For Testicular Cancer Discovered
of international scientists said (2/1/00) they have located the
first gene for susceptibility to testicular cancer. British researchers
who led the study said the gene dubbed TGCT1 on chromosome X is
inherited from the mother and can increase a man's risk of testicular
cancer by up to 50 times. The finding brings scientists a step closer
to finding the gene, which could lead to earlier detection, treatment
and cure of the most common cancer among young men. "What we have
achieved is the localization of the first testicular cancer susceptibility
gene. What we need to do now is actually isolate the gene itself,"
Professor Mike Stratton, of the Institute of Cancer Research in
the UK, told a press conference in London. The gene is one of about
300 on the long arm of chromosome X. Stratton and his colleagues
hope to work out which one is TGCT1 within the next 2 to 5 years.
will be facilitated enormously by the newly emerging genome sequence,
the first draft of which we expect to see late this year," Stratton
added, referring to the Human Genome Project, which will map all
of the genes in the human body. Testicular cancer affects about
one in 500 men and is most common among men aged 25 to 29. The disease
has increased steadily since the 1930s. Cases in Denmark, which
along with Switzerland and Norway have the highest rates in the
world, have trebled. Familial testicular cancer accounts for an
estimated 20% of cases, so scientists know that other genes are
also involved. Doctors also suspect that environmental factors and
exposure to higher levels of the female hormone estrogen in the
womb are contributing factors to the increase in the disease. The
scientists working for the International Testicular Cancer Linkage
Consortium located the TGCT1 gene by studying 134 families worldwide
with two or more cases of the disease. It is found in a third of
families with a history of the disorder. The finding, which is the
culmination of 10 years of research, is published in the journal
Nature Genetics. In addition to improving detection and treatment
of testicular cancer, which has a 90% to 95% cure rate if found
early, Stratton said the discovery has wider implications for other
cancers with higher death rates.
cancer is unusual because of its high cure rate. By finding out
more about the molecular biology of the underlying causes and its
pathogenesis we hope to be able to work out why it is so curable,"
he said. "The implications of that may be that we can see why other
cancers, which are not so curable, are different." Risk factors
for testicular cancer include a family history of the disease and
malformed or undescended testicles. There is also a higher incidence
among first-born sons and non-identical twins.
Health, Feb. 4, 2000.