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

Prognostic role of the updated Kiel classification in canine high-grade T-cell lymphomas

BACKGROUND

The aim of this study was to determine and describe the prognostic role of the morphological subtype determined according to the updated Kiel classification in dogs with high-grade T-cell lymphomas (HGTCLs) depending on the treatment applied.

OBJECTIVES

The HGTCLs were classified into three subtypes according to the updated Kiel classification: pleomorphic mixed (PM), lymphoblastic lymphoma/acute lymphoblastic leukaemia and plasmacytoid (P). The treatment was divided into a palliative therapy (PlT) group and a chemotherapy (ChT) group.

METHODS

The study was conducted between 2009 and 2017, and it enrolled 58 dogs in which cytomorphological and immunocytochemistry diagnoses were HGTCL.

RESULTS

Overall survival (OS) was significantly longer in the ChT group (median OS-4 months, interquartile range [IQR] from 2 to 8 months) than in the PlT group (median OS-6 weeks, IQR from 1 week to 3 months). In the PlT group, PM subtype and glucocorticosteroids (GCSs) treatment proved significantly and independently linked to longer OS and approximately three-fold lower risk of death during the study period (adjusted hazard ratio [HRadj] = 0.26, confidence interval [CI] 95%: 0.08-0.81; p = 0.020 and HRadj = 0.30, CI 95%: 0.11-0.77; p = 0.013, respectively), although due to small group size, precision of estimations was poor (wide CI 95%). In the ChT group, >7 days elapsing between diagnosis and the beginning of chemotherapy and GCS treatment prior to chemotherapy were significantly associated with lower chance of complete remission (CR; p = 0.034 for both); GCS treatment prior to chemotherapy was significantly associated with shorter OS (p = 0.016); chemotherapy based on the modified CHOP protocol was significantly associated with higher chance of CR (p = 0.034) and longer OS (p = 0.039); and CR was significantly linked to longer OS (p = 0.001).

CLINICAL SIGNIFICANCE

The morphological subtype of HGTCL has some prognostic value in dogs treated palliatively (with PM subtype associated with longer OS than P subtype); however, this effect is no longer visible when a dog is treated with chemotherapy.

Evaluation of clinical response and prognostic factors in canine multicentric lymphoma treated with first rescue therapy

Despite an initial strong response in most dogs with multicentric lymphoma treated with chemotherapy, relapse remains common. There is no clearly superior first rescue protocol described either for resistant or relapsed canine multicentric lymphoma. The objectives of this study were to assess clinical response and outcomes for canine multicentric lymphoma treated with first rescue protocols. The secondary objective was to assess prognostic variables for dogs undergoing these protocols. This was a bi-institutional retrospective cohort study. Two hundred and sixty-five dogs were treated with first rescue chemotherapy, including anthracycline-based combination chemotherapy (CHOP-like, n = 50), nitrosourea alkylating agent-rich chemotherapy (n = 45), anthracycline-based or related compound chemotherapy (n = 34), or nitrosourea single-agent chemotherapy (n = 136). The overall median progression free survival time of first rescue protocol was 56.0 days (0-455 days). Important prognostic factors identified for first rescue protocol included the attainment of a complete response to the first rescue chemotherapy (p < .001), the use of a CHOP-like first rescue protocol (p = .009), duration of first remission (HR 0.997, p = .028), and if prednisolone was included in the first rescue protocol (HR 0.41, p = .003). Adverse events (AE) were common, with 81.1% of dogs experiencing at least one AE during first rescue chemotherapy. This study highlights the need for improved first rescue therapies to provide durable remission in canine resistant or relapsed lymphoma.

Evaluation of a multiagent chemotherapy protocol combining vincristine, cyclophosphamide, mitoxantrone and prednisolone (CMOP) for treatment of feline intermediate-large cell lymphoma

OBJECTIVES

The aim of this study was to determine response rates, median progression-free intervals (PFIs) and median survival times (MSTs) for cats with intermediate-large cell lymphoma treated with a vincristine, cyclophosphamide, mitoxantrone and prednisolone (CMOP) protocol. A secondary objective was to determine the tolerability of mitoxantrone used within this multiagent protocol.

METHODS

The medical records of 31 cats treated at a single institution between 2009 and 2022 were reviewed to identify suitable cases. Cats were included in the study if they had a confirmed diagnosis of intermediate-large cell lymphoma, had received a CMOP protocol as first-line treatment and had completed at least one 4-week cycle of this protocol. Modifications allowed in the protocol included the use of l-asparaginase, vinblastine substitution for vincristine, chlorambucil substitution for cyclophosphamide and dexamethasone or methylprednisolone substitution for prednisolone.

RESULTS

The overall response rate was 74% (n = 23), with 45% (n = 14) achieving complete remission (CR), 29% (n = 9) achieving partial remission (PR) and 26% (n = 8) achieving stable disease (SD). The Kaplan-Meier median PFI and MST were 139 days and 206 days, respectively. Responders (CR or PR) had a significantly longer (P <0.001) median PFI and MST compared with non-responders (SD) (176 days vs 62 days, and 251 days vs 61 days, respectively). Cats that achieved CR had a significantly longer median PFI and MST (P <0.001) at 178 days and 1176 days, respectively. The 6-month and 1- and 2-year survival rates in cats with CR were 64%, 57% and 35%, respectively. Treatment with mitoxantrone was generally well tolerated, with no cats experiencing Veterinary Cooperative Oncology Group adverse effects above grade 2.

CONCLUSIONS AND RELEVANCE

The CMOP protocol is an alternative and well-tolerated treatment for cats with intermediate-large cell lymphoma. As demonstrated with previous chemotherapy protocols, cats that respond to treatment, particularly those that achieve CR, are likely to have more durable responses.

Multimodal machine learning models identify chemotherapy drugs with prospective clinical efficacy in dogs with relapsed B-cell lymphoma

Dogs with B-cell lymphoma typically respond well to first-line CHOP-based chemotherapy, but there is no standard of care for relapsed patients. To help veterinary oncologists select effective drugs for dogs with lymphoid malignancies such as B-cell lymphoma, we have developed multimodal machine learning models that integrate data from multiple tumor profiling modalities and predict the likelihood of a positive clinical response for 10 commonly used chemotherapy drugs. Here we report on clinical outcomes that occurred after oncologists received a prediction report generated by our models. Remarkably, we found that dogs that received drugs predicted to be effective by the models experienced better clinical outcomes by every metric we analyzed (overall response rate, complete response rate, duration of complete response, patient survival times) relative to other dogs in the study and relative to historical controls.

An Evaluation of Hemostatic Dysregulation in Canine Multicentric Lymphoma

Multiple hemostatic abnormalities are associated with paraneoplastic syndrome and some malignant tumors. Lymphoma is the most common hematopoietic neoplasm in dogs, sometimes associated with hemostatic changes. The objectives of this study were to evaluate the behavior of coagulation parameters in dogs with multicentric lymphoma compared with diseased dogs without lymphoma, to separately evaluate the effect of immunophenotype (B lymphoma versus T lymphoma) on the variables of interest as well as the effect of disease stage (stage II to IV versus stage V). Specifically, a cross-sectional study was performed with a matched comparison group considering 170 dogs with B or T lymphoma (group 1) and 170 dogs with no lymphoma or other neoplastic processes but other diseases (group 0). Eight coagulation parameters were evaluated: platelet count (Plt), activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin time (TT), fibrinogen, fibrin/products of fibrinogen degradation (FDPs), fibrin D-dimers, and antithrombin (AT). Dogs with lymphoma showed prolonged PT and TT, decreased fibrinogen, increased FDP, and decreased Plt compared with group 0. The effect of disease stage was evaluated separately for dogs with stage II to IV lymphoma and dogs with stage V lymphoma; patients with stage II-IV lymphoma showed no significant differences, while in dogs with stage V lymphoma, a prolongation of PT and TT, a decrease in fibrinogen, an increase in FDPs and a decrease in Plt were found compared with the group 0. Finally, the comparison between B lymphoma and T lymphoma showed no significant differences in coagulation parameters between the two groups. Logistic regression analysis demonstrated that low fibrinogen and platelet levels were the most significant predictors of lymphoma in a cohort of canine patients. These hemostatic abnormalities in lymphoma appeared to be associated with the stage of the disease rather than the lymphoma immunophenotype. These findings pave the way for the possible scenario of lymphoma-associated fibrinolysis and the so far undescribed pattern of hyperfibrinolysis associated with the most severe stage of lymphoma.

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.

Prognostic value of peripheral blood and bone marrow infiltration assessed by flow cytometry in dogs with de novo nodal peripheral T-cell lymphoma receiving alkylating-rich chemotherapy

Peripheral T-cell lymphoma (PTCL) is highly aggressive in dogs and demonstrates a poor response to traditional chemotherapy. The aim of this retrospective study was to assess the prognostic significance of peripheral blood (PB) and bone marrow (BM) infiltration evaluated by flow cytometry (FC) in dogs with treatment-naïve and histologically confirmed PTCL. To be included, dogs had to undergo complete staging, including FC on lymph nodes, PB and BM samples. Additionally, dogs had to receive an alkylating-rich protocol and have a complete follow-up. Treatment response was evaluated based on RECIST criteria at each chemotherapy session, and the end-staging was conducted at the completion of treatment. Endpoints were time to progression (TTP) and lymphoma-specific survival (LSS). The relationship between TTP/LSS and the percentage of PB and BM infiltration, categorized as > 1%, > 3%, > 5%, > 10%, > 15% and > 20% was investigated. Fifty dogs were included: based on imaging and FC, 78.0% had stage 5 disease, 14.0% had stage 4, 6.0% had stage 3 and 2.0% had stage 1. By multivariable analysis, the CD4-negative phenotype was the only factor associated with a shorter TTP (P = 0.049), while BM infiltration was significantly associated with LSS (P = 0.037). Dogs with BM infiltration > 5% had shorter median LSS (114 days; 95%CI: 0-240) compared to dogs with BM infiltration ≤ 5% (178 days; 95%CI: 145-211). Lack of complete response (P = 0.039) and administration of corticosteroids before chemotherapy (P = 0.026) also significantly worsened LSS. BM flow cytometric evaluation could be considered an essential part of staging work-up for dogs with PTCL and has prognostic relevance.

Unexpected diagnosis of canine lymphoma when performing an ultrasound-guided cystocentesis on a 3-year-old Rottweiler dog

A 3-year-old spayed female Rottweiler dog was brought to a veterinary clinic because of weakness, lethargy, and hair coat changes. Hematology and clinical chemistry assessments revealed anemia, hypoalbuminemia, hyperglobulinemia, and hypothyroid. After persistent pyuria, an ultrasound-guided cystocentesis was completed, which revealed a large abdominal mass. A presumptive diagnosis of canine lymphoma with renal spread was made. Due to a poor prognosis, the dog was euthanized.

Genomic Analysis of Lymphoma Risk in Bullmastiff Dogs

Lymphoma is the most common haematological malignancy affecting dogs and has a high incidence in the Bullmastiff breed. The aim of this study was to identify risk loci predisposing this breed to the disease. The average age of lymphoma diagnosis in 55 cases was less than 6 years, similar to the median age of 64 cases from our clinical and pathology databases. When fine-scale population structure was explored using NETVIEW, cases were distributed throughout an extended pedigree. When genotyped cases (n = 49) and dogs from the control group (n = 281) were compared in a genome-wide association analysis of lymphoma risk, the most prominent associated regions were detected on CFA13 and CFA33. The top SNPs in a 5.4 Mb region on CFA13 were significant at a chromosome-wide level, and the region was fine-mapped to ~1.2 Mb (CFA13: 25.2-26.4 Mb; CanFam3.1) with four potential functional candidates, including the MYC proto-oncogene bHLH transcription factor (MYC) and a region syntenic with the human and mouse lncRNA Pvt1 oncogene (PVT1). A 380 Kb associated region at CFA33: 7.7-8.1 Mb contained the coding sequence for SUMO specific peptidase7 (SENP7) and NFK inhibitor zeta (NFKBIZ) genes. These genes have annotations related to cancer, amongst others, and both have functional links to MYC regulation. Genomic signatures identified in lymphoma cases suggest that increased risk contributed by the regions identified by GWAS may complement a complex predisposing genetic background.

Lymphoma in Border Collies: Genome-Wide Association and Pedigree Analysis

There has been considerable interest in studying cancer in dogs and its potential as a model system for humans. One area of research has been the search for genetic risk variants in canine lymphoma, which is amongst the most common canine cancers. Previous studies have focused on a limited number of breeds, but none have included Border Collies. The aims of this study were to identify relationships between Border Collie lymphoma cases through an extensive pedigree investigation and to utilise relationship information to conduct genome-wide association study (GWAS) analyses to identify risk regions associated with lymphoma. The expanded pedigree analysis included 83,000 Border Collies, with 71 identified lymphoma cases. The analysis identified affected close relatives, and a common ancestor was identified for 54 cases. For the genomic study, a GWAS was designed to incorporate lymphoma cases, putative "carriers", and controls. A case-control GWAS was also conducted as a comparison. Both analyses showed significant SNPs in regions on chromosomes 18 and 27. Putative top candidate genes from these regions included DLA-79, WNT10B, LMBR1L, KMT2D, and CCNT1.