Cancer chemotherapy

                     


Definition
Chemotherapy is treatment of cancer with anticancer drugs.


Chemotherapy Precautions During and After Treatment

The medications that you receive during your chemotherapy are very strong. We use them to kill the cancer cells in your body. Because they are so good at their job, they can also be toxic to others who come in direct contact with you. It is important that you know about the precautions you need to take during and after receiving chemotherapy. These precautions will help those around you avoid contact with toxic and dangerous chemicals.

Chemotherapy drugs are broken down and excreted (removed) from your body once their job is done. This usually happens in the kidneys and sometimes by the liver/intestines.

The chemotherapy drugs are strong. They can still be toxic and dangerous to others even as they are being removed from your body. For example, they can cause abnormal changes in DNA, they can alter the development of an unborn baby, they may be able to cause other kinds of cancer and some may cause localized skin irritation or damage. This occurs by others having contact with the toxic by-products once they have been eliminated by your body. That is why it is important for you to take certain steps to ensure that people around you do not become sick.

Nurses will wear special gloves and gowns when preparing and giving you chemotherapy drugs. Additionally, pharmacists prepare the drugs in areas with special ventilation systems. Special procedures are used for disposing of materials after mixing and administering the drugs. There are separate plastic containers to dispose of sharp items, syringes, IV tubing and medication bags. Gowns and gloves are disposed of in special containers. If any drug leaks or spills, special precautions are used to clean up the drug.

When do you start taking these precautions?

You should start as soon as you begin your chemotherapy.

How long do you continue these precautions?

Different chemotherapy drugs take different lengths of time to be removed from your body. To be safe, you should continue all precautions until 48 hours (2 full days) after the completion of your chemotherapy.

Does it matter whether or not you take the chemotherapy in the hospital or in the clinic?

No. The doctors and nurses in the hospital and in the clinic already know about the necessary precautions to protect themselves from the chemotherapy. The people that you need to protect are those who come into contact with you during and after your chemotherapy treatments. You will need to take the same precautions with these people whether you receive your chemotherapy in the hospital or in the outpatient clinic.

What are the precautions that you need to take?

• No one should come into contact with your urine or your feces (stool). You must flush the toilet twice after each use. If possible use a separate toilet from others in your home. If you are in the hospital, do not allow visitors to use your toilet.
• Emesis (the contents you vomit from your stomach) can also contain toxic chemicals. If you vomit in the toilet, remember to flush twice and be sure to wipe around the edges of the toilet to clean any splashes. If you vomit into a bucket or pan, carefully pour the emesis into the toilet and flush twice. Then thoroughly rinse the bucket or pan with hot soapy water and dry with a disposable paper towel. Discard the paper towel right away. Do not use a regular dish cloth or tea towel.
• You must use a condom during sexual intercourse for the first 48 hours after the last dose of chemotherapy. Chemotherapy and other drugs can be found in vaginal secretions and sperm.

What if you are too sick or weak to take these precautions and you need someone to help you?

• If you are in the hospital, please allow the staff to help you and remind your visitors to avoid your body fluids (urine, stool, vomit, etc.).
• If you are at home and you need help, make sure that whoever is helping you understands the dangers involved and has read this information sheet. They need to wear disposable gloves and should avoid allowing their clothes and skin to come in contact with your body fluids. Once they are finished, they must throw out their gloves and wash their hands thoroughly.

What if you get body fluids on your bed or sheets?

• If you are in the hospital, please let the staff know.
• If you are at home, wash any soiled linen or clothes in hot water twice with regular detergent in your washing machine (do not hand wash these items), and be sure to wash the soiled linens and clothes separately from the other laundry. If you are unable to wash right away, place the dirty items in a washable pillowcase and keep separate from other household items.

What if you wear absorbable undergarments (such as Depends) or you are menstruating and are using sanitary napkins?

Any items that are absorbable (can hold body fluids) and are disposable can be thrown away. They should be sealed in a plastic bag and placed directly in the trash.

What happens if someone accidentally comes into contact with some of my body fluids?

Don't panic! Have the person wash the area thoroughly with warm soapy water. Repeat several times. If necessary, they can even take a shower. A single, accidental exposure will not likely have any serious effects. But it is important that this person avoid any further exposures. This person should also discuss the exposure with their family doctor during their next scheduled visit.

Is there anything else you can do to help limit the exposure to your family and friends?

Yes. One of the most important things you can remember to do is wash your hands often. Wash them after you have handled any of your body fluids and after every trip to the bathroom. This also has the added benefit of helping you to avoid infections and getting sick!

Chemotherapy Drugs

More than 50 chemotherapy drugs are currently available to treat cancer and many more are being tested for their ability to destroy cancer cells. Most chemotherapy drugs interfere with the ability of cells to grow or multiply. Although these drugs affect all cells in the body, many useful treatments are most effective against rapidly growing cells. Cancer cells grow more quickly than most other body cells. Other cells that grow fast are cells of the bone marrow that produce blood cells, cells in the stomach and intestines, and cells of the hair follicles. Therefore, the most common side effects of chemotherapy are linked to the treatment's effects on other fast growing cells.

Types of Drugs

Depending on the type of cancer and the kind of drug used, chemotherapy drugs may be administered differently. They can be administered orally (oral chemotherapy), or injected into a muscle (intramuscular injection), injected under the skin (subcutaneous injection), or into a vein (intravenous chemotherapy). In special cases, chemotherapy drugs may be injected into the fluid around the spine (intrathecal chemotherapy). Two or more methods of administration may be used at the same time under certain circumstances. No matter what method is used, chemotherapy drugs are absorbed into the blood and carried around the body.

Of all the methods of chemotherapy drug administration mentioned above, intravenous injection is most commonly used. It is the most efficient way to get the medication into the bloodstream. Oral chemotherapy is more convenient and does not require any specialized equipment.

In chemotherapy, cancer patients may be given one or several drugs from the available anti-cancer drugs. Since different chemical agents damage cancer cells in different ways and at different phases in the cell cycle, a combination of drugs is often employed to increase the cancerous cell-killing effectiveness. This is called combination chemotherapy.

Listed below are several major categories (classes) of chemotherapy agents based on their chemical structures and the way they act on cancer cells:

Alkylating agents

Alkylating agents were among the first anti-cancer drugs and are the most commonly used agents in chemotherapy today. Alkylating agents act directly on DNA, causing cross-linking of DNA strands, abnormal base pairing, or DNA strand breaks, thus preventing the cell from dividing. Alkylating agents are generally considered to be cell cycle phase nonspecific, meaning that they kill the cell in various and multiple phases of the cell cycle. Although alkylating agents may be used for most types of cancer, they are generally of greatest value in treating slow-growing cancers. Alkylating agents are not as effective on rapidly growing cells. Examples of alkylating agents include chlorambucil, cyclophosphamide, thiotepa, and busulfan.

Antimetabolites

Antimetabolites replace natural substances as building blocks in DNA molecules, thereby altering the function of enzymes required for cell metabolism and protein synthesis. In other words, they mimic nutrients that the cell needs to grow, tricking the cell into consuming them, so it eventually starves to death.

Antimetabolites are cell cycle specific. Antimetabolites are most effective during the S-phase of cell division because they primarily act upon cells undergoing synthesis of new DNA for formation of new cells. The toxicities associated with these drugs are seen in cells that are growing and dividing quickly. Examples of antimetabolites include purine antagonists, pyrimidine antagonists, and folate antagonists.

Plant alkaloids

Plant alkaloids are antitumor agents derived from plants. These drugs act specifically by blocking the ability of a cancer cell to divide and become two cells. Although they act throughout the cell cycle, some are more effective during the S- and M- phases, making these drugs cell cycle specific. Examples of plant alkaloids used in chemotherapy are actinomycin D, doxorubicin, and mitomycin.

Antitumor antibiotic

Antitumor antibiotics are cell cycle nonspecific. They act by binding with DNA and preventing RNA (ribonucleic acid) synthesis, a key step in the creation of proteins, which are necessary for cell survival. They are not the same as antibiotics used to treat bacterial infections. Rather, these drugs cause the strands of genetic material that make up DNA to uncoil, thereby preventing the cell from reproducing. Doxorubicin, mitoxantrone, and bleomycin are some examples of antitumor antibiotics.

One of the most important decisions for the oncologist is prescribing the right amount of anti-cancer drugs. Although large doses will kill more cells, greater amounts of drugs will produce more severe side effects. However, lowering the dosage to minimize side effects will also reduce the chances of success. The usual practice is to use the maximum safe dose for effectiveness, even at the cost of temporary side effects. The following section will discuss some common side effects caused by anti-cancer drugs and ways to cope with them.

How chemotherapy is given

Chemotherapy is administered in different ways, depending on the drugs to be given and the type of cancer. Doctors decide the dose of chemotherapy drugs considering many factors, among them being the patient's height and weight.

Chemotherapy may be given by one or more of the following methods:

• orally
• by injection
• through a catheter or port
• topically

Oral chemotherapy is given by mouth in the form a pill, capsule, or liquid. This is the easiest method and can usually be done at home.

Intravenous (IV) chemotherapy is injected into a vein. A small needle is inserted into a vein on the hand or lower arm. The needle usually is attached to a small tube called a catheter, which delivers the drug to the needle from an IV bag or bottle.

Intramuscular (IM) chemotherapy is injected into a muscle. Chemotherapy given by intramuscular injection is absorbed into the blood more slowly than IV chemotherapy. Because of this, the effects of IM chemotherapy may last longer than chemotherapy given intravenously. Chemotherapy also may be injected subcutaneously (SQ or SC), which means under the skin. Injection of chemotherapy directly into the cancer is called intra-lesional (IL) injection.

Chemotherapy also may be given by a catheter or port permanently inserted into a central vein or body cavity. A port is a small reservoir or container that is placed in a vein or under the skin in the area where the drug will be given. These methods eliminate the need for repeated injections and may allow patients to spend less time in the hospital while receiving chemotherapy. A common location for a permanent catheter is the external jugular vein in the neck. Intraperitoneal (IP) chemotherapy is administered into the abdominal cavity through a catheter or port. Chemotherapy given by catheter or port into the spinal fluid is called intrathecal (IT) administration. Catheters and ports also may be placed in the chest cavity, bladder, or pelvis, depending on the location of the cancer to be treated.

Topical chemotherapy is given as a cream or ointment applied directly to the cancer. This method is more common in treatment of certain types of skin cancer.

Adverse effects

chemotherapy drug techniques have a range of side-effects that depend on the type of medications used.

• Depression of the immune system, which can result in potentially fatal infections. Although patients are encouraged to wash their hands, avoid sick people, and take other infection-reducing steps, about 85% of infections are due to naturally occurring microorganisms in the patient's own GI (including oral cavity) and skin.
• Tiredness. The treatment can be physically exhausting for the patient, who might already be very tired from cancer-related fatigue. It may produce mild to severe anemia. 
• Bleeding disorders.  Extremely low platelet counts may be temporarily boosted through platelet transfusions. 
• Gastrointestinal distress. Nausea and vomiting are common side-effects of chemotherapeutic medications that kill fast-dividing cells. This can also produce diarrhea  and constipation.Malnutrition and dehydration can result when the patient does not eat or drink enough, or when the patient vomits frequently, because of gastrointestinal damage. This can result in rapid weight loss, or occasionally in weight gain, if the patient eats too much in an effort to allay nausea or heartburn. Weight gain can also be caused by some steroid medications.
• Loss of hair. Some medications that kill rapidly dividing cells cause dramatic hair loss; other medications may cause hair to thin. These are most often temporary effects: hair usually starts to regrow a few weeks after the last treatment, sometimes with a tendency to curl, resulting in "chemo curls." Permanent hair loss can result from some standard chemotherapy regimens.

Damage to specific organs is possible:

• Cardiotoxicity (heart damage)
• Hepatotoxicity (liver damage)
• Nephrotoxicity (kidney damage)
• Ototoxicity (damage to the inner ear), producing vertigo
• Encephalopathy (brain dysfunction)

Chemotherapy Aftercare

Cancer treatments such as chemotherapy, and cancer itself, may cause mild cognitive impairments, including problems with thinking, memory, language skills, learning, and concentration. Chemotherapy-related cognitive dysfunction is known as “chemobrain” among cancer patients. Some symptoms of chemobrain include memory problems, difficulty thinking clearly, difficulty processing information, inability to focus or concentrate, and mental cloudiness or foggy-headedness.

Since cognitive changes vary from person to person, an individual assessment is an important first step in ruling out other conditions and developing appropriate intervention strategies. Medications for depression, attention-deficit hyperactivity disorder (ADHD), and dementia are being investigated for their potential to improve thinking and memory problems in cancer patients. Your doctor may also recommend behavioral strategies, lifestyle alterations, rehabilitation therapies, and counseling.

Tips for Coping with Cognitive Dysfunction

• Establish a daily routine and keep the same schedule each day.
• Create an organized environment that is free of clutter.
• When you need to complete tasks that require concentration, try to minimize distractions.
• Work and read in a quiet, uncluttered environment.
• Make a checklist, or a “to-do” list, of daily chores, errands and important things to remember (e.g., grocery list, medication schedules).
• Write your appointments in a calendar
• Carry a personal organizer and/or notebook with you.
• Place post-it notes around your house and workplace, or leave yourself voice mail messages as reminders.
• To sharpen your memory, try to learn a new skill, take a class, or do crossword puzzles (e.g., Sodoku puzzles) or other games.
• Get plenty of sleep, exercise regularly, maintain a proper diet, and manage your stress.
• Keep a daily journal to track changes in your thinking, memory and behavior, including when symptoms began, what time of day they occur, and what influences them throughout the day. Share this information with your doctor.
• Share your experiences with others (e.g., friends, family, other cancer survivors).

Normal results

The main goal of chemotherapy is to cure cancer. Many cancers are cured by chemotherapy. It may be used in combination with surgery to keep a cancer from spreading to other parts of the body. Some widespread, fast-growing cancers are more difficult to treat. In these cases, chemotherapy may slow the growth of the cancer cells.

Doctors can tell if the chemotherapy is working by the results of medical tests.Physical examination, blood tests, and x rays are all used to check the effects of treatment on the cancer.

The possible outcomes of chemotherapy are:

• Complete remission or response. The cancer completely disappears. The course of chemotherapy is completed and the patient is tested regularly for a recurrence.
• Partial remission or response. The cancer shrinks in size but does not disappear. The same chemotherapy may be continued or a different combination of drugs may be tried.
• Stabilization. The cancer does not grow or shrink. Other therapy options may be explored. A tumor may stay stabilized for many years.
• Progression. The cancer continues to grow. Other therapy options may be explored.
• A secondary malignancy may develop from the one being treated, and that second cancer may need additional chemotherapy or other treatment.

Links

• en.wikipedia.org/wiki/Chemotherapy
• www.lef.org/protocols/cancer/chemotherapy_01.htm
• www.ecancerchemotherapy.com/