Care During Chemotherapy and Beyond
What Is Chemotherapy Resistance?
Chemotherapy resistance occurs when cancers that have been responding to a therapy
suddenly begin to grow. In other words, the cancer cells are resisting the
effects of the chemotherapy. You may hear statements like the "cancer chemotherapy
failed." When this occurs, the drugs will need to be changed.
There are several possible reasons for chemotherapy resistance:
- Some of the cells that are not killed by the chemotherapy mutate (change) and become
resistant to the drug. Once they multiply, there may be more resistant cells
than cells that are sensitive to the chemotherapy.
- Gene amplification. A cancer cell may produce hundreds of copies of a particular
gene. This gene triggers an overproduction of protein that renders the anticancer
- Cancer cells may pump the drug out of the cell as fast as it is going in using a
molecule called p-glycoprotein.
- Cancer cells may stop taking in the drugs because the protein that transports the
drug across the cell wall stops working.
- The cancer cells may learn how to repair the DNA breaks caused by some anti-cancer
- Cancer cells may develop a mechanism that inactivates the drug.
Research is underway to investigate ways of reducing or preventing chemotherapy
The development of drug resistance is one reason that drugs are often given in combination.
It is thought that this may reduce the incidence of developing resistance to any
one drug. Often, if a cancer becomes resistant to one drug or group of drugs,
it is more likely that the cancer may be resistant to other drugs. This is
why it is very important to select the best possible treatment protocol FIRST.
In other words, when treating cancer, one should use the best weapon when there
is the smallest possibility of chemotherapy resistance.
More Chemotherapy Information:
Protocols - How Chemotherapy Works
How Chemotherapy Is Given
How Doctors Decide Which Chemotherapy Drugs To Give
How Long Chemotherapy Is Given
How To Tell If Chemotherapy Is Working
Cancer Cells & Chemotherapy
Short & Long Term Side Effects of Chemotherapy
Cancer Clinical Trials
Chemocare.com is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit www.4thangel.org