By: Sankave Muraleetharan, Kezia Thaneswaran, Nawshin Nazat
Purpose of Chemotherapy
The purpose to chemotherapy is to destroy and kill cancer cells. It involves toxic drugs to eliminate the cancer cells. Chemotherapy is used as a treatment for cancer patients, which will result in no further tumors to develop. It can also stop the rapidly growing cancer cells, or slow them down. This works along with surgical treatment, biological treatment/therapy and radiation therapy. Biological therapy, also called immunotherapy, is also a form of treatment for cancer. It involves products that are naturally produced from our bodies. This form of treatment stimulates the immune system, which will force the body to act and fight against the disease, either directly or indirectly. Both chemotherapy and biological therapy work together, which will result in less side effects, eliminating cancer cells or stopping the growth of cancer cells, and an easygoing process for the patient.
How does it work?
Chemotherapy
is a treatment for cancer that uses different types of drug, to kill the cancer
cells that are inside a person’s body. This
type of treatment is worked by preventing and reducing the progress of cancer
cells. Cancer cells are cells that divide uncontrollably, that would eventually
create a tumor and that tumor will get bigger and would spread to the rest of
the body. Chemotherapy can cure cancer, control cancer and even ease a cancer
symptom that is also known for palliative care.
It is known that chemotherapy is the only cancer treatment
that is used. In other hands, cancer can be treated with surgery, radiation
therapy or biological therapy. It is used to make smaller tumor just before a
surgery or a radiation therapy is going to occur. It is referred to be known as
neo-adjuvant chemotherapy. Chemotherapy helps destroy the cancer cell that is
being reproduced and could continue after surgery or radiation therapy had
happened. This is known as adjuvant chemotherapy. Radiation therapy and
Biological therapy is being helped by chemotherapy in order for this to work
better. Chemotherapy also eliminates cancer cells that have returned or also
eliminates cancer cell that had spread to other parts of the body.
The doctors determine which type of chemotherapy drug to use
on patients regarding on the type of cancer the patient has. There are chemotherapy
drugs that are used for several different types of cancer and some drugs that are
only specified for one or two types. Also, chemotherapy drugs can be determined
by if you had chemotherapy before or if it is the patients' first time. Another
fact is that, if the patient has health problems such as heart disease,
diabetes and many more.
Chemotherapy
can be given to a patient in several ways, such as Injection. The chemotherapy
drugs can be given by a shot in the muscles that are in your arms, thighs,
hips, legs, or belly. Intra-arterial is another way, the chemotherapy will go
directly into the artery where the cancer cells are. Intraperitoneal is when
the chemotherapy goes directly into the area that consists of the organs,
intravenous is when it goes directly into a vein. Topically is when the
chemotherapy comes as a cream product that you can apply by rubbing onto your
skin, and orally is when chemotherapy is produced as pills, capsules, or
liquids that you may swallow
Video
A video that discusses about chemotherapy.
Types of Chemotherapy
There
are different types of chemotherapy. One type of chemotherapy is called alkylating
agents. This drug harms the DNA from preventing the cancer cells to replicate. This
drug works in all stages in the cell cycle. This type of drug is only used for
cancers like, lymphoma, lungs, Hodgkin disease, breast, leukemia, multiple
myeloma, sarcoma and ovary. Due to the fact that this drug damages the DNA,
this can affect the bone marrow for a long period of time. Platinum drugs
sometimes are assembled with alkylating agents since both methods kill cancer
cells in a comparable method.
Another
type of chemotherapy is antimetabolites. In this method, the DNA interferes
with the drugs and the RNA is being replaced by the growth to get the normal
building blocks of the DNA and RNA. This method causes damages for the cell
during the S phase in a cell cycle. This treatment treats ovary, leukemias,
breast and many more.
Anthracycline
is another type of method. But in this method, it is mostly referred as an
anti-tumor antibiotic. In this treatment, it is interfering with the enzymes
that are elaborated in the DNA duplication. This drugs works in all stages of
the cell cycle. If this drug is given in high doses, then it can permanently
damage the heart. Other types of antibiotics are Actinomycin-D, Bleomycin and
Mitomycin-C.
Topoisomerases
is an enzyme that helps split the strands of the DNA, so that they can be duplicated.
This is used to cure certain leukemias, ovarian, gastrointestinal, lungs and
other types of cancers. There are two types of topoisomerase. Examples for the
first type would be topotecan and irinotecan. Examples for the second type
would be teniposide, etoposide (VP-16) and mitoxantrone. Doing treatment for
type 2 can bring back cancer again for the second time and can come back 2 to 3
years after this drug is taken.
Mitotic
inhibitors are another type of method where this drug is usually planted alkaloids
and other types of compounds resulting it from natural products. This method
can break or end mitosis or even inhibit enzymes by producing proteins that are
needed for the cell reproduction. This
works during the M phase but it can also harm cells in all the other phases in
a cell cycle. Cancers that can be treated with this drug would be lymphomas, lung,
myelomas, breast and leukemias. This drug is considered to cause nerve damage
that can be considered to be a side effect of dose-limiting.
There are many different types of drugs for
chemotherapy. The list above states some of the chemotherapy treatments that
people use often.
Ethical issues
There are several ethical issues that are associated with chemotherapy, such as
1. One important ethical issue is that, there is no point for patient to proceed with chemotherapy, when the cure is unrealistic, because in this case there is no evidence, that the chemotherapy is helpful. This might make patients hesitant about going through with the procedure because maybe it’s not worth all the side effects that come with chemotherapy for a very large large of the chemotherapy not working.
2. Another issue might be that some of the drugs used for chemotherapy might have been tested on animals, which becomes an ethical issue due to animal rights and whether or not it's appropriate, especially if the animal never had cancer in the first place.
3. Another ethical argument that may come up would be if it is beneficial for a patient to go through a harsh course of treatment, especially if the treatment will not do much for the patient, so will the risks outweigh the benefits? And is it really worth taking the chance to live a longer life, for an enormous amount of pain that may or may not slow down the disease and comes with side effects?
4) Lastly, another ethical issue would be whether or not the chemotherapy will do more damage to your health that the cancer would have if it was left untreated. If the chemotherapy does not increase one’s chance of having a longer life span and better quality of life, they might as well have left the cancer untreated. It is also very expensive, so it's worth putting, family members or an individual under so much pressure , if the procedure is not beneficial at all?
Cancer cells are known to multiply rapidly, and chemotherapy kills these fast-growing cells, but because the drugs travel throughout the whole body, they may also affect normal healthy cells that are fast growing too. The damages done to the healthy cells are what cause these side effects.
The normal, healthy cancer cells that are usually damaged are the blood-forming cells in the bone-marrow, hair follicles, cells in the mouth, digestive tract and reproductive system. Some chemotherapy drugs are known to damage cells in the heart, kidney, bladder, lungs and nervous system. There is some medicine that may or may or help these normal cells, if damage does occur.
Diagrams
This brain scan clearly
demonstrates the effects on one's brain before and after chemotherapy. The
dents in the second picture are the after affects, showing the resulting
damages due to chemotherapy.
This graph demonstrates the life span of survival for
a cancer patient. Even though chemotherapy stops the growth of cancer cells,
there is a chance the cancer cells may develop again. This graph also shows
that having surgery done would be a better choice for someone who has cancer to
eliminate the cancer cells permanently.
Bibliography
Chemotherapy
Treatment Information and Drug Side Effects on MedicineNet.com. (n.d.).
Retrieved from http://www.medicinenet.com/chemotherapy/article.htm
Chemotherapy
Uses, Side Effects, Types, How It's Given, and More. (n.d.). Retrieved
from http://www.webmd.com/cancer/questions-answers-chemotherapy?page=1
How does
chemotherapy work? - National Library of Medicine - PubMed Health. (n.d.).
Retrieved from http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0041062/
Retrieved from
http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/chemotherapy/chemotherapyprinciplesanin-depthdiscussionofthetechniquesanditsroleintreatment/chemotherapy-principles-types-of-chemo-drugs
Rosenbaum, E. (2005), Everyone’s
Guide to Cancer Support Care. Canada: Andrews McMeel
Publishing
Another side of Chemotherapy. (n.d.). Retrieved
from
http://http://www.npr.org/blogs/health/2012/12/28/168141465/another-side-effect-of-
chemotherapy-chemo-brain
Leukemia.
(n.d.). Retrieved from http://www.chiff.com/health/disease/leukemia.htm
Survival. (n.d.). Retrieved from http://http://www.joplink.net/prev/201007/02.html
Normal Blood and Leukemia Blood. (n.d.). Retrieved from
http://www.wisegeek.com/how-effective-is-chemotherapy-for-cancer.htm#
Melanoma. (n.d.). Retrieved from http://www.melanoma.org.nz/About-Melanoma/Key-Information/
Breast cancer. (n.d.). Retrieved from http://openi.nlm.nih.gov/
detailedresult.php?img=3290025_cro-0005-0009-g01&req=4
Mesothelioma Chemotherapy. (n.d.). Retrieved
from
http://www.mesothelioma.com/treatment/conventional/chemotherapy/
Chemotherapy
and/or Radiation. (n.d.). Retrieved from
http://www.fitnessential.co/blog/chemotherapy/
Chemotherapeutic
Agents. (n.d.). Retrieved from
http://www.asbestos.com/treatment/drugs.php
