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Hodgkin's Survivor Gives Birth Following Ovarian Tissue Implant
For the first time, a woman who became sterile as a result of chemotherapy has
given birth to a healthy baby following implantation of her own ovarian tissue,
which had been cryopreserved before she underwent chemotherapy. The baby girl
was born on September 23, approximately 7 years after the 32-year-old Belgian
woman's initial chemotherapy treatment for Hodgkin's disease and 3 years after
she had been cleared by her oncologists as disease free. "Our findings open new
perspectives for young cancer patients facing premature ovarian failure," said
lead investigator Dr. Jacques Donnez of the Catholic University of Louvain in
Brussels. A report on the procedure that led to the birth was published on The
Lancet Web site on September 24. The patient presented with clinical stage IV
Hodgkin's disease in 1997. Dr. Donnez's team took five biopsy samples via
laparoscopy from the left ovary (12-15 mm long and 5 mm wide). One tissue strip
was kept intact, while the remaining four were cut into smaller cubes. The
tissue was frozen and stored for 7 years. Seven days before the actual tissue
implantation, the team surgically created a small pocket, or "peritoneal
window," near the woman's right ovary. "The goal was to induce angiogenesis and
neovascularization in this area," the authors explained. A week later, some of
the thawed tissue samples were implanted. The remaining samples were implanted
after 4 months, with signs of ovulatory activity several months later. In early
2004, the patient became pregnant by natural means. Although the authors
acknowledged there is a chance that the pregnancy did not originate from the
transplanted tissue, they offered several lines of evidence to support that it
was. In addition, they stressed that the procedure presents some ethical and
medical considerations that must be addressed. "One major concern...is the
potential risk that the frozen-thawed ovarian tissue might harbor malignant
cells, which could induce a recurrence of disease after transplantation," they
wrote in the paper. "Screening methods to detect minimal residual disease must
be developed to eliminate risk of cancer cell transmission with
reimplantation."
Artificial Neural
Networks Can Predict Clinical Outcomes of
Neuroblastoma Patients
Researchers at NCI, in collaboration with colleagues from Germany and
Australia, have used artificial neural networks (ANNs) to successfully predict
the clinical outcomes of patients diagnosed with neuroblastoma (NB). They also
used the ANNs to identify a set of 19 genes whose expression levels were
closely associated with outcome. The study, which appears in the October 1
Cancer Research, suggests the predictive power of ANNs could assist physicians
in the treatment of individual patients, especially those considered high risk.
Dr. Javed Khan and his team at NCI's Pediatric Oncology Branch first used cDNA
microarrays containing over 25,000 genes to create gene expression profiles of
primary tumors from 49 NB patients with a known clinical outcome: good
(event-free survival for more than 3 years) or poor (death due to disease).
Next, they adapted an ANN algorithm - a specialized pattern recognition program
modeled after the human brain - to identify patterns in tumor gene expression.
They found that the ANN could predict the clinical outcome from any individual
gene profile with about 88 percent accuracy. The researchers then optimized the
profiles and found 19 genes whose expression could act as a predictor set.
Using only these 19 genes, ANN accuracy increased to 95 percent. "What was most
exciting was that we were able to predict which high-risk patients would have
good or poor outcomes," said Dr. Khan. "This has major clinical implications,
since we are now able to distinguish a group of ultra-high-risk patients who
will not respond to conventional therapy and therefore require alternative
treatment. We may also be able to reduce the intensity of the treatment regimen
to high-risk patients predicted to survive based on their gene expression
profiles." "Because we are using 19 genes instead of 25,000," he added, "we can
translate our findings to the clinic because simple prognostic assays can be
developed quickly, based on this small number of genes."
Antioxidant Supplements May Not Prevent GI Cancers
Populations with diets rich in antioxidants from fruits and vegetables show low
rates of cancer and heart disease. But in a recent analysis of studies from the
last 20 years involving people considered to be at high risk for
gastrointestinal (GI) cancers, there was no significant link between
antioxidant nutritional supplements and the prevention of digestive cancers.
The study, sponsored by Denmark's Knowledge and Research Center for Alternative
Medicine and the Copenhagen Trial Unit at the Centre for Clinical Intervention
Research, is published in the October 2 issue of The Lancet. The research team,
led by Dr. Goran Bjelakovic of the University of Nis in Serbia and Montenegro,
and colleagues at the Cochrane Hepato-Biliary Group, looked at 14 randomized
trials that jointly involved more than 170,000 participants, where the
supplements beta-carotene, vitamins A, C, and E, and selenium were compared,
either alone or in combination, against a placebo. The results showed no link
between antioxidants and digestive cancer prevention and, in half of the
trials, there was a small increase in mortality among people who took the
antioxidant supplements. Four of the trials, however, did show a possible link
between selenium supplements and decreased risk for digestive cancers. In an
interview with the Associated Press, Dr. Bjelakovic deemed antioxidant pills
(excepting selenium) as "useless for prevention of gastrointestinal cancers."
But this type of analysis can be misleading, notes Dr. Peter Greenwald,
director of NCI's Division of Cancer Prevention. "Analyzing all types of GI
cancers together, when they have differing etiologic factors, is an
oversimplification," says Dr. Greenwald. "When you look at the studies in each
organ site, the relative risk for gastric cancer suggests a slight increase in
risk from supplements, while the relative risk for colorectal cancer shows a
tendency toward a decrease in risk." None of the results are statistically
significant, but those trends suggest that antioxidant supplements may yet be
useful in some kinds of GI cancers, he notes.
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