Feline Mammary Gland Tumours Research Articles

Epidemiology and classification for canine and feline mammary gland tumors: a histopathological survey of 437 mammary gland tumor biopsies performed in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019.

Metastatic disease resulting from mammary gland tumors (MGTs) is a known cause of death among dogs and cats. Keys to successful prevention and management strategies involve the accurate recording of diagnostic data. This retrospective study reviewed the epidemiology and classification of canine mammary gland tumors (CMTs) and feline mammary gland tumors (FMTs), as well as the factors including sex, age, and breed related to the occurrence of these tumors. Accordingly, 1,736 tumor biopsy cases were reported from 2012 to 2019 at Chiang Mai University Small Animal Hospital, Thailand, with 1,639 canine tumor biopsy cases and 97 feline tumor biopsy cases. The proportion of CMTs was reported at 24.5% (401/1,639) for all canine tumor biopsy cases. Benign and malignant tumors were reported at 14.5% (58/401) and 85.5% (343/401) for all CMT cases, respectively. The mean age of dogs affected by benign CMTs was 9.0±3.0 years, which was significantly lower than for malignant CMTs at 9.9±2.8 years (P=0.0239). According to histopathological classification, benign mixed tumors and simple carcinoma types were highest among benign and malignant CMT cases, respectively. Moreover, female dogs were at significantly higher risk of developing mammary gland tumors (OR = 45.8, 95% CI [3.9-86.0], P<0.0001) than male dogs, as well as older dogs (>8 years) (OR = 1.7, 95% CI [1.2-2.2], P=0.0001) compared to young ones (≤8 years). The proportion of FMTs was 37.1% (36/97) for all feline tumor biopsy cases. Benign and malignant tumors for all FMTs were reported at 16.7% (6/36) and 83.3% (30/36), respectively. According to histopathological classifications, adenoma and simple carcinoma were present in the highest proportion among benign and malignant FMTs, respectively. Female cats were at a significantly higher risk of developing mammary gland tumors than male cats (OR=25.7, 95% CI [3.9-272.8], P<0.0001). There was a high proportion of MGT cases compared with other tumor cases reported in a secondary care hospital in Chiang Mai, Thailand from 2012 to 2019, and malignant tumor biopsies have been more frequently observed than benign tumor biopsies in both CMT and FMT cases. The resulting data originating from this study can be an aid for veterinary oncologists in better educating clients and planning treatment and prevention strategies and it can be used as a basis for further experimental studies in the oncology section.

Correlation between fine-needle aspiration biopsy and routine histopathology in the diagnosis of spontaneous feline mammary gland tumours

The present study evaluated the correlation between fine-needle aspiration biopsy and routine histopathological examination in the diagnosis of spontaneous mammary gland tumours in cats. From the studied 120 neoplastic growths, cytological diagnosis was correct in 111 cases (92.5%), and incorrect in 9 (7.5%) patients. Out of all studied tumours, 3 false positive (2.5%) and 6 false negative (5%) results were found out. Among benign tumours, cytological diagnosis was correct in 17 cases (94.44 %). Only one false negative diagnosis was demonstrated (5.56% of all benign tumours). As to malignant tumours, cytological diagnosis was correct in 94 (92.15%), and incorrect in 8 patients (7.85%). For diagnostics of feline mammary neoplasms, the sensitivity of cytology was 95.23%, the specificity - 75%, positive predictive value: 97.5% and negative predictive value: 60% compared to routine histopathology. The analysis with Cohen’s kappa test showed agreement of 99.17% (Cohen’s κ 0.96) between cytology and histopathology for benign and 94.17% (Cohen’s κ 0.75) for malignant mammary neoplasms.

Clinicopathological Diversity and Epidemiological Aspects of Canine and Feline Mammary Gland Tumors in Tehran: A Survey (2020-2022)

Background: Mammary tumors are common in dogs and cats. They are models for investigating carcinogenesis and designing treatment protocols that benefit human beings. Senescence, sex, and reproductive status affect the development of such neoplasms. Objectives: In Iran’s absence of a national animal tumor registry, the present study determined clinicopathological and epidemiological aspects of canine and feline mammary tumors in referral cases of four veterinary practices across Tehran from 2020 to 2022. Here, the incidence and types of canine and feline mammary tumors are described, in addition to sex, reproductive status, age, breed, the affected mammary gland(s), grades, lymphatic invasion, and lymph node metastases. Methods: All canine and feline patients with masses in the mammary gland region were considered in this study. The resected tumors and occasional lymph nodes were macroscopically scrutinized. Hematoxylin-Eosin slides were reviewed by light microscopy and immunohistochemistry was utilized when necessary. Results: Of the 76 dogs and eight cats, 100% were females, and the majority were intact. Most patients were 10-11 years old. Purebreds were the most frequent referrals. In some patients, more than one mammary gland had developed neoplasm, i.e. 141 affected glands in 76 bitches and nine affected glands in eight queens. Tumors were presented in both chains and even on the ventral midline, with an increased preponderance of caudally located glands. Thus, the caudal-most glands, i.e. inguinal and caudal abdominal glands, constituted 31.2% and 66.7% of the affected glands in bitches and queens, respectively. Intraductal papillary carcinoma (17%) and complex carcinoma (16.3%) had the highest incidence in dogs. The most commonly observed lesions in cats were lobular hyperplasia with atypia, and duct ectasia, each encompassing 22.3% of the affected glands. Most canine neoplasms were grade I (90.3%), while grade II neoplasms had the highest incidence in cats (50%). Lymphatic invasion and lymph node metastases were seen in canine anaplastic carcinoma, solid carcinoma, and complex carcinoma, as well as feline comedocarcinoma and tubular carcinoma. Conclusion: The risk of developing malignant tumors increases as the individual ages, and generally, caudally located mammary glands in intact purebred females are at increased risk. Moreover, anaplastic carcinomas must be precisely examined, both clinically and histopathologically, for lymph node metastases.

Mammary tumors of the dog and the cat: modern approaches to classification and diagnosis (review)

The study of oncopathology of the mammary gland of cats and dogs is a very relevant problem. This is evidenced by the presence of numerous scientific works and experimental research data of scientists from many countries. For a long time, there were no systematic approaches to the nomenclature and classification of canine and feline mammary gland tumors. That is why different countries of the world had their own national approaches to defining these pathologies. Long-term incomplete analysis of clinical cases, gaps in histopathology and interpretation of the obtained results were reflected in contradictory results, inaccuracies in terminology, definition of diagnosis and interpretations. This also inhibited clinical and experimental research, development and testing of effective drugs. Accumulation of clinical data, consolidated work of morphologists became the basis of lively discussions, which in turn was reflected in decisions to create unified classifications. Histological classification became the basis for the division of tumors of the mammary gland of cats and dogs. When conducting a scientific review, modern data from information resources and information from numerous international symposia and conferences were used. The authors also highlighted the key mechanisms of immune regulation of the oncogenic process. The role of immune cells, mediators of immune protection, in the development of oncopathology of the mammary gland is emphasized. Certain immunological tumor markers have been characterized, which are of great importance in the early stages of diagnosis. Special instrumental methods used by veterinary medicine doctors in routine diagnostics are also described. Prospects for the use of cell therapy with the use of modern immunological technologies were also made. The publication has a review and analytical nature and aims to attract the attention of scientists, diagnosticians and clinicians of various profiles to this issue, which will certainly become a continuation in the study of oncopathology. The unified classification will definitely be useful to scientists and practicing doctors, will enrich their knowledge about the mechanisms of tumor growth. We believe that a unified classification will allow researchers to use informative methods of diagnosis – both as a powerful tool in making an accurate diagnosis, and for effective approaches to differentiation and treatment strategies for patients.

Epithelial-to-Mesenchymal Transition and Phenotypic Marker Evaluation in Human, Canine, and Feline Mammary Gland Tumors

Epithelial-to-mesenchymal transition (EMT) is a process by which epithelial cells acquire mesenchymal properties. EMT has been closely associated with cancer cell aggressiveness. The aim of this study was to evaluate the mRNA and protein expression of EMT-associated markers in mammary tumors of humans (HBC), dogs (CMT), and cats (FMT). Real-time qPCR for SNAIL, TWIST, and ZEB, and immunohistochemistry for E-cadherin, vimentin, CD44, estrogen receptor (ER), progesterone receptor (PR), ERBB2, Ki-67, cytokeratin (CK) 8/18, CK5/6, and CK14 were performed. Overall, SNAIL, TWIST, and ZEB mRNA was lower in tumors than in healthy tissues. Vimentin was higher in triple-negative HBC (TNBC) and FMTs than in ER+ HBC and CMTs (p < 0.001). Membranous E-cadherin was higher in ER+ than in TNBCs (p < 0.001), whereas cytoplasmic E-cadherin was higher in TNBCs when compared with ER+ HBC (p < 0.001). A negative correlation between membranous and cytoplasmic E-cadherin was found in all three species. Ki-67 was higher in FMTs than in CMTs (p < 0.001), whereas CD44 was higher in CMTs than in FMTs (p < 0.001). These results confirmed a potential role of some markers as indicators of EMT, and suggested similarities between ER+ HBC and CMTs, and between TNBC and FMTs.

Genetic variants of BRCA1 and BRCA2 genes in cats with mammary gland carcinoma.

Mammary tumours are the first and third most incident neoplasm in women and cats, respectively. Approximately 85% of feline mammary gland tumours are malignant and aggressive, especially the triple-negative and HER-2+ molecular subtypes. Triple-negative basal-like feline mammary carcinomas (FMCs) are considered suitable models due to the clinical and morphological similarities with human basal-like triple-negative breast cancer (TNBC). In women, TNBC has a poor prognosis and is often associated with mutations in the tumour suppressor genes BRCA1 and BRCA2. In light of this, the aim of the present investigation was to screen somatic and germline variants of BRCA1 and BRCA2 in nine female cats bearing FMCs. Matched whole blood and FMC samples were obtained for genetic analysis. Additional tumour samples were obtained for histopathological and immunohistochemical evaluation. Genomic DNA was isolated and 27 exonic regions of BRCA1 and BRCA2 genes were amplified and screened by next-generation sequencing. A somatic variant with high functional impact was found in exon 11 of BRCA2 at a frequency of 4.34% in one FMC-bearing cat. Four germline variants with moderate impact were detected in three of the nine FMC-bearing cats and were restricted to exon 9 of BRCA1. It is concluded that the germline genetic variants found in one-third of FMC-bearing animals might be associated with a higher risk of hereditary mammary carcinogenesis.

The anti-proliferative and apoptotic effects of curcumin on feline mammary gland tumor cells in vitro.

Feline mammary gland tumors (FMGTs) are the third most diagnosed tumors in cats. Feline mammary gland tumors have aggressive biological behavior and poor response to both surgical and medical treatments, thus, new therapeutic approaches are essential to improve. Curcumin (CUR) is a polyphenol component exhibiting anti-cancer effects and induces apoptosis through different mechanisms especially in human breast cancer. However, there is no study investigating the effects of CUR on FMGTs. The aim of this study was to determine the anti-proliferative and apoptotic effects of CUR on primary cell lines from FMGT tissue samples of two cases classified as carcinoma-simple, tubular type (grade III). The cytotoxic effect of CUR was determined by water-soluble tetrazolium salt-1 (WST-1) assay. Annexin V, cell cycle, and acridine orange (AO) analyses were performed to determine the apoptotic effect of CUR. Our results showed that CUR had an anti-proliferative and apoptotic effect through induction of apoptosis and cell cycle arrest (G0/G1) on FMGT cells. Therefore, this is the first study that shows the effects of CUR on FMGTs. However, further molecular studies are required to compare the effects of CUR on different histopathological phenotypes and to determine the further molecular mechanisms including the potential apoptotic and cellular pathways affected by CUR.

Histological Characterization of Some Feline Mammary Gland Tumors with Whole Slide Images Scan as a Trial of Remote Diagnosis

Histological Characterization of Some Feline Mammary Gland Tumors with Whole Slide Images Scan as a Trial of Remote Diagnosis

Retraction Note: Comparative value of clinical, cytological, and histopathological features in feline mammary gland tumors; an experimental model for the study of human breast cancer.

The diagnosis of breast lesions is usually confirmed by fine-needle aspiration cytology (FNAC) or histological biopsy. Although there is increasing literature regarding the advantages and limitations of both modalities, there is no literature regarding the accuracy of these modalities for diagnosing breast lesions in high-risk patients, who usually have lesions detected by screening. Moreover, few studies have been published regarding the cytopathology of mammary tumors in cats despite widespread use of the animal model for breast cancer formation and inhibition. The objective of the present study was to evaluate the diagnostic interest of cytological and histopathological analysis in feline mammary tumours (FMTs), in order to evaluate its possible value as an animal model. The study was performed in 3 female cats submitted to surgical resections of mammary tumours. The mammary tumours were excised by simple mastectomy or regional mastectomy, with or without the superficial inguinal lymph nodes. Female cats were of different breeds (1 siamese and 2 persians). Before surgical excision of the tumour, FNA cytology was performed using a 0.4 mm diameter needle attached to a 8 ml syringe held in a standard metal syringe holder. The cytological sample was smeared onto a glass slide and either air-dried for May-Grunwald-stain and masses were surgically removed, the tumours were grossly examined and tissue samples were fixed in 10%-buffered-formalin and embedded in paraffin. Sections 4 μm thick were obtained from each sample and HE grade III, (2/3) with high mitotic index. The preferential localization of mammary neoplasms was in the inguinal lobe (1/3 case) and abdominal lobes (2/3 cases). Furthermore, 1case of the inguinal mass affected the left caudo-inguinal lobe and 2cases right cranio and caudo abdominal lobes. The study concluded that cytology could be used as a quick, rapid, field diagnostic technique in combination with histopathology for the diagnosis of feline mammary tumors (FMTs). Our findings in feline MTs indicate that FMTs could be useful as an animal model of human breast cancer. Moreover, because of the similarity of the cytohistopathological findings in the human and feline mammary gland tumours, it is possible to use the same cytopathological criteria applied in human pathology for the diagnosis of feline mammary gland tumours. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2047361423103295

Properties of the feline tumour suppressor reduced expression in immortalized cells (REIC/Dkk-3).

Reduced expression in immortalized cells (REIC/Dkk-3), a member of the human Dickkopf (Dkk) family, is a growth suppressor in human and canine mammary tumours. Mammary gland tumours are common neoplasms with high malignancy in female cats. The purpose of this study was to clone the feline REIC/Dkk-3 homolog, investigate its expression in cell lines established from feline mammary gland tumours, and test its tumour suppressor function. Western blot analysis revealed that expression of the REIC/Dkk-3 protein was reduced in feline mammary carcinoma cell lines. Forced expression of REIC/Dkk-3 induced apoptosis in feline mammary tumour cell lines. These results demonstrate that REIC/Dkk-3 expression, which is downregulated in feline mammary tumour cell lines, results in the induction of apoptosis in these cells. Our findings suggest that feline REIC/Dkk-3 represents a potential molecular target for the development of therapies against feline mammary cancers.

Aberrant expression of sLex and sLea as candidate prognostic factors for feline mammary gland tumour.

Expression of the carbohydrate antigens sialyl Lewis x (sLe(x)) and a (sLe(a)) was evaluated in feline mammary gland tumours (FMGT). Immunohistochemical analysis of tissues from 21 FMGT patients and 11 healthy cats revealed significantly higher sLe(x) and sLe(a) antigen expression in adenocarcinoma tissues compared with that of normal mammary tissues (P <0.01). Serum concentration of sLe(x) was evaluated using an enzyme-linked immunosorbent assay and was significantly higher in the 11 FMGT patients (4.71 ± 10.1 U/ml) than the 22 patients with other disease (2.69 ± 1.59 U/ml) (P = 0.03) and the 22 healthy cats (3.71 ± 1.10 U/ml), although the latter difference was not significant. Although the number of cases examined in this study was small, our findings suggest that aberrant expression of sLe antigens may be induced by tumourigenesis in FMGT and that sLe antigens are potential prognostic tumour markers for FMGT.

RETRACTED ARTICLE: Comparative value of clinical, cytological, and histopathological features in feline mammary gland tumors; an experimental model for the study of human breast cancer

BackgroundThe diagnosis of breast lesions is usually confirmed by fine-needle aspiration cytology (FNAC) or histological biopsy. Although there is increasing literature regarding the advantages and limitations of both modalities, there is no literature regarding the accuracy of these modalities for diagnosing breast lesions in high-risk patients, who usually have lesions detected by screening. Moreover, few studies have been published regarding the cytopathology of mammary tumors in cats despite widespread use of the animal model for breast cancer formation and inhibition. The objective of the present study was to evaluate the diagnostic interest of cytological and histopathological analysis in feline mammary tumours (FMTs), in order to evaluate its possible value as an animal model.MethodsThe study was performed in 3 female cats submitted to surgical resections of mammary tumours. The mammary tumours were excised by simple mastectomy or regional mastectomy, with or without the superficial inguinal lymph nodes. Female cats were of different breeds (1 siamese and 2 persians). Before surgical excision of the tumour, FNA cytology was performed using a 0.4 mm diameter needle attached to a 8 ml syringe held in a standard metal syringe holder. The cytological sample was smeared onto a glass slide and either air-dried for May-Grünwald-stain and masses were surgically removed, the tumours were grossly examined and tissue samples were fixed in 10%-buffered-formalin and embedded in paraffin. Sections 4 μm thick were obtained from each sample and H&E stained.ResultsCytologically, atypical epithelial cells coupled to giant nucleus, chromatin anomalies, mitotic figures, spindle shape cells, anisocytosis with anisokaryosis and hyperchromasia were found. Histologically, these tumors are characterized by pleomorphic and polygonal cell population together with mitotic figures, necrotic foci and various numbers inflammatory foci. Also, spindle shaped cells, haemorrhage localized in the different regions, local invasiveness and enlarged nuclei were observed. The samples included 3 tumors of mammary glands mammary tumors were complex carcinomas (n = 2) and adenocarcinoma (n = 1). The histological grades of the 3 cases were as follows: grade II, (1/3); grade III, (2/3) with high mitotic index. The preferential localization of mammary neoplasms was in the inguinal lobe (1/3 case) and abdominal lobes (2/3 cases). Furthermore, 1case of the inguinal mass affected the left caudo-inguinal lobe and 2cases right cranio and caudo abdominal lobes.ConclusionThe study concluded that cytology could be used as a quick, rapid, field diagnostic technique in combination with histopathology for the diagnosis of feline mammary tumors (FMTs). Our findings in feline MTs indicate that FMTs could be useful as an animal model of human breast cancer. Moreover, because of the similarity of the cytohistopathological findings in the human and feline mammary gland tumours, it is possible to use the same cytopathological criteria applied in human pathology for the diagnosis of feline mammary gland tumours.Virtual slideThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2047361423103295

Expression of Multidrug Resistance-Associated P-Glycoprotein in Feline Tumours

Permeability glycoprotein (P-gp) is a membrane-bound efflux pump that mediates the active transmembrane transport of a variety of substrates. Several studies in human and canine normal and neoplastic tissues indicate that P-gp is involved in resistance to chemotherapy and in the development of multidrug resistance (MDR). The purpose of this study was to evaluate P-gp expression with the monoclonal antibody C494 in common feline tumours from 88 patients not pretreated with chemotherapy. Tumours arising from tissues with intrinsic P-gp expression consistently showed positive labelling for P-gp in a cellular pattern identical to that described for the normal feline tissues. Both P-gp positive and negative tumour cells, however, were found in mammary gland tumours, lymphomas, mastocytomas and squamous cell carcinomas. Feline mammary gland tumours in particular showed strong membranous P-gp labelling, especially in areas with infiltrative growth and atypical cells, although this was not correlated with the grade of malignancy. These findings might have implications for future response to chemotherapy.

Immunohistochemical evaluation of STAT3-p-tyr705 expression in feline mammary gland tumours and correlation with histologic grade

STAT3 (signal transducer and activator of transcription 3) is a cytoplasmic transcription factor that plays a role in the G1 to S phase cell-cycle transition and is induced by cytokines and growth factors. The expression of STAT3 phosphorylated on tyrosine 705 (STAT3-p-tyr705) in normal, hyperplastic and neoplastic feline mammary gland tissue was assessed by immunohistochemistry in 45 cats. The samples included 4 normal mammary non-lactating tissues, 9 hyperplastic tissues (5 fibroepithelial hyperplasia and 4 lobular epithelial hyperplasia), 2 benign tumours (1 complex adenoma, and 1 simple adenoma), and 30 carcinomas (18 simple tubular papillary, 6 simple tubular, 2 simple solid, 3 cribriform, and 1 adenosquamous carcinoma). For immunohistochemistry, tissue sections were incubated with an anti-STAT3-p-tyr705 monoclonal antibody and visualized with EnVision-DAB polymer. STAT3-p-tyr705 positivity was quantified in a semi-quantitative manner. All positive samples showed cytoplasmic and/or nuclear positivity. Normal non-lactating mammary tissue showed a low number of positive cells, similar to hyperplastic tissue. In neoplastic tissues, a high number of positive cells with a moderate to intense reaction was observed. Moreover, a correlation was observed between nuclear positivity for STAT3-p-tyr705 and histologic grade ( P = 0.013; r = 0.447), tubular formation ( P = 0.043; r = 0.820), and mitotic activity ( P < 0.0001; r = 0.689). In contrast, no such correlations were observed for cytoplasmic reactivity of STAT3-p-tyr705. A significant difference was observed between malignant lesions and hyperplasia with regards to expression of STAT3-p-tyr 705 in the cytoplasm ( P = 0.008; U = 59.00) and nuclei ( P = 0.002; U = 47.00). These results confirm previous our data and reinforce the potential role of STAT3 in malignancy as reported for human breast cancer and other sporadic tumours.

Expression of Stat3 in Feline Mammary Gland Tumours and its Relation to Histological Grade

The expression of Stat3 (signal transducer and activator of transcription 3) in normal and neoplastic feline mammary gland tissue was assessed by immunohistochemistry in 72 cats. The samples included 3 normal nonlactating mammary tissues, 17 hyperplastic lesions (11 lobular and 6 fibroepithelial) and 52 neoplasms (5 benign and 47 malignant). For immunohistochemistry, tissue sections were incubated with anti-Stat3 monoclonal antibody and visualized with EnVision-DAB polymer. Stat3 positivity was assessed in a semiquantitative manner. Normal mammary tissue showed occasional cytoplasmic and nuclear positivity, although the number of positive cells was lower than in the hyperplastic specimens. In neoplastic tissue, high numbers of neoplastic cells with a moderate to intense cytoplasmic and nuclear positivity were observed. Selected variations in the staining pattern correlated with malignancy. Moreover, a positive association was seen between the histological grade and the Stat3 score (p < 0.0001; correlation coefficient 0.750). A linear regression model showed a positive association between mitotic count and Stat3 expression (p < 0.001). These results further support published data found in humans regarding to the relation between the expression of Stat3 and malignancy.

Immunohistochemical Detection of Mdm2 and p53 in Feline Mammary Gland Tumors

The objective of this study was to evaluate nuclear reactivity of Mdm2 and p53 proteins by immunohistochemical means in feline mammary gland tumors; 12 adenomas which included 6 adenomatous lesions obtained from the tissue adjacent to adenocarcinomas, and 22 adenocarcinomas. Seven adenomas and 18 adenocarcinomas showed moderate or marked Mdm2 reactivity. Sixteen adenocarcinomas showed moderate to marked p53 reactivity, but 9 adenomas showed none. Discordant Mdm2 overexpression was found in 5 adenomas and 3 adenocarcinomas, although co-overexpression of Mdm2 and p53 was found in 15 adenocarcinomas. These results suggest that nuclear overexpression of Mdm2 is present in the tumors of early stage without p53 overexpression and related to feline mammary gland tumorigenesis. Nuclear overexpression of p53 is more frequent in adenocarcinomas, but not in adenomas.

Principles of treatment for mammary gland tumors

The mammary glands are frequent locations for the development of tumors. In the dog and cat, early detection and rapid therapy are necessary to prevent both local and distant metastasis. In the dog, this disease can have a range of biologic behaviors, whereas in the cat it is almost always an extremely aggressive disease. Treatment options depend on tumor staging and can include surgery, radiation therapy, chemotherapy, or a combination. As we become better at early diagnosis and are able to implement aggressive therapy, we are becoming more and more successful in the treatment of this disease. In the following article, we will discuss current thoughts surrounding the diagnosis and treatment options for both canine and feline mammary gland tumors.

Progesterone receptors in normal, dysplastic and tumourous feline mammary glands. Comparison with oestrogen receptors status

The aims of the study were to standardise an immunohistochemical (ihc) method for the detection of progesterone receptors (pr) on formalin-fixed, paraffin wax-embedded tissue sections of feline mammary gland tumours and dysplasias, comparing the results with those obtained using the radiolabelled ligand dextran coated charcoal (dcc) assay applied to frozen tissue samples from the same cases. Also, to define the immunohistochemical distribution of pr in the different cellular compartments of the lesions and to compare the oestrogen receptor (er) and pr status of the feline mammary lesions. Proliferative mammary lesions collected from 34 cats were studied; 25 malignant tumours and 9 benign tumours and dysplasias. pr protein was present at a concentration of 5fmolmg−1 (positivity threshold) in 37·5 per cent of malignant tumours and 66·7 per cent of benign tumours and dysplasias while immunoreative products to pr antibody were found in the nuclei of tumour cells in 38·5 per cent and 66·7 per cent of the cases, respectively. Concordance between dcc-pr and ihc-pr was 88·5 per cent (P<0·001). The specificity (true negatives) and sensitivity (true positives) of the ihc method were 89·4 per cent and 87·5 per cent respectively. The presence of pr was linked to the absence of ovariectomy (P<0·02). Oestrogen receptors, detected by either method, were also detected in half the cases in which pr had been detected. In malignant tumours, the most prevalent groups were the er + pr + ander −pr + groups.

The expression of sialyl Lewis X in canine and feline mammary gland tumors.

The expression of sialyl Lewis X (sLe(x)) in 93 canine and 15 feline mammary gland tumors (MGT) obtained by surgical resection at Veterinary Medical Center, the University of Tokyo was examined by immunohistochemistry. Their clinicopathological features and prognosis were also reviewed. Approximately 60% of MGT tissues showed sLe(x) positive expressions, while all normal mammary gland tissues were negative. However, its expression was not correlated with clinicopathological features and prognosis significantly. This study suggests that sLe(x) may be a tumor-associated antigen in canine and feline MGTs.