The cancer, Kaposis sarcoma, is caused by a virus
that the body usually can eliminate. It has become associated with the
AIDS epidemic because the virus affects people with weakened immune
systems.
Kaposis sarcoma appears in about one out of every
200 transplant recipientswhich is 400 to 500 times the rate of the
general population.
It had been thought the virus was able to take hold
in these patients because their immune systems were suppressed in order
to prevent rejection of the new organ.
But that European research team has found evidence
that, at least in some transplant patients, seed cells for the cancer
tumors seem to have originated in the organ donor.
The findings of the team (led by Patrizia Barozzi and
Mario Luppi of the University of Modena and Reggio Emilia in
Modena, Italy) have been reported in medical journals.
The study shows that "tumor cells from the organ
donor can contribute to one of the most frequent transplant-related
malignancies," Patrick S. Moore of the University of
Plattsburgh Cancer Institute commented. He was not part of the research
team.
Several weeks earlier, Scottish physicians reported
on two cases of patients developing melanoma (the skin cancer) from
transplanted kidneys, even though the donor was successfully treated for
the cancer many years earlier.
Transfer of cancer from a donated organ to a
transplant patient is rare; and the chances of it happening long after
the donor was treated for the condition is thought to be extremely
unlikely.
In the cases involving Kaposis sarcoma,
researchers studied eight patientssix women and two menwho
received kidneys from male donors and who developed Kaposis sarcoma
nine months to 40 months later.
In analyzing the cancer cells from the women, the
researchers detected Y-chromosome DNA in four cases, indicating the
cells originated with a man. There was no evidence of Y-chromosomes in
the cancer in the other two women or in normal cells from any of the
women. These facts are considered highly significant.
Using the DNA analysis of the cancer cells in the
men, the researchers discovered that in one case the cancer DNA was
related to that of the organ donor.
Kaposis sarcoma can be treated by reducing or
ending the suppression of the patients immune system, allowing it to
battle the cancer.
That also can mean the immune system will begin
attacking the transplanted organ, causing it to be rejected.
Dr. Moore made note of the fact that the organ donors
had no symptoms of Kaposis sarcoma. This suggests that they are
infected with the cancer-causing virus, but that their bodies are able
to destroy the cancer cells when they form.
However, once the infected organ is transplanted into a patient who
has a weakened immune system, the cancer cells are able to grow and
cause the disease.
BOOKSTORE