Outcomes of 43 small breed dogs treated for splenic hemangiosarcoma

Prognostic value of tumour-related factors associated with canine retroperitoneal hemangiosarcoma in comparison with other anatomic presentations: A retrospective observational study

BACKGROUND

Dogs with retroperitoneal hemangiosarcoma (HSA) exhibit variable postoperative median survival times (MST).

OBJECTIVE

To retrospectively evaluate the prognostic value of selected tumour-related factors, such as tumour size, rupture, invasion into adjacent tissue, involvement of lymph node and distant metastasis, they were analysed in dogs with retroperitoneal HSA.

METHODS

Ten dogs with retroperitoneal HSA managed solely with surgical excision were reviewed and compared with spleen (71) and liver (9) HSA. The Kaplan-Meier method and log-rank analysis were used compare MSTs between factors. Multivariable Cox proportional-hazard analysis was used to compare differences between arising sites.

RESULTS

Retroperitoneal HSA showed comparatively longer postoperative MST compared with that of spleen and liver HSA and demonstrated significantly longer MST (p = 0.003) for tumours ≥5 cm (195 days) than <5 cm (70 days). Spleen HSA revealed significantly shorter MSTs in involvement of distant lymph nodes (23 days) and distant metastasis (39 days) than those in negative (83 days, p = 0.002 and 110 days, p < 0.001, respectively). Liver HSA also revealed significantly shorter MST (16.5 days compared with 98 days, p = 0.003) for distant metastasis. Additionally, hazard ratios (HRs) and their forest plot for overall HSA revealed as poor prognostic factors, arising sites (spleen; HR 2.78, p = 0.016 and liver; HR 3.62, p = 0.019), involvement of distant lymph nodes (HR 2.43, p = 0.014), and distant metastasis (HR 2.86, p < 0.001), and as better prognostic factor of tumour size ≥5 cm (HR 0.53, p = 0.037).

CONCLUSION

In combination with overall HSA, retroperitoneal HSA shows comparatively longer postoperative MST compared to spleen and liver HSA, associated with tumour size ≥5 cm suggesting better prognostic factor.

Current understanding of comparative pathology and prospective research approaches for canine hemangiosarcoma

Hemangiosarcoma (HSA) is a malignant tumor originating from endothelial cells. HSA typically develops in dogs, but is rare in other animals, including humans. Although surgery and chemotherapy are conventional treatments for HSA, neither treatment can significantly improve patient prognosis. To develop novel and effective therapeutics, a deeper understanding of HSA pathogenesis must be acquired. However, the limited research tools for HSA have been unable to make a breakthrough; therefore, it is crucial to widely utilize or establish novel research tools such as patient-derived xenograft models, organoids, and chicken embryo xenograft models. The pathogenesis of the human counterpart of HSA, angiosarcoma (AS), also remains incompletely understood, preventing the extrapolation of findings from humans to dogs, unlike other diseases. In this review, we summarize the clinicopathological and morphological features of HSA, and then we discuss the current understanding of the molecular pathology of HSA. Finally, we highlight promising research tools that may accelerate HSA basic research toward developing novel therapeutics. We also briefly summarize AS to help researchers comprehend HSA from the perspective of comparative pathology.

Molecular Profile of Canine Hemangiosarcoma and Potential Novel Therapeutic Targets

Canine hemangiosarcoma (HSA) is a relatively common neoplasia, occurring mainly in the skin, spleen, liver and right atrium. Despite the numerous studies investigating the treatment of canine HSA, no significant improvement in survival has been achieved in the last 20 years. Advancements in genetic and molecular profiling presented molecular similarities between canine HSA and human angiosarcoma. It could therefore serve as a valuable model for investigating new and more effective treatments in people and dogs. The most common genetic abnormalities in canine HSA have been found in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and neuroblastoma RAS viral oncogene homolog (NRAS) pathways. Mutations are also found in tumor protein p53 (TP53), phosphatase and tensin homolog (PTEN) and cyclin dependent kinase inhibitor 2A (CDKN2A). Known abnormal protein expression could be exploited to trial new target treatments that could be beneficial for both canine and human patients. Despite the high expression of vascular endothelial growth factor (VEGF) and its receptor (VEGFR), no correlation with overall survival time has ever been found. In this review, we explore the most recent developments in molecular profiling in canine HSA and discuss their possible applications in the prognosis and treatment of this fatal disease.

Retrospective evaluation of surgical site infection after open splenectomies with and without perioperative prophylactic antibiotic coverage

OBJECTIVES

Perioperative prophylactic antibiotics (PPA) are widely used in veterinary medicine to prevent surgical site infections (SSI). Current guidelines advocate the use in clean procedures only if surgeries exceed 90 minutes, or in patients with an ASA score ≥3. Procedure specific recommendations are currently lacking. The following study aimed to analyze the protective effect of PPA in dogs undergoing open splenectomy.

METHODS

The electronic database of our institution was searched for dogs that underwent splenectomy between 10/2017 and 01/2023. Data collection included age at presentation, breed, weight, reason for splenectomy, diagnosis, ASA class, PPA regime, surgery time, anesthesia time, lowest blood oxygen concentration during anesthesia, lowest body temperature, and lowest blood pressure during surgery as well as duration of hospitalization. Dogs were included if a follow-up of 30 days after surgery was available, or if death occurred within this timeframe.

RESULTS

A total of 112 dogs were included. Of these, 46 dogs received PPA, and 66 did not. Most dogs were classified ASA 3 or higher (PPA 87%, non-PPA 80.3%). One SSI (1.5% SSI rate) occurred in the non-PPA group (overall SSI rate 0.9%). Due to the low SSI rate, statistical analysis of risk factors for SSI development was not possible.

CONCLUSION

The described infection rate of 1.5% without PPA indicates, that splenectomy does not qualify as high-risk surgery for SSI, even in patients with ASA class 3 or higher.

CLINICAL RELEVANCE

As splenectomies are frequently performed, the findings of the current study could have a major impact on the overall antimicrobial burden in routine veterinary practice.

Diagnosis, Prognosis, and Treatment of Canine Hemangiosarcoma: A Review Based on a Consensus Organized by the Brazilian Association of Veterinary Oncology, ABROVET

Hemangiosarcoma is a mesenchymal neoplasm originating in the endothelial cells of blood vessels; they can be classified as non-visceral and visceral types. Non-visceral hemangiosarcomas can affect the skin, subcutaneous tissues, and muscle tissues; visceral hemangiosarcomas can affect the spleen, liver, heart, lungs, kidneys, oral cavity, bones, bladder, uterus, tongue, and retroperitoneum. Among domestic species, dogs are most affected by cutaneous HSA. Cutaneous HSA represents approximately 14% of all HSA diagnosed in this species and less than 5% of dermal tumors, according to North American studies. However, Brazilian epidemiological data demonstrate a higher prevalence, which may represent 27 to 80% of all canine HSAs and 13.9% of all skin neoplasms diagnosed in this species. Cutaneous HSA most commonly affects middle-aged to elderly dogs (between 8 and 15 years old), with no gender predisposition for either the actinic or non-actinic forms. The higher prevalence of cutaneous HSA in some canine breeds is related to lower protection from solar radiation, as low skin pigmentation and hair coverage lead to greater sun exposure. Actinic changes, such as solar dermatosis, are frequent in these patients, confirming the influence of solar radiation on the development of this neoplasm. There are multiple clinical manifestations of hemangiosarcoma in canines. The diagnostic approach and staging classification of cutaneous HSAs are similar between the different subtypes. The definitive diagnosis is obtained through histopathological analysis of incisional or excisional biopsies. Cytology can be used as a presurgical screening test; however, it has little diagnostic utility in cases of HSA because there is a high risk of blood contamination and sample hemodilution. Surgery is generally the treatment of choice for dogs with localized non-visceral HSA without evidence of metastatic disease. Recently, electrochemotherapy (ECT) has emerged as an alternative therapy for the local ablative treatment of different neoplastic types; the use of radiotherapy for the treatment of dogs with cutaneous HSA is uncommon. There is greater consensus in the literature regarding the indications for adjuvant chemotherapy in subcutaneous and muscular HSA; doxorubicin is the most frequently used antineoplastic agent for subcutaneous and muscular subtypes and can be administered alone or in combination with other drugs. Other therapies include antiangiogenic therapy, photodynamic therapy, the association of chemotherapy with the metronomic dose, targeted therapies, and natural products. The benefits of these therapies are presented and discussed. In general, the prognosis of splenic and cardiac HSA is unfavorable. As a challenging neoplasm, studies of new protocols and treatment modalities are necessary to control this aggressive disease.

Analysis of the Prevalence of Canine Splenic Mass Lesions in Republic of Korea via Histopathological Diagnosis with Immunohistochemistry

The histopathological diagnosis of canine splenic mass lesions is crucial for prognostication. However, thus far, no study has been conducted on the histopathology of canine splenic mass lesions in Republic of Korea. Herein, the prevalence of splenic diseases was analyzed in 137 canine splenic mass lesions via histopathological diagnosis, and the microscopic pattern associated with each disorder was described. Immunohistochemistry was performed for CD31, CD3, PAX5, Iba1, and C-kit for a more accurate diagnosis of splenic tumors. The proportion of non-neoplastic disorders, including nodular hyperplasia (48.2%, n = 66) and hematoma (24.1%, n = 33), was 72.3%. Splenic tumors, including splenic hemangiosarcoma (10.2%, n = 14), splenic lymphoma (nodular and diffuse types, 8.0%, n = 11), splenic stromal sarcoma (7.3%, n = 10), myelolipoma (1.5%, n = 2), and mast cell tumors (0.7%, n = 1), accounted for 27.7% of cases. The results of this study will aid veterinary clinicians in communication with pet owners about prognoses, recommendations for splenectomy, and subsequent histopathological diagnoses. This study will facilitate further investigations with more detailed comparisons of splenic mass lesions between small- and large-breed dogs.

Pilot safety evaluation of doxorubicin chemotherapy combined with non-specific immunotherapy (Immunocidin®) for canine splenic hemangiosarcoma

Canine splenic hemangiosarcoma (HSA) is an aggressive tumor with a short overall survival time (OST) despite treatment with splenectomy and adjuvant doxorubicin. Modulation of the immune system has been shown to be effective for a variety of human tumors, and may be effective for canine tumors, including HSA. Immunocidin® is a non-specific immunotherapy based on a mycobacterial cell wall fraction. Preliminary work suggests Immunocidin® is safe to give intravenously (IV) in tumor-bearing dogs. This work aimed to evaluate the safety of doxorubicin and Immunocidin® combination in dogs with naturally occurring splenic HSA. A secondary aim of this study was to collect preliminary efficacy data to support a subsequent comprehensive, prospective clinical trial in canine patients with HSA, if the combination of doxorubicin and Immunocidin® was found to be safe. Eighteen dogs with stage II-III splenic HSA were recruited to receive 5 doses of sequential IV doxorubicin and Immunocidin® at two-week intervals following splenectomy. Adverse events (AEs) were graded according to the Veterinary Cooperative Oncology Group v1.1 (VCOG) scheme. Overall survival time was calculated from the date of splenectomy to date of death or loss to follow-up. AEs during administration were infrequent, the most common being hypertension. One patient developed limb and facial twitching and was removed from the study. After infusion, common AEs included lethargy, hyporexia, and diarrhea. One patient developed VCOG grade 5 diarrhea, thrombocytopenia, and anemia. Modifications in the treatment regimen were made to prevent these signs in subsequent patients. The median OST in dogs treated with the combination therapy was estimated at 147 days (range: 39-668 days). Although generally safe, the combination of doxorubicin and Immunocidin® appeared to cause more gastrointestinal effects than doxorubicin alone, and no apparent improvement in OST was noted in this population of dogs.

Investigation of Prognostic Value of Claudin-5, PSMA, and Ki67 Expression in Canine Splenic Hemangiosarcoma

Simple Summary

Canine splenic hemangiosarcoma (HSA) is an aggressive cancer that originates from endothelial cells. In clinical practice, it is commonly noted among canine patients with ruptured tumors, inducing internal bleeding. Although it is highly important in veterinary medicine, very limited information regarding HSA prognostic markers is available. Thus, this study aimed to evaluate the prognostic value of Claudin-5, prostate-specific membrane antigen (PSMA), and Ki67 in HSA-affected canine patients. We evaluated Claudin-5 and PSMA gene and protein expression, assessed the Ki67 index, and compared these with patients’ clinical data. We identified an association between Claudin-5 expression and metastatic status. Patients with higher Claudin-5 expression developed metastasis, and there was an association between PSMA expression and overall survival. Our results suggest that these proteins could be useful prognostic markers for patients with HSA.

Abstract

Splenic hemangiosarcoma (HSA) is a malignant tumor of endothelial cells that affects middle-aged and elderly dogs and is characterized by the formation of new blood vessels, commonly associated with necrotic and hemorrhagic areas. Despite its importance in veterinary medicine, few studies have identified markers with prognostic value for canine HSA. Thus, this study aimed to associate the clinicopathological findings (prostate-specific membrane antigen [PSMA], Claudin-5, and Ki67 gene and protein expression) with overall survival in HSA-affected patients. Fifty-three formalin-fixed and paraffin-embedded canine splenic HSA samples, previously diagnosed by histopathological examination, were used in this study. Claudin-5, PSMA, and Ki67 protein expression levels were evaluated by immunohistochemistry, and gene expression was evaluated by quantitative polymerase chain reaction. Claudin-5 protein overexpression was observed in patients with metastasis (p = 0.0078) and with stage III tumors compared to those with stage I and II tumors (p = 0.0451). In patients treated with surgery alone, low PSMA gene and protein expression (p = 0.05 and p = 0.0355, respectively) were associated with longer survival time. Longer survival time was observed in patients with a low Ki67 index (p = 0.0488). Our results indicate that Claudin-5 protein expression is associated with metastatic status, and PSMA gene and protein expression, and Ki67 index are associated with survival time.