"Renal Tumors in Dogs" TUMOR TIDBITS, A BIWEEKLY VETERINARY ONCOLOGY E-LETTER Volume 3; Number 1; January 9, 2002. Editor: Kevin A. Hahn, DVM, PhD, Dipl - ACVIM (Oncology) & Overall Nice Guy! ANNOUNCEMENTS * Happy New Year from the Doctors at Gulf Coast Veterinary Oncology. * Welcome our newest Doctor - Dr. Janet Carreras! That brings us up to 6 doctors serving the Gulf Coast Community - Drs. King, Harris, Turner, Freeman, Carreras and yours truly - more than any practice in the Southeast Region of the USA! * Keep in touch with us - we're negotiating a number of clinical trials and hope to have some available by Summer 2002! *****THIS WEEK'S TUMOR TIDBIT: Renal Tumors in Dogs***** OVERVIEW OF WHAT'S IN THE TEXTBOOKS: Primary renal tumors are uncommon (approximately 1% of all reported neoplasms in dogs), highly metastatic, locally invasive, and often bilateral malignant tumor, accounting for most primary renal tumors. Female German shepherd dogs are prone to renal cystadenocarcinoma, a less aggressive disease with a better long-term prognosis than renal adenocarcinoma. SIGNALMENT * Renal adenocarcinoma--older dogs; 1.5:1 male to female ratio. * Renal cystadenocarcinoma--female German shepherd dogs predominates. SIGNS * Renal adenocarcinoma--primarily insidious, nonspecific signs such as weight loss, inappetance, lethargy, hematuria, and anemia. * Renal cystadenocarcinoma--physical examination findings include painless, firm, fibrous lesions of the skin and subcutaneous tissues (nodular dermatofibrosis) and uterine polyps in some animals. CAUSES AND RISK FACTORS * Unknown for both diseases. DIFFERENTIAL DIAGNOSIS * Other primary neoplasia. * Renal adenoma or cyst. * Pyelonephritis. DIAGNOSTIC TEST RESULTS * Polycythemia, Anemia, Biochemistry normal or reveals evidence of renal failure, Proteinuria and microscopic or gross hematuria; findings nonspecific in many animals. * Thoracic radiographs--metastatic disease up to 30% of patients. * Abdominal radiographs, intravenous pyelography, ultrasonographic examination of abdomen--to assess extent of local disease and regional lymph nodes. * Renal biopsy for definitive diagnosis. TREATMENT * Renal adenocarcinoma is often a bilateral disease. * In a patient with unilateral disease, survival is approximately 6-10 months after nephrectomy. * Renal cystadenocarcinoma has a much better prognosis, with affected dogs surviving 12 months or longer with no definitive treatment. * Definitive drug therapy for renal adenocarcinoma has not been reported. * Supportive treatment to patients with renal failure. POSSIBLE COMPLICATIONS * Renal failure if bilateral disease. * Even if disease is localized, long-term prognosis is poor. * Hypertrophic osteopathy in some animals. * Renal failure concurrent in some animals. * Nodular dermatofibrosis in some animals with renal cystadenocarcinoma. PROGNOSIS * Without treatment, renal failure or hematuria is life-threatening and survival is less than 2 months. * With unilateral nephrectomy, median survival times of 4 to 6 months have been reported. WHAT DO WE DO AT GULF COAST? If a dog presents with a unilateral primary tumor of the kidney and a complete abdominal ultrasound examination and thoracic radiography survey (3 views) is normal in appearance, we consider nephrectomy followed by combination chemotherapy (Adriamycin or Mitoxantrone induction with Vincristine/Cytoxan maintainence) for 1 year. Although purely anecdotal, we have about 2 in 3 dogs survive 1 year or longer. Don't hesitate to call or email us at Gulf Coast Veterinary Oncology! ALL THE BEST AND HAPPY NEW YEAR, Kevin A. Hahn, DVM, PhD Diplomate ACVIM (Oncology) & Overall Nice Guy Gulf Coast Veterinary Specialists 1111 West Loop South, Suite 150 Houston, TX 77027 P: 713.693.1166 F: 713.693.1167 http://www.gcvs.com mailto:drhahn@gulfcoastvetspec.com