Postoperative Adjuvant Treatment of Invasive Malignant Mammary Gland Tumors in Dogs with Doxorubicin and Docetaxel

Abstract

Background: Treatment outcome after surgery alone is unsatisfactory in dogs with invasive malignant mammary gland tumors.Hypothesis: Adjuvant doxorubicin or docetaxel will improve the treatment outcome in dogs with high-risk malignant mammary gland tumors, and the use of docetaxel will be feasible in affected dogs.Animals: Thirty-one dogs with malignant mammary gland tumors of histologic stages II and III (vascular or lymphatic invasion, regional lymph node metastasis, or distant metastasis) were used.Methods: A prospective clinical trial in which dogs were treated with surgery alone (n 5 19) or also received adjuvant chemotherapy (n 5 12) with doxorubicin or docetaxel was conducted. Docetaxel was given as an IV infusion at a dose of 30 mg/m 2 preceded by dexamethasone and diphenhydramine administration. Results: The recurrence-free interval ranged from 13 to 2,585 days (median not reached); the median metastasis-free interval and overall survival were 294 days and 370 days, respectively. Dogs treated with chemotherapy had a tendency toward higher long-term local control and survival rates, but there was no significant difference in the recurrence-free interval (P 5 .17), time to metastasis (P 5 .71), and overall survival (P 5 .12). Factors found to influence the time to metastasis and overall survival included lymph node metastasis (P 5 .009) and tumor fixation to underlying structures (P 5 .043, time to metastasis), as well as age (P 5 .018) and histologic stage (P , .001, survival). Mild allergic skin reactions were the most frequently observed complications of docetaxel treatment.Conclusions and Clinical Importance: Chemotherapy did not lead to an improved outcome in this population. Docetaxel treatment was well tolerated. Additional investigations of adjuvant chemotherapy in dogs with high-risk mammary cancer are warranted.

Canine Mammary Tumors: Risk Factors, Prognosis and Treatments

“…Another clinical trial comprised the treatment of bitches with MMT, with doxorubicin or docetaxel, but no benefit in overall survival rates was observed (Simon et al, 2006).…”

Use of an oncolytic vaccinia virus for the treatment of canine breast cancer in nude mice: preclinical development of a therapeutic agent

“…4 In addition, the use of chemotherapeutic drugs in dogs has produced complete and partial remissions of disease in only some isolated cases. 5,6 These facts emphasize the need for the development of new therapies for cancer in dogs. One of the most promising new strategies in this field could be the oncolytic virotherapy.…”

Postoperative adjuvante Therapie mit einem Mistelextrakt (Viscum album ssp. album) bei Hündinnen mit Mammatumoren

“…Bei 6743 Tumorbiopsien eines Registers von Krebserkrankungen bei Kleintieren in Italien waren etwa 70% aller Tumore der Hündin im Gesäuge und wiesen eine Malignitätsrate von knapp 50% auf [5]. Die meisten betroffenen Tiere sterben im ersten Jahr post operationem [6][7][8][9]. Neben der Größe der Tumoren und dem Alter der Hunde verringern vor allem Lymphknotenund Fernmetastasen die Überlebensrate signifikant [10,11].…”

“…Zu den verschiedenen, die Chirurgie ergänzenden Therapieansätzen wie Chemo-, Radio-oder auch Hormontherapie, wie sie in der Humanmedizin etabliert sind, liegen nur wenige veterinärme-dizinische Studien vor [9,11,[13][14][15][16][17][18]. Keine der untersuchten adjuvanten Therapien zeigte bisher ein überzeugendes Resultat, sodass bisher kein empfehlenswerter «Goldstandard» festgelegt werden konnte.…”