Cancer That Kills the Young May Have Met Its Match
Dec. 6, 2000 -- Neuroblastoma, which attacks the nervous
system, is one of the most deadly forms of childhood cancer. A few decades ago
doctors from the University of Michigan developed a radioactive compound to
better view these types of tumors inside the body. Now, doctors from this same
institution discovered that not only can this compound help detect the tumor,
but it may also help kill it as well.
The compound, which consists of adding radioactive material to
MIBG or meta-iodobenzylguanadine, has an advantage over other treatments
because it directly targets the tumor cells without damaging normal tissue.
Gregory Yanik, MD, of the U of M Comprehensive Cancer Center, presented the
findings of the first clinical trial of the protocol at the annual meeting of
the American Society of Hematology in San Francisco Tuesday.
"MIBG was discovered at University of Michigan in the
mid-1970s. We found at the time that MIBG would be taken up by the tumor almost
like a sponge," Yanik tells WebMD. "If we attached a small amount of
radiation to the MIBG, the tumor would also take up the radiation. Then we
could scan for the radiation. If it was all taken up in one part of the body
then we could find the tumor."
If there is no tumor, the compound quickly passes out of the
body through urine, he says. The compound targets the cancer cells specifically
because the MIBG binds with a chemical called catecholamines produced by these
types of tumors.
Neuroblastoma is the third most common form of childhood cancer
and strikes about 550 American youngsters annually, according to the American
Cancer Society. In infants, this form of cancer accounts for 50% of
The average age of those diagnosed is 22 months and in about
70% of the cases, the cancer has already spread beyond its original location
before doctors find it. In these cases, experts say the cure rate currently is
only about 25%.
Researchers don't know why neuroblastoma forms but they know
how it forms. Developing nerve cells, or neurons, that are part of the nervous
system controlling involuntary body functions such as heart rate, blood
pressure, and digestion, never fully mature. Instead they keep dividing, often
becoming tumors. These are called neuroblastomas and usually originate around
the ganglia, clusters of nerve cells along the spinal cord, in the abdomen,
chest, pelvis, or neck.
Surgery, radiation, and/or chemotherapy have been the standard
treatment for neuroblastoma. But because so many of cases are at an advanced
stage of disease at diagnosis, the success rate is low. In addition, radiation
and chemotherapy badly damage normal cells. One of the reasons researchers are
testing the MIBG compound is the ability to deliver the radiation directly to
the tumor without affecting the other cells.