Serum neopterin levels in female dogs with malignant mammary tumours

In this study, we have determined serum neopterin levels in female dogs with primary malignant mammary tumours. The study involved 50 female dogs which had a malignant mammary tumours removed surgically (32 animals with carcinoma, 12 animals with sarcoma and 6 animals with carcinosarcoma) and 10 clinically healthy female dogs. Serum neopterin levels were determined using a commercial ELISA kit. The mean neopterin levels were lower in the malignant tumour groups than in healthy animals but differences were statistically significant only in carcinoma and sarcoma groups. The decrease of neopterin levels in animals with malignant mammary tumours may suggest their decreased cellular immunity. Moreover, it might indicate that decreased activity of cellular mechanisms of the anti‐neoplastic response is one of the factors associated with the development and course of malignant mammary tumours in female dogs; however, further studies are necessary.     

Perioperative desmopressin prolongs survival in surgically treated bitches with mammary gland tumours: a pilot study

Desmopressin (1-deamino-8-d-arginine vasopressin, also known as DDAVP) is a safe haemostatic compound capable of inhibiting lymph node and lung metastasis in a mouse model of mammary tumour manipulation and surgical excision. The aim of this study was to test the efficacy and safety of perioperative DDAVP (1microg/kg) in surgically treated bitches with mammary gland tumours (MGT). Twenty-one, otherwise healthy, intact bitches, with malignant MGT stage III or IV were randomly allocated to DDAVP (n=11) or placebo (n=10) groups. En bloc mastectomy of the affected gland/s was performed. DDAVP had a significant beneficial effect on disease-free period (P<0.01) and overall survival time (P<0.05). No side effects were seen in any of the cases. Whatever the mechanism of action, it seems that DDAVP may have a novel use in cancer surgery to minimise spread or survival of residual malignant cells. Additional, large scale controlled trials are required to fully evaluate this adjuvant pharmacological protocol.     

Adjuvant gemcitabine after surgical removal of aggressive malignant mammary tumours in dogs

Canine mammary tumours are generally treated with surgery alone, despite the fact that 50% of them are malignant and many will eventually lead to recurrence or metastases. A prospective clinical trial in which dogs with aggressive mammary carcinoma of clinical stages IV and V were treated with surgical excision (n = 9) or with surgery and adjuvant weekly gemcitabine (n = 10) for at least four cycles was conducted. Gemcitabine was given as an intravenous infusion at the dose of 800 mg m^?2. Aim of the study was to explore potential beneficial effects of gemcitabine on time to local recurrence (TTR), time to distant metastases (TTM) and overall survival (OS) in canine patients with operated mammary tumours bearing high risk for locoregional failure and distant metastases. Also, factors associated with OS, including neutering status, body weight, age, clinical stage at presentation, tumour size, histological grade and, in dogs receiving chemotherapy, the number of gemcitabine treatments, were investigated. Finally, acute toxicities related to chemotherapy and quality of life were assessed in dogs receiving gemcitabine. Dogs treated with surgery alone or surgery followed by gemcitabine had no difference in TTR, TTM or OS (P > 0.05). In the group of dogs receiving adjuvant chemotherapy, the number of gemcitabine treatments was positively correlated with OS (P = 0.017). Gemcitabine treatment was well tolerated, with no dogs experiencing clinically relevant haematological or gastrointestinal toxicity. Despite being safe at the present dose, gemcitabine chemotherapy as an adjunct treatment to surgical excision may not be recommended in dogs with aggressive mammary carcinoma.     

Haemostatic abnormalities in canine Cushing's syndrome

Selected parameters of the haemostatic system were evaluated in 12 consecutive cases of canine Cushing's syndrome. The dogs did not exhibit evidence of thromboembolic complications. Levels of factors V and X were increased significantly (P less than 0.01) and fibrinogen concentration was increased modestly (P less than 0.05) in these dogs. Levels of factors IX and VIII:C remained in the reference range. Antithrombin III (ATIII) and plasminogen concentrations were markedly elevated (P less than 0.001). The low factor VIII:C and elevated ATIII levels in the plasma were not consistent with characteristics of a hypercoagulable state. These results demonstrated that haemostatic abnormalities which occur in canine Cushing's syndrome do not necessarily represent a state predisposed to thrombosis.     

Xenobiotic-metabolizing enzymes in canine mammary tumours

Mammary tumours are the most common neoplasms in female dogs. The present study was designed to evaluate the relationship between different clinical stages with activities of phase I and phase II carcinogen-metabolizing enzymes in canine mammary tumours. The levels of cytochrome P450 and cytochrome b5 and the activities of glutathione S-transferase (GST), gamma-glutamyl transpeptidase (GGT), DT-diaphorase (DTD) and NADPH diaphorase in tumour tissues of 25 bitches was estimated. Enhanced levels of cytochrome P450 and b5 and phase II enzyme activities were observed in tumour tissues compared to the corresponding uninvolved adjacent tissues. The magnitude of the changes in phase I and phase II enzyme status was, however, more pronounced in stages I and II compared to stages III and IV. The results suggest that the balance between phase I carcinogen activation and phase II detoxification systems may play an important role in canine mammary tumour development.     

Cytological lymph node evaluation in dogs with mast cell tumours: association with grade and survival*

The purpose of this retrospective cohort study is to describe the association of cytological assessment of lymph node metastasis with survival and tumour grade in dogs with mast cell tumours. Regional lymph node aspirates of 152 dogs diagnosed with a mast cell tumour were reviewed and classified according to specific cytological criteria for staging. 97 dogs (63.8%) had stage I tumours, and 55 (36.2%) had stage II tumours. Stage II dogs had a significantly shorter survival time than dogs with stage I disease (0.8 and 6.2 years, respectively; P < 0.0001). Dogs with grade III mast cell tumours were more likely to have stage II disease (P = 0.004). These results suggest that cytological evaluation of lymph nodes in dogs with mast cell tumours provides useful and valuable clinical information, and the results correlate with tumour grade and outcome thus providing a practical and non‐invasive method for staging.     

Studies on canine mammary tumours. I. Age, seasonal and breed distribution.

The incidence as well as age, seasonal and breed distribution of canine mammary tumours (n = 521) were studied at the Clinic of Obstetrics and Gynaecology of the University of Veterinary Science, Budapest, between 1985 and 1989. In 39 cases of mammary tumour, blood plasma oestradiol (E2) and progesterone (P) concentrations were also determined. Of all dogs referred to the clinics of the University in 1985, 0.7% had mammary tumour. On the average, 104 +/- 9.3 cases of mammary tumour were recorded at the Clinic of Obstetrics per year. This number did not increase after the Chernobyl atomic reactor catastrophe of 1986. The age distribution of canine mammary tumour found in this study shows good agreement with earlier data of the literature: mammary tumour showed the highest incidence in 10 years old dogs. The incidence of mammary tumour kept increasing with age until the 14th year of life (as expressed in per cent of animals of identical age). The number of mammary tumours was markedly higher in the spring (April-May) and autumn (September). This seasonality was demonstrable in 11 to 16 years old bitches, too. On the basis of the blood plasma E2 and P profiles, 61.5% of the clinically anoestrous animals were found to be cycling. The strikingly high ratio of pulis among dogs with mammary cancer was suggestive of a breed disposition.     

Expression of tissue factor in canine mammary tumours and correlation with grade,stage and markers of haemostasis and inflammation

Tissue factor (TF) expression in human cancers has been associated with a procoagulant state and facilitation of metastasis. This study was conducted in order to evaluate if TF was expressed in canine mammary tumours. Forty epithelial mammary tumours from 28 dogs were included. TF expression of the tumours was evaluated by immunohistochemistry using a polyclonal antibody against recombinant canine TF. In addition, thromboelastography, haemostatic and inflammatory parameters were evaluated in the patients. TF was recognized in 44% of benign and 58% of malignant tumours. TF localized to the cytoplasmic membrane of neoplastic luminal epithelial cells and/or diffusely in the cytoplasm. No association was found between TF expression and stage or grade of disease. A significant association between TF expression and antithrombin and plasminogen was found, and extensive TF expression was seen in a lymph node metastasis classified as anaplastic mammary carcinoma from a dog with concomitant disseminated intravascular coagulation (DIC).     

Oxidative stress parameters in bitches with mammary gland tumours

The aim of the present study was to describe some of the oxidative stress parameters in bitches suffering from spontaneously occurring mammary gland tumours. The experiment involved 28 bitches which had mammary gland tumours removed surgically (15 bitches with malignant tumour and 13 with benign tumour) as well as 10 clinically healthy bitches. The activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were determined in haemolysates of erythrocytes derived from the animals. The concentrations of thiobarbituric acid reactive substances (TBARS), as well as -SH groups, were determined in blood plasma. GSH-Px activity was significantly higher in the malignant tumour group than in healthy animals. SOD activity was significantly higher in animals with tumours compared with the control group. Activities of both enzymes were higher in animals with malignant tumours than in benign groups, but the differences were not statistically significant. The concentrations of TBARS and -SH groups were similar in all examined groups. The increase of antioxidative enzyme activities in these animals may suggest the activation of antioxidative defence mechanisms in mammary gland carcinogenesis. Moreover, it might indicate the participation of oxidative stress in malignancies. Further experiments involving more animals, with more frequent sample collection and the use of other oxidative stress markers are necessary.     

Haemostatic alterations in a group of canine cancer patients are associated with cancer type and disease progression

Background

Haemostatic alterations are commonly detected in human and canine cancer patients. Previous studies have described haemostatic dysfunction in canine patients with haemangiosarcomas and carcinomas, and haemostasis has been assessed in dogs with various malignant and benign neoplasias. Few studies have addressed the effect of cancer type and progression of disease on the presence of haemostatic alterations in canine patients. The objective of the present study was to evaluate haemostatic variables of coagulation and fibrinolysis in a group of canine cancer patients, and to compare haemostatic changes to the cancer type and progression of disease.

Methods

The study population consisted of 71 dogs with malignant neoplasia presented to the University Hospital for Companion Animals, Faculty of Life Sciences, University of Copenhagen, Denmark. The study was designed as a prospective observational study evaluating the haemostatic function in canine cancer patients stratified according to type of cancer disease and disease progression. The coagulation response was evaluated by thromboelastrography (TEG), platelet count, activated partial thromboplastin time (aPTT), prothombin time (PT), fibrinogen and antithrombin (AT); and fibrinolysis by d-dimer and plasminogen.

Results

Hypercoagulability was the most common haemostatic dysfunction found. Non mammary carcinomas had increased clot strength (TEG G), aPTT and fibrinogen compared to the other groups. When stratifying the patients according to disease progression dogs with distant metastatic disease exhibited significantly increased fibrinogen, and d-dimer compared to dogs with local invasive and local non-invasive cancers.

Conclusion

Hypercoagulability was confirmed as the most common haemostatic abnormality in canine cancer patients and haemostatic dysfunction in canine cancer patients was found related to the cancer type and progression of disease. Increase in TEG G, aPTT and fibrinogen were observed in non-mammary carcinomas and were speculated to overall represent a proinflammatory response associated with the disease. Dogs with distant metastatic disease exhibited increased fibrinogen and d-dimer. Future studies are needed to elucidate the clinical importance of these results.     

Hemostatic abnormalities in dogs with carcinoma: a thromboelastographic characterization of hypercoagulability

Hemostatic abnormalities were investigated in 32 dogs with carcinoma and 19 age-matched healthy dogs. Thromboelastography, hemostasis profile (i.e. prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen concentration), platelet count (PLT), thrombin-antithrombin complexes (TAT), and plasminogen activator inhibitor-1 (PAI-1) activity were evaluated. Dogs with carcinomas had faster thrombus generation (TEG(TG), a mathematic value obtained from the first derivate of the thromboelastographic tracing; 834.8±91.1 vs. 707.8±75.8mm/min; mean±SD), increased fibrinogen concentration (276 vs. 151mg/dL), and PLT (425 vs. 324U×10(9)/L), but had decreased PAI-1 activity (15.7 vs. 26.2IU/mL).The most common hemostatic abnormalities found in carcinoma dogs were hypercoagulability (TEG(TG)>mean+2 SD of healthy dogs) and thrombocytosis (PLT>424×10(9)U/L) in 46% of cases, and hyperfibrinogenemia (fibrinogen >384mg/dL) in 32% of cases. Disseminated intravascular coagulation was uncommon and the extent of disease was not correlated with hypercoagulability. TEG(TG) showed good correlation with fibrinogen (r=0.80) and hyperfibrinogenemia seems to be a main factor of the hypercoagulable state in carcinoma dogs. In conclusion, TEG(TG) is a valid parameter to diagnose hypercoagulability.     

Outcomes and prognostic variables associated with primary abdominal visceral soft tissue sarcomas in dogs: A Veterinary Society of Surgical Oncology retrospective study

Primary abdominal visceral soft tissue sarcomas (STSs) are rare tumours in dogs with little information available on outcomes. The goal of this retrospective, multi‐institutional study was to describe the common tumour types, location and prognostic factors associated with primary abdominal visceral STSs. Medical records were searched for dogs with primary abdominal visceral STSs at six institutions and were retrospectively reviewed. Tumours were graded using the previously described grading scheme for STSs of the skin and subcutis when information in the histopathology report contained adequate details. Forty‐two dogs were included in the study. Five dogs had grade I tumours, 11 had grade II and 15 had grade III tumours. The most common tumour type was leiomyosarcoma (38.1%). The most common tumour locations were the spleen (47.6%) and small intestine (23.8%). The local recurrence rate was low (4.7%). Metastasis was present at the time of surgery in 23.8%, and the overall metastatic rate was 40.4%. Mitotic index of ≥9 was associated with significantly shorter survival time (MST 269 days) compared with a mitotic index of <9 (MST not reached). The MST for grade I STSs was not reached, was 589 days for grade II and 158 days for grade III. Dogs with grade III tumours were more likely to develop metastatic disease. Neither location of the primary tumour nor the histologic subtype was associated with survival time. Histologic grading of abdominal visceral STSs using the previously described scheme is prognostic and should be provided on histopathology reports.     

Canine mammary gland tumours; a histological continuum from benign to malignant; clinical and histopathological evidence*

This study describes the clinical and histopathological findings in dogs with mammary gland tumours, and compares the histopathological and clinical evidence consistent with progression from benign to malignant to human breast cancer epidemiology. Clinical and histopathological data on 90 female dogs with 236 tumours was included. Dogs with malignant tumours were significantly older than dogs with benign tumours (9.5 versus 8.5 years), P = 0.009. Malignant tumours were significantly larger than benign tumours (4.7 versus 2.1 cm), P = 0.0002. Sixty‐six percent had more than one tumour, and evidence of histological progression was noted with increasing tumour size. Dogs with malignant tumours were significantly more likely to develop new primary tumours than dogs with benign tumours, P = 0.015. These findings suggest that canine mammary tumours progress from benign to malignant; malignant tumours may be the end stage of a histological continuum with clinical and histopathological similarities to human breast carcinogenesis.     

A statistical assessment of the biological relationship between simultaneous canine mammary tumours

Simultaneous canine mammary tumours (CMTs) are frequently reported in the literature, but few studies have addressed their biological relationship in detail or performed statistical assessments. In this study, 269 canine mammary gland tumours from 216 dogs were categorized using an extended histopathological classification, where semiquantitative and binomial scales enumerated morphological parameters of the tumours. The classification facilitated a statistical study of the biological relationship between simultaneous within‐dog tumours. Seventy‐seven percent of the dogs had single tumours and 23% had simultaneous tumours. Sixty‐one percent of the neoplasias were benign, with complex adenoma as the most frequent diagnosis and 39% were malignant, with complex carcinoma as the most common malignancy. Simultaneous tumours within dogs more often had equal diagnoses and neoplastic level (benign or malignant) than would be expected by chance alone, as compared with random pairs of single tumours from different dogs. This statistically supported finding indicated the presence of a biological relationship between simultaneous tumours.     

Abnormal Hemostatic Profiles and Gastric Necrosis in Canine Gastric Dilatation-Volvulus

Hemostatic profiles (prothrombin time, activated partial thromboplastin time, fibrinogen concentration, fibrin degradation product concentration, platelet count, and antithrombin III activity) were acquired prospectively in 20 dogs with a diagnosis of gastric dilatation-volvulus. Eighteen dogs had abnormal results of one or more hemostatic test, including eight dogs that had hemostatic profiles consistent with a diagnosis of disseminated intravascular coagulation. During surgery, or at necropsy, the dogs' stomachs were evaluated for gross abnormalities, and lesions were graded subjectively as mild, moderate, or severe. Eight dogs had mild gastric lesions, five had moderate lesions, and seven had severe changes indicating gastric necrosis. Seventy percent (7/10) of the dogs with two to six abnormal hemostatic test results had gastric necrosis, whereas none of the 10 dogs with no or one abnormality had gastric necrosis (p < .001). A multiple linear regression equation, based on fibrin degradation product concentration, activated partial thromboplastin time, and antithrombin III activity was derived to predict gastric necrosis. This equation correctly identified gastric necrosis with 86% sensitivity, 100% specificity, 100% positive predictive value, and 93% negative predictive value.     

Evaluation of the haemostatic profile in the pre- and post parturient mare, with particular focus on the perinatal period.

Various haemostatic analytes were systematically evaluated for four months pre-partum and five months post partum in 14 healthy mares. The plasma fibrinogen concentration and both Factor VIII:C and von Willebrand factor activity showed gradual increases from mid-gestation and reached maximal, or near maximal activity at parturition. These increases were paralleled by an increase in plasma fibronectin concentration, the appearance of fibrinogen degradation products, and a modest rise in antithrombin III concentration. In contrast, the activity of Factor VII and Factor IX, and the one-stage prothrombin (PT) time and the activated partial thromboplastin (APTT) time remained relatively constant throughout the pre- and post parturient period.     

Changes in the blood coagulation profile after ovariohysterectomy in female dogs

This study investigated changes in the coagulation profile of 10 healthy female dogs subjected to ovariohysterectomy. Blood samples were collected three times--before, directly after and 24 h after surgery. Plasma samples were analyzed to determine thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen content, D-dimer content and antithrombin (AT) III activity. The results revealed post-operative haemostatic system disorders related to prolonged APTT, higher fibrinogen and D-dimer concentrations and lower levels of AT III activity.     

Diagnosis of disseminated intravascular coagulation in dogs admitted to an intensive care unit.

OBJECTIVE: To describe and evaluate hemostatic function in critically ill dogs with clinical signs of diseases that predispose to disseminated intravascular coagulation (DIC). DESIGN: Prospective case series. ANIMALS: 59 critically ill dogs (affected dogs) with clinical signs of diseases known to predispose to DIC and 52 clinically normal dogs (control dogs). PROCEDURE: Activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin clotting time (TCT), plasma fibrinogen concentration, serum concentration of fibrin and fibrinogen-related antigens (FRA), and plasma antithrombin III (AT III) activity were determined for all dogs. Results from affected dogs were compared with those of control dogs. In some affected dogs, postmortem tissue specimens were examined for evidence of microvascular thrombosis. A diagnosis of DIC was made by fulfilling at least 3 of the following criteria: 1) abnormal aPTT, PT, or TCT value, 2) low plasma fibrinogen concentration, 3) low plasma AT III activity, 4) high serum FRA concentration, or 5) low platelet count. To evaluate the severity of hemostatic dysfunction, 3 arbitrary categories (mild, moderate, and severe) were proposed. RESULTS: A diagnostic strategy based on moderate hemostatic dysfunction identified DIC in 16 of 59 (27.1%) affected dogs. The AT III activity was < 70% in 15 of 16 dogs with DIC. Microvascular thrombosis was observed in tissue specimens from 7 of 8 affected dogs. Serum FRA and plasma fibrinogen concentrations did not contribute in establishing a diagnosis of DIC. CONCLUSIONS AND CLINICAL RELEVANCE: A diagnosis of DIC can be made when hemostatic dysfunction is moderate in dogs with clinical signs of diseases associated with DIC.     

Treatment of spontaneous malignant tumours in dogs with PTMC

The chemical analysis of the caffeine salt of a phosphomolybdic-tungstic acid compound (PTMC) is described. Twenty-seven dogs with advanced malignant tumours have been treated with PTMC by intramuscular or intravenous injection. Five dogs - one case of metastatic osteosarcoma, two cases of metastatic mammary carcinoma, one case of metastatic squamous cell carcinoma and one case of primary fibrosarcoma showed objective tumour regression for periods varying from four weeks to 20 months. Only two of the 27 dogs treated showed toxic effects.     

Genetic variations of BRCA1 and BRCA2 genes in dogs with mammary tumours

Mammary tumours are the most common tumour type in female dogs. The formation of the mammary tumours is multifactorial but the high incidence of tumour disease in certain canine breeds suggests a strong genetic component. BRCA1 and BRCA2 are the most important genes significantly associated with mammary tumours. The aim of this study was to determine the association between the variations of these two genes and canine mammary tumours. 5′-untranslated region, intron 8 and exon 9 of BRCA1 and exons 12, 24, 27 of BRCA2 were sequenced in order to detect the genetic variations. In addition to six previously identified polymorphisms, six novel single nucleotide polymorphisms (SNPs) were detected. Five of the coding SNPs were synonymous and three of them were non-synonymous. The comparison of the sequences from 25 mammary tumour bearing and 10 tumour free dogs suggested that the two SNPs in intron 8 and exon 9 of BRCA1 and two SNPs in exon 24 and exon 27 of BRCA2, which are firstly identified in this study, might be associated with mammary tumour development in dogs. Especially one SNP in exon 9 of BRCA1 and one SNP in exon 24 of BRCA2 were found to be significantly associated with canine mammary tumours.