A Patient's Guide to Managing Hormone-Refractory Prostate Cancer  

Chapter 15. Managing Chemotherapy Side Effects

Introduction

Chemotherapy treatments have many side effects that affect patients in various degrees. It is important to know that in most cases mitigation of side effects is possible. Although most side effects caused by chemotherapy are reversible, it is important to identify the side effects and to consult your oncologist as soon as possible. Oncology nurses are also a good source of information about side effect mitigation. They are experienced and knowledgeable in this process. Side effects such as peripheral neuropathies can become permanent if not identified early enough. Be perceptive of any and all changes you perceive as induced by treatment.

For a more complete coverage of side effects and symptoms visit our section on Side Effects and Symptoms Management.

1. Side effects affecting blood counts (also see CBC).

Anemia

Anemia is characterized as a reduction of the concentration of hemoglobin and the circulating red blood cell amounts. A decreased hemoglobin level, hematocrit value, or RBC count could signify anemia. Such a condition is associated with cancer and chemotherapy treatments. Hemoglobin levels can respond to therapy with recombinant human erythropoietin (hEPO). Procrit, Aranesp and Epogen are commercial names of forms of erythropoietin. In severe cases of bone marrow depression, blood transfusions are necessary.

Leukopenia-Granulocytopenia

Leukopenia is characterized as a reduction of circulating white blood cells (WBC). The reduction is usually reflected by a low count of neutrophil granulocytes which are the immune system cells that first recognize and fight infections. Reduced number of these cells can make the patient susceptible to opportunistic infections. This condition can be severe and even result in death. Normal signs of infection other than fever might not be present making this condition a possible silent killer. Neupogen, Neulasta and Leukine are commercial names of products that stimulate production of white blood cells.

Thrombocytopenia

A normal platelet count ranges from 150,000 to 350,000 cells/mm3. Thrombocytopenia is commonly caused by the suppressive effects of chemotherapy, disease or prior therapy. There is an increasing risk of bleeding as the platelet count drops. If the platelet count falls to less than 50,000 cells/mm3 there is a high risk of bleeding. The situation can become critical at 20,000 cells/mm3 and platelet transfusions are required at 15,000 cells/mm3 or below.

2. Side effects affecting the gastrointestinal track

Nausea and Vomiting

Two of the most distressing side effects of chemotherapy are nausea and vomiting. The severity and incidence of these toxicities can vary greatly, but these symptoms can be bad enough in patients to cause them to stop treatment.

Some drugs such as Cisplatin and Cyclophosphamide(cytoxan) have a very high incidence of inducing nausea and vomiting. Carboplatin and Doxorubicin have a high incidence while Etoposide and Mitoxantrone are moderate inducers. Taxotere, Taxol and Navelbine are at the lowest rating to induce nausea and vomiting. This of course varies greatly among patients. Some the latest and most frequently used antinausea products are: Kytril, Anzamet, Zofran, Aloxi and Emend.

Anorexia and Taste Changes

Anorexia is the loss of appetite, even to the point of the thought of food inducing nausea. Anorexia can be induced by chemotherapy or by anti-pain medications.

Changes in taste sensation and repugnance to certain foods and food odors can cause a decreased in appetite in the cancer patient. Abnormalities can include a metallic taste after drug therapy. Remedies include treatment with steroids and/or dietary supplementation with specially fortified nutritional products that are commercially available.

Stomatitis

Stomatitis is an inflammation of the lining of any of the soft-tissue structures of the mouth. Stomatitis is usually a painful condition, associated with redness, swelling, and occasional bleeding from the affected area. The cells of the oral mucosa are characterized by their high proliferating rate. As such they are highly affected by chemotherapy agents. Oral hygiene is critical in preventing infections. Oral infections can affect proper nutrition in a cancer patient causing a cascade of side effects.

Diarrhea and constipation are common side effects of cancer treatment. Persistent diarrhea can cause dehydration, electrolyte imbalance, weakness, interference with nutrition and loss of body weight. Constipation, on the other extreme, can cause cramping, difficult evacuation, feeling of fullness impacting nutrition and in severe cases intoxication by reabsorption of toxic waste. Both these conditions must be addressed promptly in the cancer patient to maintain the proper timing in a chemotherapy schedule. Over the counter (OTC) medications are widely available to treat these conditions.

3. Side effects affecting the skin or hair

Alopecia or drug induced hair loss is a common side effect of some chemotherapy drugs and is mostly reversible. Chemotherapy agents most commonly associated with this side effect are: Cyclophosphamide, Doxorubicin, Vincristine, Etoposide and the taxanes (taxol and taxotere.)

Systemic dermatologic side effects such as dermatitis, nail changes, photosensitivity and others are usually limited to the duration of therapy. Nail lifting or complete loss can be extremely painful and impact quality of life by limiting patient dexterity in performing daily tasks such as inserting buttons etc.

4. Toxicity to Other Organ Systems

Chemotherapy induced renal toxicity is related to an alteration in kidney function. Plasma concentration of blood urea nitrogen (BUN) and creatinine are commonly used to assess renal function. Cisplatin and Suramin are two drugs capable of impacting renal function in prostate cancer treatment.

Chemotherapy induced pulmonary toxicity is present when the chemicals affect lung tissues. The most common toxicities are pneumonitis, pulmonary fibrosis and pulmonary edema. Symptoms may be acute and cause respiratory distress. Dypsnea (Shortness of breath or difficulty catching ones breath), cough, chills, myalgia(Pain in a muscle; or pain in multiple muscles. Myalgia means muscle pain), fatigue and headache have been reported with chemically induced pneumonitis. Doxorubicin, Cyclophosphamide and to a lesser amount, Taxotere, have been reported to induce pulmonary toxicities.

Cyclophosphamide (cytoxan) can cause bladder problems in the form of hemorrhagic cystitis or scarring.  This is due to a byproduct called acrolein which causes the irritation. The usual recommendation is to drink a lot of water while taking it.  At high doses of cytoxan, a drug called Mesna(Mesnex) is sometimes given to help prevent bladder problems.

Cardiac toxicity associated with chemotherapy is mostly related to anthracycline drugs. Cardiomyopathy(Cardiomyopathy is a serious disease in which the heart muscle becomes inflamed and doesn't work as well as it should.) and congestive heart failure are the most commonly reported carditoxicities. Ischemia, pericarditis(a condition that can cause chest pain, occurs when the sac that envelops the heart becomes inflamed), arrhythmia and angina have been reported less frequently. Doxorubicin and Mitoxantrone are anthracycline drugs known to cause severe cardiotoxicity with prolonged treatment. Continuous infusions seem to minimize risk. The drug, zinecard(dexrazoxane), may have some cardioprotective properties.

Toxicity of the central nervous system (CNS). Several chemotherapy drugs can cause distinct neurologic side effects. Often there is no drug treatment for these toxicities and sometimes the side effects are irreversible. Peripheral neuropathies are the most common of these neurological side effects. Patients should be on guard and alert their oncologists immediately at the onset of symptoms such as tingling or numbness in hands and feet. Caught early, there is a better chance of reversing the condition. Peripheral neuropathy can and does affect quality of life in patients. Visit pngeneral, for an excellent review of the topic by Bill Aishman. The drug, ethyol, at low doses (500mg) may prevent worsening of peripheral neuopathy or possibly prevent it from developing.

Authors: Ralph Valle and Howard Hansen,  1/23/06




Continue with Chapter 16