
yields significantly better survival, notes Dr.
Edward Trimble, a specialist at the National Cancer
Institute. In part, that's because Taxol works
differently, by binding to a cellular structure
called tubulin. When it binds, the chromosomes can't
pull apart and the cell can't divide.
Another relatively new drug called
Hycamtin (topotecan) works in yet another way, by
blocking an enzyme called topoisomerase-1, without
which DNA can't unwind and the cell can't divide.
Already approved for women whose
ovarian cancer has recurred, Hycamtim is now being
studied as a first-line treatment. A drug called
Doxil works similarly, by inhibiting an enzyme
called topoisomerase-2.
Still another emerging strategy is
to borrow chemotherapy drugs from other types of
cancer. A pancreatic cancer drug called Gemcitabine,
for instance, shows enough promise against ovarian
tumors that doctors are now designing studies to
test it in newly-diagnosed women. Doctors are also
trying a lung cancer drug called Navelbine for women
with recurrent tumors.
An even more high-tech solution
was reported recently by Tayyaba Hasan, a biochemist
at the Massachusetts General Hospital Laser Center,
and others, in the Journal of the National Cancer
Institute. Hasan's team studied ovarian cancer that
was resistant to cisplatin.
The researchers hooked together a
drug called a monocloncal antibody (designed to find
its way to markers on ovarian cancer cells) with a
light-sensitive molecule called a chlorin.
A laser light activates the
chlorin, which then destroys the cancer cells - but
not normal cells - in the immediate area. "The
exciting finding," says Hasan, is that this approach
was 13 times more effective than standard
chemotherapy alone. Other researchers, including a
team at the University of Pennsylvania, are pursuing
a similar approach.
And even that's just the
beginning. In a collaborative effort, researchers at
the Dana-Farber, MGH, and Brigham and Women's
Hospital are freezing bits of ovarian cancer tissue
in hopes of making individually-tailored vaccines.
The idea is to kill the cells, insert genes that
make an immune-boosting protein called GM-CSF, then
re-inject the cells back into the patient.
Other researchers are trying gene
therapy to beef up production of cancer-fighting
proteins produced by a gene called p53. Still others
are working on SERMS, or selective estrogen receptor
modulators, to block hormonally-driven cancers. And
others, including researchers at New England Medical
Center, are conducting trials of a monoclonal
antibody called OvaRex to help the immune system
attack ovarian cancer cells.
There is no question that ovarian
cancer is still a horribly stubborn disease. But the
research is beginning to pay off.
Carolyn Mostecki, 54, a
professional gardener in Gloucester, appears to be
in remission after six years of treatment. She took
an experimental drug called Taxotere, a cousin of
Taxol, but thinks Tibetan herbs have helped, too.
Alice Rouff, 60, a restaurant
hostess from Ashland who was diagnosed 10 years ago,
is also optimistic. "I'm totally fine now," she
says, though she's scared to use the word "cure."
"And every day, I make a good
day."
SIDEBAR:
FIGURING A WOMAN'S RISK FOR CANCER OF THE OVARIES
There are no definitive ways to prevent ovarian
cancer, but some factors may reduce or increase
risk.
Last week, for instance, Italian
researchers reported in the Journal of the National
Cancer Institute that taking a drug related to
vitamin A (fenretinide) may protect against ovarian
cancer, in part by triggering apoptosis, or cell
death.
In general, scientists believe
that the more ovulatory cycles a woman has in her
life, the greater the risk, and the fewer cycles she
has - whether they are interrupted by pregnancy,
birth control pills or breastfeeding - the lower the
risk.
Every time a woman ovulates, there
is microscopic damage to the surface of the ovary
where the egg pops out. Usually, this damage is
quickly healed, but cells must work overtime to
repair it. During this repair, researchers theorize,
there is an increased risk of genetic mutations,
which may lead to cancer.
Studies show that a full-term
pregnancy, during which there is no ovulation,
reduces the ovarian cancer risk by 50 percent;
subsequent pregancies offer additional protection.
Breast feeding, which can also inhibit ovulation,
reduces ovarian cancer risk, too, but this data is
less convincing.
There is good evidence, though,
that oral contraceptives, which keep the pituitary
gland from triggering ovulation, decrease ovarian
cancer risk by about 50 percent if they're taken for
a total of five years, not necessarily continuously.
And what of the interplay between
infertility and ovarian cancer? That's dicey. If
infertility means there's no full-term pregnancy,
that increases risk just as it would in a fertile
woman who never had a baby. On the other hand, if
infertility is caused by lack of ovulation, as it
can be, that could reduce risk, though this hasn't
been proved.
Fertility drugs such as Clomid and
Pergonal have been suspected in some cases of
ovarian cancer. Some evidence suggests that
ovulation-inducing drugs may increase risk,
particularly if the drugs don't work and a woman
never gets the risk-reducing benefits of pregnancy.
On the other hand, a recent California study found
no such association.
Curiously, tubal ligation, in
which a woman's fallopian tubes are tied to prevent
eggs from getting from the ovaries to the uterus,
may reduce the risk of ovarian cancer by 30 percent,
for unclear reasons. One theory is that ligation
blocks potentially carcingenic substances from
travelling from the vagina, cervix or uterus up to
the ovaries.
In support of this, scientists
point to several studies suggesting that talcum
powder, which some women put on diaphragms or on
genital skin, can raise ovarian cancer risk.
Some women, including some
Ashkenazi Jews, also have mutations in BRCA1 and
BRCA2 genes that increase risk of both breast and
ovarian cancer. In general, women have about a 1.4
percent chance of getting ovarian cancer over a
lifetime; in women with one close family member who
has had the disease, the risk rises to 5 percent. If
more close family members are affected, it rises
more.< Doctors suggest that women who test positive
for the mutations or have a strong family history of
the disease consider having their ovaries removed
surgically in hopes of preventing ovarian cancer.
Even after such surgery, however, it may be possible
to develop a related cancer in the peritoneum, the
tissue that lines the abdomen.