Saturday, July 14, 2012

What Is Chemotherapy? What Are The Side Effects Of Chemotherapy?

Chemotherapy is the use of chemicals (medication) to treat disease - more specifically, it usually refers to the destruction of cancer cells. However, chemotherapy also includes the use of antibiotics or other medications to treat any disease. This article focuses on chemotherapy for cancer treatment. Cytotoxic medication prevents cancer cells from dividing and growing. When health care professionals talk about chemotherapy today, they generally tend to refer more to cytotoxic medication than others.

How did chemotherapy start?

After a military operation in World War II some sailors were accidentally exposed to mustard gas. They were later found to have very low white blood cell counts. White blood cells usually grow very quickly - cancer cells also divide and grow very quickly.

The doctors wondered whether the effect of mustard gas - slowing down the rapid growth of white blood cells - may have the same effect on cancer cell growth.

Doctors tried testing patients with advanced lymphomas by injecting a chemical in mustard gas. Even though the effect was temporary, the patients did experience a remarkable improvement.

This led to research into other substances that might slow down or stop the division and growth of cancer cells. Over the decades several new improved drugs were created.

There are more than 100 different types of chemotherapy drugs today which can treat most cancers.

Genetic testing is helping doctors target chemotherapy more accurately. Testing for genetic mutations can help identify breast cancer patients who will not benefit from a specific type of chemotherapy, scientists from the USA and Norway reported.

Chemotherapy has five possible goals

  • Total remission - to cure the patient completely. In some cases chemotherapy alone can get rid of the cancer completely.

  • Combination therapy - chemotherapy can help other therapies, such as radiotherapy or surgery have more effective results.

  • Delay/Prevent recurrence - chemotherapy, when used to prevent the return of a cancer, is most often used after a tumor is removed surgically. Scientists at the Charite School of Medicine, Germany, found that the use of the drug gemcitabine for chemotherapy significantly delays the recurrence of cancer, compared to no chemotherapy.

  • Slow down cancer progression - used mainly when the cancer is in its advanced stages and a cure is unlikely. Chemotherapy can slow down the advancement of the cancer.

  • To relieve symptoms - also more frequently used for patients with advanced cancer.

How does chemotherapy work?

When our body cells are damaged or die we produce new ones to replace them. This is done in an orderly way, in a balanced way. Cancer cells do not have that orderly capacity - their reproduction (division and growth) is out of control - more and more of them are produced and they start to occupy more and more space, until eventually they push out space occupied by useful cells.

Chemotherapy (chemo) drugs interfere with a cancer cell's ability to divide and reproduce. Chemo drugs may be applied into the bloodstream to attack cancer cells throughout the body, or they can be delivered directly to specific cancer sites.

Chemotherapy drugs work in various ways:
  • Impairing mitosis (prevent cell division) - these are known as cytotoxic drugs.

  • Targeting cancer cell's food source, enzymes and hormones they require in order to grow.

  • Stopping the growth of new blood vessels that supply a tumor. In a study, researchers at the Johns Hopkins University School of Medicine discovered how a whole class of commonly used chemotherapy drugs can destroy cancer by blocking blood vessel growth.

  • Triggering suicide of cancer cells - cell suicide is known medically as apoptosis.
Patients may receive monotherapy or combination therapy:
  • Monotherapy - the patient is given just one drug.

  • Combination therapy - the patient receives more than one drug.
Which type the patient receives will depend on the kind of cancer the patient has, as well as some other health considerations.

Chemotherapy may be given at different stages
  • Neo-adjuvant therapy - if the tumor is large the surgeon may want to shrink it before surgery. This may involve some pre-operative chemotherapy and/or radiotherapy.

  • Chemoradiation therapy - the chemotherapy is given in combination with radiotherapy. Patients with localized Hodgkin's lymphoma where the tumor is situated above the diaphragm should be given chemotherapy combined with radiotherapy, European scientists reported after carrying out a clinical trial. Another study reported that the solid tumor cells that survive chemoradiation therapy often end up stronger than they were before.

  • Adjuvant therapy - chemotherapy given after surgery. The use of chemotherapy following surgery reduces the risk of death from operable pancreatic cancer by around 30%, a UK study found.
Often age will determine whether chemotherapy should be used at all for patients with certain cancers. Researchers at The Mayo Clinic, USA, found that the combination of chemotherapies 5FU and oxaliplatin compared to 5FU alone after surgery for colon cancer decreases colon cancer recurrence and promotes longer survival for patients under 70 - but not for those who are older.

How long is a course of chemotherapy?

In the majority of cases for best results the patient will need regular chemotherapy over a specific period. A protocol plan is drawn up which specifies when treatment sessions will occur and for how long.

A course of chemotherapy may be just a one-day treatment, or can last for a few weeks - it will depend on the type and stage of the cancer (how advanced it is). If the patient requires more than one course of treatment there will be a rest period for his/her body to recover. This could be a one-day treatment followed by a week's rest period, followed by another one-day treatment followed by a three-week rest period, etc. This may be repeated many times.

How many health care professionals are involved in chemotherapy treatment?

This will depend on working practices of your hospital, or even the country you live in. In most countries there will be a multi-disciplinary team who treat the patient's cancer. These may include:
  • A clinical oncologist - a doctor who specializes in cancer but does not do surgery. He/she is specialized in chemotherapy.

  • A cancer nurse - probably the first person the patient will meet when coming in for chemotherapy.

  • A hematologist - this is a doctor who is specialized in the study of blood and bone marrow.

  • A pathologist - this is a doctor who specializes in the identification of diseases by examining cells and tissues under a microscope.

  • A psychologist - he/she will help the patient deal with the mental and emotional ordeal of chemotherapy.

Blood tests before and during chemotherapy treatment

Blood tests are needed to assess the health of the patient as well as ensuring that he/she will be able to cope with possible side-effects. For example, blood tests can detect liver problems, which could mean that chemotherapy is unsuitable for the patient unless the liver recovers. Chemotherapy chemicals are metabolized (broken down) in the liver which could be harmed if it is not working properly.

Before chemotherapy it is important to test the patient's blood count because the treatment will reduce the number of red and white blood cells, as well as platelets. If a blood test reveals a low blood count the doctors may decide to delay treatment.

Researchers at the Paul Papin Cancer Center in Angers, France, reported that measuring drug levels in patients' blood and adjusting them for optimal dosing can substantially reduce severe toxicity and improve efficacy in colorectal cancer.

Regular blood tests will continue during the treatment period so that the medical team can keep an eye on blood count and the state of the patient's liver. As you may read under side-effects further down this page, there is a risk that chemotherapy may lower white, red, and platelet blood level counts.

Monitoring the patient's blood can also provide doctors with important data on how well the chemotherapy is working.

Two ways of giving chemotherapy

Depending on the type of cancer, chemotherapy may be administered orally or intravenously (directly into the vein).
  • Oral chemotherapy (swallowing tablets)

    These will be in the form of tablets. If the patient's health allows it he/she will be able to take them at home. However, regular hospital visits will still be needed to check on the patient's health and response to treatment.

    It is vital that the tablets be taken exactly when specified. If the patient forgets to take one at a specific time he/she should call the medical team immediately.

  • Intravenous chemotherapy (straight into the vein)

    Intravenous chemotherapy may be given as:

    • An injection straight into a vein.
    • Through a drip (intravenous infusion).
    • Through a drip or pump.
    • Through a pump that the patient wears for several weeks or months. This is called continuous infusion, protracted venous infusion, or ambulant infusion (meaning the patient can walk about while receiving the medication).
    There are different ways of getting the medication into the patient. These include:

    • A cannula - a thin tube is inserted through the skin into the vein - usually it enters the body via the back of the hand or the lower arm.

    • A drip (intravenous infusion) - in order to dilute the medication it may be injected into a bag. The solution in the bag will pass through a tube into the patients arm and into a vein (intravenous infusion). A cannula will be used. The solution will enter the vein slowly.

      Chemotherapy through a drip generally is pushed through with a pump. The pump does not hurry the process up, rather it makes sure the solution enters the vein at a constant rate over a specific period - the slower the rate, the longer the whole thing will take.

    • A central line - this is a long, flexible, plastic line (thin tube) which ends up in a central blood vessel in the chest, close to the heart. The central line usually enters the body through the center of the chest and goes up under the skin into a large vein by the collarbone (clavicle). The only visible part is the length of line that hangs out of the small entry hole in the chest.

    • A peripherally inserted central catheter (PICC) line - a long, thin, flexible tube that is inserted into a peripheral vein, usually in the upper arm and makes its way into a large vein in the chest near the heart. It is similar to a central line but has a different point of entry.

    • A portacath (implantable port) - a thin, soft, flexible plastic tube goes into a vein. It has a port (opening) just under the skin of the chest or arm. The port has a thin rubber disc which special needles can pass medicines into, or take blood from.

Pregnancy and contraception

Many chemotherapy drugs may cause birth defects. It is important that a woman undergoing chemotherapy avoids becoming pregnant. As most chemotherapy medications interfere with oral contraceptives it is important to use a barrier method of contraception, such as condoms, during the whole chemotherapy treatment period and for a year after treatment is completed. If you are pregnant you need to tell the medical team straight away beforehand. If you become pregnant during treatment tell the medical team straight away.

What are the side effects of chemotherapy?

Most people immediately link chemotherapy with uncomfortable side effects. However, side-effect management has improved considerably over the last twenty years. Many side effects that were once inevitable can be either prevented or well controlled today.

There is no reliable way to predict how patients may react to chemotherapy. Some experience very mild side-effect, others will have none at all, while some people will report various symptoms.

Depending on the type of cancer and treatment, chemotherapy may have a bigger impact on the patient's work status than radiotherapy. Women with breast cancer who receive chemotherapy appear more likely than those treated with radiation therapy to experience a major change in work status, according to researchers at the Dana-Farber Cancer Institute.

Below is a list of the most commonly reported side effects:

Nausea and vomiting

Over half of all patients receiving chemotherapy will experience nausea and vomiting. Doctors will usually prescribe anti-emetics for this. These need to be taken even when symptoms have gone as they will prevent them from coming back. If the anti-emetics do not work the patient should contact his/her doctor who may switch to another anti-emetic.

Ginger - scientists at the Rochester University Medical Center found that taking ginger supplements with standard anti-vomiting drugs beforehand can reduce the nausea that often accompanies chemotherapy treatment by 40%.

Alopecia (Hair loss)

Some chemotherapy medications cause hair loss while others don't. If hair does start to fall out this will usually happen a few weeks after treatment starts. On some occasions the hair will just become thinner and more brittle (without falling out). Hair loss can occur in any part of the body.

Although hair loss has no physical health consequences, it may cause distress and embarrassment for some people. The psychological impact tends to be greater among women than men. If you experience hair loss and find it is causing distress and embarrassment, there are several steps you can take:
  • Tell your doctor, who may refer you to a counselor who can provide effective help and support.

  • Many people find that if they purchase a wig their quality of life improves significantly.

  • If there is a cancer support group in your area, go to their meetings. Meeting people who share similar experiences to yourself may help give you a boost, as well as providing you with some useful tips, and possibly an opportunity to make new friends.

  • Cold cap - this looks a bit like a bicycle helmet and keeps the scalp cool while the chemotherapy dose is being administered. If the scalp can be kept cool less chemotherapy medication reaches the scalp, thus preventing the occurrence or reducing the severity of hair loss. Some people cannot wear a cold cap - leukemia (blood cancer) patients need the medication to reach their scalp.
The hair loss is NOT permanent - it will grow back soon after treatment if finished.

Fatigue

Most patients receiving chemotherapy will experience some degree of fatigue. This may be a general feeling which exists most of the day, or may only appear after certain activities. Doctors say patients need to make sure they get plenty of rest and not to perform tasks which are overtiring.

While light exercise has been shown to help, it is important to remember to keep the activities 'light'.

If the tiredness becomes severe it is important to tell the doctor, as this could be caused by a significant drop in red blood cells (anemia).

Hearing impairment (deafness, ototoxicity)

Scientists from Oregon Health & Science University reported that deafness as a side effect of chemotherapy has long been underreported by the medical community, because a well-known classification system doctors use for reporting toxicities in patients does not consider high-frequency hearing loss, allowing the magnitude of ototoxicity (hearing damage) in children treated with platinum agents to be miscalculated.

Children with cancer who suffer hearing loss due to the toxic effects of chemotherapy might one day be able to get their hearing back through pharmacological and gene therapy, said researchers from St. Jude Children's Research Hospital after carrying out a study on mice.

Neutropenia (low white blood cells) - Susceptibility to infections

When receiving chemotherapy the immune system will be weakened because the white blood cell count will go down. White blood cells form part of our immune system - they fight infection. Consequently, patients become more susceptible to infections.

Some patients will be prescribed antibiotics which may reduce their risk of developing infections. The following precautions will help reduce the risk of infections:
  • Personal hygiene - the cleaner you are, the fewer bacteria there will be around which can infect you. Regularly wash your hands with warm water and soap, have a bath/shower at least once a day, change your clothes and bathroom towels and flannels daily. Change your bed linen regularly.

  • Preparing food - make sure your food is free of food borne pathogens (organisms, such as bacteria that can make you ill). If you handle raw meat make sure you wash your hands before touching plates and cutlery or work surfaces. Thoroughly cook animal sourced proteins before eating them. Wash your dishes thoroughly and always use a clean plate and cutlery - keep the kitchen clean.

  • Infected people - stay away from people who are ill. This may include those who just have a temperature.

  • Skin wounds - bacteria find it hard to get in through your skin, unless there is a cut. If you graze or cut your skin, clean the area well with warm water, dry it, and cover it with a sterile dressing.
Patients receiving chemotherapy who develop an infection need immediate treatment. This may mean being hospitalized and receiving antibiotics via an intravenous drip.

Thrombocytopenia (low blood platelet count) - Blood clotting problems

Chemotherapy may lower the patient's blood platelet count. A platelet is a type of blood cell that helps the blood to clot (coagulate). Coagulation is essential, otherwise bleeding does not stop. Lower blood platelet counts linked to chemotherapy is a risk, but less so than lower red or white blood cell counts. If you are affected you will bruise more easily, you will be more likely to have nosebleeds and bleeding gums, and if you cut yourself it may be harder to stop the bleeding.

Patient's whose blood platelet counts fall too low will need a blood transfusion.

Below are some steps you may wish to take to reduce your risk of bleeding:
  • Shave with an electric razor (or don't shave)
  • Avoid hard toothbrushes
  • Use kitchen utensils and gardening equipment carefully
  • If you are gardening, wear gloves
Anemia (low red blood-cell count)

As well as lowering you white blood cell count, chemotherapy will also lower your red blood cell count. Tissues and organs inside your body get their oxygen from the red blood cells. If your red blood cell count goes down too many parts of your body will not get enough oxygen and you will develop anemia.

People with anemia feel very tired. A patient on chemotherapy who has anemia will feel extra tired - much more tired than straightforward fatigue caused by the treatment. Dyspnea (shortness of breath) is also another symptom of anemia, as are palpitations (when the heart beat is irregular).

Anemia linked to chemotherapy requires immediate treatment. A blood transfusion will bring the red blood cell count back up immediately. Erythropoietin (EPO) is a drug that makes the body produce more red blood cells.

The following foods are rich in iron, which helps red blood cells carry more oxygen. Dark green leafy vegetables, beans, meat, nuts, prunes, raisins, and apricots.

Scientists from The Medical University of Vienna, Austria found that patients with breast cancer who developed anemia during chemotherapy had nearly three times the risk of local recurrence as those who did not.

Mucositis (inflammation of the mucous membrane)

Chemotherapy attacks rapidly dividing cells, such as blood cells, bone marrow cells, and cells of the mucous membranes that line the digestive system - this includes the mouth, esophagus, stomach, intestines, and the rectum to the anus. Chemotherapy may damage and even destroy some of those mucous membrane cells.

Oral Mucositis (in the mouth) - patients more commonly experience symptoms in their mouth.

If symptoms do appear, they will usually do so about 7 to 10 days after treatment starts. The inside of the mouth may feel like sunburn; some people say it feels as if the area had been scalded. Ulcers often appear on the lining of the mouth, the tongue, and sometimes around the lips. The severity of symptoms is closely linked to the strength of the chemotherapy dose.

Some may find it painful when they eat, drink, or even talk. If the ulcers bleed there is a risk of infection.

Caphosol is often prescribed for mucositis.

A clinical trial showed that out of 100 cancer patients that were treated with DAVANAT® and chemotherapy that included 5-FU, none developed mucositis.

As better drugs are appearing, mucositis is becoming less common. Symptoms clear up a few weeks after treatment is completed.

Loss of appetite

Loss of appetite is a common side effect of chemotherapy. It is possible that the chemotherapy, or the cancer itself, affects the body's metabolism. If the loss of appetite is just due to the chemotherapy it will come back when the treatment is finished - although this may sometimes take a few weeks.

The severity of appetite and consequent weight loss depends on the type of cancer and chemotherapy treatment.

Although this is sometimes easier said than done, it is important to keep trying to eat well and take in plenty of fluids. Many patients find that smaller and more frequent meals are easier to get down than the typical three meal-a-day regime. Also, drinking liquids through a straw may result in a better fluid intake.

Patients who become seriously affected by lack of food and liquid intake may need to be hospitalized and fed through a nasogastric tube. The tube goes into the patient's nose and down to his/her stomach.

Nails and skin

Chemotherapy can sometimes cause dry and sore skin. Nails may also become flaky and brittle. The skin may become more sensitive to sunlight. It is important to protect yourself from too much sunlight exposure. This includes staying out of the sun during peak times of the day, using sun blocks, and wearing clothes that provide maximum protection. Surprisingly, scientists at Michigan University, USA, reported that the chemotherapy drug fluorouracil appeared to reduce the appearance of sun-damaged and aging skin as well as the number of potentially pre-cancerous skin patches.

Cognitive problems

About one fifth of patients undergoing chemotherapy report some kind of cognitive problem, including attention, thinking and memory. This can sometimes have an impact on daily tasks. Patients who do experience these symptoms should talk to their doctor, and social worker.

Symptoms may include:
  • Shorter attention span; concentration, focus and attention problems
  • Memory problems; especially the short-term memory
  • Comprehension and understand problems
  • Judgment and reasoning problems
  • Organizational skills may be affected
  • Multitasking problems (performing/thinking about several things at the same time)
  • Mood swings
Experts are unsure how much is due to the chemotherapy, and how much is due to fatigue, stress and anxiety that comes with having cancer.

Libido (sex drive) and fertility

For a significant proportion of patients, chemotherapy may result in a lower sex drive (less interest in sex). This is temporary and usually returns after treatment is completed.

Depending on the type of medication administered, chemotherapy may also damage men's sperm. Some women may become infertile. In most cases - though not all - fertility returns after treatment is over.

Men who wish to father children and women who plan to become pregnant one day should discuss possible options with their doctors before starting treatment. It is possible to freeze sperm and embryos.

Bowel movement problems (diarrhea or constipation)

Sometimes when damaged cells in the intestinal tract are rapidly expelled from the body there is a risk of diarrhea. Constipation is also a possible risk for chemotherapy patients. You should talk to your doctor if you experience any unpleasant change in your bowel movements. Symptoms, if they do occur, will do so a few days after chemotherapy begins.

Depression

The risk of developing depression is already higher for patients with cancer. It is normal to feel distressed, anxious, sad and stressed - especially if you are concerned about what the future holds and whether treatment is going to be effective.

It is important that you talk to a member of the medical team if you feel it is all getting to be too much, or if you no longer get pleasure out of the things that you used to like. Joining a support group and talking to people who are going through the same as you and understand how you feel has helped many people with cancer.

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