MAMMARY GLAND ADENOCARCINOMA IN A MALE BORNEAN ORANGUTAN (PONGO PYGMAEUS).

An adult male Bornean orangutan ( Pongo pygmaeus ) was diagnosed with invasive, poorly differentiated grade 9/9 mammary gland adenocarcinoma from a subcutaneous mass that was surgically removed during a routine preventative health examination. The tumor was tested for estrogen and progesterone receptors, human epidermal growth factor receptor 2 (HER2), and HER2 fluorescence in situ hybridization (HER2 FISH). Whole blood was tested for breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes. The orangutan was treated orally with two common human breast cancer drugs; tamoxifen and anastrozole. The orangutan lived for 4.5 yr postdetection, dying from an unrelated cause. This is the first reported case of mammary gland adenocarcinoma in a male great ape.

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

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.

Autoradiographic evidence of a loss of iodination within hormone-dependent GR mouse mammary tumors as they progress to independence.

The purpose of this study was to determine by use of light- and electron-microscope autoradiography whether or not iodination occurred in mammary tumors of female GR mice. Of the sixty tumors studied it was found that pregnancy-dependent and hormone-induced tumors possessed iodinating ability. Although mammary glands from nonpregnant GR mice lacked the ability to iodinate, by the 16th day of pregnancy in response to hormonal stimulation the glands readily iodinated casein, and some epithelial cells contained ultrastructural cytochemical evidence of mammary peroxidase. Preneoplastic mammary gland lesions known as hyperplastic alveolar nodules were also able to iodinate, as were plaques, the disc-shaped lesions which give rise to the hormone-responsive mammary tumors in this strain. Plaques also contained epithelial cells with mammary peroxidase activity. When hormone-induced mammary tumors were transplanted into syngeneic mice they retained the ability to iodinate for several generations. However, as the tumors progressed to hormone independence, the ability to iodinate was gradually lost. Hormone-independent mammary tumors from GR mice lacked both iodinating ability and cytochemical evidence of mammary peroxidase. These findings suggest that iodination depends upon hormone-responsive cells within the mammary tumors and that as these cells become hormone unresponsive, the ability to iodinate is lost.

Feline mammary hypertrophy/fibroadenoma complex: clinical and hormonal aspects.

Abnormal mammary enlargement, characterized microscopically by hyperplasia of both epithelial and mesenchymal tissues, was studied in 26 cats which were mostly young, sexually intact females. Clinicopathologic data indicated that mammary hypertrophy was likely progesterone-dependent. Administration of progestins preceded this condition in 5 cats, 4 of which were neutered. Serum progesterone concentrations (6.7 ng/ml) were increased in 1 of the 3 cats tested. Estrogen receptors were not found in the cytosols or nuclei of mammary tissues in the 2 cats studied. However, there were convincing 4S [3H]progesterone or 5S [3H]R5020 binding peaks which were suppressible by nonlabeled progestins. Progesterone receptors were measured at 14.9 and 8.6 fm/mg of protein, respectively. The apparent influence of progesterone, whether present as exogenous therapy in the male or female or as endogenous steroid of ovarian origin, has thus been demonstrated directly and indirectly in cats with mammary hypertrophy.