Capecitabine

Capecitabine (Xeloda) is an oral chemotherapy medicine used to treat early-stage and metastatic breast cancer.

Capecitabine is part of a class of chemotherapy drugs called antimetabolites that stop cancer cells from multiplying.

How capecitabine works

Capecitabine is an inactive form of fluorouracil, a chemotherapy medicine. When you take capecitabine, it stays inactive until it reaches your liver. Your liver and the enzymes in the cancer cells then convert the capecitabine to its active form. The active fluorouracil then kills the cancer cells when they try to divide.

Who gets capecitabine

Capecitabine is used to treat early-stage and metastatic breast cancers.

For early-stage triple-negative breast cancer, capecitabine may be given after surgery when cancer cells are still found after neoadjuvant chemotherapy (chemotherapy given before surgery). Capecitabine after surgery is called adjuvant capecitabine, and it is used to lower the risk of the cancer coming back.

A clinical trial called CREATE-X showed that in people with early-stage HER2-negative breast cancer, treatment with capecitabine significantly reduced the risk of a new breast cancer, a recurrence, or death. People with triple-negative breast cancer benefited most.

For metastatic breast cancer, capecitabine can be used alone or in combination with other medicines. For HER2-positive metastatic breast cancer, capecitabine is commonly given together with trastuzumab (Herceptin) and tucatinib (Tukysa), or with lapatinib (Tykerb). Your doctor will recommend the combination that is right for your situation.

If you also need radiation therapy, your care team will help determine the best timing and sequence of your treatments.

How capecitabine is given

Capecitabine is taken as a pill, usually twice a day for 14 days, followed by 7 days off. This 21-day period is called one cycle. However, your dose and schedule may be different depending on your specific treatment plan.

Side effects and things to remember

Common side effects include:

• Decrease in appetite
• Diarrhea, which can sometimes lead to dehydration
• Hand and foot syndrome — redness, swelling, pain, or peeling on the palms of your hands or soles of your feet
• Low red and white blood cell counts
• Fatigue
• Menopausal symptoms
• Mouth sores
• Nausea and vomiting

Less common side effects include:

• Constipation
• Eye problems
• Hair thinning or hair loss
• Nail changes
• Fertility problems

If you have painful hand-foot syndrome or ongoing diarrhea, tell your care team right away. A lower dose or alternate schedule may be able to keep your treatment just as effective while making side effects more manageable.

Before starting capecitabine, tell your doctor about any medicines you are taking, including vitamins, herbal supplements, and over-the counter-medicines. You should not become pregnant while you are taking capecitabine.

Your care team can help you manage side effects. You can also visit our section on side effects for more information.

Capecitabine and DPD deficiency

If you and your doctor are considering capecitabine as part of your treatment, it is important to know about a rare inherited genetic condition called DPD deficiency. Research has shown that total DPD deficiency is rare, occurring in fewer than 0.1% of people. Partial DPD deficiency has been reported in about 6.8-11.5% of people.

People with any level of DPD deficiency were born with an inherited mutation in the DYPD gene. Inherited DYPD gene mutations reduce the amount of DPD enzyme in the body. The DPD enzyme helps certain body processes, including the breakdown of capecitabine and fluorouracil chemotherapies.

People with DPD deficiency may be at risk for very serious reactions, including death, while taking capecitabine or fluorouracil. If you are considering capecitabine or fluorouracil, ask your care team about DPD deficiency.

Here are some questions to ask:

• Should I be tested for an inherited DYPD mutation?
• How can we work together to manage the risk of serious side effects while I’m taking this medicine?
• Is there a different chemotherapy option for me?