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varian
cancer is known as the “silent” killer because so often the
diverse and varied nature of its symptoms leads to a diagnosis
in late stage when it is very difficult to control and almost
impossible to cure.
That
could all be changing now.
Earlier this year, research concluded that there IS a
constellation of symptoms that has significance in the early
detection of ovarian cancer.
According to Patricia Goldman, ovarian cancer survivor
and President of the Ovarian Cancer National Alliance, clinical
support for this concept is “the most encouraging thing
we’ve seen” in the last year.
Even
though symptoms vary by patient, physicians can now be on the
lookout and may be less likely to dismiss symptoms that could
point to early disease.
“The
text books have historically informed practitioners that there
are no symptoms until advanced stage, therefore when a frontline
practitioner sees a woman who manifests the subtle signs of
ovarian cancer, they have been sometimes dismissed, ” Goldman
tells cancerpage.
Symptoms
Common
symptoms are abdominal cramping, bloating, and distension, early
satiety, constipation or diarrhea, gas, indigestion, and changes
in bladder habits.
Prevention - many
questions, few answers
In
the area of prevention, Goldman is encouraged by work being done
with oral contraceptives as chemo-preventative agents against
the fifth leading cause of cancer death in U.S. women.
There’s
a growing body of evidence that oral contraceptives reduce the
risk of developing ovarian cancer. The question is why.
Theories have suggested the process of repeated ovulation
offers many opportunities for something to go wrong on the
cellular level that can develop into ovarian cancer. Does the
pill lower risk because it stops women from ovulating? Recent
research may be pointing to another explanation.
New
research suggests that oral contraceptives that contain higher
levels of the hormone progestin have “twice the protective
effect of the low-progestin pills” according to Gustavo C.
Rodriguez (MD) of Duke University Medical Center who delivered
his findings in March to the annual meeting of the Society of
Gynecological Oncologists.
Progestin may increase the production of a substance
associated with cell death Rodriguez hypothesizes.
Unfortunately,
the data suggests women who may have a genetic predisposition to
develop ovarian cancer aren’t helped by oral contraceptives. (New
England Journal of Medicine 2001;345:235-240) For some of
them – those with the BRCA1 gene mutation – getting their
fallopian tubes tied appears to have some protective value
according to Dr. Steven Narod of the University of Toronto and
the Hereditary Ovarian Cancer Clinical Study Group.
He and his co-workers concluded that his research data
supports “the recommendation that tubal ligation be offered to
women with BRCA1 mutations as a means of reducing ovarian cancer
risk.” (Lancet 2001;357:1467-1470.)
Evidence
that aspirin use is linked to lower ovarian cancer risk was also
reported this year. Researcher Arsian Akhmedkhanov of the New
York University of Medicine was not ready to recommend that
women take aspirin as a prophylactic but his 12-year study of
748 women concluded women who took aspirin at least three times
a week over six months had a 40% lower risk of developing one
type of ovarian cancer - epithelial ovarian cancer - that is
cancer that starts in the thin membrane surrounding each ovary.
It’s
thought that inflammation may have a role to play in the
development of ovarian cancer thus explaining the benefits of
aspirin and NSAIDs (non-steroid anti-inflammatory drugs) such as
ibuprofen. Another
report this past year found lower ovarian cancer risk among
women who used various barrier methods of birth control
including condoms and diaphragms leading one of the researchers
to suggest studying whether sperm contains inflammation-causing
substances that are blocked by barrier method contraceptives. (Epidemiology
2001; 12:307-312)
Though
researchers don’t know why this is the case, a report in the Journal
of the American Medical Association this year concluded that
use of estrogen replacement therapy by postmenopausal women
“increased risk of fatal ovarian cancer.”
They also concluded that risk decreased “with length of
time since last use.”(JAMA 2001; 285:1460-1465)
Dr. Rodriguez of Duke believes his progestin findings, if
confirmed in larger trials could point to the benefits of
increasing progestin levels in Hormone Replacement Therapies.
Detection –
developing tests, improving the odds
Early detection
is key to long-term survival in most cancers including ovarian
cancer. There are no tests such as mammography for breast
cancer, pap smear for cervical cancer, colonoscopy for colon
cancer or PSA for prostate cancer that have proven cost
effective or reliable for early stage ovarian cancer.
Testing
for elevated CA125 protein levels in the blood has proved
ineffective because for pre-menopausal women levels may be
elevated for many reasons.
It’s thought this test could be useful for
post-menopausal women however and a clinical trial being
conducted by the National Cancer Institute is currently
enrolling patients to assess whether CA125 tests coupled with
transvaginal ultrasound is an effective detection tool for women
between the ages of 55 and 74.
In
January, a study published in the journal Cancer found
that women with malignant ovarian tumors had significantly
higher vascular epithelial growth factor (VEGF) levels in their
blood than did women who had non-malignant or borderline tumors.
A
clinical trial being sponsored by the National Cancer Institute
is currently enrolling up to 6,000 women to help "identify
and develop highly sensitive and specific tumor markers for the
detection of early rather than advanced stage ovarian cancer”
and to determine if performing “Ovarian Pap Tests” on high
risk women makes sense.
“Ovarian Pap Test" is a new diagnostic test to
detect pre-cancerous or early changes on the ovaries. Using
minimally invasive office laparoscopy, the "Ovarian Pap
Test" involves direct visualization of the ovaries and
collection of cells from the surface of the ovary and from the
peritoneal cavity by the use of a laparoscopic cytologic
sampling instrument.
Treatment – new
ways of administering old drugs
Once
diagnosed, ovarian cancer has proved difficult to treat. This is
primarily true because most ovarian cancers are diagnosed in
late stage after the disease has spread to surrounding tissues.
Cancer that has spread is always harder to treat. The
first line of treatment for early stage ovarian cancer is
surgery. Later stage disease is usually treated with surgery and
platinum-based chemotherapy.
The
problem is that many ovarian cancers develop a resistance to the
platinum based chemo agents and recur.
A
University of Wisconsin researcher found that raising the
patient’s body temperature in a process called hyperthermia to
107 before administering the drug carboplatin helps break
through some of that platinum resistance. H. Ian Roberts (MD)
has treated 14 patients in his phase I trial and achieved one
complete response, four partial responses and four cases of
stable disease.
Policy - funding
research
Research
provides hope and according to Patrician Goldman of the Ovarian
Cancer National Alliance increasing research funding is the top
priority.
“Our
concern with more research is to get a screening test which
could be routinely applied as a pap smear is or a mammogram,
that would go a long way toward wiping out the problem of late
diagnoses,” she says.
The
National Alliance has asked Congress to increase the budget for
the Department of Defense Ovarian Research Program from $12
million to $20
million. The
National Cancer Institute’s budget for ovarian cancer research
has jumped from $20 million in 1992 to about $65 million
dollars, Goldman says. The
Alliance wants to see a Centers for Disease Control program to
track population differences in ovarian cancer expanded from its
current funding level of $1 million to the $2.6 million proposed
for FY 2001. The CDC program, Goldman says, will shed light on a
number of interesting issues such as race differences in the
incidence of ovarian cancer – African and Asian Americans
appear to have lower risk. Goldman also wants to know what’s
happening among younger women.
“There
are a lot of questions about the age women are getting this
disease. Anecdotally, the age appears to be getting younger, is
there something in the life style of younger women?
The thought would be that with more women on oral
contraceptives, the rate would decrease,” Goldman says.
Clinical Trials –
on the front lines
There
are more than 60 clinical trials related to ovarian cancer
sponsored by the National Cancer Institute currently enrolling
patients or preparing to do so.
For
a list, click here for NIH sponsored clinical trials currently
recruiting.
To
read more about the research mentioned above, look to the news
list in the column on the
right hand side of this page.
Written
By
Rachael Myers Lowe, editor
cancerpage.com
Reviewed
by
Katie Mullaly, RN, MSN
Jane Quigley, RN, BSN
cancerpage.com
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