View Single Post
Old 02-29-2012, 08:19 AM   #41
gdpawel
Senior Member
 
gdpawel's Avatar
 
Join Date: Aug 2006
Location: Pennsylvania
Posts: 1,080
Re: any tumor tests to predict which chemos work better?

Rich

Based on the little amount of information given, it doesn't seem like chemosensitivity testing. In order to do drug sensitivity testing, you need to actually measure drugs against any tumor specimen. Genetic testing never measures drugs against your actual cancer cells. It is "theoretical" analysis. Receiving results of that theoretical analysis a few months later tells me it is genetic testing. Drug sensitivity tests are usually given within a week.

If Amanda's understanding of "cores" is correct, an core biopsy (tru-cut) takes a sample of tissue with preservation of the histological architecture of the tissue cells. It takes an entire lump or suspicious area and removes it. They do use this "minimum" amount of biopsy to do drug sensitivity testing. If it is kept "fresh" live for analysis, it could be used for drug sensitivity testing. But after a few days, they are "dead" cells, which is what genetic testing does.

Donating tissue for research purposes is cell-lines (what I described previously). They immortalize the tumor cells. But this is not chemosensitivity testing.

If the key findings so far are that the cancer was/is "resistant" to anthracyclines and taxotere, it seems like a "cell-growth" assay. The old "cell-growth" assay is excellent at identifying drugs most likely "not" to work. They assay is not as good at identifying drugs which are "more likely" to work or to identify the disease-specific activity patterns of targeted drugs (like Tykerb). The results of this type of testing are to be used only for the purpose of drug "de-selection" and not for drug "selection."

"In Australia, the government funds it but you need to qualify and to qualify, I have to have had 3 taxotere treatments." Sounds more like a clinical trial. Simon says you can't do this or that unless Simon Says. So no. I still have no idea what Amanda's actual tests were.

As for "massive release of cells into the circulation" thought to happen during surgery, if the chemotherapy given was effective (sensitive to the cancer cells), it would have taken care of these cells. Don't forget, the Pachmann, et al research, quantifying circulating tumor cells, found that neoadjuvant chemotherapy with paclitaxel (Taxol) causes a massive release of cells into the circulation, while at the same time reducing the size of the tumor, explaining the fact that complete pathologic responses (tumor shrinkage) do not correlate well with improvements in survival.

Greg
gdpawel is offline   Reply With Quote