A Closer Look at The Side Effects of Chemotherapy for Breast Cancer

The experience of undergoing chemotherapy is undoubtedly challenging and can feel like a never-ending journey. It is typical to encounter a range of side effects that can have a considerable impact on your physical, mental, and emotional well-being. It is entirely understandable to feel uneasy about this. However, while some risks are more serious, it is crucial to note that some side effects may be mild and short-lived. Almost all side effects can be managed through medication, lifestyle changes including physical activity, or changing chemotherapy dose or type. It is essential to remain aware of the potential risks associated with chemotherapy and to discuss any concerns or questions you may have with your doctor. By working together, you can take steps to mitigate side effects and make your journey through chemotherapy as smooth and comfortable as possible. It is important to know that while some people may experience serious chemotherapy side effects, others may experience very few or almost no side effects. Many people are able to continue working full-time while receiving chemotherapy and to participate in most of their usual everyday activities with either no or small modifications.

As with all treatment methods, chemotherapy does come with a range of possible side effects. These include:

• Hair loss
• Loss of appetite / changes in taste
• Weight changes
• Nausea / vomiting
• Diarrhea or constipation
• Higher chance of serious and life-threatening infections
• Fatigue

Chemotherapy often causes temporary side effects that are common. Fortunately, they typically disappear after treatment. Medication can often be used to manage these side effects. Your healthcare team will assist you in managing them, so be sure to keep them updated.

Other less common side effects of chemotherapy for breast cancer are also possible:

• Menopausal symptoms or early menopause

If you are premenopausal (still having your menstrual periods), chemotherapy may disrupt your ovaries' hormone (estrogen) production. Depending on your age, when you start treatment and the types of drugs used, the ovaries may or may not work again after treatment. For some, their menstrual periods may return after treatment, but others may have an early menopause. Unfortunately, this may lead to an increased risk of heart disease, bone loss, and osteoporosis, which may occur with too much bone loss. However, some medications may help to ease or manage these symptoms.

• Infertility

If your menstrual period does not resume within a year after chemotherapy treatment ends, it is unlikely to return. This can lead to infertility, which can be difficult to accept. If you plan to have children, it is important to discuss this with your doctor before starting chemotherapy so that you can be referred to a fertility specialist to discuss options for fertility preservation. These include egg retrieval and freezing either alone or as part of an embryo, ovarian tissue preservation, and leuprolide injections that may help protect ovarian function during chemotherapy and improve the chance of pregnancy following chemotherapy. It is usually safe to wait several weeks to complete procedures for fertility preservation prior to starting breast cancer treatment. Unfortunately, these procedures may be very expensive and are usually not covered by health insurance; most women must pay for them out of pocket.

Some women are unfortunately diagnosed with breast cancer during pregnancy. In this case, chemotherapy can generally be used safely after the first trimester and is paused during delivery.

• Heart problems

Although rare (about 1–3% of all cases), chemotherapy drugs used to treat breast cancer, such as doxorubicin and epirubicin, can cause heart toxicity issues like insufficient delivery of blood and oxygen, high blood pressure, weakened heart muscles or irregular heartbeats. Patients who have high blood pressure, diabetes, and a family or personal history of heart problems are at a higher risk of heart failure during and after chemotherapy treatment. Doctors usually screen cancer patients for underlying or developing heart failure before, during, and after treatment. They may perform an echocardiogram, or heart ultrasound, to evaluate heart function. If heart function worsens during treatment, doctors may temporarily or permanently stop the drugs used and consider alternative treatments. Ongoing research aims to establish evidence-based guidelines for the surveillance and prevention of cardiac dysfunction in chemotherapy patients.

• Peripheral neuropathy

Breast cancer patients receiving chemotherapy, particularly taxane-based chemotherapy (drugs such as paclitaxel, docetaxel), may experience long-term peripheral neuropathy, or damage to the nerve endings in their hands and feet. Peripheral neuropathy symptoms which include numbness, pain, burning, or tingling sensations that are either come and go or are constant. The symptoms are caused by the chemotherapy drugs damaging the nerves in the hands and feet. These symptoms may improve after finishing chemotherapy, stay the same, or even worsen. A clinical trial showed that over 40% of participants still experience tingling and numbness in their hands or feet two years after treatment, and 10% rated their symptoms as severe. It is important to note that while patients are often aware of the immediate side effects, they should also be aware of the possibility of peripheral neuropathy and discuss it with their doctor if necessary. Treatment for peripheral neuropathy includes medication, pain management, and rehabilitation.

• Loss of memory and cognitive function

Breast cancer patients often experience a decline in their memory and cognitive function after undergoing chemotherapy, which is commonly known as "chemo brain". Neuropsychological studies have shown this as a side effect of chemotherapy for many years. Additionally, "chemo brain" symptoms appear to be more prevalent among patients with pre-existing fatigue, menopause, lower cognitive reserve, and those with depression and anxiety.

• Increased risk of leukemia

Chemotherapy can cause new types of cancer to develop in normal cells several years after treatment. Alkylating agents and melphalan, as well as a combination of chemotherapy and radiation therapy, have been linked to a small (about 1–3%) increased risk of leukemia. While this is a rare complication, the benefits of chemotherapy usually outweigh the potential risks.

• Long-term fatigue

After going through chemotherapy, breast cancer patients may experience fatigue for several months or even years. While it is a long-term issue, it can be controlled with proper management, specifically by engaging in physical activity where one’s heart beats faster than usual and one breathes faster than normal for 30–50 minutes per day 5 days per week. It is advisable to discuss this with your healthcare team to ensure that physical activity is safe for the patient during and after treatment; it is for most.

Breast cancer patients often worry about side effects from chemotherapy, including acute, long-term, and late effects. However, it's important to be informed about these possible side effects and discuss them with your doctor. Medical oncologists and their teams are skilled in helping patients manage and control chemotherapy side effects. If you have any concerns, your doctor can take them into consideration when planning your treatment. While side effects can be troubling, chemotherapy is often an effective way to manage or even cure breast cancer. It's important to remember that the benefits of this treatment usually outweigh the risks of serious and rare side effects.