A combination of medications, known as chemotherapy, is used to treat some cancers. These medications work by attacking certain rapidly dividing cells, or by preventing cells from growing and dividing. Because the body is made up of many types of cells, and treatments can’t differentiate between cancer cells and healthy cells, chemotherapy harms or kills healthy cells, as well as cancer cells.
It is the treatment’s impact on healthy cells that causes the side effects of chemotherapy. These effects may include anemia, nausea, a weakened immune system, and hair loss. Not everyone reacts the same way to treatment so these effects vary from patient to patient. Knowing what’s happening in your body during chemotherapy helps you to understand the side effects experienced during treatment.
The main types of healthy cells that chemotherapy impacts are red blood cells, white blood cells, and platelets, hair cells, and cells that make up the mucus membranes of the mouth, throat, and digestive system. The damage that chemotherapy causes to these cells can lead to certain side effects. Here are five common side effects and why they occur.
Your body delivers oxygen to your body from the lungs with red blood cells. Anemia occurs when chemotherapy harms the cells, lowering red blood cell counts. Symptoms are tiredness and weakness but it can also cause an irregular heartbeat, shortness of breath, dizziness, cold hands or feet, and headaches. Your cancer care team will monitor your blood carefully and may recommend treatment with an iron-rich diet, iron supplements, and in some cases, blood transfusions.
A component of the blood involved in clotting called platelets is sometimes affected. Cancers also predispose you to develop blood clots in different parts of the body, like the calf or lung. This can manifest with symptoms such as leg swelling and pain and unexplained shortness of breath. Please notify your provider if you have any of these symptoms so appropriate tests can be performed and treatment can be provided.
Many chemotherapies target rapidly dividing cells, and with those medications, hair loss is a side effect. Not all types of chemotherapy cause hair loss, when it does hair usually grows back after treatment stops.
When chemotherapy lowers white blood cell counts, the immune system can be compromised. Risk of infection increases and it’s harder for the immune system to fight off viruses, bacteria, and other pathogens. This means the risk of infection is high. Wearing a mask, washing your hands regularly, avoiding crowded places and people who may be sick are key. Careful food preparation and cooking reduces the risk of food-borne pathogens.
Chemotherapy medications can cause nausea and vomiting. Preventing nausea before it starts is part of our care and effective drugs are available to prevent this side effect.
Chemotherapy can also cause mouth sores and diarrhea by killing the cells that line our mouth and gut. Medication, good oral hygiene, regular dental exams and not smoking may help prevent mouth sores.
Diarrhea can also be treated by using medications that reduce the frequency of bowel movements and maintaining adequate hydration. Similarly, many cancer medications can result in constipation that can also be effectively treated with dietary modifications and medication.
Most side effects are short-term and treatable. Our cancer care team will monitor your health with regular testing. Medications, dietary changes, and complementary therapies are effective treatment options recommended by experienced staff. The side effects caused by chemotherapy medications are usually short term in duration and go away or diminish after treatment has stopped.
Patient Centered Care Makes Your Preferences Central to Your Care
For patients and their physicians, the goal of chemotherapy depends on the type of cancer, its location, and a person’s unique circumstances. It is often just one part of a patient’s treatment plan along with radiation therapy, cancer surgery, or additional medications.
Through respect for patient preferences, the sharing of information and education, and the integration of care, a specific goal is set from the three main categories of chemotherapy treatment:
- Curative – Patient treatment attempts to destroy or remove all cancer; the patient becomes cancer-free.
- Adjuvant or neoadjuvant - Targeting cancer that remains following surgery or attempts to shrink cancerous growths prior to surgery.
- Palliative - When cancer cells can’t be eliminated, treatment focuses on relieving symptoms or slowing cancer growth.
The immune system, with organs and tissue, fights off the common cold as well as serious disease including cancer. Harnessing the body’s immune system to fight cancer cells, immunotherapy is a type of treatment offered at SSM Health Cancer Care for certain cancers. Human cells that develop into cancerous cells are not foreign to the body the way a virus is, so science is used to help the immune system identify them. There are a number of ways.
A group of immune cells referred to as T cells seek out foreign invaders identified by your immune system and destroy them. In T-cell therapy these cells are retrieved from the patient and tested in a lab to identify those cells most responsive to cancer cells. Grown in large quantities in a lab, these T cells are then injected back into the body. Specifically, a type of T-cell therapy called CAR -cell therapy, adds a modification to extracted T cells by adding a receptor to their surface. These modified T cells better recognize and destroy cancer cells when they’re reintroduced into your body.
CAR T-cell therapy is currently being used to treat several types of cancer, such as adult non-Hodgkin’s lymphoma and childhood acute lymphoblastic leukemia. Clinical trials are in progress to determine how T-cell therapies might be able to treat other types of cancer.
B cells, another type of immune cell, produce antibodies that recognize specific targets called antigens and bind to them. Once an antibody binds to an antigen, another type of immune cell, the T-cell, can find and destroy the target cell.
During Monoclonal antibody based immunotherapy, monoclonal antibodies designed to target cancer specific antigens are infused or injected into the body. These antibodies than allow the T-cells to kill the cancer target.
There are many types of monoclonal antibodies that have been developed for cancer therapy. Some examples include:
- Rituximab - used to treat non-Hodgkin’s lymphoma.
- Ado-trastuzumab emtansine - used to treat some types of breast cancer.
- Blinatumomab - used to treat acute lymphocytic leukemia.
Like vaccines for childhood diseases there are now vaccines that protect against certain types of cancer. The Human Papilloma Virus (HPV) can cause a number of cancers including cervical cancer, oral cancer and others of the head and neck, penile cancer and others. Gardasil, Gardasil9, and Cervarix are vaccines given by primary care physicians to patients as young as age nine to block the HPV from being sexually transmitted and preventing cancer.
Provenge (Sipuleucel-T) is the only vaccine currently approved to treat cancer. Used to treat advanced prostate cancer that hasn’t responded to other treatments the vaccine is unique because it’s a customized to the patient. Immune cells are retrieved from the patient, modified in a lab to recognize prostate cancer cells, and injected back into the body. These cells help the immune system find and destroy cancer cells.
Immune Checkpoint Inhibitors
Immune checkpoint inhibitors represent a class of revolutionary cancer drugs. The immune system is designed to detect and eliminate foreign cells. To make sure the immune system does not attack normal cells, these cells have brakes called immune check points. These breaks shut down the immune response after the foreign cell has been killed. In many cancers, these breaks can prevent our immune cells from attacking the cancer cells. Immune checkpoint inhibitors are drugs that take the breaks off so the immune cells can now attack the cancer cells.
Another form of therapy that researchers are studying is the use of certain viruses to destroy cancer cells. Only one form of virotherapy is currently used. T-VEC (talimogene laherparepvec) is a modified herpes virus used to treat melanoma skin cancer that can’t be surgically removed.
Hormone therapy blocks production of specific hormones with medication. By blocking hormones, growth of some of cancers is inhibited. Hormone therapy is used to treat breast cancer, prostate cancer, and uterine cancer and to improve outcomes in lung cancer treatment.
Gene Therapy & Gene Editing
Researchers are studying gene therapies, treating cancer by editing or altering the human genes containing the code that produces many different kinds of proteins. Affecting cell growth, behavior, and communication, proteins are at the heart of this research. When genes become defective or damaged, some cells grow out of control forming a tumor. Replacing or modifying damaged genetic information with healthy code is the goal.