Immune-bolstering vaccine extends lives of patients in cancer
study
May 23, 2000
Web posted at: 3:28 p.m. EDT (1928
GMT)
From Eileen O'Connor
CNN Medical Correspondent
WASHINGTON (CNN) -- Scientists at Georgetown University are testing a
cancer vaccine that so far has produced survival rates far exceeding those
achieved by patients receiving conventional therapy alone.
The experimental vaccine helps to stimulate the body’s immune system by
targeting CEA, a protein found on different types of cancers.
"We've learned that in virtually everybody we give the vaccine to, we
can create T cells -- those are the immune fighting cells which can seek
out and recognize colon cancer or any type of cancer with CEA on it, and
actually kill those cells," said Dr. John L. Marshall of Georgetown's
Lombardi Cancer Center.
The survival rate for recurring cancers treated with chemotherapy,
surgery and other conventional approaches is 5 percent, researchers said.
But among 20 patients receiving the CEA vaccine, 10 patients in the study
are doing well after three years.
Through these trials, doctors have learned that the immune system seems
limited in its ability to fight large cancer growths, and for that reason,
they said, vaccines may be best used with conventional therapies, rather
than as replacements.
Scientists said vaccines work best when used with other drugs that
excite the immune system, like Interleuken-2.
"The challenge now is to determine how to make those immune reactions
strong enough to cause the rejection of established, invasive and deadly
cancers," said Dr. Steven Rosen of the National Cancer Institute.
If the vaccine studies continue to go well, the new treatment may be
available to the public in two or three years.
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