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Patient Education: Diseases Conditions Treatments & Procedures

Breast Cancer

Types of Treatment Tests

Adjuvant therapy is a term used to describe a treatment given in addition to the primary surgical treatment for breast cancer. The goal of adjuvant therapy is to destroy any cancer cells that may remain after surgery or that spread from the tumor and have traveled to other parts of the body.

Radiation therapy, chemotherapy, hormonal therapy and biological therapy, alone or in combination, are all treatments that can be used after surgery to give you the best chance to reduce the risk of a recurrence of breast cancer. In some cases, radiation therapy or chemotherapy may be given before surgery to shrink the tumor and make it easier to remove. This is called neoadjuvant therapy.

All treatment methods can damage healthy cells and lead to side effects, but the side effects are very different for each type of treatment. You can discuss the specific side effects with your physician or nurse once your specific treatment plan is determined.

Blood Tests Monitored During Breast Cancer Therapy
Your physician may order some or all of the following blood tests as part of your diagnostic work-up or throughout your treatment of breast cancer:

Complete Blood Count (CBC): This test is done before starting chemotherapy and before each cycle of chemotherapy. Patients and clinicians may refer to this test as "counts". A CBC test looks at the red blood cell counts, Hemoglobin (Hgb), white blood cell (WBC) counts and platelet counts. All of these are normal cells growing quickly in the bone marrow and can be reduced by chemotherapy in the same way cancer cells are.

  • White blood cells (WBC's) are what protect you from bacterial infections. Neutrophils are the most mature type of WBC and are most effective in fighting infections. Generally, if the neutorphil count is lower than 1.0 on the day of chemotherapy, you will not receive chemotherapy. The WBC count can recover on its own very quickly (within days) and therefore, chemotherapy may be delayed for a few days or a week rather than skipping an entire cycle of chemotherapy. At times, your oncologist may recommend an injection, called a growth factor (e.g. Neupogen), to prevent your counts from dropping too low after chemotherapy.
  • Red blood cells transport oxygen to the vital organs in the body including the heart and lungs. A low hemoglobin level (Hgb) can be an indication of anemia. These counts also recover on their own after chemotherapy. If you are symptomatic from the anemia (low Hgb), meaning you become short of breath, have profound weakness or experience chest pain, you should contact your nurse or oncologist right away. At times your oncologist may recommend an injection, called a growth factor (e.g. Aranesp), to increase your Hgb levels.
  • Platelets are important to stop bleeding from a cut or bruise. A low platelet count can affect your ability to stop bleeding. If the platelet count is less than 20,000, you will be given instructions about how you can avoid any potential risk of bleeding or bruising. A platelet count of less than 10,000 may require a platelet transfusion. Platelets recover on their own after chemotherapy but depending on the drugs used, may take longer to fully recover. Low platelet counts are very rare during chemotherapy for breast cancer.


Liver Function Tests
There are 4 values tested that can show if the liver has experienced any damage or will be able to process the chemotherapy drugs when given. Abnormal liver tests occasionally indicate the possibility of a recurrence of cancer in the liver or bones.

Kidney Function Tests
BUN/Creatinine are two tests that are sometimes done before treatment begins and to monitor your health after treatments are over. These tests show how well the kidneys are working and if they can safely eliminate certain chemotherapy drugs. Some chemotherapy drugs are more toxic to the kidneys than others and will require a BUN/Creatinine before each cycle of chemotherapy in order to give a safe dose of chemotherapy.

Tumor or Cancer Markers
These blood tests are sometimes helpful to detect or follow breast cancer. Some oncologists use them to see if the cancer has returned. Your oncologist may sometimes use these tests for patients with metastatic breast cancer to monitor their response to therapy. The use and/or frequency of these tests are determined by your physician. You can discuss the goal of using these tests with your oncologist.

  • CEA (carcinoembryonic antigen) is a marker for colon, lung and liver cancers and can be used in breast cancer to detect evidence of metastasis of the breast cancer to these organs.
  • CA15.3 is a marker used to detect breast and ovarian cancers.

Visit the Breast Care Group at Odette Cancer Centre