Different treatment methods exist each with their own advantage and disadvantages. As we go through the different methods, we will also list their side effects but keep in mind that side effects depends on the individual: Some people might get none, others few while some will have the whole hell loose on them. In others the same side effects will be mild while for others it can be very severe and might even lead to further complications. Under this section, we will look at 7 treatment method; Chemotherapy, Targeted therapy or Molecular Targeted therapy, Surgery, radiation therapy or radiotherapy, Hormone therapy, Immunotherapy, and Clinical Trials. Under immunotherapy, we will also look at the so called cancer vaccines.
This method uses a drug or chemical to target rapidly dividing cells by obstructing several processes such as DNA replication, protein folding and unfolding, obstruction of metabolic pathway etc. Chemotherapeutic drugs have no specific target and hence usually attack normal cells as well. But because cancer cells divide more rapidly than normal cells, they will be killed faster than normal cells. A selectivity index (SI) is usually used to determine the effectiveness or potential of a chemotherapeutic drug. SI = 10 for example will mean the drug can kill 10 cancer cells before it will kill 1 normal cell. Therefore the higher the Selectivity Index the better. Because normal cells are also attacked, chemotherapeutic drugs results to severe side effects or toxicity and can even cause death of the patient. Besides different drugs have different side effects and no single drug results to all possible side effects, it is good practice to therefore always inquire from your doctor about the side effects of your drug. Note however that in chemotherapy one or more drugs may be used simultaneously as judge suitable by your doctor. Another disadvantage to chemotherapy is that they are not active against all cancer type, will not always destroy all the cancer cells and usually induce drug resistance to cell.
Side effects and complications of chemotherapy
Side effects and complications commonly encountered during chmotherpy treatment include:
- Hair loss
- Mouth sores
- Loss of appetite
- Easy bruising
- Suppression of the immune system
- Damage to organs such as heart, kidney, liver and lungs
- Damage to nerves
- A second cancer type may emerge
- May results to abnormal development during pregnancy
Aim of Chemotherapy
Chemotherapy can be used to achieve different goals and usually administered under 4 major settings.
- As the primary or only form of treatment
- To get you ready for other treatments such as surgery or radiation. This approach is called neoadjuvant therapy Here the drug may help for example to reduce or shrink the tumor in order to increase the success rate with other treatment types.
- To reduce signs and symptoms associated with a given cancer, by killing some of the cells. This approach is called palliative chemotherapy. It’s done with no curative intent but rather to help improve your quality of life, or increase your life expectancy.
- To kill any hidden cancer cell that might have survived or escape during other treatments such as surgery. This approach is called adjuvant therapy.
Targeted Therapy or molecular Targeted Therapy
Unlike chemotherapeutic drugs, targeted therapies are a class of drugs (small molecules, antibodies or a combination of both) which target specific processes or molecules involved in carcinogenesis and tumor growth. Because they are specific, more cancer cells are killed by far compared to normal cells and many of the side-effects observed with chemotherapy will be absent although severe side-effects have been observed in some cases. Targeted therapy is not widely used because targeted therapy is extremely expensive. Secondly the specific target of the targeted therapy could undergo mutation or the cancer can find a different way of surviving which does not depend on this target. Either case will render treatment completely useless. If target has changed, then unnecessary side effects are likely to be observed. It is therefore good for your doctor to ensure that the specific target of the drug you are receiving be it a gene, protein or the tissue environment of the cancer hasn’t undergone mutation or alteration.
Uses and limitations of targeted therapy in cancer treatment
The following is true for targeted therapy:
- Targeted therapy can be optimized for a specific patient.
- There aren’t drugs for every cancer target. Drugs against certain cancer target are very difficult to develop.
- Targeted therapies can be cytostatic in that they simply inhibit the proliferation of the cancerous tumor but don’t necessarily kill it.
- Targeted therapies can be used in combination with other treatment type such as chemotherapy.
Side Effects of Targeted Therapy
Side effects are also observed with targeted therapy although less compared with chemotherapy. These include but not limited to:
- High blood pressure
- Impaired blood clotting and wound healing: Notify your doctor immediately you notice black stool or blood in your stool and whenever you vomit blood or anything that looks dark red, brown or black.
- Swell in certain parts of the body such as face, legs, feet and hands.
- Immune suppression or autoimmunity
- Heart damage: May manifest as chest pain, difficulties breathing, intense coughing, swelling in the ankles or leg, dizziness, fainting and rapid weight gain.
- Liver problems such as hepatitis and elevated level of liver enzymes
- Skin problems such as dry skin, rashes, hair depigmentation, nail changes
- Gastrointestinal perforation: This may be associated with severe abdominal pain, fever, increase breathing, increase heart rate and even confusion.
Most side effects associated with chemotherapy may also be observed in targeted therapy.
It’s usually one of the first options for cancer treatment especially when the primary tumor is localized (still in its site of origin). The success of surgery in the treatment of cancer will depend on the type of cancer, its size, its stage, its distribution, and location. Other factors such as age, presence of other illnesses or physical fitness of patient also determines success outcome.
How Surgery is used to Treat Cancer
Surgery can be used in different ways during cancer and its treatment
- To prevent cancer or lower the risk of developing cancer (Preventive or Prophylactic Surgery).
Here the surgeon searches for precancerous conditions in tissues. Tissues with high probability or risk of developing into cancer are carefully removed. This is usually the case with people having genetic predisposition to cancer such as an inherited disease or people with certain infections. Very large amounts of tissues or even an entire organ can be removed if necessary to prevent cancer.
- To diagnose and determine the stage of cancer.
Here a surgeon extracts a cell or tissue sample from the patient’s body and studies it under a microscope. From the studies, he/she can determine the follow:
- If the cell or tissue is cancerous
- The type of cancer
- The extent or stage of the cancer
- If any of the neighboring tissues have also become cancerous
Based on the surgeon’s findings, a proper treatment plan will then be developed for the patient.
- To relieve cancer symptoms
Cancer causes obstructions or blockage in certain parts of the body such as the intestines or bile duct. This can be associated with severe pain or pressure. Surgery in this case will help to open up such obstructions or to create a bypass around the blockage in order to relieve symptoms and hence improve your quality of life. Such surgeries are not meant to cure you of cancer.
- To support other treatments
Here the surgeon provides direct access to a blood vessel to facilitate blood sampling or other treatments such as chemotherapy and antibiotics. Direct access may involve the placement of a central venous catheter.
- To support other body functions
Cancer can cause obstructions or blockages in certain organs therefore impair their functions. For people who have difficulties eating or drinking for example, the surgeon will create an opening through the abdominal wall into the stomach and place a tube directly there. An opening through the neck into the trachea may also be done to aid breathing.
- Treat cancer and lower its chances of reoccurrence
This can take several forms
Complete removal of the cancer cells: Surgery becomes very effective when the tumor is still localized and at its early stage. However, surgery may also be used to treat metastatic cancer (cancer that has started to spread from where it all started). In a typical surgery procedure, the surgeon will also remove a certain quantity of normal tissues in the vicinity of the cancer (usually called the surgical margin). Lymph nodes in the vicinity of the cancer that are infected with cancer cells are also removed completely. A radical surgery can result even to the removal of an entire organ. All these is done make sure no cancer cells are left behind or will have the capacity to spread to other parts of the body. It also decreases the chances of reoccurrence.
To reduce the size of the cancers (cytoreductive surgery): Some tumors are too big and can’t be completely removed through surgery or their complete removal through surgery might cause more harm than good. Here the surgeon will aim at removing as much of the cancerous cells as possible. This will precede and help to increase the effectiveness of other treatments such as chemotherapy or radiotherapy.
Combination therapy: To lower the risk of reoccurrence and increase treatment outcome, surgery is usually undertaken with other forms of therapy. In neoadjuvant therapy, chemotherapy and/or radiotherapy is used to shrink the tumor so that surgery can be easier. In adjuvant therapy however, chemotherapy and/or radiotherapy is given after surgery to destroy any cancer cell that was left behind or too small to be seen and to kill any cancer cell which might have spread to other body parts.
- To help repair damaged tissues
Tissues damaged by cancer, or its treatment are usually repaired through surgery. It is called reconstructive or plastic surgery and will help the body to regain its appearance or function before it was infected with cancer. It may be done immediately or at a later stage following treatment. It uses either the patient’s own tissues or materials called silicon.
Surgery can be open or less invasive. In open surgery, the surgeon makes one large cut through the body to remove the cancer. In less invasive approaches however, the surgeon makes small cuts or incision through the body. Such an approach speeds up recovery and decreases side effects or damage that might arise. Examples of less invasive surgeries include laparoscopic surgery, laser surgery, and cryosurgery.
Surgery may not be useful under the following circumstances:
- If the tumor is very small and cannot be detected visually by the surgeon nor through laboratory examinations
- If the location of the tumor could make surgery impossible as attempts could result to damage to other body organs.
- The patient’s general health conditions could render surgery very risky
Side effects of surgery
The nature and extent of the side effects will vary from person to person based on the person’s general health, type of surgery performed, the type and location of the cancer and other forms of treatment patient has undergone before surgery. Common side effects however will involve the following:
- Loss of appetite
Radiation Therapy (Radiotherapy)
What is radiation?
Radiation is energy that is moving through space or through a material medium and takes several forms such as infrared, x-ray, gamma, ultrasound radiation etc. Depending on the amount of energy it carries, radiation can either be classified as ionizing or non-ionizing. Ionizing radiations such as x-ray are very dangerous to the human health. Low levels of radiation called background radiation are everywhere and can be emitted naturally by the rocks, soil, sun and animals. Background radiation is not dangerous, medium levels can cause discomforts such as headache, fever and vomiting but high levels of radiation can kill by causing damage to cells. Radiation may also be produced artificially and use for medical purposes. An example of such is x-ray which is use for medical imaging.
How does radiotherapy work?
The use of radiotherapy just like chemotherapy is based on the principle that cancer cells divide faster than normal cells and as such they will be destroyed faster. Normal cells can recover from radiation faster than cancer cells but damage to normal cells always leads to side-effects. In radiotherapy, care is taken to make sure normal cells are not damaged beyond a point where they cannot recover from the radiation.
Radiotherapy uses high doses of ionizing radiations to kill cancer cells completely as the only form of treatment, to shrink cancer cells before another treatment, to destroy any remaining cells after another treatment or in combination with other treatments such as chemotherapy, surgery or hormone therapy. Radiotherapy is a continuous treatment and will not cause cancer cells to die immediately. Death of cancer cells occurs after days or weeks when they must have suffered sufficient damage.
External and internal radiotherapy
In external radiation therapy also called external beam radiation therapy, a machine is used to direct a beam of radiation to the cancer cells. In internal radiotherapy, a radioactive substance is placed directly inside your body. The radioactive substances can either be solid or liquid. When a solid radiation source is used (brachytherapy), it is placed in or around the cancerous tumour. When the radiation source is a liquid (systemic radiation therapy), it is given orally or intravenously and will move through your blood and tissues killing cancerous cells. Which one will be used between external or internal radiotherapy will depend on the type of cancer, its stage, size and location, your general health conditions, and on other treatment plans you will follow.
Side effects of radiotherapy
Side effects with radiotherapy will depend on the individual receiving the treatment, the duration of the treatment, the radiation dose applied and the part of the body where the radiation is being applied. Generally, you will experience fatigue, hair loss, lymphedema and skin reactions. For other side effects, discuss with your doctor based on your treatment. Note that side effects with radiotherapy may be immediate, later or even after several years.
What are hormones?
Hormones are chemical messengers secreted directly into the blood stream by glands where they travel to exert or carryout their functions. Only cells with receptors to the secreted hormones will respond to its signal. Hormones regulate and coordinate complexes processes within the body such as growth and development, metabolism and behavior. They are released in response to a signal from the brain.
How does hormone therapy works and what is the principle behind its use?
Some cancer cells take advantage of the body’s own hormones to grow. Examples of such cancers are prostate, breast, endometrial and thyroid cancer. Hormone therapy therefore aims to block these hormones or stop their production or interfere with their function and by so doing cancer cell growth is slowed down or inhibited completely. Hormone therapy is also called endocrine therapy. It may be regarded as a form of targeted therapy and treatment is usually personalized to the patient being treated. Most hormone therapies last for a very long time and in some cases throughout the patient’s life.
Inhibiting or altering hormones level in the body may be accomplished in one of the following ways:
- Removal of the glands or organs that produce the hormone. This may be achieved through surgery.
- Bombarding hormone producing glands or organs with radiation in order to destroy the hormone producing cells.
- Using drugs which suppress hormone producing cells or which work against a hormone and/or his effect in the body.
When is hormone therapy used?
- To shrink tumour before surgery or radiotherapy (neoadjuvant therapy).
- Decreases the risk of reoccurrence of the cancer cell following a main treatment. It does so by slowing down or stopping growth of the cancer cell (adjuvant therapy).
- To reduce symptoms or prevent symptoms (palliative chemotherapy)
- To destroy any remaining cancer cells that might have escaped to other body parts
Side effects of hormone therapy
Hormone therapy involves blocking the production of vital hormones or interfering with their function. It therefore comes as no surprise that unwanted side effects will be observed. Side effects will depend on the type of hormone which is being affected, whether you are a male or female and on the patient’s general health conditions. Generally fatigue and nausea will be experienced. For more specific symptoms, talk to your healthcare team.
What is the immune system?
It is the defense system the body has put in place to fight pathogens or anything foreign such as bacteria or virus. Immunodeficiency occurs when the immune system is comprised and does not work properly anymore. Immunodeficiency will expose your body to all kinds of diseases and illnesses. This is how the HIV virus kills his host. The immune system will also destroy any normal cell that is misbehaving such as cancer cells. But cancer cells usually have ways to hide away from the immune system or weaken it such that it does not work properly. Immunotherapy essential aims to restore or enhance the immune system so that they can better destroy the cancer cells.
The role of immunotherapy in cancer treatment
Immunotherapy will achieve the following outcomes during cancer treatment
- Slows down or completely inhibit cancer cell growth
- Boost the immune system so that it can better destroy cancer cells
- Prevent cancer cells from reaching other body parts
- Monoclonal antibodies
When the immune system recognizes a substances as foreign or harmful, it produces blood proteins called antibodies which will then go on to destroy the harmful substances. Monoclonal antibodies are laboratory produced antibodies that bind to specific markers (antigen) on the surface of cancer cells. Once they bind, they trigger a set of reactions which will eventually kill the cancer cell.
Radioactive substances may also be attached to monoclonal antibodies such that when they bind to antigens on the surface of the cancer cells, they will release radiation that will kill the cancer cell. Such monoclonal antibodies are called conjugated monoclonal antibodies and when they are attached to radioactive substances, the treatment is called radioimmunotherapy.
- Immune checkpoint inhibitors
The immune system uses proteins called checkpoint proteins located on the surface of immune cells (e.g. T-cells) to differentiate between normal and abnormal cells. Cancer cells have the ability to send fraudulent signals to the immune cells to turn on the checkpoint proteins. When this happens the immune system gets confuse and consider cancer cells to be normal cells and as such it would not kill the cancer cells. Immune checkpoint inhibitors are drugs which work by blocking or turning off checkpoint proteins. When this happens, the cancer cells will now be exposed and the immune system will deal with them accordingly.
- Immunomodulating agents
These are drugs which boost or enhance the way the immune system’s ability to responds against cancer. They are used during advanced cancer treatment and to manage side effects. Examples of immunomodulating agents are interleukin 2 (IL-2), interferon alpha (INF-alpha) and cytokins.
- Cancer vaccines
A vaccine is a substances or medicine that protects the body against any disease or pathogen. It does so by training the immune system how to fight the disease or pathogen. Once that pathogen or disease enters your body, the immune system (now well trained against it) will act swiftly to take it out before the disease or pathogen have time to established itself. This is however possible only if you take the vaccine before the pathogen gets to you. Otherwise the pathogen may outsmart your immune system.
Cancer vaccines are substances that train your body to fight cancer. But they do not do so directly. They either attack any pathogen (or substances) that may cause cancer or enhance the immune system to better differentiate between normal cells and cancer cells. Based on this, there are 2 types of cancer vaccines:
Preventive vaccines: Protects you from viruses that cause cancer. Examples include; HPV vaccine which protects against the human papilloma virus (HPV). This virus have been reported to cause anal cancer, cervical cancer, vaginal cancer and vulvar cancer; Hepatitis B vaccine which protects against the hepatitis B virus (HBV). This virus has been reported to cause liver cancer.
Treatment vaccines: It is given to patients who have already test positive for cancer. It tries to kill the cancer directly and not by attacking something that is responsible for causing the cancer. It does so by stimulating and boosting the immune system for it to better distinguish between normal and cancer cells and for it to better kill cancer cells. An example of a treatment vaccine is sipuleucel-T used to treat metastatic (or advanced) prostate cancer.
Side effects of immunotherapy
Because immunotherapy involves manipulation of the immune system, the immune cells could sometimes mistakenly attack normal cells. If normal cells are attacked, then side effects are evident. Side effects will off course depend on several factors such as the patient general health condition, cancer type or the type of immunotherapy used. However, common symptoms such as nausea, fatigue and flu-like symptoms are usually seen. Speak to your healthcare team about any possible side effect based on your situation.
These are research studies which investigate how cancer can be prevented, diagnose and treated. It may also be used to investigate how to manage cancer symptoms, improve quality of life or compare current treatment with a new approach. Clinical trials are available for very type or stage of cancer. Clinical trials exist in different stages and represent a process through which a drug or process developed in the lab will eventually become usable in humans. Usually clinical trial may be your last option as no drug or treatment might be available for your disease. Your doctor will help you determine if you need clinical trial and will also help you find one. Note that taking part in clinical trial is purely the patient choice and it might either work or not.