P-Glycoprotein and Breast Cancer Resistance Protein in Canine Inflammatory and Noninflammatory Grade III Mammary Carcinomas

P-glycoprotein (P-gp/ABCB1) and breast cancer resistance protein (BCRP/ABCG2) expression are frequently related to multidrug resistance (MDR) in neoplastic cells. Canine inflammatory and grade III noninflammatory mammary carcinomas (IMC and non-IMC) are aggressive tumors that could benefit from chemotherapy. This study describes the immunohistochemical detection of P-gp and BCRP in 20 IMCs and 18 non-IMCs from dogs that had not received chemotherapy. Our aim was to determine if P-gp and BCRP expression was related to the \u201cinflammatory\u201d phenotype, to establish a basis for future studies analyzing the response to chemotherapy in dogs with highly malignant mammary cancer. Immunolabeling was primarily membranous for P-gp with a more intense labeling in emboli, and immunolabeling was membranous and cytoplasmic for BCRP. P-gp was expressed in 17 of 20 (85%) IMCs compared to 7 of 18 (39%) non-IMCs (P = 0.006). BCRP was expressed within emboli in 15 of 19 (79%) emboli in IMC, 12 of 15 (80%) primary IMCs, and 12 of 18 (67%) non-IMCs, without statistically significant differences (P >.05). All IMCs and 67% of non-IMCs expressed at least 1 of the 2 transporters, and 63% (12/19) of IMCs and 39% (7/18) of non-IMCs expressed both P-gp and BCRP. P-gp and BCRP evaluation might help select patients for chemotherapy. P-gp, expressed in a significantly higher percentage of IMCs vs non-IMCs, might play a specific role in the chemoresistance of IMC

Monitoring the response of canine hyperadrenocorticism to trilostane treatment by assessment of acute phase protein concentrations

<b>Background</b>: Acute phase proteins (APPS) include haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA). Increased Hp concentrations may be induced by endogenous or exogenous glucocorticoids in dogs. <b>Objectives</b>: To assess whether control of hyperadrenocorticism (HAC) affects the concentrations of Hp, CRP, SAA, alkaline phosphatase (ALKP) and cholesterol, to determine whether these analytes can be used to assess control of HAC following trilostane treatment, and whether a combination of these tests offers a valid method of assessing disease control. <b>Methods</b>: Hp, CRP, SAA, ALKP and cholesterol were assessed in 11 dogs with spontaneous HAC before and after treatment with trilostane. Adequate control of HAC was defined as post-ACTH cortisol less than 150 nmol/l. <b>Results</b>: Significant reductions in Hp, ALKP, cholesterol and SAA (P<0·05) but not of CRP were found after control of HAC. Only Hp, cholesterol and ALKP were moderately informative (Se & Sp>0·7) of disease control when compared to adrenocorticotropin or corticotropin (ACTH) stimulation test. SAA and CRP were unhelpful (Se & Sp<0·7). The analysis of the combination of the analytes did not improve the correlation with ACTH stimulation test. <b>Clinical Relevance</b>: Relying on these analytes does not provide additional information over ACTH stimulation test results when assessing control of HAC treated with trilostane

Use of deoxycorticosterone pivalate by veterinarians: A western european survey

open9siThis research was supported by FCT—Fundação para a Ciência e Tecnologia IP, grant UIDB/00276/2020This study aims to gather knowledge about the use of deoxycorticosterone pivalate (DOCP) by Western European Veterinarians (WEV) in dogs with typical hypoadrenocorticism. An observa-tional cross-sectional study was conducted using an online survey, translated into four languages and disseminated to veterinary affiliates and mailing lists in six countries of Western Continental Europe. Respondents were tasked to share their therapeutic approach to hypoadrenocorticism, whether they preferred DOCP or fludrocortisone and the specific practical use of DOCP. One-hundred and eighty-four responses were included. Of these, 79.9% indicated that they preferred prescribing DOCP over fludrocortisone as a first-line treatment for mineralocorticoid supplementation. A total of 154 respondents had used DOCP at least once. Eighty percent of those who reported their initial dosage prescribed 2.2 mg/kg. After starting DOCP, 68.2% of the respondents assess electrolytes 10 and 25 days after administration following manufacturer instructions. In stable dogs, electrolytes are monitored quarterly, monthly, semi-annually, and annually by 44.2%, 34.4%, 16.9%, and 4.6% of respondents respectively. When treatment adjustment is required, 53% prefer to reduce dosage while 47% increase the interval between doses. Overall, DOCP is the preferred mineralocorticoid supple-mentation among WEV. Reported variability underlies the need to investigate the best strategies for DOCP use and therapeutic adjustments.openRebocho R.; Dominguez-Ruiz M.; Englar R.E.; Arenas C.; Perez-Alenza M.D.; Corsini A.; Fracassi F.; Bennaim M.; Leal R.O.Rebocho R.; Dominguez-Ruiz M.; Englar R.E.; Arenas C.; Perez-Alenza M.D.; Corsini A.; Fracassi F.; Bennaim M.; Leal R.O

Imaging diagnosis: ultrasonographic appearance of small bowel metastasis from canine mammary carcinoma

A 10-year-old entire female Beagle dog was evaluated for an acute history of lethargy, anorexia, and diarrhea. Mammary tumors were detected during physical examination. Ultrasonographic scanning revealed the presence of a unique pattern of multiple, well-defined and well-marginated hypoechoic nodules in the muscularis layer of the jejunum. These nodules were not associated with changes in the rest of the normal intestinal layering and were not causing signs of intestinal obstruction. Mammary carcinoma metastases to the intestinal muscularis layer were diagnosed based on histopathological examination

Neoadjuvant in situ vaccination with cowpea mosaic virus as a novel therapy against canine inflammatory mammary cancer

BackgroundInflammatory mammary cancer (IMC), the counterpart of human inflammatory breast cancer (IBC), is the deadliest form of canine mammary tumors. IMC patients lack specific therapy and have poor outcomes. This proof-of-principle preclinical study evaluated the efficacy, safety, and effect on survival of neoadjuvant intratumoral (in situ) empty cowpea mosaic virus (eCPMV) immunotherapy in companion dogs diagnosed with IMC.MethodsTen IMC-bearing dogs were enrolled in the study. Five dogs received medical therapy, and five received weekly neoadjuvant in situ eCPMV immunotherapy (0.2–0.4 mg per injection) and medical therapy after the second eCPMV injection. Efficacy was evaluated by reduction of tumor growth; safety by hematological and biochemistry changes in blood and plasma; and patient outcome by survival analysis. eCPMV-induced immune changes in blood cells were analyzed by flow cytometry; changes in the tumor microenvironment were evaluated by CD3 (T lymphocytes), CD20 (B lymphocytes), FoxP3 (Treg lymphocytes), myeloperoxidase (MPO; neutrophils), Ki-67 (proliferation index, PI; tumor cell proliferation), and Cleaved Caspase-3 (CC-3; apoptosis) immunohistochemistry.ResultsTwo neoadjuvant in situ eCPMV injections resulted in tumor shrinkage in all patients by day 14 without systemic adverse events. Although surgery for IMC is generally not an option, reduction in tumor size allowed surgery in two IMC patients. In peripheral blood, in situ eCPMV immunotherapy was associated with a significant decrease of Treg$^{+}$/CD8$^{+}$ ratio and changes in CD8$^{+}$Granzyme B$^{+}$ T cells, which behave as a lagging predictive biomarker. In the TME, higher neutrophilic infiltration and MPO expression, lower tumor Ki-67 PI, increase in CD3$^{+}$ lymphocytes, decrease in FoxP3$^{+}$/CD3$^{+}$ ratio (p<0.04 for all comparisons), and no changes in CC-3$^{+}$ immunostainings were observed in post-treatment tumor tissues when compared with pretreatment tumor samples. eCPMV-treated IMC patients had a statistically significant (p=0.033) improved overall survival than patients treated with medical therapy.ConclusionsNeoadjuvant in situ eCPMV immunotherapy demonstrated anti-tumor efficacy and improved survival in IMC patients without systemic adverse effects. eCPMV-induced changes in immune cells point to neutrophils as a driver of immune response. Neoadjuvant in situ eCPMV immunotherapy could be a groundbreaking immunotherapy for canine IMC and a potential future immunotherapy for human IBC patients

First description of feline inflammatory mammary carcinoma: clinicopathological and immunohistochemical characteristics of three cases

INTRODUCTION: Inflammatory breast cancer is a special type of locally advanced mammary cancer that is associated with particularly aggressive behaviour and poor prognosis. The dog was considered the only natural model in which to study the disease because, until now, it was the only species known to present with inflammatory mammary carcinoma (IMC) spontaneously. In the present study we describe clinicopathological and immunohistochemical findings of three cats with IMC, in order to evaluate its possible value as an animal model. METHODS: We prospectively studied three female cats with clinical symptoms of IMC, identified over a period of 3 years. Clinicopathological and immunohistochemical evaluations of Ki-67, and oestrogen, progesterone and androgen receptors were performed. RESULTS: All three animals presented with secondary IMC (postsurgical) characterized by a rapid onset of erythema, severe oedema, extreme local pain and firmness, absence of subjacent mammary nodules, and involvement of extremities. Rejection of the surgical suture was observed in two of the cats. Histologically, highly malignant papillary mammary carcinomas, dermal tumour embolization of superficial lymphatic vessels, and severe secondary inflammation were observed. The animals were put to sleep at 10, 15 and 45 days after diagnosis. Metastases were detected in regional lymph nodes and lungs in the two animals that were necropsied. All tumours had a high Ki-67 proliferation index and were positive for oestrogen, progesterone and androgen receptors. CONCLUSION: Our findings in feline IMC (very low prevalence, only secondary IMC, frequent association of inflammatory reaction with surgical suture rejection, steroid receptor positivity) indicate that feline IMC could be useful as an animal model of human inflammatory breast cancer, although the data should be considered with caution

Neoadjuvant Intratumoral Immunotherapy with Cowpea Mosaic Virus Induces Local and Systemic Antitumor Efficacy in Canine Mammary Cancer Patients

The lack of optimal models to evaluate novel agents is delaying the development of effective immunotherapies against human breast cancer (BC). In this prospective open label study, we applied neoadjuvant intratumoral immunotherapy with empty cowpea mosaic virus-like particles (eCPMV) to 11 companion dogs diagnosed with canine mammary cancer (CMC), a spontaneous tumor resembling human BC. We found that two neoadjuvant intratumoral eCPMV injections resulted in tumor reduction in injected tumors in all patients and in noninjected tumors located in the ipsilateral and contralateral mammary chains of injected dogs. Tumor reduction was independent of clinical stage, tumor size, histopathologic grade, and tumor molecular subtype. RNA-seq-based analysis of injected tumors indicated a decrease in DNA replication activity and an increase in activated dendritic cell infiltration in the tumor microenvironment. Immunohistochemistry analysis demonstrated significant intratumoral increases in neutrophils, T and B lymphocytes, and plasma cells. eCPMV intratumoral immunotherapy demonstrated antitumor efficacy without any adverse effects. This novel immunotherapy has the potential for improving outcomes for human BC patients

ERBB2 in Cat Mammary Neoplasias Disclosed a Positive Correlation between RNA and Protein Low Expression Levels: A Model for erbB-2 Negative Human Breast Cancer

Human ERBB2 is a proto-oncogene that codes for the erbB-2 epithelial growth factor receptor. In human breast cancer (HBC), erbB-2 protein overexpression has been repeatedly correlated with poor prognosis. In more recent works, underexpression of this gene has been described in HBC. Moreover, it is also recognised that oncogenes that are commonly amplified or deleted encompass point mutations, and some of these are associated with HBC. In cat mammary lesions (CMLs), the overexpression of ERBB2 (27%–59.6%) has also been described, mostly at the protein level and although cat mammary neoplasias are considered to be a natural model of HBC, molecular information is still scarce. In the present work, a cat ERBB2 fragment, comprising exons 10 to 15 (ERBB2_10–15) was achieved for the first time. Allelic variants and genomic haplotype analyses were also performed, and differences between normal and CML populations were observed. Three amino acid changes, corresponding to 3 non-synonymous genomic sequence variants that were only detected in CMLs, were proposed to damage the 3D structure of the protein. We analysed the cat ERBB2 gene at the DNA (copy number determination), mRNA (expression levels assessment) and protein levels (in extra- and intra protein domains) in CML samples and correlated the last two evaluations with clinicopathological features. We found a positive correlation between the expression levels of the ERBB2 RNA and erbB-2 protein, corresponding to the intracellular region. Additionally, we detected a positive correlation between higher mRNA expression and better clinical outcome. Our results suggest that the ERBB2 gene is post-transcriptionally regulated and that proteins with truncations and single point mutations are present in cat mammary neoplastic lesions. We would like to emphasise that the recurrent occurrence of low erbB-2 expression levels in cat mammary tumours, suggests the cat mammary neoplasias as a valuable model for erbB-2 negative HBC.POCI/CVT/62940/2004 and by the PhD grants (SFRH/BD/23406/2005 and SFRH/BD/31754/2006, of the Science and Technology Foundation (FCT) from Portugal

Comparative aspects of canine and human inflammatory breast cancer

Inflammatory breast cancer (IBC) in humans is the most aggressive form of mammary gland cancer and shares clinical, pathologic, and molecular patterns of disease with canine inflammatory mammary carcinoma (CIMC). Despite the use of multimodal therapeutic approaches, including targeted therapies, the prognosis for IBC/CIMC remains poor. The aim of this review is to critically analyze IBC and CIMC in terms of biology and clinical features. While rodent cancer models have formed the basis of our understanding of cancer biology, the translation of this knowledge into improved outcomes has been limited. However, it is possible that a comparative “one health” approach to research, using a natural canine model of the disease, may help advance our knowledge on the biology of the disease. This will translate into better clinical outcomes for both species. We propose that CIMC has the potential to be a useful model for developing and testing novel therapies for IBC. Further, this strategy could significantly improve and accelerate the design and establishment of new clinical trials to identify novel and improved therapies for this devastating disease in a more predictable way