Chemotherapy Information

When is Chemotherapy Used for Breast Cancer?

There are many different classes of chemotherapy drugs. Some of the more common ones are called anti-metabolites, DNA alkylators and anti-microtubule drugs.[1] They stop the growth of cancer cells by affecting the machinery that the cells use to divide. Chemotherapy is given through the veins so that it enters your blood stream and can kill all cancer cells that may have spread throughout the body. Consequently, chemotherapy can also damage normal cells.

Delivery of Chemotherapy

Chemotherapy for breast cancer can be given through an IV in your arm or a specialized IV called a port. A port is an IV that is placed surgically into a central vein and has a circular port that is felt under the skin. A needle is placed through the skin and into the port to deliver the chemotherapy drugs.

Your doctor may decide to give you chemotherapy before (neoadjuvant) or after (adjuvant) your cancer surgery. Often, chemotherapy is given after surgery to treat any cancer cells that have already spread to lymph nodes or may have already spread to other parts of the body. However, if a tumor is so large or has spread already, chemotherapy can be given before surgery in an effort to shrink the tumor, making it resectable.

The drugs used are cytotoxic, which means they kill cells. Often, a combination of drugs are given to enhance their efficacy. Some common treatment combinations for breast cancer include[2]:

  • Doxorubicin and cyclophosphamide
  • Cyclophosamide, methrotrexate and 5-fluorouracil – given intravenously or orally

What are the Side Effects of Chemotherapy?

Different chemotherapy regimens will have various side effects based on their mechanism of action. Not all patients have the same symptoms. The most common side effects for breast cancer chemotherapy include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Fatigue
  • Hair loss from the entire body
  • Mouth sores
  • Brittle finger and toenails

There are other effects of chemotherapy that can only be detected by blood tests. For example, your platelet counts may drop keeping you from being able to form blood clots. Moreover, chemotherapy affects the bone marrow, which compromises the immune system making you more susceptible to infections. Your doctor may decide to hold off on a few doses of your chemotherapy if you have these symptoms, in order to let your bone marrow recover. There are medicines that can alleviate these side effects and your doctor will give them to you throughout your treatment process.

Complications

The worst complication with chemotherapy is that it does not work.[3] As mentioned above, it can also damage normal cells, which affects the function of other organs in the body. The organs that are often affected by certain drugs include the lungs, heart, kidneys, nerves and reproductive organs. Your doctor will tell you about the complications that are specific to the medicines that you are taking. They will also monitor these organs for signs of damage with blood tests, EKG, or x-rays. Most of these complications are reversible and your doctor may want to change the doses of your chemotherapy or the drugs used in your regimen if you start to show signs of organ dysfunction.

Conclusion

Chemotherapy is an important part of breast cancer treatment. Not all breast cancer patients will require chemotherapy as part of their treatment. But your doctor will tell you all you need to know about your cancer and as a team, you and your doctors can decide if chemotherapy is best for you.

References

1 Braddock, SW; Kercher, JM; Edney, JJ; and Clark, MM (2007). Straight Talk About Breast Cancer. Omaha, Nebraska: Addicus Books.
2 S. Aebi, S; Davidson, T; Gruber, G; and Cardoso, F (2011). Primary Breast Cancer: ESMO Clinical Practice Guidelines for Diagnosis, Treatment and Follow-Up. Ann Oncol, 22 (suppl 6):vi12-vi24.
3 Hirshaut, Y; and Pressman, PI (2008). Breast Cancer. The Complete Guide. 5th edition. New York: Bantam Books.

This article was originally published on July 27,2012 and last revision and update of it was 9/2/2015.