Ovarian function suppression with a GnRH analogue: d‐ser(But[t])[6]‐Arzgly[10]‐LHRH (Goserelin) in hormone dependent canine mammary cancer

Abstract

Hormones and hormone level modifying substances have long been used to treat hormone-dependent tumours in humans. Recently, attempts have been made to use hormone manipulation regimens for the treatment of these tumours in veterinary medicine. The aim of the present study was to evaluate the activity of the luteinizing hormone-releasing hormone (LHRH)-agonist, D-ser(But[t])[6]-Azgly[10]-LHRH (Goserelin) in hormone-dependent mammary cancer in dogs. Eighteen female dogs with hormone-dependent mammary cancer (T2-T4, N0, M0 according to TNM clinical staging classification) were selected and allocated into two groups: nine dogs not treated with Goserelin (Group 1) referred to as control; and nine dogs treated with 60 microg/kg depot Goserelin every 21 days for 12 months (Group 2). Goserelin treatment decreased circulating levels of oestradiol and progesterone and reduced the size of mammary tumours; all the animals showed objective response (OR) to treatment after 3 months, and the relapse-free survival after 2 years was 88%. Haematology and blood chemistry parameters, measured every month from the beginning of treatment, as well as physical examination, showed that the drug was without toxic effects. This suggests that, at the dose administered, Goserelin blocks the hypothalamus-pituitary-ovary axis, and consequently can be useful to treat hormone-dependent mammary tumours in female dogs.

Canine Mammary Tumours, an Overview

“…1994). A study in a group of 18 dogs with hormone‐dependent CMTs showed similar results (Lombardi et al. 1999).…”

“…Although there are no established guidelines for treatment beyond surgery, dogs with locally advanced disease, with metastatic CMTs or with a biologically aggressive histological type of CMT may benefit from adjuvant treatment such as radiotherapy, anti‐Cox‐2 treatment, chemotherapy, desmopressin, hormonal therapy, chemotherapy or anti‐angiogenic therapy (Morris et al. 1993; Lombardi et al. 1999; Klijn et al.…”

Clinical Use of Deslorelin for the Control of Reproduction in the Bitch

“…Controlling the risk of recurrence of mammary neoplasia has been proposed as an indication for using a long-acting GnRH agonist in the bitch. An implant of goserelin acetate (Goserelin acetate, Zeneca, Milan, Italy), administered SC at the dose of 60 mcg ⁄ kg every 21 days for 12 months suppressed cyclicity in nine adult bitches with mammary neoplasia reducing their circulating concentrations of oestradiol and P4, thus lowering the risk of recurrence of such neoplasia (Lombardi et al 1999). However, bitches with mammary neoplasia are often older dogs potentially with other reproductive conditions, which may be exacerbated by the use of long-acting GnRH agonist implants.…”

Clinical Use of GnRH Agonists in Canine and Feline Species

“…Lombardini et al. (1999) showed that goserelin 60 mg/kg given every 3 weeks reduced the size of mammary tumours after 3 months in nine study bitches.…”