Breast cancer – Symptoms and treatment
My doctor checks my blood count just before I get my next dose of chemotherapy. Why does he also need to check it 1-2 weeks later?
Your blood counts reach their nadir about 1-2 weeks after you get your chemotherapy. After a few days, they start to rise, and usually return to normal in time for you to start your next cycle of chemotherapy. Your doctor checks your blood counts on the day that you get chemotherapy (or the day before) so that he will know if it safe for you to start your next cycle of chemotherapy.
If your white blood cells or platelets are too low, you will probably need to wait until they return to a safe level before you get your next treatment. Your oncologist may also want to know how low your counts get at their nadir. This helps her decide if she needs to modify the dose of your chemotherapy or the interval between your treatments. If your WBC nadir is unusually low, or if you have neutropenic fever or infection, your oncologist may decide to give you a cytokine (Neulasta or Neupogen) the day after your next chemotherapy infusion, to try to prevent this from happening again. He also uses these mid-cycle nadir blood counts to advise you on the need for any special precautions or treatments to protect yourself from infection (due to low WBC counts) or bleeding (due to low platelet counts).
Terms:
Platelets – Components of blood that assist in clotting and wound healing.
Neutropenic fever – A fever due to a low white blood cell count, usually caused by a side effect of chemotherapy.
Is there anything that I can do to bring my counts up?
Not really. Your bone marrow makes your blood cells, and it is particularly sensitive to chemotherapy. Chemotherapy causes some degree of bone marrow suppression in almost everybody. Some chemotherapy drugs are harder on the bone marrow than others, but with time, your blood counts will rise. If your blood counts continue to be low, your doctor may need to decrease the dose of chemotherapy that you are getting. A lower dose of chemotherapy will probably kill fewer cells and allow you to get chemotherapy on schedule. Another approach is for your doctor to give you a cytokine (for example G-CSF, Neupogen, or Neulasta) injection the day after you get your chemotherapy.
An oncology nurse usually gives you this injection subcutaneously, or under the skin. If you are curious about the physiology of how this works, cytokines or colony-stimulating factors (CSFs) are growth factors that stimulate your bone marrow to make white blood cells. CSFs increase the recovery rate from bone marrow side effects of chemotherapy and radiation. Bone marrow side effects lower blood counts. Sometimes oncologists give CSFs in the middle of a chemotherapy cycle to limit the period of neutropenia, especially if you have a severe infection. You may experience some bone discomfort a day or two after you get a CSF. This is due to the rapid growth of blood cells in the confined space of the bone marrow. This pain is usually mild and controlled with acetaminophen (Tylenol) or ibuprofen, but sometimes you have to take stronger medicine for a few days.
When I have a problem, should I call my primary care doctor or my oncologist?
That depends on what the problem is. Your cancer or treatment may affect your other medical problems, and it is critical that all of your doctors communicate with each other. For example, the corticosteroids (prednisone or Decadron) that oncologists use as chemotherapy premedication, or to help control nausea and vomiting, may make gastric acid problems worse or increase your blood sugar making your diabetes worse. If you have high blood pressure, your doctor may need to adjust your antihypertensive medicines. Most oncologists prefer that your
A primary care doctor continue to manage your non– A cancer-related problems, but since your primary care doctor may not always be aware of some of the problems associated with certain cancers or cancer treatments, it is important that you tell your oncologist about all of your medical problems. For example, the low-grade fever and sore throat that your primary doctor usually tells you to treat with acetaminophen and salt water gargles may require hospitalization and intravenous antibiotics in the setting of a chemotherapy-induced low white blood count. A good rule of thumb is, when in doubt, call your oncologist’s office, and let them decide who should take care of the problem.
Term:
Primary care doctor – The physician (internist or family doctor) who takes care of your general healthcare needs.
Why do I need intrathecal chemotherapy?
Chemotherapy reaches cancer metastases through the bloodstream, but the blood-brain barrier interferes with its ability to reach brain metastases. This barrier prevents germs and other disease-causing agents from reaching the brain. The same barrier that prevents germs from reaching the brain and protects you from infections also prevents chemotherapy from reaching your brain and protects brain metastases from chemotherapy. It is very difficult to break down this barrier. The only effective way to get chemotherapy into the brain or the tissues surrounding it (meninges) is to bypass it. Doctors do this by putting the chemotherapy directly into the fluid that surrounds the brain. From there, it can penetrate the cancer cells that seed the lining of the brain (carcinomatous meningitis). The fluid that is in contact with the meninges of the brain also circulates down the spinal canal. Therefore, it is possible for your doctor to treat these metastases by doing a spinal tap and injecting chemotherapy into the spinal canal. If you need repeated injections of chemotherapy, it is usually easier to do this through an Ommaya reservoir placed directly into one of the ventricles (lakes of spinal fluid) in your brain. This may sound dangerous, but it really is not. This relatively minor surgical procedure is quite similar to having a port placed in the large veins in your chest.
Term:
Blood-brain barrier – A special layer that protects the brain from infection. This layer is made up of a network of blood vessels with thick walls.
