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Cancer cells are stem cells
Cancer cells are stem cells
excerpt economist,com
For one of the most important medical discoveries made in
recent years is that cancers, too, have stem cells and that these
appear to be the source of the rest of the tumour.
This helps to explain why cancers are so hard to deal with. Treatments
that kill the bulk of a tumour, but leave the stem cells alive, are
only buying time. On the other hand, if all of a tumour's stem cells
could be killed then it would torpedo the old wisdom that no patient
is ever cured of cancer, but merely goes into remission. True cures
for cancer would be possible.
The cancer-stem-cell theory, though plausible, was based on animal
experiments and its relevance to humans was untested. But a series of
studies reported this week at a meeting of the American Association
for Cancer Research, in San Diego, has changed that. They suggest both
that cancer stem cells are very relevant indeed to survival, and that
going after them is an excellent idea.
The relevance of cancer stem cells to survival was shown by William
Matsui of the Johns Hopkins Sidney Kimmel Cancer Centre in Baltimore.
He looked at samples from 268 people with pancreatic cancer and found
that the pattern of stem cells in their tumours predicted how long
they would live. Those whose tumours had stem cells at their edges
(the “invasive margin” in the militaristic jargon of the
cancer-warriors) lived on for an average of 14 months. Those who did
not lived an average of 18 months. Not a huge difference, but
confirmation that cancer stem cells have an impact on the outcome of
disease.
Bombs away
Such stem cells, then, are as bad as theory suggests they should be.
The question is, can they be eradicated?
Animal tests suggest this is hard. For reasons as yet unknown, stem
cells are resistant to standard cancer chemotherapies. With this in
mind, Jeffrey Rosen and his colleagues at Baylor College of Medicine
in Houston, Texas, compared samples from breast-cancer patients taken
before and after 12 weeks of chemotherapy. They reasoned that if stem
cells were resistant in people as well as mice, then the proportion of
stem cells within a tumour would increase as more vulnerable cells
were killed off in disproportionate numbers.
And that is exactly what happened. Among women treated with
old-fashioned chemotherapy, the share of s
excerpt economist,com
For one of the most important medical discoveries made in
recent years is that cancers, too, have stem cells and that these
appear to be the source of the rest of the tumour.
This helps to explain why cancers are so hard to deal with. Treatments
that kill the bulk of a tumour, but leave the stem cells alive, are
only buying time. On the other hand, if all of a tumour's stem cells
could be killed then it would torpedo the old wisdom that no patient
is ever cured of cancer, but merely goes into remission. True cures
for cancer would be possible.
The cancer-stem-cell theory, though plausible, was based on animal
experiments and its relevance to humans was untested. But a series of
studies reported this week at a meeting of the American Association
for Cancer Research, in San Diego, has changed that. They suggest both
that cancer stem cells are very relevant indeed to survival, and that
going after them is an excellent idea.
The relevance of cancer stem cells to survival was shown by William
Matsui of the Johns Hopkins Sidney Kimmel Cancer Centre in Baltimore.
He looked at samples from 268 people with pancreatic cancer and found
that the pattern of stem cells in their tumours predicted how long
they would live. Those whose tumours had stem cells at their edges
(the “invasive margin” in the militaristic jargon of the
cancer-warriors) lived on for an average of 14 months. Those who did
not lived an average of 18 months. Not a huge difference, but
confirmation that cancer stem cells have an impact on the outcome of
disease.
Bombs away
Such stem cells, then, are as bad as theory suggests they should be.
The question is, can they be eradicated?
Animal tests suggest this is hard. For reasons as yet unknown, stem
cells are resistant to standard cancer chemotherapies. With this in
mind, Jeffrey Rosen and his colleagues at Baylor College of Medicine
in Houston, Texas, compared samples from breast-cancer patients taken
before and after 12 weeks of chemotherapy. They reasoned that if stem
cells were resistant in people as well as mice, then the proportion of
stem cells within a tumour would increase as more vulnerable cells
were killed off in disproportionate numbers.
And that is exactly what happened. Among women treated with
old-fashioned chemotherapy, the share of s
