Acid mucopolysaccharides in mammary tumors of dogs.

The predominant acid mucopolysaccharides found in selected epithelial mammary tumors of dogs stained with alcian blue and were labile to hyaluronidase digestion. These histochemical characteristics identified them as hyaluronic acid, chondroitin-4- and chondroitin-6-sulfate. The intensity of the staining of these acid mucopolysaccharides varied in a transitionary process from a precartilaginous to a pseudocartilaginous intercellular matrix to mature hyaline cartilage. The tumor acid mucopolysaccharides were indistinguishable from those associated with formation of cartilage in developing mammals; such cartilage is reported to be produced only by cells of mesodermal origin. There was no evidence to suggest transitional changes in myoepithelial cells, neoplastic epithelial cells or their components that could contribute to the formation of the acid mucopolysaccharides. It was concluded that the heterotopic tissues (cartilage, bone and fibrous connective tissue) in the epithelial mammary tumors were derived from cells of mesodermal origin and formed the adjacent stroma in areas of neoplasia.     

Influence of host factors on survival in dogs with malignant mammary gland tumors

The purpose of our study was to determine if specific host factors, such as age at diagnosis, obesity, and hormone status, influence the prognosis of canine mammary gland carcinomas and to confirm if previously reported risk factors (ie, histologic subtype, tumor size, and World Health Organization [WHO] stage) were important in a large series of affected dogs. Ninety-nine female dogs with mammary gland carcinomas, no previous therapy, an excisional biopsy, and known cause of death were studied. No significant association with survival was noted for age at diagnosis (chronologic or physiologic), obesity, or hormone status (ie, spayed versus intact, regardless of time of being spayed). Of the tumor factors analyzed, the histologic subtype anaplastic carcinoma (P = .02), WHO stage I (P = .01), evidence of metastasis at the time of diagnosis (P = .004), and tumor size of 3 cm or smaller (P = .005) all significantly influenced survival. Dogs that were classified as having tumor-related mortality had a shorter postoperative survival compared to dogs that died of other causes (14 months versus 23 months; P = .03). In conclusion, histologic subtype, WHO stage, and tumor size remain important prognostic factors in canine mammary gland tumors. Further study of other prognostic factors is needed to determine which tumors are adequately addressed with local therapy only and which dogs may require adjuvant treatment with chemotherapy.     

Routine hematology and clinical chemistry in female dogs with benign and malignant mammary tumors

Routine hematological and serum biochemical screening was done in 61 female dogs with benign mammary tumors and 51 female dogs with malignant mammary tumors. Most parameters were not significantly different from age-matched female controls; moreover, no significant difference could be observed between animals with benign and malignant tumors. It is concluded that routine hematology and biochemistry offer little diagnostic or prognostic benefit in female dogs with mammary tumors.     

Sialic acid and sialyltransferase activity in serum and tissues of dogs with mammary tumors

In humans, the glycosylation pattern of serum and of membrane glycoproteins is associated with invasiveness of tumors: specifically, α2,6-sialylation and α2,3-sialylation are associated with metastasizing and nonmetastasizing tumors, respectively. In turn, the type of sialylation depends on the activity of α2,6 or α2,3 sialyltransferase (ST) enzymes. Because of the high prevalence of metastasizing tumors with biological behavior similar to the human counterpart, female dogs with metastasizing neoplasms could provide a good animal model for investigating the potential roles of sialic acid (Sia) and ST enzymes in the pathogenesis of metastatic tumors. The aims of this study were (1) to validate a solid-phase method based on lectin staining of serum and tissue homogenates to investigate sialylation and ST activity and (2) to compare the results obtained with this method and with lectin staining and to collect preliminary information on sialylation and ST activity in dogs with (n = 8) and without (n = 8) mammary tumors. The data recorded in healthy dogs revealed that serum and tissue glycoproteins are prevalently characterized by a α2,6 sialylation, but ST-α2,3 seems to be the most active enzyme in both samples. Sia-α2,3 and ST-α2,3 activity decreases in serum and tissues of dogs with tumors, especially in a dog with metastasis, suggesting that the equilibrium between ST-α2,6 and ST-α2,3 activity shifts toward the former, as reported in humans.     

Clinical significance of circulating vascular endothelial growth factor in dogs with mammary gland tumors

Increase in circulating vascular endothelial growth factor (VEGF) is suggested as a prognostic indicator in human patients with malignant tumors. The purpose of this study was to evaluate the clinical significance of circulating VEGF in dogs with mammary gland tumors (MGT). Both plasma and serum VEGF were significantly higher in dogs with MGT when compared with those in the healthy dogs. In dogs with MGT, the plasma and serum VEGF of the malignant group increased significantly compared with those of the benign group. Additionally, there was a significant difference between the plasma and serum VEGF in the groups with postoperative metastasis and no metastasis. Circulating VEGF is expected to be clinically available for the determination of prognosis in canine MGT.     

Deleted chromosome 32 in mammary neoplasms in two domestic dogs

Tumour cells of two cases of mammary neoplasm in dogs were investigated cytogenetically. A small marker chromosome, a deleted chromosome 32, was detected in many cells (35 and 40 per cent respectively) in both dogs.     

Prognostic factors associated with survival two years after surgery in dogs with malignant mammary tumors: 79 cases (1998-2002)

OBJECTIVE: To identify prognostic factors for female dogs that have undergone surgical removal of malignant mammary tumors. DESIGN: Retrospective case series. ANIMALS: 79 female dogs with malignant mammary tumors. PROCEDURE: Information obtained from the medical records included breed, age, sex, tumor size (maximum diameter), number and location of affected mammary glands, time between tumor identification and surgical removal, radiographic evidence of distant metastasis, surgical procedure, ovariohysterectomy (OHE) status, histologic classification of the tumor, and survival time. RESULTS: Results of univariate analyses indicated that clinical stage, tumor size, OHE status, metastasis to adjacent lymph nodes or distant sites, and histologic classification of the tumor were significantly associated with survival 2 years after surgery. Tumors > or = 5 cm in diameter and tumors that had been identified > 6 months before surgery were more likely to metastasize to adjacent lymph nodes. Ovariohysterectomy was more beneficial in dogs with complex carcinomas than in dogs with simple carcinomas. In multivariate analyses, clinical stage, tumor size, and OHE status were significantly associated with survival 2 years after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that tumor stage, tumor size, and OHE status were significant prognostic factors associated with survival 2 years after surgery in dogs with malignant mammary tumors. Further, either dogs with tumors > or = 5 cm in diameter or dogs with tumors present for > 6 months prior to surgery had a higher risk of having lymph node metastases.     

Analysis of mammary gland tumors in dogs in the South Bohemian Region

149 biopsies and excisions of tumorous tissues of the mammary gland it bitches were examined histologically at a workplace of the State Veterinary Institute at Ceské Bud?jovice in the years 1970 to 1987. The tumours were classified according to the criteria recommended by the WHO classification system. The tumours were divided into three groups with respect to their histogenesis: epithelial (58.4%), mesenchymatous (2%) and mixed (39.6%). The ratio of malignant to benign tumours made 65.1% to 34.9%.     

Survey radiography and computerized tomography imaging of the thorax in female dogs with mammary tumors

Background

Accurate early diagnosis of lung metastases is important for establishing therapeutic measures. Therefore, the present study aimed to compare survey thoracic radiographs and computerized tomography (CT) scans to specifically identify lung metastases in female dogs with mammary tumors.

Methods

Twenty-one female dogs, weighing 3 to 34 kg and aged from 5 years to 14 years and 10 months, with mammary tumors were studied. In all dogs before the imaging examinations, fine-needle aspiration cytology of the mammary tumors was performed to confirm the diagnosis. Three-view thoracic radiographs were accomplished: right lateral, left lateral and ventrodorsal views. Sequential transverse images of the thorax were acquired on a spiral Scanner, before and after intravenous bolus injection of nonionic iodine contrast. Soft-tissue and lung windows were applied. All the mammary tumors were surgically removed and examined histologically.

Results

The correlation between the cytological and histological results regarding presence of malignancy was observed in only 17 cases. In radiographic examinations, no dog displayed signs of lung metastases or thorax chest lesions. CT detected lung metastasis in two cases, while small areas of lung atelectasis located peripherally were found in 28.57% of the dogs.

Conclusion

In this study population, spiral CT showed higher sensitivity than chest radiographies to detect lung metastasis; this indicates that CT should be performed on all female dogs with malignant mammary tumors.     

Evaluation of serum haptoglobin and C‐reactive protein in dogs with mammary tumors

Background: In veterinary medicine, there is increasing interest in measuring acute phase proteins as a tool in the diagnosis and monitoring of neoplastic diseases. Although mammary neoplasms are the most common type of cancer in dogs, acute phase proteins have not been extensively evaluated in dogs with mammary tumors. Objectives: The aim of this study was to evaluate serum haptoglobin (Hp) and C‐reactive protein (CRP) concentrations in the dogs with mammary tumors and assess their potential association with malignancy. Methods: A retrospective study of dogs with mammary tumors was performed. Serum concentrations of CRP and Hp were determined in healthy control dogs (n=20) and dogs with mammary tumors before surgery (n=41). Mammary tumors were grouped as carcinomas (n=24), fibrosarcoma (n=1), malignant mixed tumors (n=7), benign mixed tumors (n=6), and adenomas (n=3). CRP and Hp concentrations were compared in dogs with different tumor types and were also compared based on tumor size, lymph node infiltration, skin ulceration, fixation to underlying tissue, and time between tumor identification and removal. Results: Hp concentration was significantly (P<.043) higher in dogs with mammary tumors (median 2.03 g/L, range 0.09–2.94 g/L) compared with controls (1.38 g/L, range 0.08–3.00 g/L), but the range of values overlapped considerably. CRP concentration was higher in dogs with carcinomas (4.70 mg/L, range 0.63–128.96 mg/L) vs controls (2.11 mg/L, range 0.25–6.57 mg/L) (P=.0008) and in dogs with ulcerated skin (14.8 mg/L, range 5.7–128.9 mg/L, n=3) compared with those without ulceration (2.4 mg/L, range 0.11–30.3 mg/L, n=38) (P=.048). Conclusions: Serum Hp and CRP do not appear to have value in diagnosing or predicting malignancy of mammary tumors in dogs. Higher CRP concentrations in dogs with mammary carcinoma suggest a role for inflammation in this tumor type.     

Postoperative adjuvant treatment of invasive malignant mammary gland tumors in dogs with doxorubicin and docetaxel

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 = 19) or also received adjuvant chemotherapy (n = 12) with doxorubicin or docetaxel was conducted. Docetaxel was given as an IV infusion at a dose of 30 mg/m2 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 = .17), time to metastasis (P = .71), and overall survival (P = .12). Factors found to influence the time to metastasis and overall survival included lymph node metastasis (P = .009) and tumor fixation to underlying structures (P = .043, time to metastasis), as well as age (P = .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.     

Comparison of B-mode and Doppler ultrasonographic findings with histologic features of benign and malignant mammary tumors in dogs

OBJECTIVE: To compare and correlate B-mode and color Doppler ultrasonographic characteristics with the histologic findings of benign and malignant mammary tumors in dogs. STUDY POPULATION: 49 mammary tumors in 26 dogs. PROCEDURES: Before excision, tumors were evaluated via B-mode and color Doppler ultrasonography to assess size, echogenicity, echopattern, acoustic transmission, invasiveness, and vascularity. Paraffin-embedded microsections of the tumors were stained with H&E and examined for presence of necrosis, cysts, cartilage, bone, mineralization, invasion of surrounding tissue, and tissue heterogeneity. To assess vascularity, the number and distribution of vessels that were stained by the Verhoeff van Gieson technique were recorded. RESULTS: Tumor echogenicity and echopattern on ultrasonographic images correlated with tissue heterogeneity detected histologically. Acoustic enhancement was correlated with the presence of necrotic or cystic areas. Tumor invasion into surrounding tissues as determined ultrasonographically did not correlate with the histologic findings. There was a significant correlation between the number of detected vessels and distribution of flow within the tumors determined via ultrasonographic and histologic examinations. CONCLUSIONS AND CLINICAL RELEVANCE: In canine mammary tumors, ultrasonographic characteristics appear to be correlated with histopathologic changes. Data suggest that ultrasonography may have an important role in the evaluation of mammary tumors in dogs, particularly in the evaluation of tissue composition and tumor vascularity.     

Histologic, immunohistochemical, and clinical features of 27 mammary tumors in 18 male dogs

Twenty-seven mammary tumors from 18 male (3 intact, 15 neutered) dogs were collected. The average age at diagnosis was 9.2 years (range, 2-14 years). Seven of the dogs were Cocker Spaniels. Five dogs had multiple mammary tumors. All tumors were benign. Twenty-six were simple adenomas with mixed acinar and papillary patterns. The acinar pattern was predominant in 17 cases. One adenoma was complex with a prominent myoepithelial component. The myoepithelial component of 25 of the 25 tumors was immunohistochemically positive for calponin and p63. In the cases for which relevant clinical information was available, there was no reported history of obesity, testicular tumors, or sex hormone therapy. Surgery was the only reported treatment for these tumors. Only 1 dog was reported to have developed an additional mammary tumor. None of the dogs for which case outcome was known died or was euthanatized as a result of mammary tumor. Although uncommon, mammary tumors do occur in male dogs. Although mammary tumors may be quite cellular, the presence of an intact myoepithelium, which can be demonstrated with immunohistochemistry for calponin and p63, indicates benignancy, as the clinical behavior documents.     

Feline mammary tumors

The characteristics of feline mammary cancer--that is, the rapid growth of primary mammary tumors, the high rate of tumor recurrence, and the poor survival statistics--demonstrate the need for (1) early diagnosis of the primary tumor; (2) immediate, aggressive surgical therapy; and (3) frequent follow-up examinations to detect early clinical signs of recurrent disease. A number of factors that influence prognosis have been described. As more information becomes available concerning the behavior of feline mammary tumors and the results of various forms of treatment, more effective protocols can be developed. Continued etiologic research may play a vital role in determining the direction of therapy.     

Sertoli cell tumors associated with feminizing syndrome and spermatic cord torsion in two cryptorchid dogs

The association of cryptorchidism, functional Sertoli cell tumors, and spermatic cord torsion has been rarely reported in the literature. Two dogs were admitted for bilateral skin alopecia and weight loss. Both animals were cryptorchid and displayed a pendulous preputial sheath, prostate hypertrophy, and increased levels of circulating oestrogen. Transabdominal palpation and ultrasonography revealed the presence of neoplastic retained gonads. During surgery, spermatic cord torsion was also detected in the enlarged neoplastic testes of both dogs. Histologic examination confirmed the presence of Sertoli cell tumors that were primarily responsible for the feminizing syndrome. Complete remission of all symptoms occurred within 3 months after orchiectomy.