A "Conceptual Revolution"
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Part Two
Part 1
A friend sent along a story from TIME
magazine that addresses a "conceptual revolution" in
the treatment of cancer. My associate Liz Townsend
was kind enough to outline what the article says. I
will then take a crack at explaining its connection
to us and our concerns.
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Researchers studying the causes of cancer are
beginning to focus on specific mutated adult stem
cells that seem to be the source of tumor growth.
TIME puts it this way:
"Known as a cancer stem cell, it could be the
culprit behind a malignant tumor's nasty habit of
recurring year after year and popping up in distant
parts of the body long after the primary growth is
gone. Studies of that cell are helping scientists
unravel some of cancer's deepest secrets and leading
doctors closer to the ultimate goal of any cancer
therapy--a cure. Think of the stem cell as a tumor's
master print; as long as the original exists, copies
can be made, and the disease can persist. But
destroy the tumor at its source, and the abnormal
cells can't survive."
Current cancer treatments that attempt to reduce the
size of tumors may fail if they don't target the
small percentage of cancer stem cells that actually
cause the cancer to grow and spread throughout the
body, according to TIME.
"This represents a conceptual revolution in cancer
biology," Dr. Robert Weinberg of the Whitehead
Institute in Cambridge, Massachusetts, told TIME.
"This is going to explain the way a wide variety of
human cancers originate and the way they grow."
Scientists studying leukemia, a type of cancer in
the blood, found that when leukemia cells were
transferred from humans to mice, only some of the
cells replicated and caused tumors, TIME
reported. They have since isolated a particular
protein that, when present in large amounts, seems
to indicate which stem cells are cancer-causing.
Now researchers are studying other cancers to
identify the particular markers that indicate
these dangerous cells. The next generation of
cancer treatments will likely involve destroying
these root stem cells or cutting off the
nutrients that help them grow. "It requires a
reorientation in people's thinking," Weinberg
told TIME. "We need to focus on wiping
out the stem cells rather than eradicating the bulk
of the tumor."
This is potentially good news for everyone. But it
also addresses our concerns in two ways.
First, ironically, for all the hype about embryonic
stem cells, this potential breakthrough comes as a
result of funding for adult stem cell research.
"Everybody wants to talk about cancer stem cells
now," John Dick, a professor at the University of
Toronto professor, told TIME. "From funding
agencies to institutions to scientists, people are
recognizing that this is probably the game to be
in."
Second, TIME writes about scientists putting
aside what the magazine calls "their decades-old
obsession" with a particular treatment regimen. The
conventional scientific wisdom can change, albeit
very reluctantly and over time.
Right now, scientists are obsessed with stem cells
lethally extracted from human embryos. Nothing other
than "potential" drives this obsession, since there
have been no breakthroughs whatsoever in humans.
For the most part, most scientists extend the back
of their hand to proven therapies in humans that use
stem cells that come from sources other than human
embryos, in particular umbilical cord blood. If the
orthodoxies that have guided cancer research and
treatment for decades can be revisited, there is
good reason to believe the reigning group-think on
stem cells will change as well.
If you have any questions or comments, please write
Dave Andrusko at dandrusko@nrlc.org
Part 1
