"Common Questions About Chemotherapy" TUMOR TIDBITS, A BIWEEKLY VETERINARY ONCOLOGY E-LETTER Number 65; August 16, 2002. Editor: Kevin A. Hahn, DVM, PhD, Dipl - ACVIM (Oncology) & Overall Nice Guy! ANNOUNCEMENTS *Did you know that reducing the chemotherapy dosage by 25% oftentimes reduces the risk or severity of complications by 75-90% in most instances without severely compromising cancer care? Please consult with our oncologist. *We are continuing to enroll dogs with lymphoma in our clinical trial evaluating an antiangiogenic (anti-blood vessel) agent. We also anticipate this fall enrolling dogs with hemangiosarcoma in an antiangiogenic clinical trial. Don't forget that we are offering growth hormone supplementation in dogs with cancer or chronic illness. *Check our web site regularly for additional information and updates. Subscribe to our weekly email newsletter online! Call any of our 3 Oncologists (Hahn, King, Carreras), 2 Oncology Residents (Freeman, Turner) or our Oncology Nurses Monday-Friday or email Dr. Hahn for more information and patient consultations. ============================================ THIS WEEK'S TUMOR TIDBIT: COMMON QUESTIONS ABOUT CHEMOTHERAPY ============================================ Cancer cells are, to some extent, similar to normal cells. Any drug that can damage and kill cancer cells, carries a potential to damage normal cells as well. As a result, treatment with chemotherapy drugs may have significant side effects such as nausea, vomiting, diarrhea, appetite loss, bruising, fever, and hair loss. Nausea, vomiting, diarrhea, and appetite loss are the most uncomfortable side effects of chemotherapy. With the development of new anti-nausea medications, this problem can now be prevented in almost every patient. During chemotherapy, drugs can stimulate and irritate certain key areas in the brain and cause nausea and vomiting. Chemotherapy will decrease the number of cells that line the inner portion of the small intestine and colon about 3-7 days after drug administration. This may cause a decrease in nutrient and fluid absorption resulting in nausea, diarrhea, appetite loss and possibly dehydration. Call the clinic or an emergency veterinarian if these signs persist for more than 24 hours or fresh blood is noted in the stool. Thrombocytopenia refers to lowering of platelets in the blood and if severe, it can cause bleeding. In cancer patients, it is normally due to impaired production of the platelets from the bone marrow. Severity of thrombocytopenia determines the signs and problems that it may cause. In mild cases, patients may have no symptoms at all. In moderate cases, you may notice red spots or bruising on your pets skin, most commonly along the abdominal wall and along the legs. In severe cases a low platelet count can cause bleeding from any site of the body and be very dangerous. Bleeding may be obvious, like from gums, or vaginal bleeding, or could be obscure. If you see these signs, call the clinic or an emergency veterinarian immediately. There are various types of cells in the blood. The lowering of the white blood cells that fight infections is known as neutropenia. It is the most important complication of chemotherapy. It is almost always due to impairment of bone marrow to produce cells and normally occurs 3-7 days after chemotherapy. It is most severe in patients who receive aggressive treatments. The signs and symptoms of neutropenia depend on its severity. However, patients with even mild forms can develop major problems. Even in the most severe cases, it may have no signs at all, or it may cause fever and infection. A fever in patients who have received chemotherapy must be taken seriously, requiring a complete evaluation. Febrile neutropenia is a medical emergency and must be dealt with immediately. Any rectal temperature over 103.5 F (Fahrenheit) should be reported to your medical oncologist or emergency veterinarian without delay. Hours and minutes are critical. If left untreated, this complication may become fatal in a matter of hours. Hair loss is the most noticeable side effect of cancer treatment. Severity of hair loss, as well as the timing of it will depend on the breed of the dog as well as the type, schedule and the amount of the drugs used. Hair loss usually starts 2-3 weeks after initiation of chemotherapy. It may be complete or just thinning and partial loss of hair. Hair may be lost gradually and over a period of few weeks or it may happen in matter of a few days. Hair loss can involve every part of body. Hair will grow back following the completion of chemotherapy. Re-growth starts about a month after completion of chemotherapy. The new hair may grow and look exactly the same as prior to chemotherapy or it may feel and look completely different. Color of hair may be slightly different. Hair may grow thicker, or thinner, less curly or curlier. What you can do at home? Call your veterinarian or an emergency veterinarian if any sign persists for more than 24 hours or if the sign worsens at any time. If nausea, vomiting or diarrhea occur, withhold all food for 24 hours. Always offer plenty of water, including ice chips. Reintroduce food slowly by feeding small, frequent meals versus one larger meal. Offer small bland meals such as chicken or veal baby food. If your pet is not drinking, offer chicken or beef broth. Before your next visit with your veterinarian, call one week in advance to schedule your appointment and withhold all food the morning of the visit. Please let the staff know of any complications that may have occurred between visits. What's the bottomline? - If any thing bothers you - bother your veterinarian, your oncologist, or an emergency veterinarian!!!!!!!!! SUGGESTED READING * Veterinary Oncology, From "The Practical Veterinarian Series". By Hahn KA. Butterworth-Heinemann Press, 2002. ============================================ I hope this info helps and don't hesitate to call or email us at Gulf Coast Veterinary Oncology! Kevin Kevin A. Hahn, DVM, PhD Diplomate American College of Veterinary Internal Medicine (Oncology) & Overall Nice Guy Gulf Coast Veterinary Diagnostic Imaging & Oncology 1111 West Loop South, Suite 150, Houston, TX 77027 P: 713.693.1166 F: 713.693.1167 W: www.gcvs.com Email: drhahn@gcvs.com