Happy
Far too many ovarian cancer histories go like this. First, the cancer is diagnosed, often by
accident (OVCA symptoms are notoriously subtle), and found to be in an advanced
state (Linda was stage 3C, indicating that the original tumor had spread
throughout her abdomen.) The first therapeutic
step involves so-called “debulking surgery” – all visible traces of the cancer
are cut out. Next comes “adjuvant
chemotherapy”, involving a cocktail of drugs that, hopefully, will kill any
remaining cancer cells. Workhorses among
these drugs often are platinum-based.
Normally this puts the patient into “remission” – that is, no trace of
the disease can be detected. (Remission
often is monitored by periodic determination of the level of the protein CA 125
in the blood. “Normal”, which varies
considerably, ranges from 0 to 30 or so; Linda was at 650 when diagnosed and at
6 after treatment.)
In remission the patient can live a normal life. Her
hair grows back, she regains strength and mobility, she can be happy. However, after a few months or years in all
too many cases remission is gradually lost.
In Linda’s case her CA 125 count remained at 6 for about two years. Then, one month it rose to 8. No problem, right? The next month it was 15. The cancer was coming back.
Apparently the cisplatin-based drug cocktail was effective
initially, but had left behind a few cancer cells that were “immune”, rendering
it futile to repeat the original chemotherapy.
In Linda’s case another selection of drugs was tried, resulting in only
a short, partial remission.
Well, researchers at the University of Michigan may have
discovered a way to deal with this apparent immunity. They found that fibroblasts (a type of cell
involved in connective tissue) located in the tumor’s microenvironment acted to
prevent buildup of platinum in the cell.
They also found that immune T cells could pry open the fibroblast barrier,
thereby allowing the platinum poison in to kill the cell. (Mice, again, of course.) My reading of this is two-fold. Maybe administering T cell based
immunotherapy along with standard platinum-based chemo would wipe the cancer
out in one fell swoop. Barring that,
maybe T-cells would make it possible to use the same drugs after an initial remission,
thereby prolonging remission indefinitely.
More I cannot say; there are important parts of these two articles that
I don’t understand.
And here is something else I don’t understand: how in heck
are we supposed to understand “relapse”?
I have written about “cancer stem cells”; are there such, and how do
they operate? Also I keep reading about
the accelerated rate of mutation in cancers, presumably making it difficult to
eradicate the beast completely before it changes. Now I read that an army of misguided fibroblasts
promote relapse by combating cisplatin.
Are all of these things true? If
so, God help us.
No comments:
Post a Comment