Chemotherapy drugs are a specific class of medications called cytotoxic agents. They’re designed to kill cancer cells. Cancer cells grow faster than regular cells. These drugs disrupt the growth of fast-growing cells and leave slower-growing cells generally unharmed.

Some chemotherapy, or “chemo,” drugs damage the genetic material of the cells. Others interfere with the way the cells divide. Unfortunately, some also affect other fast-growing cells in the body, such as hair, blood cells, and cells in the stomach lining and mouth. This accounts for some of the more common side effects.

Not all people who receive a diagnosis of breast cancer will need chemotherapy. Cancer can often be effectively treated with local therapies like surgery and radiation, and no systemic treatment is necessary.

Those who receive a diagnosis of larger tumors, whose cells have spread to nearby lymph nodes, may find themselves facing a few rounds of chemo. In these cases, chemo is used as adjuvant therapy, or to prevent cancer from returning after the tumor has been removed.

People who receive a diagnosis of some stage 3 cancers and larger tumors may go straight to systemic treatment before turning to surgery. This is called neoadjuvant treatment. While the idea of chemotherapy may be scary, there have been significant improvements in controlling side effects. Going through chemotherapy is much easier than it used to be.

In cases of early stage cancer, an oncologist can make an informed decision about which drugs are best to use. A person’s age, the stage of the cancer, and other health problems will all be taken into consideration before deciding on a chemo regimen.

These drugs will be injected into a vein, either at your doctor’s office or at a hospital. Locations that provide chemotherapy injections are often called infusion centers.

You may need a port implanted if you have weak veins or are being given a more corrosive drug. A port is a device that’s surgically placed in your chest that allows for easy needle access. The port can be removed when therapy is finished.

Typically, a person is given several drugs, often called a regimen. Regimens are designed to attack the cancer at different stages of growth and in different ways. Your chemo drugs will be given on a regular schedule in doses called rounds. According to the American Cancer Society, the most common drugs and regimens used for breast cancer today are:

Regimen name (drug initials)List of drugs in treatment
CAF (or FAC)cyclophosphamide (Cytoxan), doxorubicin (Adriamycin), and 5-FU
TACdocetaxel (Taxotere), doxorubicin (Adriamycin), and cyclophosphamide (Cytoxan)
AC-Tdoxorubicin (Adriamycin) and cyclophosphamide (Cytoxan) followed by paclitaxel (Taxol) or docetaxel (Taxotere)
FEC-T5-FU, epirubicin (Ellence), and cyclophosphamide (Cytoxan) followed by docetaxel (Taxotere) or paclitaxel (Taxol)
TCdocetaxel (Taxotere) and cyclophosphamide (Cytoxan)
TCHdocetaxel (Taxotere), carboplatin, and trastuzumab (Herceptin) for HER2/neu-positive tumors

While chemotherapy treatments have greatly improved over time, there are often still noticeable side effects of treatment.

Hair loss

Many chemotherapy drugs don’t cause hair loss, but most of those mentioned above for early stage cancer will have that side effect. Hair loss is one of the most visible side effects of cancer treatment. It can also be the most distressing. Many stores sell wigs and scarves, and some charities help provide them.


Vomiting and nausea is another feared side effect. But in today’s world, this is becoming less common and seen more on TV than in infusion centers. You’ll be given steroids and powerful anti-nausea meds along with your infusion. You’ll also be given some medication to take at home. Most people are pleasantly surprised to find that they don’t have any nausea at all and can even gain weight on chemo.


Constipation can be a real problem. You must be vigilant about getting enough fiber and taking stool softeners.

Mouth sores

Mouth sores are a problem for some. If this happens, you can ask your oncologist for a prescription for “Magic Mouthwash,” which has a numbing agent. Taste changes are possible with some chemo drugs.


The most common and persistent side effect is tiredness. Chemotherapy affects your blood and bone marrow. Often a person undergoing chemo will become anemic, which causes fatigue. The effect on the blood also leaves you potentially susceptible to infection. It’s important to rest and only do what’s necessary.

Potential long-lasting effects

While most of those side effects go away when you complete your chemo regimen, a few problems may remain. One of these is neuropathy. It occurs when the nerves of the hands and feet are damaged. People with this problem feel tingling, stabbing sensations, and numbness in these areas.

Osteoporosis is another potential lasting side effect. Someone who has had chemo should have regular bone density checks.

Cognitive difficulties that occur with treatment can cause short-term memory loss and problems concentrating. This is known as “chemo brain.” Usually, this symptom improves shortly after therapy concludes. However, sometimes it can persist for years.

In some cases, chemo can leave you with a weak heart. Rarely, an allergic reaction to chemotherapy drugs can happen as well. You’ll be watched very closely for any signs that this may occur.

Learning that you have to undergo chemotherapy is naturally frightening. But most people are surprised to find that it’s quite manageable. Many can even keep up with their careers and other regular activities at a reduced level.

While undergoing chemo, it’s important to eat right, get as much rest as possible, and keep your spirits up. Finding out that you must undergo chemo can be difficult. Remember that it will end in a few short months.

It may help to talk to others who have gone through the same thing, either through a support group or online. Check out our best breast cancer blogs of the year to learn more.