PARIS--Nearly 90% of patients with resected Dukes B and C colorectal
carcinoma were still alive 3 years after active specific immunization
with a new autologous tumor vaccine, researchers from the German
Cancer Research Center, Heidelberg, and the University Hospital,
Mannheim, Germany, have found.
V. Schirrmacher, PhD, of the Heidelberg center, presented the
findings at the Eighth Annual European Cancer Conference (ECCO-8).
To prepare the colorectal cancer vaccine, purified and inactivated
cells from the patient's own tumor are incubated with the Newcastle
Disease Virus (NDV), a chicken virus with unique antitumor and
The virus binds almost immediately to the cancer cells and begins
replicating within 4 hours, Dr. Schirrmacher said. Transfection
of the tumor cells with the virus bolsters their antigen-presenting
capacity so that, after inoculation, the patient's immune response
is mobilized against his or her own cancer cells.
Noting that immune reactivity, as reflected by delayed hypersensitivity
skin reactions, increases after each successive inoculation, he
suggested that the strength of this reaction may forecast a more
favorable clinical outcome.
After charting the clinical course of 48 patients who received
three doses of the NDV vaccine at 2-week intervals, starting 6
to 8 weeks after surgery, the Heidelberg-Mannheim team documented
survival rates of 98% at 2 years and 88% at 3 years. Three-year
overall survival was 86% in patients with Dukes B colon cancer,
88% in Dukes C colon cancer, 93% in Dukes B rectal cancer, and
88% in Dukes C rectal cancer.
In comparison, Dr. Schirrmacher said, 2-year survival was 74%
in a historical control group of more than 600 patients treated
with surgery alone, and only 67% in nine patients who received
an experimental vaccine made with BCG (Bacillus Calmette Guerin).
Side effects of the NDV vaccine were limited to induration and
erythema at the inoculation site, in contrast to the persistent
ulceration observed after injection of the BCG vaccine.