Chemotherapy in the treatment of cancer | Type, What to Expect, Treatement Process (Before, During, After), Side Effects

Chemotherapy | Type, What to Expect (Before, During, After), Side Effects

 Chemotherapy in the treatment of cancer

In chemotherapy (sometimes called chemo) refers to drugs, or agents, are used to destroy cancer cells. Chemotherapy is used to treat many types of cancer. Those drugs can be used alone or in combination with others (combination chemotherapy). Chemotherapy can be given alone or with other treatments, such as radiation therapy or targeted therapy. It is also given in high doses as part of a stem cell transplant. Some chemotherapies can be administered orally, others intravenously, some are not very toxic, others more…

Similarly, the different tumors are not sensitive to the same chemotherapies. Chemotherapy therefore does not designate a drug, but a principle of treatment that includes a wide range of drugs.

How chemotherapy works?

Chemotherapy is most effective on cells that are actively growing and dividing. Cancer cells tend to grow and divide quickly, making them good targets for chemotherapy. But chemotherapy cannot tell the difference between cancer cells and normal cells. Some normal cells, such as those found in hair follicles and lining of the digestive system, also tend to grow and divide faster than other cells in the body. Chemotherapy can also affect these cells. This is why some people lose their hair or have vomiting and diarrhea. Normal cells can usually repair damage over time, and these side effects tend to go away after chemotherapy is finished.

How chemotherapy is used?

Chemotherapy can be given alone to treat cancer or in combination with other treatments such as surgery or radiation therapy. It can be used before surgery to reduce the size of a tumor or after surgery to destroy residual cancer cells and prevent the cancer from coming back (recurrence). Chemotherapy also helps relieve symptoms, improve quality of life and extend the life of people with advanced cancer (palliative chemotherapy).

Most of the time, chemotherapy is used as a systemic treatment. This means that the drugs circulate in the blood and can attack cancer cells almost anywhere in the body.

Frequency of administration

The frequency of administration depends on the chemotherapy protocol chosen by the doctor.
This can be daily chemotherapy (especially when taken orally), or chemotherapy every week, or chemotherapy every 15 days, 3 weeks, etc.
Similarly, the total duration also depends on the protocol. Nevertheless, there are some standards. For example, in testicular tumours, the number of cycles generally varies from 2 to 4. In breast cancers after surgery, 6 cycles of chemotherapy are generally carried out.

Infusion chemotherapy

The duration of infusion is variable: from 10 minutes to more than 72 hours.
Chemotherapy infusions can be performed in a day hospital or in “conventional” hospitalization, sometimes in the context of Hospitalization at Home (HAD). The administration of chemotherapy in a day hospital allows the patient to go home without spending the night in the hospital.

Chemotherapy requires conventional hospitalization when it lasts several days, or when hydration must be carried out concomitantly.

Infusion may sometimes require the implantation of an implantable port into a vein in the neck. This is due to the fact that chemotherapy damages the veins, and cannot be performed constantly on the veins of the arm. Information on implantable ports is available from the nurses and at the Meeting and Information Center.

Chemotherapy treatement process

Types of chemotherapy

There are many chemotherapy drugs that are grouped into different categories (classes) depending on how they work. Combining chemotherapy drugs from different classes can make treatment more effective because different agents attack cancer cells at different times in their growth cycle. It can also help prevent resistance and help reduce the risk of the cancer coming back (coming back).

Some types of chemotherapy include the following:
  • DNA-altering agents are also called alkylating agents. These agents prevent cells from dividing by changing their DNA so that they cannot copy it. Since cancer cells grow and divide quickly, they eventually die because they don’t have time to repair damaged DNA.
  • Antimetabolites act as the building blocks of DNA or RNA that cancer cells need to grow and survive. When a cancer cell uses the chemotherapy drug’s antimetabolites rather than its own substances, DNA is damaged and the cell dies.
  • Antimitotics block the process of cell division, called mitosis, and thus prevent cells from dividing and multiplying.
  • Antitumor antibiotics bind to DNA and prevent it from working properly, causing the cell to die. These agents are different from antibiotics used to treat infections.
  • DNA repair enzyme inhibitors prevent normal repair of DNA damage inside the cell. These chemotherapy drugs attack enzymes that usually repair DNA damage. If a cancer cell cannot repair DNA damage, it dies.

Going for chemotherapy

Your chemotherapy treatment will be scheduled by a medical oncologist, who is a cancer specialist who monitors drug treatments. The medical oncologist works with other members of the healthcare team to plan and administer treatment.

Chemotherapy sessions can be given daily, weekly, or monthly. Chemotherapy drugs are often given at regular intervals called cycles. A cycle could be, for example, a treatment for 3 days followed by a 25-day rest period. The rest period allows the body to produce new, healthy cells and regain strength. The duration of full treatment, from start to finish of chemotherapy treatment, may be 3 months or more. It is therefore possible that you will have 4 or more cycles during your full treatment. Your healthcare team will tell you how long your treatment should be.

Your healthcare team will tell you what you can eat, drink and what to avoid while you are taking chemotherapy drugs. Tell your doctor about any medications you are taking, including prescription drugs, vitamins, and supplements like herbs.

Before treatment

Before starting chemotherapy, your healthcare team may suggest that you get your teeth cleaned and checked. This is because chemotherapy can cause pain and dryness in the mouth, and can also decrease your ability to fight infection.

Chemotherapy can also be hard on your heart, so your healthcare team may suggest that you have an echocardiogram to check how well your heart is working.

Chemotherapy can also affect your fertility (the ability to get pregnant or carry a pregnancy to term, or the ability to make someone else pregnant). Before starting cancer treatment, talk to your healthcare team if you want to have children later. There may be ways to protect your fertility before or during treatment.

If you are given chemotherapy through a vein (intravenously, or IV), you may have surgery to put in a special, smooth and flexible catheter called a central venous catheter or injection chamber. This type of catheter is used to deliver drugs when chemotherapy is needed over a long period of time. It keeps you from having a needle stick every time.

Medicines to reduce side effects, such as nausea and vomiting, are often given about 20 to 30 minutes before chemotherapy.

Where is chemotherapy given

Where chemotherapy takes place depends on your situation, the medications used, and the services available in the community. Chemotherapy can be given:

  • in a cancer treatment center or hospital;
  • at home;
  • at the doctor’s office.

Most people receive chemotherapy on an outpatient basis and do not need to stay overnight in the clinic or hospital. You may need to be hospitalized if treatment is to be given for 24 hours or more. Some people stay in the hospital when they first start chemotherapy so the healthcare team can watch for side effects.

How chemotherapy is given

Chemotherapy can be given in different ways, called routes of administration. The route of administration depends on the type of medicine used, the purpose of treatment, and the type of cancer and its location.

Most chemotherapy drugs are given directly into a vein (intravenously) using a needle or a small plastic tube called a catheter. This allows the drugs to go directly into the bloodstream where they can be carried to the tumor and any cancer cells that have spread from the tumor. Sometimes a pump is used to control the rate at which chemotherapy drugs are given.

Chemotherapy can also be given in other ways:
  • by mouth, as tablets or capsules (oral chemotherapy)
  • in the cerebrospinal fluid (CSF) surrounding the spinal cord (intrathecal chemotherapy)
  • in CSF in the brain (intraventricular chemotherapy)
  • in an artery (intra-arterial chemotherapy)
  • in a body cavity, such as the abdomen or chest (intracavitary chemotherapy)
  • in a muscle (intramuscular chemotherapy)
  • directly into the tumor (intralesional chemotherapy)
  • using a cream or ointment applied to the skin (topical chemotherapy)
Security measures

Chemotherapy drugs are strong, powerful drugs that can damage and destroy cells. They should be handled with great care and disposed of safely. Healthcare workers may wear gloves, a mask, protective glasses and a hospital gown to avoid direct contact with the drugs. Some medicines (blisters) can also damage tissue if they leak from the vein, so a member of the healthcare team may stay with you while they are being given.

You and your caregivers will also need to handle body fluids with care since chemotherapy drugs can also be passed in urine, stool and vomit for 48 hours after treatment.

Your healthcare team will give you instructions on the following topics:

  • precautions to take when using the toilet
  • what to do if there are body fluids on your clothes or linens
  • how to handle chemotherapy drugs if you bring them home
  • if you should avoid having sex or when it is safe to have sex
  • any precautions to take during sex (including oral sex)

It is important to avoid becoming pregnant or making another person pregnant during treatment, as some chemotherapy drugs can cause genetic mutations or birth defects in a developing fetus. A woman can remain fertile during chemotherapy treatment, even if her menstrual cycle becomes irregular or interrupted. Talk to your healthcare team to find out which birth control methods are best for you and your partner.

Since chemotherapy drugs can weaken your immune system, you should also:

  • wash your hands often;
  • protect yourself when you are around other people who are sick to help prevent infections. In some cases, your
  • doctor may suggest that you avoid people who are sick until they feel better;
    follow food safety rules.
Medicines to relieve side effects

Sometimes medicine is given after each chemotherapy session to help with delayed side effects, such as nausea, vomiting and diarrhea. These medicines are usually taken by mouth and you may need to do this for a few days after treatment. Your healthcare team will tell you how often to take these supportive medications that will help relieve your symptoms.

Monitoring during chemotherapy

Because chemotherapy affects cells that divide quickly, it is possible that it also affects blood cells because they grow quickly. You will have regular blood tests to check the level of blood cells throughout treatment. A complete blood count (CBC) or other tests could also be done before each chemotherapy session.

A decrease in the number of blood cells indicates that chemotherapy drugs are working. A slight drop in the number of blood cells is usually not harmful. If the number of blood cells remains within the reference values, it is not dangerous to continue giving chemotherapy drugs. However, if the level of any type of blood cell is too low, your doctor may need to adjust the dose or delay treatment for a while.

You may have more blood tests, x-rays or imaging tests to check how well the treatment is working.

Resistance to chemotherapy

Some cancer cells are known to resist chemotherapy by acquiring protective genetic mutations that give them increased resistance to drugs. Certain types of chemotherapy may not be effective in destroying certain types of cancer.

These cancer cells are resistant to treatment. Resistance to chemotherapy may occur early in treatment or it may develop over time. This is why an agent that was effective in destroying cancer cells may cease to be effective. If you develop resistance to a certain type of chemotherapy, your doctor will prescribe a chemotherapy drug or a different treatment.

After chemotherapy

In addition to the safety guidelines, the healthcare team will tell you what to eat or drink and when you can be physically active or return to work. Some people may find that they need more rest for a while after treatment.

Chemotherapy may weaken your immune system. During and shortly after treatment, chemotherapy can change the number of blood cells that help protect the body against disease, infection, and excessive bleeding. Wash your hands often, especially after using the toilet and before preparing food.

Types of Cancer Treatments and Medications: Comprehensive Overview of How They Work

Oral chemotherapy at home

You may have been prescribed oral chemotherapy at home. These are medicines, either as tablets or capsules, to be taken by mouth to treat your cancer.

For your treatment to be as effective as possible, it is important to follow the instructions given to you by your pharmacist.

Make sure you understand:

  • What is the dose to take;
  • When to take each dose;
  • If you have been prescribed more than one medicine, in which order you should take them;
  • What to do if you miss a dose.
  • Take care to store and handle your medications safely.
  • Keep them out of the reach of children and away from light, heat and humidity.
  • Swallow the capsules or tablets whole, without cutting, chewing, or crushing them.
  • Wash your hands immediately after handling them.
  • Return unused medications to the pharmacy for safe disposal.

If you are worried about side effects from your oral chemotherapy at home, talk to your pharmacist or a member of your healthcare team. They can tell you what to expect. It may be helpful to write down how you feel after taking your medicine.

Chemotherapy Drugs Combinations | Chemo Medications: Understanding Medications for Cancer Treatment

Side effects of chemotherapy (immediate effects or short term)

Chemotherapy drugs destroy cancer cells, but they can also damage healthy cells. Damage to healthy cells causes side effects. Different tissues and cells in the body respond to chemotherapy differently. Chemotherapy drugs affect actively growing and dividing cells, such as blood cells in the bone marrow, cells that line the mouth and digestive tract (gastrointestinal tract, GI), and cells in hair follicles.

Regardless of the treatment, it is always possible for some side effects to occur. However, they do not affect all people; if so, not all of them feel the same way. If side effects do occur, they can do so any time during, immediately after, or a few days or even a few weeks after chemotherapy. Sometimes side effects may appear months or years after chemotherapy (late effects). Most go away on their own or can be treated, but some may last a long time or be permanent.

Read also: Long term side effects of cancer treatment (Late effects) for cancer survivors

You may be concerned about the side effects of chemotherapy. However, many types of chemotherapy given today are easier to tolerate than they were in the past. Plus, your healthcare team is there to help prevent and treat side effects. The side effects of chemotherapy depend mainly on the type of medicine used, the dose given, how it is given and your overall health.

The following side effects are those that are most experienced by people who receive chemotherapy. Tell your healthcare team if you have these side effects or any other side effects you think may be from the chemotherapy. The sooner you tell them about any problem, the sooner they can tell you how to help relieve them.

Low number of blood cells

The decrease in the number of blood cells is the result of chemotherapy on the blood cells made in the bone marrow. The number of blood cells often reaches its lowest level 7 to 14 days after chemotherapy. The most common and serious side effect of chemotherapy is a drop in the number of blood cells. When it occurs, the dose is immediately adjusted or treatment is temporarily stopped.

A low number of white blood cells (neutropenia, or leukopenia) increases the risk of infection.
A low number of platelets (thrombocytopenia) increases the risk of bruising and bleeding.
A reduction in the number of red blood cells (anemia) causes fatigue, pallor, dizziness, shortness of breath and feeling unwell.


Fatigue makes a person feel more tired than usual and can interfere with daily activities and sleep. Fatigue can be caused by anemia, specific chemotherapy drugs, poor appetite, or depression. It can also be linked to toxic substances that are produced in the body when cancer cells break down and die. Fatigue can appear in the days following chemotherapy and can last a long time after treatment is finished. It also tends to get worse if you receive other treatments, such as radiation therapy. Usually, fatigue wears off gradually over time.

Fatigue in Cancer: Strategies for Managing Tiredness

Nausea and vomiting

Nausea and vomiting may appear within the first few hours after receiving chemotherapy drugs and usually last about 24 hours. However, nausea and vomiting can also appear more than 24 hours after treatment and last for several days (late nausea and vomiting). In some people, anticipatory nausea may develop after a few sessions, that is, they feel nauseous even before the drug is given because they expect to be sick. The healthcare team can help you relieve nausea and vomiting by prescribing anti-nausea medication.

Not all chemotherapy drugs cause nausea and vomiting. Nausea and vomiting are more likely to occur when taking chemotherapy drugs together.

Loss of appetite

Nausea and vomiting, fatigue, or a buildup of wastes caused by the death of cancer cells can cause loss of appetite. Some chemotherapy drugs may temporarily cause changes in taste and smell, which can make food less appetizing. Some people sometimes don’t feel like eating at all,

Even if they know they have to, which can lead to weight loss and malnutrition. Eating a good diet during and after chemotherapy is important to help you recover from treatment.

Hair loss

Hair loss (alopecia) is a common side effect of many chemotherapy drugs, but not all. The hair follicles are damaged by chemotherapy because the drugs affect cells that are growing rapidly. It is difficult to predict how much body hair and hair you may lose and how long the hair loss will last, as it depends on the type and dose of medication being given and your body.

It can affect any part of the body, not just the head. You can start to lose hair and hair within a few days or 2 to 3 weeks after the first dose of chemotherapy is given. Hair and small hair usually grow back after you finish chemotherapy. Tips: you can try and buy a wig, head or hair accessory before you start your chemo.


Diarrhea is the frequent passing of loose, watery stools. It happens because chemotherapy drugs often affect the cells that line the digestive tract (gastrointestinal tract, GI). There are many factors that increase your risk of developing diarrhea, including the type and dose of chemotherapy drug given. Diarrhea is often more severe when chemotherapy drugs are used. It starts soon after you start chemotherapy and is likely to last for up to 2 weeks after treatment.


It occurs when the stool becomes hard and dry and it is difficult to pass. Constipation can happen for many reasons, including the type of chemotherapy drug used, drugs given during chemotherapy to relieve nausea and vomiting, and less fluid intake. Constipation tends to appear a few days after the first dose of chemotherapy is given.

Pain in the mouth

Pain in the mouth (also called oral stomatitis or mucositis) is the result of chemotherapy on cells in the mouth. Many medicines can make your mouth sore, but this is more common with high doses. Your mouth may become sore 5 to 10 days after starting chemotherapy. It often resolves on its own a few weeks after treatment.

You may have painful sores, ulcers, or infections in your mouth, throat, or on your gums. Regular oral hygiene can help prevent pain and reduce the risk of infection. The healthcare team will tell you how often to clean and rinse your mouth and what products to use. Some people may need to take pain relievers.

Inflammation of the mucous membranes

The mucous membranes line many organs in the body, such as the mouth, rectum, and vagina. Chemotherapy can damage cells in the mucous membranes which eventually become inflamed, a condition called mucositis. This can cause painful ulcers, bleeding and infections. Mucositis is usually temporary and goes away a few weeks after treatment.

Any difficulty or pain upon swallowing, heartburn, or pain in the upper abdomen should be reported to the doctor or healthcare team. Pain caused by inflammation of the esophagus (esophagitis) can affect how much you eat. You may need to change your diet or take pain relievers if you have difficulty swallowing or experience pain when swallowing.

Itching, discharge, odor, pain or bleeding from the vagina should be reported to the doctor or healthcare team. You can relieve vaginal pain and itching by applying cool compresses or taking a lukewarm bath. Avoid using scented tampons or sanitary napkins. If you have a vaginal infection or severe pain, your doctor may prescribe medicines to help relieve it.

Changes in taste and smell

Some chemotherapy drugs can affect the taste buds and thus cause taste changes. For example, you might find that meat has a metallic taste. Even foods that you normally crave, like sweets or salty snacks, can taste bad. You may become more sensitive to smells. Smells that others don’t notice can make you nauseous. It may take several months before. Do not let taste and smell return to normal after chemotherapy is finished.

Skin changes

Some medications can cause skin problems or skin irritation. Skin changes can occur during chemotherapy and for some time afterwards. Skin reactions that can occur include redness, itching, dryness, rashes, or changes to the nails.

The skin may also be more sensitive or irritate easily in the sun during chemotherapy.

Nail modification

Nails may gradually become brittle, ridged or dark. This phenomenon is not serious. They return to the same as before when the treatment is stopped.

Eye vision changes

Some chemotherapy drugs can cause changes in the eyes, such as slightly blurred vision, tearing of the eyes, or making it difficult to wear contact lenses. Tell your doctor or healthcare team if you notice any changes in your eyes.


Some chemotherapy drugs can cause painful side effects, such as muscle and joint pain, headaches, and upset stomach. You may experience pain, such as a burning sensation, numbness, tingling, or shooting pain in your hands and feet (damage to peripheral nerves). This type of pain can continue long after treatment is finished. The healthcare team will tell you which medicines to use for pain relief.

Pain is a common side effect of cancer and its treatments, but having cancer doesn’t mean you have to live with the pain. Treating pain is part of your overall treatment plan. Talking about your pain helps your healthcare team understand it and find ways to control it.

It is important to treat cancer pain because it can affect you both physically and emotionally. It may interfere with healing and cause fatigue, loss of appetite and trouble sleeping. Dealing with pain also requires the energy you need to get better and to carry out your normal daily activities.

Pain at the injection site

Many chemotherapy drugs are given by injection, usually into a vein (intravenously, or IV). Inserting the needle or catheter into the vein may cause some discomfort or pain. But you probably won’t feel any pain or discomfort when you are given the drugs intravenously.

There is a small risk that the chemotherapy drugs will leak from a vein and pass into nearby tissue. This is called extravasation. Some chemotherapy drugs irritate the tissues; these drugs are called blisters. In some cases, chemotherapy drugs that leak from a vein can cause significant damage to the skin and nearby soft tissues. Your healthcare team will monitor you for any signs of extravasation. Tell your healthcare team if you notice any redness, swelling, pain, or a burning or tingling sensation at the injection site.

Inflammation of a vein

An intravenous (IV) needle or catheter can cause inflammation of a vein, a condition called phlebitis. The area around the insertion site or along the vein may become red, hot, tender or painful and swollen. The risk of phlebitis increases depending on the following factors:

  • time that the needle or IV catheter remains in place
  • type of medication or solution given
  • size and location of the needle or catheter

Nurses often check intravenous access for any sign of phlebitis. In the presence of phlebitis, the needle or IV catheter is usually removed and placed elsewhere. You may be given warm, moist compresses to help reduce inflammation.

Hearing impairment

Some types of chemotherapy drugs can damage the inner ear, causing hearing loss or disturbance of balance. These effects usually go away after treatment, but your doctor may reduce the dose of chemotherapy or change your treatment to prevent further hearing damage from occurring.

Organ damage

Some chemotherapy drugs can cause organ damage. The healthcare team takes precautions to limit damage to healthy cells, but sometimes organs are damaged. Organs that canbe affected by chemotherapy include the following:

  • heart
  • lungs
  • liver
  • kidneys
  • bladder
  • female reproductive system
  • male reproductive system
  • reproductive organs
  • nervous system, including damage to peripheral nerves

Some types of organ damage appear later than others. For example, some types of chemotherapy drugs increase the risk of developing heart and lung problems later in life, years after chemotherapy is given.

Changes in thinking and memory

Chemotherapy can make it difficult for you to think clearly or concentrate. This is often referred to as a “chemo-brain”. This effect may go away after chemotherapy is finished or last for up to a year after treatment. Sometimes it can also show up well after chemotherapy. Your healthcare team can suggest ways to improve your focus and reduce changes in your memory. She can suggest cognitive exercises to help improve memory and concentration.

Sexual and fertility disorders

Chemotherapy can make you feel tired and affect your sexual interest. It can also damage reproductive organs and cause fertility problems. A woman may also experience menopause caused by the treatment.

If preserving your fertility is important to you, talk to your doctor before starting treatment. There may be ways to protect your reproductive organs during treatment, making it possible to become pregnant or make someone else pregnant after treatment.

Secondary cancers

Some types of chemotherapy drugs increase the risk of secondary cancer, but this does not happen very often. People who have received chemotherapy as well as radiation therapy are at greatest risk of developing secondary cancer. The benefits of cancer treatment usually far outweigh the risk of developing a secondary cancer. If secondary cancer does show up, it tends to do so later in life.

Note: Other side effects can occur. For more details on specific medications, please consult your doctor.

Long term side effects of cancer treatment (Late effects) for cancer survivors

Chemotherapy and other drug treatments

Drug treatments work in different ways to destroy cancer cells, stop them from spreading, or slow down their growth. Medicines used to treat cancer are also called anti-cancer medicines or anti-cancer agents. Medicines can also be used to reduce or relieve the side effects of cancer or its treatment.

  • Chemotherapy, sometimes called chemo, destroys cancer cells or slows their growth. In some cases, only one chemotherapeutic agent is administered at a time. But in most cases, several chemotherapy drugs are combined to destroy cancer cells.
  • Hormone therapy slows the growth of cancers such as breast, prostate and uterine cancers that use natural sex hormones (such as estrogen, progesterone and testosterone) to develop. Hormone therapy stops cancer cells from using the hormones they need to grow, or stops the body from making the hormone that causes cancer to grow.
  • Immunotherapy helps strengthen or restore the immune system’s ability to fight cancer.
  • Targeted therapy uses drugs to target specific molecules, such as genes or proteins, in cancer cells to stop their growth and spread. This means that by targeting cancer cells, these drugs do not damage many normal cells.
  • Supportive drugs prevent, control or relieve side effects caused by cancer or cancer treatments. Bisphosphonates, for example, help strengthen bones and protect them from the effects of certain cancers and their treatment.

Sometimes the only treatment to be given is drug treatment. You may receive only one type of drug treatment or a combination of treatments.

Most drug treatments used to treat cancer are systemic. This means that the drugs circulate in the blood and can attack cancer cells almost anywhere in the body.

Goals of drug treatment

As part of your treatment plan, drug therapy may be used in the following ways:

  • Can help cure cancer by destroying all cancer cells and reducing the risk of the cancer coming back.
  • Can be aimed at controlling cancer by stopping the growth and spread of cancer cells or by destroying cancer cells that have spread to other parts of the body.
  • Can help prevent the growth or spread of new cancer cells.
  • Can help relieve the symptoms of cancer and help you feel more comfortable when a cure from cancer is not possible.

How and when to administer medication

The drug treatment used to treat cancer can be given alone or in combination with other treatments.

Drug therapy may be used as adjuvant therapy. This means that the drug treatment is given in addition to the first-line treatment. The drugs aim to destroy any cancerous cells that are still in the body after surgery or radiation therapy and help reduce the risk of the cancer coming back (recurring).

Sometimes drug therapy is given as a neoadjuvant therapy. It thus makes it possible to reduce the size of the tumor before the first-line treatment. Reducing the size of the tumor makes it easier to remove it with surgery or to treat it with radiation therapy.

When a drug treatment is given at the same time as other treatments, we are talking about concomitant treatments. For example, certain chemotherapeutic agents can be administered during the same period as radiotherapy. This can help make cancer cells more sensitive to radiation.

Drug treatment can be used to control the cancer if a cure is not possible. The first drug or combination of drugs used to control cancer is called the first-line treatment, which may be followed by other treatments called second-line later.

In some cases, drug therapy alone may be used to try to cure the cancer; in this situation, it is said to be a definitive or primary treatment.

Chemotherapy Drugs Combinations | Chemo Medications: Understanding Medications for Cancer Treatment

Decide which drugs to use

Chemotherapy drugs and other drugs used to treat cancer are prescribed by a medical oncologist. Your doctor will discuss with you which chemotherapy drugs are most likely to work, and decide on the dose, how to give it and how long to take it.

Treatment plans for chemotherapy and other drug treatments, called protocols, depend on the following:

  • type of cancer
  • stage of cancer
  • your age
  • your overall health and if you have any other health problems (such as heart, liver or kidney disease)
  • types of cancer treatments you have already received or are planned
  • your preference


Chemotherapy drugs and other drugs used to treat cancer may not destroy all cancer cells the first time they are given. Some cancer cells can survive and continue to grow. Chemotherapy and other drug treatments are given according to a set plan, or protocol, to kill as many cancer cells as possible.

Chemotherapy and other drug treatments are often repeated and usually given at regular intervals called cycles. Each cycle of these drugs is usually followed by a period of rest, for example several days or weeks, during which no treatment is given. The rest period allows normal cells to recover.

Administration mode

The duration of chemotherapy or other drug treatments, the schedule followed and the number of cycles given depend on the combination of drugs used and the type of cancer. The medical oncologist usually determines how to administer it when treatment is started. It may also do this later, depending on how well the medicine is working and your body’s ability to tolerate it.

Chemotherapy is given for about 3 to 6 months when the goal is to cure the cancer. Chemotherapy may be used for a longer period of time when it is used to relieve or control the symptoms of advanced cancer (palliative chemotherapy). Hormone therapy or targeted therapy can be given for longer periods of time.

Dose calculation

Doctors calculate drug doses in different ways, depending on the drug (s) to be administered. The overall dose is usually determined based on a person’s body surface area, calculated based on their height and weight, and expressed in square meters. For some drugs, the dose is calculated by taking into account only the person’s weight expressed in kilograms.

The bodies of children and some adults process drugs differently, and their sensitivity thresholds may be different. After taking body surface area into consideration, a doctor may change the doses for children and some adults.

The doses of some medicines may be adjusted in people:
  • elderly
  • not consuming the recommended amount of calories and nutrients
  • obese
  • taking or having taken other medications
  • needing or having already received radiation therapy
  • have low blood cell counts
  • have liver or kidney disease

Chemotherapy and other drug treatments used to treat cancer are given in doses high enough to destroy cancer cells and cure or control the disease, while minimizing side effects.

Dose limitation

The use of very large doses of drugs can cause serious side effects and thus limit the amount of chemotherapeutic agents that can be given (dose limiting factor). From time to time the doctor may adjust the treatment to help you recover.

Maximum dose

Chemotherapy may be used again if the cancer comes back (comes back). However, some medicines are limited in the total amount that can be given (maximum total dose for the entire lifetime) because they can affect organs such as the heart or lungs. Once you have received this maximum dose, it is not possible to use this medicine again.

How the drugs are administered

Most drugs used to treat cancer are given by injection into a vein (intravenously, or IV) or by mouth (oral). Some medicines are given by injection into an artery or parts of the body, such as a body cavity or the fluid around the spinal cord.

List of all Cancers

The word “cancer” is a generic term for a large group of diseases that can affect any part of the body. We also speak of malignant tumors or neoplasms. One of the hallmarks of cancer is the rapid multiplication of abnormal growing cells, which can invade nearby parts of the body and then migrate to other organs. This is called metastasis, which is the main cause of death from cancer. Types of cancer (in alphabetical order of the area concerned):

Types of Cancer | List all of Cancers | Adult, Children, Head and neck, Digestive and Types of Blood Cancer

Diseases | List of Diseases: dermatological, cardiovascular, respiratory, cancer, eye, genetic, infectious, mental illness, rare

Information: Cleverly Smart is not a substitute for a doctor. Always consult a doctor to treat your health condition.

Sources: PinterPandai, NHS UK, Cancer, Mayo ClinicOncovia

Photo credit: Pacific Air Force

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