L-LOP/LOPP for the treatment of canine gastrointestinal/hepatosplenic lymphoma

Canine gastrointestinal (GI) and hepatosplenic (HS) high-grade (large cell) lymphomas are uncommon forms of canine lymphomas, with a very poor response to chemotherapy and a very poor prognosis. Currently, there are no established effective chemotherapy protocols for canine GI/HS lymphomas. This case series aimed to retrospectively evaluate the efficacy of lomustine-based protocols L-LOP (L-asparaginase, lomustine, vincristine, and prednisolone) and L-LOPP (with the addition of procarbazine) for treatment of canine GI/HS lymphomas. Medical records of dogs with cytologically or histologically diagnosed lymphoma at CityU Veterinary Medical Centre from 2019 to 2022 were retrospectively reviewed. The L-LOP/LOPP treatment protocol was well tolerated with rare severe adverse events. Median progression-free survival for GI and HS lymphoma was 56 days (range, 10-274 days) and 57 days (range 8-135 days) respectively; while median survival time for GI and HS lymphoma was 93 days (range 10-325 days) and 210 days (range 8-240 days) respectively.

Hematological and blood biochemistry parameters as prognostic indicators of survival in canine multicentric lymphoma treated with COP and L-COP protocols

Background and Aim

Hematological and blood chemistry parameters are crucial for evaluating and monitoring canine multicentric lymphoma during chemotherapy. Pre-treatment hematological and blood chemistry parameters can be used as prognostic survival outcomes for this disease. Therefore, this study aimed to investigate the effect of hematological and blood chemistry parameters pre-treatment and 4 weeks post-treatment on the survival outcomes of dogs treated with either a combination of cyclophosphamide, vincristine, and prednisolone (COP) or a combination of COP with L-asparaginase (L-COP) protocols.

Materials and Methods

We conducted a retrospective study. Medical records and hematological and blood chemistry parameters of 41 dogs with multicentric lymphoma treated with L-COP (n = 26) and the COP protocols (n = 15) were obtained from the hospital information system. Most cases were classified as high-grade lymphoma based on the Kiel cytological classification. The effects of hematological and blood chemistry parameters on survival outcomes were investigated using the Cox proportional hazard regression model. The median survival time (MST) for each hematological and blood chemistry parameter affecting survival outcome was established and compared using the Kaplan-Meier product limit method with the log-rank test.

Results

Dogs with high-grade multicentric lymphoma that were treated with the COP protocol and had monocytosis at pre-treatment had a significantly shorter MST than dogs with normal monocyte counts (p = 0.033). In addition, dogs with azotemia, both pre-treatment and 4 weeks post-treatment, had a significantly shorter MST than dogs with normal serum creatinine levels (p = 0.012). Dogs with high-grade multicentric lymphoma treated with the L-COP protocol who had hypoalbuminemia (serum albumin concentration <2.5 mg/dL) at both pre-treatment and 4 weeks post-treatment had a significantly shorter MST than dogs with normal serum albumin levels (p < 0.001). Furthermore, dogs with leukocytosis at 4 weeks post-treatment had a significantly shorter MST than those with a normal total white blood cell count (p = 0.024).

Conclusion

Serum albumin level can serve as a simple negative prognostic indicator of survival outcomes in dogs with high-grade multicentric lymphoma treated with the L-COP protocol. Dogs with hypoalbuminemia pre-treatment and 4 weeks post-treatment tended to have a shorter MST than those with normal serum albumin concentrations.

Review of Canine Lymphoma Treated with Chemotherapy-Outcomes and Prognostic Factors

While canine lymphoma is a relatively common and important disease seen by veterinarians, there are limited comprehensive reviews of the literature regarding the remission and survival times following chemotherapy, and the associated prognostic factors. This comprehensive thematic review covers the available veterinary literature covering treatment outcomes and identified prognostic factors. A lack of standardised approaches to evaluate and report the outcomes was identified, including factors that would alter the duration of responses by weeks, or occasionally months. After publication of the suggested reporting criteria, this has improved but is still not uniformly applied. The prognostic factors included for evaluation varied from as few as three to seventeen, with over 50 studies using only univariate analysis. Individual papers reported much longer outcomes than others, but assessing the outcomes overall, there has been minimal change over the last 40 years. This supports the belief that novel approaches for lymphoma therapy will be required to substantively improve outcomes.

Clinical Utility of Cytology from Preoperative Percutaneous Fine Needle Aspirates of Solitary Liver Masses in 220 Dogs: A Retrospective Study (2009-2019)

When a solitary liver mass is identified in a dog, a fine-needle aspirate (FNA) is commonly employed to attempt to obtain a diagnosis. Little information is provided in the literature evaluating the sensitivity/specificity of FNA cytology for solitary liver masses. We hypothesized that liver lesion size nor the presence of cavitation would impact the success of cytological diagnosis. Medical records were obtained for 220 client-owned dogs. Inclusion criteria included preoperative abdominal imaging, percutaneous FNA of a solitary hepatic mass with cytologic interpretation by a board-certified pathologist, and a surgical biopsy or mass excision yielding a histopathological diagnosis. Six dogs (2.7%) experienced a complication after FNA, none considered severe. The agreement rate for correct cytologic diagnosis was 22.9% (49/220). Of the neoplastic masses 18.9% (35/185) were correctly diagnosed via cytology. The overall sensitivity was 60%, and the specificity was 68.6%. Neither institution (P = 0.16), lesion size (P = 0.88), cavitation (P = 0.34), or needle gauge (P = 0.20) had an association with correct diagnosis. This study demonstrates that, although there is a low risk of complications following FNA of a hepatic mass, overall success rate for correct cytologic diagnosis based on FNA was low compared to histopathologic diagnosis.

Do socioeconomic factors impact management of suspected canine multicentric lymphoma in UK first opinion practice?

BACKGROUND

This study aimed to describe the management of cases of suspected and confirmed canine multicentric lymphoma (ML) in first opinion practice (FOP) and investigate whether socioeconomic factors are associated with initial management.

METHODS

Clinical narratives from electronic health records collected by the Small Animal Veterinary Surveillance Network (SAVSNET) were searched to identify dogs with peripheral lymphadenomegaly in which ML was the major differential. Cases were grouped as either ML confirmed (ML-C) or ML suspected but not confirmed (ML-S). Associations between initial management and socioeconomic factors were assessed via multivariable logistic regression.

RESULTS

Two hundred and sixty-four cases with ML-C and 410 with ML-S were identified. There was an increased probability that owners of ML-C cases resided in less deprived areas. Moreover, a diagnosis was made more commonly in insured dogs. Only insured pets were more likely to be treated with chemotherapy following diagnosis. The majority of dogs in both groups were treated with corticosteroids alone (ML-S, n = 256/410; ML-C, n = 123/264). A small minority were referred (n = 30/674).

CONCLUSION

Socioeconomic inequalities appear to be associated with the diagnosis and management of dogs with suspected or confirmed ML in FOP. Most dogs with suspected multicentric lymphoma (in the UK) are managed in FOP (n = 644/674). Consequently, expanding the knowledge base relevant to this setting offers an opportunity to improve the management of canine lymphoma.

Bilateral Renal Large B Cell Lymphoma in a Dog: A Case Report and Review of the Literature

Canine lymphoma is a commonly reported neoplasia and, in most dogs, arises from lymph nodes before spreading to other organs. Renal lymphoma rarely occurs, and kidneys usually are a secondary site of origin. Primary renal lymphoma is infrequently described in the veterinary literature. In this study, we present a rare case of primary renal lymphoma in a dog and a review of similar cases. A 3-year-old male dog was admitted due to anorexia, weakness and vomiting. Clinical examination revealed bilaterally enlarged kidneys. Imaging demonstrated the presence of multiple renal masses. Cytology of abdominal fluid and kidneys led to the diagnosis of large cell lymphoma. Histopathology and immunohistochemistry on tissue samples taken from the kidneys confirmed the cytological diagnosis of lymphoma and categorized it as primary bilateral renal large B-cell lymphoma (LBCL).

Clinical characteristics and outcome of dogs with presumed primary renal lymphoma

OBJECTIVES

To characterise the presentation, clinicopathologic data and outcome of 29 dogs with presumed primary renal lymphoma.

MATERIALS AND METHODS

Retrospective analysis of medical records of dogs with suspected primary renal lymphoma from 11 institutions.

RESULTS

All dogs were substage b, and lethargy and gastrointestinal signs were common presenting complaints, as were azotaemia (n=25; 86%) and erythrocytosis (n=15; 51%) on biochemical testing. Ultrasonography typically revealed bilateral renal lesions (n=23; 79%), renomegaly (n=22; 76%) and abdominal lymphadenopathy (n=14; 48%). Chemotherapy was the only treatment in 23 dogs, of which 11 responded, all considered partial responses. For all dogs the median progression-free survival and median overall survival times were 10 days (range: 1 to 126) and 12 days (range: 1 to 212), respectively, and for dogs that responded to chemotherapy 41 days (range: 10 to 126) and 47 days (range: 10 to 212), respectively.

CLINICAL SIGNIFICANCE

Primary renal lymphoma in dogs appears to be associated with a poor prognosis and short-lived response to chemotherapy.

T cell-lymphoma in the eyelid of a 9-year-old English Setter

BACKGROUND

Eyelid tumours are frequently found in dogs, most of these being benign. In case of an ulcerating eyelid tumour, malignancy must be considered. We report a unique case of a low-grade peripheral T-cell lymphoma in the eyelid of a 9-year-old English Setter.

CASE PRESENTATION

A 9-year-old Setter presented with a 6-month history of an eyelid ulcer. A malignant eyelid neoplasm was suspected, and the lesion was surgically excised. No other treatment was applied, and 19 months after excision the dog was still well. Histopathology revealed a diffuse lymphocytic infiltrate in the eyelid skin. Ulceration of the epithelium was seen, and the underlying tumour was composed of round and poorly demarcated pleomorphic tumour cells. The cytoplasm was pale and the nuclei heterogeneous. Numerous mitoses were present. The tumour cells stained strongly for CD3. The final diagnosis was a peripheral T-cell lymphoma not otherwise specified (NOS).

CONCLUSIONS

This is the first described case of a solitary T-cell lymphoma NOS in the haired eyelid skin in a dog. Lymphoma should be considered in case of a persistent eyelid ulcer and a biopsy should be performed. T-cell lymphoma is generally an aggressive disease; however, indolent cases are well known, and as this case shows, complete excision of a solitary T-cell lymphoma can be curable. Canine cutaneous epitheliotropic T-cell lymphoma is an important differential diagnosis, which must be recognized as the prognosis is very poor and systemic treatment is mandatory. The sub-classification of canine lymphoma is not complete, and further studies are needed to identify lymphoma subgroups and provide treatment guidelines.

Indolent T-cell-rich small B-cell hepatic lymphoma in a Golden Retriever

An 11-year-old female spayed Golden Retriever presented for an incidentally found liver mass. The hepatic mass and intra-abdominal lymph nodes had a marked heterogeneous T-cell population and far fewer numbers of small clonal B cells. This T-cell-rich small B-cell lymphoma had a unique histological pattern and indolent clinical course.

Evaluation of the modified Glasgow Prognostic Score to predict outcome in dogs with newly diagnosed lymphoma

The modified Glasgow Prognostic Score (mGPS) assigns a numerical value (0-2) from pre-treatment serum concentrations of C-reactive protein (CRP) and albumin to predict patient outcome. CRP and albumin were evaluated in 77 untreated dogs with lymphoma to determine the relationship of mGPS to clinicopathological parameters and whether it could predict progression-free (PFS) and overall survival (OS) in treated dogs. mGPS distribution was significantly associated with clinical stage, substage b, weight loss, gastrointestinal disturbances and lethargy at presentation. On univariate analysis, mGPS was significantly associated with OS and PFS, with shorter median survival times for mGPS 2 compared to mGPS 0 and 1 combined. Hypoalbuminaemia significantly reduced OS and PFS, however increased CRP had no effect. Only clinical stage was significantly associated with OS and PFS on both univariate and multivariate analysis. mGPS has potential prognostic value for canine lymphoma , but further studies are needed.