Colorectal Cancer

Treatment-Related Side Effects

The stress of a colorectal cancer diagnosis is increased by fears about the side effects of treatment. These fears grow from a belief that the discomfort of side effects cannot be relieved. However, it is now possible to prevent or manage many common symptoms related to colorectal cancer and its treatment. Treatment-related side effects vary widely among people with cancer. A friend or relative may have had a certain side effect after treatment, but that does not mean you will experience the same side effect. Whether or not you have a side effect depends on many factors, including your age, your overall health, your specific treatment plan and other medications you might be taking.

Treatment-related side effects differ according to the type of treatment, and many side effects are common to treatments for several types of cancer. For example, chemotherapy may cause nausea and vomiting, diarrhea or fatigue, and targeted therapy may cause an acne-like rash. Other side effects are specific to colon or rectal cancer. For example, radiation therapy for rectal cancer may cause soreness around the anus and problems with bowel and bladder control.

An operation for rectal or colon cancer may result in the need for an ostomy. As described earlier, an ostomy creates a new path for body wastes to be eliminated from the body when the colon or rectum must be bypassed because of disease. An ostomy is done more often in people with rectal cancer than in people with colon cancer. For people with rectal cancer, an ostomy is sometimes necessary when the tumor is located low in the rectum or when radiation therapy has been part of treatment. If an ostomy is part of your treatment, a nurse who specializes in ostomies will talk to you before you are discharged from the hospital. The ostomy nurse will teach you how to empty and replace the pouch, care for the skin around your stoma, manage your diet and daily activities, and recognize potential problems. An ostomy nurse can follow-up with you at home as well, until you feel comfortable caring for the ostomy yourself. Adapting to an ostomy may take some time. But help is available, and most studies have shown that after an initial adjustment period, the quality of life is the same with an ostomy as without. If you have an ostomy, you should consider a local or online support group to help you cope.

As with most side effects, radiation-related side effects generally go away once treatment has been completed. Until then, you and your treatment team can manage treatment-related side effects to help keep you as comfortable and active as possible (Table 1). There are six keys to managing treatment-related side effects effectively.

PREVENTION: Taking preventive steps is sometimes more effective than managing a side effect once it occurs. For example, preventing nausea and vomiting is much more effective than treating nausea and vomiting once it begins.

EARLY INTERVENTION: The earlier you start treatment for a side effect, the more likely it is for the treatment to be successful. Be sure to ask your doctor about when you should call about the signs and symptoms of side effects.

CAREFUL MONITORING: Detecting a side effect early requires close attention to the signs and symptoms of potential side effects. You and your treatment team will watch closely in order to begin treatment as soon as possible. It may be helpful to keep a journal to help track your side effects.

REDUCING/DELAYING TREATMENT: Sometimes, the most effective way to manage a side effect is to reduce the medication or radiation dose or to delay treatment until the side effect has disappeared. This approach is a common strategy and will not have a negative effect on the effectiveness of your treatment.

CHANGING STRATEGIES: If one approach to managing a side effect doesn’t work, another may. You and your treatment team will work together to make sure that the intervention effectively manages the side effect.

UNDERSTANDING SELF-HELP: There are many things you can do to help prevent/manage side effects in addition to strategies your doctor suggests.

It is impossible to predict how each person will be affected by colorectal cancer and its treatment, but talking with your treatment team can better prepare you for what may happen. Talk to your doctor about how likely side effects are with your particular treatment. You can also learn more about common side effects through several reliable online resources noted in the Additional Resources list. Knowing what to expect and how to help prevent or manage side effects can help you feel in control of your body, improve your quality of life, and, most important, ensure that you have the best chance for treatment to be effective.

Table 1. Management of the Most Common Side Effects of Treatments for Colon or Rectal Cancer

Side Effect What Usually Causes It? How Is It Prevented or Managed?
    What Your Health Care Team May Do What You Can Do
Fatigue All types of treatment (body needs extra energy to repair healthy tissue damaged by treatment).

Other treatment side effects (pain, nausea and vomiting, sleep disorders; dehydration, poor nutrition, low blood counts).
Do lab tests to see if you have anemia (low red blood cell count) or another treatable cause of fatigue, such as a metabolic imbalance. Seek relief of other symptoms that may contribute to fatigue (pain, nausea and vomiting, depression).

Maintain adequate nutrition with a well-balanced diet and sufficient fluid intake.

Engage in “distracting” or relaxing activities (perform deep breathing exercises, use imagery techniques, read, listen to music, play games, pray/meditate).

Balance activity and rest:
  • Follow a structured daily routine.
  • Attend to one activity at a time.
  • Participate in regular physical activity (walking, bike riding).
  • Take frequent rest periods or naps, but limit each nap to 45 minutes.
  • Get 8 hours of sleep each night.
Nausea and vomiting Chemotherapy drugs, especially 5-FU, irinotecan and oxaliplatin. Prescribe antiemetics (drugs to prevent nausea and vomiting) to begin before the start of chemotherapy and to continue for a specific period of time after treatment. Because some antiemetic drugs work in different ways, a combination of drugs is often the best approach, especially if you will receive a chemotherapy drug that has a high likelihood of causing nausea and vomiting. Take antiemetics exactly as your doctor has prescribed and not on an “as-needed” basis.

Eat several small meals throughout the day rather than 3 big meals.

Try eating a light meal a few hours before your scheduled treatment.

Drink plenty of fluids at small amounts throughout the day.

Rest after eating, but don’t lie flat.
Diarrhea Chemotherapy drugs, as well as surgical therapy and radiation therapy. Suggest that you take an over-the-counter anti-diarrheal medication, such as Kaopectate, Imodium, or Pepto-Bismol. If diarrhea is severe, your doctor can prescribe other medications.Talk to your doctor before using these medications; infectious causes of diarrhea need to be ruled out before these medications are taken.

Suggest that you take fiber supplements.
Follow your health care provider’s instructions for taking anti-diarrheal medications, as these instructions may differ from those on the drug label. (You should not take any over-the-counter anti-diarrheal medication without talking to your doctor first.)

Drink 6-8 glasses of fluid per day.

Eat foods high in protein, calories, and potassium that are easy to digest.

Eat 5-6 small meals rather than 3 large meals.

Avoid foods that are very high in fat.

Avoid fluids and food that can irritate the digestive tract (beverages with caffeine or alcohol, milk or milk products, chocolate, dried fruits, beans, popcorn, or spicy food).
Neutropenia (low white blood cell count), which increases the risk of infection Chemotherapy (especially
5-FU, irinotecan, oxaliplatin), radiation therapy, particularly to the pelvic area; the likelihood is greater when both these treatments are given.
Order a complete blood count (CBC) regularly, to monitor the number of white blood cells.

If the count is very low, delay your next treatment until the count has increased and consider whether adjustments to your chemotherapy dosage are necessary.

If the count is extremely low, prescribe a medication that can stimulate the bone marrow to produce more white blood cells.
To reduce the risk of infection:
  • Wash your hands frequently and carefully.
  • Avoid crowds and people with infections.
  • Wash fruits and vegetables carefully and avoid raw meat, seafood and eggs.
  • Know the signs and symptoms of infection (fever, chills, skin that is red and warm to the touch, cough or sore throat, burning when you urinate) and call your health care provider if any of these signs or symptoms occurs.
Anemia (low red blood cell count) Chemotherapy (especially
5-FU, irinotecan, oxaliplatin), radiation therapy, particularly to the pelvic area; the likelihood is greater when both these treatments are given.

Surgery, if there was a large amount of blood loss during the operation.
Order a complete blood count (CBC) regularly, to monitor the number of red blood cells.

Check the amount of iron in your blood; tell you to take an over-the-counter iron supplement and/or to eat foods high in iron if you are iron deficient.

If the count is extremely low, prescribe treatment with a blood transfusion.
Get an adequate amount of rest.

If your doctor suggests eating foods high in iron, include the following in your daily diet: green, leafy vegetables; dried fruit; seafood, chicken, and beef; eggs; and nuts.

Do not take an iron supplement unless your doctor tells you to.
Cognitive dysfunction (“chemo-brain”): problems with concentration, word-finding problems, forgetfulness, and problems with organizational ability, and arithmetic skills Chemotherapy, radiation therapy to the brain. If these problems get worse or continue for many months after treatment, your health care provider may prescribe medication.

Suggest occupational therapy or vocational rehabilitation or cognitive rehabilitation to help improve cognitive skills and learn ways to cope with cognitive deficits.
Use a calendar or daily planner to keep all your important information in one place.

Exercise your brain to strengthen your mental ability (do word games and crossword puzzles, play cards and games).

Get physical exercise to improve your mental alertness.

Track memory and attention problems to help you determine when you are most affected.

Focus on one thing at a time rather than trying to multitask.

Tell friends and family that you’re having cognitive problems.
Mouth sores (mucositis) Chemotherapy, especially
5-FU and capecitabine.
Suggest rinsing your mouth with special solutions, prescribe a medication that coats the lining of your mouth, or prescribe pain medications that can be applied to the sores. If you have poor oral health, you may want to visit your dentist before you begin cancer treatment to help get your gums and teeth healthier.

Check your mouth 2 times a day and perform mouth care every 4 hours.

Drink a large amount of fluids (goal of 2-3 quarts per day).

Use a straw to avoid mouth sores when drinking.

Eat soft foods, cut in small pieces.

Eat foods at room temperature or slightly warm.

Avoid the following:
Hot, spicy, greasy, or fried foods; very salty or high-sugar foods; sharp or crunchy foods; citrus fruits and juices; alcohol, caffeine, and carbonated beverages
Peripheral neuropathy (acute neuropathy: increased sensitivity to cold; chronic neuropathy: tingling, numbness, burning, pain, in the hands and feet) Chemotherapy drugs (oxaliplatin). Prescribe a drug to alleviate pain and other symptoms.

Give you an infusion of calcium and magnesium before and after treatment with oxaliplatin.

If the neuropathy is severe and/or persistent, reduce the dose of oxaliplatin or delay treatment.

Refer you to a physical or occupational therapist to help you gain better balance and carry out daily activities more easily.
In colder weather, be prepared with scarves, gloves and socks for protection from cold sensitivity.

Avoid excessive air-conditioning.

Take part in regular exercise, such as walking.

Do stretching and strengthening exercises every day.

Avoid tight shoes and socks with elastic.

Take safety precautions (the decreased sensation may increase the risk of injury):
Keep your house well-lighted; remove throw rugs; look at the floor or ground when you walk to avoid tripping or falling; if you drive, make sure you can feel the pedals with your feet.
Hand-foot syndrome (red, blistering, dryness, cracking, or peeling of the skin on the hands and feet; numbness, pain or tingling can occur) Chemotherapy drugs: 5-FU (given as a continuous infusion) and capecitabine. Delay or decrease the dose of the chemotherapy drug or use an alternative drug.

Prescribe moisturizing creams and pain medication, if the condition is causing you a great deal of discomfort.
Look closely at your hands and feet regularly and call your doctor or other member of your treatment team if you see any signs of hand-foot syndrome.

Reduce friction and heat exposure to the hands and feet as much as possible.

Avoid dishwashing, long showers or baths, hot water, high impact exercise, and the use of tools for which you have to squeeze a handle.

Use ice packs on affected areas to decrease pain.

Moisturize your skin two times a day with a thick cream that contains no alcohol, perfume or dye. (Apply the moisturizer while your skin is still damp after bathing.)
Acne-like rash Targeted therapy drugs, such as cetuximab (Erbitux) and panitumumab (Vectibix). Mild reactions do not need to be treated.

For moderate and severe reactions, prescribe a medicated cream to control itching and ease discomfort.

If infection is likely, prescribe an antibiotic.

If the reaction is severe, refer you to a dermatologist.
Taking special care of the skin can help minimize discomfort and promote healing; follow these Do’s and Don’ts:

Wash skin with lukewarm (not hot) water.

Take baths rather than showers.

Use mild soap that does not contain alcohol, perfume, or dye.

Moisturize your skin 2 times a day with a thick cream that contains no alcohol, perfume, or dye.

Use an electric shaver if shaving is necessary (but check first with your doctor or nurse).

Use paper (not adhesive) tape if bandaging is necessary.

Wear loose-fitting clothes.

Use gentle laundry detergents (free of perfumes or dyes).

Protect your skin from the sun during treatment and for at least 1 year after the end of treatment.
  • Avoid direct sun exposure.
  • Apply sunscreen with an SPF of 30 before going outside.
  • Wear long sleeves, long pants, and a wide-brimmed hat.
Use acne medication on the rash.

Rub skin with a washcloth or towel.

Rub or scratch sensitive areas.

Use a pre-shave or aftershave lotion or hair removal products.

Put anything hot or cold on the affected area (such as heating pads or ice packs).

Starch your clothes.

*EGFR = epidermal growth factor inhibitor

For more information on side effects please visit our Treatment Side Effects section.

Additional Sources of Information


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