Fear about side effects from cancer treatment adds to the stress of a cancer diagnosis. This fear comes from a belief that the discomfort of side effects cannot be relieved. That is not true. Many advances have been made in preventing or managing the most common treatment-related side effects.

Side Effects Differ in Many Ways

Managing side effects is important because if you feel better, you are more likely to complete your treatment as planned by your oncologist, and treatment is most effective when it is carried out as planned. Learning the facts about side effects can help people with cancer cope better with them.

The side effects of cancer treatment differ in many ways. First, not all patients will have the same side effects. 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 experience a side effect depends on many factors including your age, your overall health, your specific cancer, and your specific treatment plan.

Side effects vary in how serious they are. Some cause minor inconvenience or discomfort, and others may cause more discomfort, pain, and/or emotional distress. Occasionally, a serious side effect may require immediate medical attention. It is important to know that there are ways to relieve the discomfort of most treatment-related side effects and to prevent them from becoming severe. It is also important to know when you should call your doctor about symptoms related to side effects.

Side effects also differ according to when they occur. Those that occur during treatment are called short-term (or acute) side effects. Short-term effects usually disappear once treatment ends. In contrast, long-term side effects may not completely disappear until months or years after treatment has ended. The last category of side effects is late effects, which occur less frequently than short-term or long-term effects. Late effects do not occur during treatment; rather, they occur at least 6 months after treatment has been completed.

The most important way in which side effects differ is according to the type of cancer treatment; that is, surgery, radiation therapy, chemotherapy, hormone therapy, or targeted therapy. Many people with cancer receive a combination of treatments, which may increase the possibility of side effects.

Cancer Treatments and Their Side Effects

Sometimes there is one best treatment for a cancer, and other times there is more than one option for treatment:

Surgery
Radiation Therapy
Chemotherapy
Hormone Therapy
Targeted Biological Therapy

Your oncologist will talk to you about the treatment options for your particular cancer. You should learn all you can about side effects by asking your oncologist some specific questions when discussing treatment options.

Surgery

When possible, surgery is done to remove a cancerous tumor, and lymph nodes in the area of the tumor are also usually removed (to see if cancer has spread to the nodes). The side effects of surgery may be short-term or long-term and vary according to the area of the body where the surgery was done (Table 1). Most people have some level of pain after surgery and will usually need to limit activities in the first few days or weeks after surgery. People recover at different rates depending on their age, general health, and the location of the tumor. Surgery causes scars, may affect bodily functions, and may change your body’s appearance. There may also be tissue swelling around or near the site of surgery. These changes may affect how you feel about your body image.

Radiation Therapy

With radiation therapy, beams of radiation are delivered from a machine to the part of the body where the tumor is located. The radiation shrinks the tumor by destroying cancer cells. Much care is taken to make sure that the radiation is delivered precisely to the tumor so as to avoid damaging nearby normal cells. However, normal cells in the pathway to the tumor may be affected.
Because radiation is delivered through the outside of the body, the skin and underlying tissues in the area being treated may become sensitive. This sensitivity is short-term and usually gradually resolves within 2 months after treatment has been completed. There may be short-term or long-term swelling or scarring of the tissues in the area; scarred tissues may become firm or contracted. Other side effects vary according to the part of the body being treated and may be short-term or long-term or may occur late after treatment (Table 1).

Chemotherapy

Chemotherapy involves the use of very strong drugs that kill cancer cells throughout the body. These drugs can also damage normal, healthy cells, which may cause side effects. The normal cells most often affected are the blood-forming cells in the bone marrow, hair follicles, and cells lining the inside of the mouth and digestive tract. Many side effects of chemotherapy are short-term (Table 1). Problems with thinking, remembering, and understanding, known as “chemo-brain,” may be long-term effects. Some chemotherapy drugs have also been associated with late effects.

Hormone Therapy

Hormone therapy is sometimes used to slow or stop the growth of prostate cancer in men and to prevent the recurrence of some types of breast cancer in women. Hormone therapy acts by decreasing the amount of hormones made naturally in the body. For men, hormone therapy decreases the level of testosterone; for women, hormone therapy decreases the levels of estrogen and progesterone, causing side effects that are similar to the symptoms of menopause (Table 1). Although the side effects of hormone therapy in both men and women usually disappear when treatment ends, hormone therapy is typically given for a long period of time. This means that a side effect may be experienced for many months or years.

Targeted Biologic Therapy

Targeted therapy is the use of drugs or biologic substances that stop or slow cancer growth by interfering with specific molecules in the body involved in the process of creating cancer cells. Because targeted therapy is designed to attack specific cells, it is less harmful to normal cells than traditional chemotherapy. However, some side effects may occur (Table 1). As with hormone therapy, targeted therapy may last for a long period of time, so even short-term effects may be present for many months. Targeted therapy is the newest approach to treating cancer, and not enough information has been collected to clearly understand late effects.

Table 1.

Type of Treatment	Short-term Side Effects	Long-term Side Effects	Late Effects
Surgery (depending on the site of surgery)	Pain Limited mobility and/or activities Slow digestion	Scars Impaired wound healing Chronic pain Change in function Negative body image	Lymphedema Phantom limb sensation (if part of limb is removed)
Radiation therapy (depending on the site of radiation)	Skin sensitivity (redness, dryness, peeling, itchiness) Fatigue Anemia Hair loss (in the area of the body being treated) Nausea and vomiting (if abdomen is radiated) Mouth sores (if head or neck is radiated) Headache (if head is radiated)	Fatigue Dry mouth Loss of or changes in taste (if head or neck is radiated)	Problems with thinking, memory (if brain is radiated) Loss of motion in joints (if limb or joint is radiated) Infertility (if abdomen is radiated) Cavities and tooth decay (if head is radiated) Lymphedema
Chemotherapy	Nausea and vomiting Anemia Fatigue Hair loss Diarrhea Neutropenia (which increases risk of infection) Changes in appetite Mouth Sores Skin and nail changes	Fatigue Menopausal symptoms Never problems (known as peripheral neuropathy) “Chemo-brain” (forgetfulness or trouble concentrating) Heart problems (cardiomyopathy)	Cataracts Infertility Heart failure Abnormal liver function Osteoporosis
Hormone therapy*	Men: Hot flashes Constipation or diarrhea Nausea Dizziness, headache Trouble sleeping Impotency, decreased sex drive Weight Gain Fatigue Women: Hot flashes Vaginal discharge and irritation Joint pain Muscle aches Headache Depression Increased risk of bone fracture Increased risk of blood clot	Women: Cancer of the uterus Bone loss (osteopenia) Men and Women: Increased risk of blood clot
Targeted biologic therapy	Acne-like rash Increased risk of infection Flu-like syndrome Dry, itchy skin Nausea/vomiting Slow-growing, brittle hair Diarrhea/constipation Mouth sores Anorexia Increased risk of blood clot Fatigue Heart problems (cardiomyopathy)	Increased risk of blood clot Neutropenia (which increases risk of infection) Fatigue High blood pressure Heart problems (cardiomyopathy)

*Hormone therapy is typically given for a long period of time, so short-term side effects may last for a long period of time.

Importance of Learning About Side Effects

It is not possible to predict how each individual will be affected by cancer treatment, but talking with your healthcare team can better prepare you for what may happen. This guide will help you learn more about side effects, how they can be managed, and how to talk to your doctor about them. It provides an overview of the most common cancer treatment-related side effects and includes lists of resources to help you find more information. Learn as much as you can. 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.

Questions to Ask Your Doctor

What are the possible side effects of each of my treatment options?
How common are these side effects?
When are these side effects most likely to occur?
How do the benefits of the recommended cancer treatment compare with the risks?
How long will the side effects probably last?
Is there a way to decrease the possibility that these side effects will occur?
Are there medications available to relieve or prevent these side effects?
How will I be monitored for long term side effects such as heart problems?
When should I contact a member of my health care team about a side effect? Who should I call?