Crash Course in Chemo
Chemotherapy, or chemo, has been around since the days of the ancient Greeks. However, chemotherapy for the treatment of cancer began in the 1940s. Since then, many new drugs have been developed and tried and most recently due to technological advances there have been a proliferation of new, targetted chemo therapies developed for many different forms of cancer.
Unfortunately for the PLGA community, however, to date there has been little in the way of advancements (or even investigations) in the arena of targeted chemo for PLGA patients. While chemo is NOT a cure for PLGA it can be used effectively to help arrest tumor growth.
The following represents the most commonly asked questions about chemo and PLGA. To view an answer, please click on the question below:
1) When one hears the word "chemotherapy" the mind often goes to cancer. If our PLGA kids don’t have cancer, then why are they getting chemotherapy??
Chemotherapy is drug treatment designed to stop the division of abnormal cells. In other parts of the body a “non-cancerous” tumor may be able to be completely removed. The problem in the brain is that some “benign” tumors can not be completely removed which allows those abnormal cells left to regrow. Thus, chemotherapy and radiation may be treatments for our PLGA children.
2) How does chemotherapy work?
Chemotherapy drugs destroy cancer cells by keeping the cells from further multiplying (interfering with mitosis) causing cell death. For example, vincristine disrupts the tubulin dimers which affect the mitotic spindles so that the chromosomes can not be pulled apart in cell division. Other chemotherapy agents affect the cell’s DNA. Unfortunately, chemotherapy can affect all rapidly dividing cells so that healthy cells can also be affected. Hair loss and low blood counts are common affects on normal cells when chemotherapy is given.
3) How well does chemotherapy work if, by definition, PLGAs are slower growing tumors?
There are cases where PLGA have significant regression, however, this tends to happen slowly. With PLGAs often stability is the primary goal of chemotherapy.
4) If chemotherapy often only has a stability effect on PLGA, why do we use it?
This is a good question. Chemotherapy is often used as a first line therapy because it can help arrest the growth of PLGA tumors without exposing the child to radiation and its long term effects. Radiation not only includes the tumor site but also has some spill over to normal tissue. Depending on where the tumor a wide variety of problems can occur with radiation (such as issues with learning and endocrine function.) Often the hope is to make the tumor quiet with chemo and if it regrows the child will be older and more able to handle the late effects of radiation.
5) What is a chemotherapy protocol?
A chemotherapy protocol is the way a drug or combination of drugs are prescribed. In general, chemotherapy treatment is given in cycles. This allows the cancer cells to be attacked at their most vulnerable times, and allows the body's normal cells time to recover from the damage. There are really three issues regarding the cycle: amount of drug, cycle interval, and how many cycles. All of these variables are discussed with various medical experts and a chemo strategy is developed. New protocols in clinical trials have a clinical trial number and parents should be able to see a summary or roadmap of the trial.
6) When is chemotherapy indicated as a treatment option for PLGA kids?
Again, there is no ONE answer to this question. Most often, doctors recommend use of chemo when total surgical resection has NOT been possible (usually due to the sensitive location of the tumor within the brain) or a previously resected tumor returned. It is possible that a doctor will recommend watch-and-wait with regular MRIs, with a partially resected tumor, before starting chemotherapy. There have been some cases of spontaneous regression with partial resections.
7) What are the standard chemotherapy drugs used for PLGA patients?
While there is no ONE right answer to this question, there are several different options that are typically at the front line for chemo treatments in PLGA kids.
- Carboplatin/vincristine
- Carboplatin
- Temozolomide
- Carboplatin/vincristine/Temozolomide
- TPCV
- Vinblastine
8) How is chemotherapy administered?
Most often chemotherapy is given intravenously. Many of the PLGA children get ports or lines (such as a Hickman or Broviac) placed in the chest wall which makes access easier. Many of the protocols are given as an outpatient, where the child comes into the clinic only. Some agents can also be administered orally, like temozolomide.
9) If a child starts on one chemotherapy and it doesn't work, can another one be given?
Yes. Many of the PLGA kids are on several different chemo agents over time.
A PLGA family offers a video clip of "Helping Hailey Through Regular Chemotherapy Visits at the Hospital" as a resource for families embarking on chemotherapy.
New advancements in chemotherapy for PLGA kids is greatly needed as current treatments are not PLGA specific. Jump starting research for PLGA tumors is EXACTLY what PLGA Foundation is all about.
Unite to fight PLGA...donate to the PLGA Foundation...and help build a brighter future for PLGA kids around the world.