27 Aug What is Chemotherapy?

A lot of people know someone who has had, or have at least heard of chemotherapy. Some people call it medical oncology. Some of us know that it causes our loved ones to lose their hair, or get sick, or make them feel tired. But do you really understand what chemotherapy is? Well let’s see if I can shed some light on it.
 Chemotherapy is the treatment of cancer with drugs (“anticancer drugs”) that can destroy cancer cells. In current usage, the term “chemotherapy” usually refers to cytotoxic drugs which affect rapidly dividing cells. That is correct, I said cytotoxic drugs. This basically means that these drugs are poisons that we intentionally place into our blood stream to hopefully help reduce the number of cancer cells.
 Chemotherapy drugs interfere with cell division in various possible ways, i.e. with the duplication of DNA or the separation of newly formed chromosomes (those “rules” that dictate how many times a cell can or can not divide).  By interfering with the activity of cancer cells we can then help to destroy them. Chemotherapy accomplishes this by either directly going into the cell and trying to sabotage a specific phase of cell development or by sending confusing messages that cause the cells to do the wrong thing and thereby destroy themselves.
Most forms of chemotherapy target all rapidly dividing cells and are not specific for cancer cells. Since chemotherapy is administered through an IV, or directly into the blood stream, it travels through out the entire blood stream and our bodies. Due to chemotherapy being in our blood, traveling though out our system, and touching almost every single cell in our bodies, it has the potential to make us sick, lose our hair, or get tired. Chemotherapy is not smart enough to distinguish between cancer cells and normal cells, so it becomes a juggling act for the doctors. Physicians have to figure out a good balance between harming enough cancer cells to stop growth, and yet giving enough time to normal tissues to repair and regenerate themselves.
Chemo is different from Surgery and Radiation Oncology because of the above factor. Surgery and Radiation are administered to a very specific area of the body, such as the breast or prostate. Chemotherapy treats the entire body since it travels through our blood system. This treatment is good for those cancers that are more aggressive, that have cancer cells that divide more rapidly, or in which the physician may think there is a chance that the cancer may have spread to other areas of the body. Chemotherapy also improves the chances that any “microscopic” or small little cells that we can’t see or detect are damamged and killed as well. This is especially good to be used as a boost for an area where surgery may have happened.
Chemotherapy can be used as the only type of treatment, in addition or in combination with surgery and/or radiation therapy, or in addition to other chemotherapy drugs as well. Some chemo drugs are more effective when used in conjunction with other drugs, or in combination. Combinations have been developed for several reasons: Different drugs attack the cancer cells in different ways; some drugs may make other drugs more potent; combinations help to avoid the problem of cancer cells becoming “immune” or resistant to a certain drug; for many kinds of cancer, a combination of drugs (each one of which is effective in attacking that kind of cancer) provides more effective cancer cell kills with fewer harmful effects on healthy tissues.
 I hope this helps to shed some light on what Chemotherapy is and how it works. If you have any further questions or concerns, or I haven’t answered something and you still want to know more, please feel free to ask.
-CancerGeek