What Are the Possible Side Effects of Breast Cancer Treatment?

Treatments for advanced breast cancer target the cancerous cells, but they can also create unwanted side effects. The side effects experienced can vary between patients and depend on several factors, including the medications given, the person’s overall health, and what other treatments are being received. Each treatment option carries a different possible list of side effects, and your healthcare team can provide information on what to expect. Not everyone who receives the same treatment has the same experience, and side effects can vary in their intensity among different individuals.

While some side effects are temporary and go away once a particular treatment is over, others may persist for months or years after treatment. Some side effects may be permanent. Whether during treatment or after treatment, there are often ways to manage side effects.

Common side effects of surgery for breast cancer

Side effects from surgery may include short-term and possible long-term effects, such as^1,2:

• Pain
• Lymphedema
• Impact on body image

Common side effects of radiation for breast cancer

Radiation is the use of high-energy rays to kill cancer cells. Radiation may be directed at various areas, including the breast, under the arm, or at a site of bone metastasis. Radiation may cause side effects such as³:

• Skin irritation (redness, darkening, peeling)
• Fatigue
• Pain
• Damage to the nerves of the arm, causing numbness, pain, and/or weakness

Common side effects of chemotherapy for breast cancer

Chemotherapy is the use of medications that target fast-growing cells, such as breast cancer cells. Chemotherapy can also attack healthy cells that grow quickly in the body, including those in the digestive tract and hair, and may cause side effects such as⁴:

• Nausea
• Vomiting
• Hair loss
• Mouth sores
• Diarrhea
• Increased risk of infections
• Anemia
• Fatigue
• Premature menopause
• Infertility
• Cognitive difficulties

Common side effects of hormone therapy for breast cancer

Some breast cancers have receptors for hormones and are referred to as estrogen receptor positive (ER+) and/or progesterone receptor positive (PR+). Hormone therapy is often used to treat hormone receptor positive (ER+ and/or PR+) breast cancers and may cause side effects such as⁵:

• Hot flashes
• Night sweats
• Vaginal dryness
• Sexual difficulties
• Mood swings
• Muscle or joint pain

Common side effects of targeted therapy for breast cancer

Targeted therapies are cancer treatments that stop or slow the spread of breast cancer by interfering with specific areas of cancer cells that are involved in the cancer cell’s growth processes. The potential side effects are specific to the type of targeted therapy given but may include⁶:

• Diarrhea
• Fatigue
• Increased risk of heart damage
• Lowered blood cell counts
• Nausea
• Vomiting

Managing side effects from breast cancer treatment

Many side effects can be managed, and some can be prevented. Communication between patients and their healthcare team is critical, and any side effects experienced should be brought to the attention of a doctor or nurse.

Side effects from breast cancer treatment are often temporary and tend to go away after treatment is completed. However, some side effects may last longer or be irreversible. Reducing the dosage, changing medications, or delaying treatment regimens can be potential options to help manage some side effects.