Although it doesn't seem likely
that any man in his right mind would willingly agree to
castration, for some patients with testicular cancer it
may be the only option left to prevent the disease from
spreading.
New research in the July 29 issue
of the Lancet may be able to save victims of
this terrible disease from having to take that treatment
path. Radiation therapy in testicular cancer may soon
be replaced by a single injection, according to a study
that also opens the door to the possibility of treating
the disease without castration.
Dr Tim Oliver, professor at the
London School of Medicine, sums up his results in a
nutshell: "We found that one dose of carboplatin
in the short term is as safe as radiation and is less
toxic."
IT'S
BAAACK
Testicular cancer strikes young, and so it's often associated
with unpleasant sequels later in life, many linked to
radiation therapy. The primary disease is treated by
hemicastration, but to minimize the risk of recurrence
in the remaining testis, the patient must typically
undergo a period of radiation therapy of the pelvic
nodes after surgery.
This technique, used for nearly
50 years, produces cure rates approaching 100%, but
in recent years analysis has suggested that about 80%
of these patients are cured by orchidectomy alone. That
adds up to a lot of unnecessary radiation. Various trials
have sought to find a safe lower limit to the radiation
dose, in an effort to reduce the number of patients
suffering later cardiac problems.
Now an alternative to radiation
may be available in the form of carboplatin, a drug
originally designed to treat ovarian cancer. British
and European researchers decided to compare the drug
to radiation as a post-operative therapy after seeing
good results in preliminary experiments.
NECK
AND NECK
They recruited 1,477 patients in 70 hospitals in 14
countries, and randomly assigned them to either standard
radiotherapy or single-dose carboplatin. At the three-year
followup, they found that relapse-free survival was
almost identical in the two groups — 95.4% for
the carboplatin group and 96.6% for radiation therapy.
Better still, at five years they
also found that patients receiving carboplatin were
significantly less likely to develop tumours in their
remaining testicle. In fact only about a quarter as
many carboplatin patients developed new seminomas.
"This large randomized trial
finally establishes after 20 years of research and uncertainty
that it is safe to risk less treatment in these patients,"
said Dr Oliver. "Though needing longer followup
and larger numbers to be sure, this surprising finding,
were it to apply to primary tumours when first diagnosed,
is the first hint that it may now be safe to embark
on studies of testis conservation instead of hemicastration."
Lancet
Jul 29, 2005;366(9482):293-300
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