Chemotherapy is a common medical treatment used to treat colon cancer, rectal cancer, also a combination of the two, which is referred to as colorectal cancer. Not every patient with one of these types of cancer will need chemotherapy, while other patients may receive chemotherapy in combination with other types of drug treatments, surgery, and/or radiation. In cases of advanced colon, rectal, and colorectal cancer, chemotherapy may be used as the only treatment.
There are many research projects and clinical trials testing new drugs to treat colorectal cancer. As a patient at Rocky Mountain Cancer Centers, you can rest easy knowing that our physicians are actively engaged in clinical trials and stay updated on the latest research-based treatment advances.
Depending on many unique factors, such as what type of colon or rectal cancer you have and its stage, your age, family history, and overall health, your Rocky Mountain Cancer Centers oncologist will recommend a personalized treatment plan that may include chemotherapy, targeted therapy, immunotherapy, perhaps in combination with surgery or radiation therapy. On this page, we explain the drug-based treatments for colorectal cancer, including chemotherapy, targeted therapy, and immunotherapy.
How chemotherapy is used to treat colorectal cancer
Chemotherapy is a variety of powerful drugs that kill cancer cells or stop them from growing. It can be used alone, or in combination with surgery and/or radiation therapy. In patients whose colon or rectal cancer has not spread to other parts of the body, chemotherapy is most often only used after surgery if the cancer has a chance of recurring. Some signs your doctor will be assessing are:
- Grade of tumor
- Cancer cells have spread to nearby blood of lymph vessels
- Cancer was detected near the edge of the removed tissue (which indicates that some cancer cells may still exist)
- Cancer has blocked the colon or caused a hole in the wall of the colon
- If chemotherapy is used after surgery, it is called adjuvant chemotherapy.
In some cases, chemotherapy may be given before surgery to shrink the tumor to make it easier to remove. This is called neoadjuvant chemotherapy. It is used primarily for rectal cancer.
Types of chemotherapy to treat colorectal cancer
There are different types of chemotherapy drugs currently used to treat colon, rectal, and colorectal cancers. One or a combination of these drugs may be recommended. In addition, your physician may recommend the use of targeted therapies and/or immunotherapy, which are explained later on this page. New drugs are being developed regularly, so the types of chemotherapy used for colon cancer and rectal cancer can change.
Like every type of cancer, colorectal cancer differs by individual, so your Rocky Mountain Cancer Centers oncologist will look at many factors in determining the type of chemotherapy to use and also the schedule and frequency with which you will receive them. To develop a personalized treatment plan, your cancer physician will consider many factors, including:
- Characteristics of your cancer, such as the stage, size, and location of your cancer.
- Genomic and proteomic test results that can help determine your sensitivity – and likelihood or responding – to various chemotherapy drugs.
- Health history, age, overall health including chronic health conditions, as well as your personal goals for treatment and post-treatment. For example, one factor that your physician may discuss with you is whether there might be a need for short-term or long-term colostomy bag use.
- Your physician also will consider which types of drugs work best together and develop a plan so that if one drug stops working, there are alternatives available. Because Rocky Mountain Cancer Centers is part of the UC Oncology Network with access to clinical trials, our physicians are aware of current clinical trials of new drugs that you might qualify for. In some cases, participation is limited by what drugs have already been tried, so your doctor will consider that as well.
Targeted therapy for colorectal cancer
Rocky mountain cancer centers, which participates in clinical trials of emerging treatments, often uses a new and very effective type of medical therapy, called targeted therapy to treat colon cancer and rectal cancer. Targeted therapy is a unique type of chemotherapy drug. Unlike regular chemotherapy, which attacks and kills both cancer cells and healthy cells, targeted therapy identifies cancer cells by attaching to specific molecules and then blocks the cancer cells from growing and spreading.
Some targeted therapy drugs can be used for patients with advanced colorectal cancer. Others only work in patients with a certain type of genetic mutation (called wild-type kras). There are different types of targeted therapy drugs for advanced colorectal cancer that work in different ways. To find the best targeted therapy, we test patients to understand the unique genetic components of your cancer and match them with the appropriate targeted therapy drugs. Because each targeted therapy drug is specific to particular genetic mutations, the drugs have to be matched to individual patients and not all patients will be eligible for targeted therapy.
Immunotherapy drugs to treat colon and rectal cancer
For people with certain gene changes in their cancer cells, another option after initial chemotherapy might be treatment with an immunotherapy drug. Immunotherapy drugs are a new class of drugs that use the body’s own immune system to help fight cancer. Immunotherapy drugs are typically used for people whose cancer is still growing after treatment with chemotherapy. They also might be used to treat people whose cancer can’t be removed with surgery, has returned, or has spread to other parts of the body.
Because these drugs tend to have less severe side effects, they may seem like a good first choice. However, because of the potential for causing the immune system to attack healthy organs and functions, physicians use them with caution and are likely to try standard chemotherapy and targeted therapy drugs first.
What to expect from chemotherapy for colon cancer or rectal cancer
There are two types of chemotherapy used to treat colon cancer, rectal cancer, and colorectal cancer. The first type is systemic drugs, administered either through an iv or taken in pill form, that reach all areas of your body. These are used to reduce the risk of your cancer spreading. Regional chemotherapy are drugs that are administered through an iv directly to the location of the tumor, helping to reduce side effects.
Chemotherapy for colon, rectal, and colorectal cancer is administered in cycles made up of treatment days and rest days. Depending on the type of drugs being used, your cycle may range from two to four weeks with treatments taking place the first week and then two or three weeks of rest. Most adjuvant chemotherapy for colorectal cancer used after surgery is repeated over the course of six months. When used as a primary treatment for advanced colon cancer, the number of cycles will depend on how effective the treatment is and how well your body responds.
If your medical oncologist has prescribed oral chemotherapy, which you take in a pill or liquid form, Rocky Mountain Cancer Centers’ in-house pharmacy can fill your prescription quickly and conveniently.
Side effects of chemotherapy
Recent advances in chemotherapy have lessened the severity and duration of side effects, but patients may still have symptoms from these powerful drugs. Our specially trained chemotherapy specialists will work with you on a plan to minimized side effects. Some important things to remember is that side effects are temporary, meaning that they will stop after treatment ends. Also, side effects have no relationship to whether the drugs are working. In fact, some patients will experience minimal side effects.
The side effects most likely to occur from chemotherapy for colon, rectal, and colorectal cancer include:
- Hand-foot syndrome begins as redness in the hands and feet and can progress to pain and sensitivity in the palms and soles. If it worsens, the skin may blister or peel, sometimes leading to painful sores. It’s important to tell your doctor right away about any early symptoms, such as redness or sensitivity, so that steps can be taken to keep things from getting worse.
- Neuropathy (nerve damage) is a common side effect of one type of chemotherapy drug used to treat colon and rectal cancers. Symptoms include numbness, tingling, and sometimes pain in the hands and feet. It can also cause intense sensitivity to hot and cold in your throat or the palms of your hands.
- Diarrhea: early diarrhea occurs within 24 hours of receiving the drug, while late diarrhea occurs after 24 hours with the peak at about 11 days. Because diarrhea can cause dehydration, it’s important to alert your chemotherapy team who can help with medication and diet modifications.
- Nausea and vomiting
- Low white blood cell count that can put you at increased risk for infection or high red blood cell count (anemia), which can cause fatigue.
If you are a patient and are experiencing worsening symptoms from your treatment, such as those listed below, our medical professionals are available 24 hours a day, 7 days a week to help. We can assess signs and symptoms, schedule you for an in-office, same or next day appointment and help you avoid a trip to the urgent care, er or unplanned hospitalization. In the event of a life-threatening emergency always call 911. Call us if you are experiencing:
- Chills or fever greater than 100.4
- Burning with urination, frequency, urgency, lower back pain (uti)
- Productive cough with green, yellow, red, brown sputum
- Unmanaged diarrhea, constipation, nausea, vomiting
- Unmanaged pain
- Swelling, redness and pain on extremities
- Shortness of breath/chest pain
- Dizziness with changing position or lightheadedness
- Dark urine, less urine than normal, thirst, dry mouth (dehydration)
- Mouth sores, difficulty swallowing, frequent or sever heartburn
- Severe fatigue