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Why will it work now?
Cancer cells are not all the same.
A cancer colony is made up of "mutants." The cells are inherently unstable. When they reproduce, they do not produce identical twins like they should.
Sooo...when you see pathology reports that say ER + and give a percentage (80%), that means that 80% of the sample has ER receptors on it.
So, when you took taxane the first time, it successfully killed some percentage of the cancer colony (let's say 90%).
The remaining cells were resistant or dormant (?).
You went off of chemotherapy.
The cancer cells "bloomed" and began producing a new colony...or you produced a new primary.
The new colony is a colony of mutants. They are inherently unstable.
There is no "rule" that says the new colony is resistant to taxane.
Probability is that the taxane will be very effective.
Taxane will no longer be effective when
a. you have reached your life time maximum dose...chemotherapy is "poison." (When you have maxed out taxanes, you will have to switch to another category of drug...much more likely that you will develop resistance / allergy to the preservatives in taxol & taxotere before you reach your life time max dose...thus, the switch to Abraxane for heavily pre-medicated patients)
b. you kill all of the colony that can be killed by taxanes and there is a large population of taxane-resistant cells (they "bred" resistance)...then, you will have to switch to a different agent.
The taxanes are "first line" chemotherapy because they are very effective cancer killers.
The other "first line" drugs for breast cancer are the anthracyclines (AC, FEC...the A in AC is Adriamycin/ Doxorubicin; the E in FEC is Epirubicin...both anthracyclines). The anthracyclines are also very effective cancer killers; however, most people only take them one time (several doses) because they are cardiotoxic.
The taxanes (relatively new) are a breakthrough in chemotherapy because (to my knowledge), they are the only non-anthracycline agents that have been proven to be as effective as the anthracyclines. The bonus is that they are better tolerated by patients long-term because they are not associated with heart damage.
Tammy Lou
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