Prophylactic Trimethoprim-Sulfadiazine during Chemotherapy in Dogs with Lymphoma and Osteosarcoma: A Double-Blind, Placebo-Controlled Study

Are severe adverse events commonly observed in dogs during cancer chemotherapy? A retrospective study on 155 dogs

Overall prevalence of severe adverse events (sAE) has been poorly studied in veterinary medicine and peer-reviewed studies mostly focused on a single protocol, making it difficult to have a general overview. The aim of this retrospective study was to assess the frequency and risk factors of sAE secondary to various protocols of chemotherapy in dogs. Medical records of 155 dogs receiving chemotherapy between January 2013 and December 2018 were reviewed. Adverse events (AE) were graded according to Veterinary Comparative Oncology Group-common terminology criteria for AE (VCOG-CTCAE) grading system. Statistical analyses were performed to determine whether demographic, cancer type and chemotherapy protocol were associated with development of sAE and their consequences. AE were reported at least once in 124 (80%) dogs and sAE were observed in 50 (32.3%) dogs. Among them, 23 (14.8%) had gastro-intestinal and 31 (20.0%) had myelotoxic events. sAE led to hospitalisation in 37 (23.9%) dogs, to chemotherapy arrest in 12 (7.7%) dogs and to euthanasia or death in 9 (5.8%) dogs. Haematopoietic tumours were statistically associated with a higher frequency of sAE (p = .004), gastrointestinal sAE (p = .009) and hospitalisation (p = .004). A body weight over 10 kg was associated with less haematological sAE (p < .001). The use of a multi-agent protocol was highlighted as a risk factor for sAE (p = .038) and haematological sAE (p < .001). sAE following chemotherapy and leading to hospitalisation, chemo arrest or death were relatively common. A special attention during chemotherapy follow-up should be given to small dogs and those receiving multi-agent protocol or treated for haematopoietic tumours.

Identification and validation of RNA-binding protein-related gene signature revealed potential associations with immunosuppression and drug sensitivity in glioma

Background

Glioma is the most common central nervous system tumor in adults, and a considerable part of them are high‐degree ones with high malignancy and poor prognosis. At present, the classification and treatment of glioma are mainly based on its histological characteristics, so studies at the molecular level are needed.

Methods

RNA‐seq data from The Cancer Genome Atlas (TCGA) datasets (n = 703) and Chinese Glioma Genome Atlas (CGGA) were utilized to find out the differentially expressed RNA‐binding proteins (RBPs) between normal cerebral tissue and glioma. A prediction system for the prognosis of glioma patients based on 11 RBPs was established and validated using uni‐ and multi‐variate Cox regression analyses. STITCH and CMap databases were exploited to identify putative drugs and their targets. Single sample gene set enrichment analysis (ssGSEA) was used to calculate scores of specific immune‐related gene sets. IC50 of over 20,000 compounds in 60 cancer cell lines was collected from the CellMiner database to test the drug sensitivity prediction value of the RBP‐based signature.

Results

We established a reliable prediction system for the prognosis of glioma patients based on 11 RBPs including THOC3, LSM11, SARNP, PABPC1L2B, SMN1, BRCA1, ZC3H8, DZIP1L, HEXIM2, LARP4B, and ZC3H12B. These RBPs were primarily associated with ribosome and post‐transcriptional regulation. RBP‐based risk scores were closely related to immune cells and immune function. We also confirmed the potential of the signature to predict the drug sensitivity of currently approved or evaluated drugs.

Conclusions

Differentially expressed RBPs in glioma can be used as a basis for prognosis prediction, new drugs screening and drug sensitivity prediction. As RBP‐based glioma risk scores were associated with immunity, immunotherapy may become an important treatment for glioma in the future.

Evaluation of a 0.75 × 109 /L absolute neutrophil count cut-off for antimicrobial prophylaxis in canine cancer chemotherapy patients

Absolute neutrophil count (ANC) cut-offs for antimicrobial prophylaxis in veterinary cancer chemotherapy patients are empirical and vary between institutions. Evidence based cut-offs are vital for antimicrobial stewardship, particularly as global antimicrobial resistance rises. The primary objectives of this study were to evaluate the tolerability of a <0.75 × 10⁹ /l ANC cut-off for antimicrobial prophylaxis in dogs after receiving chemotherapy and its impact on antimicrobial prescription. Predicted nadir ANCs (pnANCs) were stratified into six groups (<0.75 × 10⁹ /l [receiving antimicrobial prophylaxis], 0.75-0.99 × 10⁹ /l, 1-1.49 × 10⁹ /l, 1.5-1.99 × 10⁹ /l, 2.0-3.59 × 10⁹ /l and 3.6-12 × 10⁹ /l [reference interval]). The incidences of post-nadir febrile neutropenia (FN) and non-haematological toxicity (NHT) were compared between groups. Five hundred and eighty-six pnANCs were recorded for 181 dogs. There were four episodes of post-nadir FN and 90 episodes of post-nadir NHT. There was no significant difference in incidence of post-nadir FN (P = .063) or post-nadir NHT (P = .084) between pnANC groups. Antimicrobial prophylaxis was prescribed following 8.8% of the chemotherapy administrations; had cut-off values of <1.0 × 10⁹ /l or <1.5 × 10⁹ /l been used it would have been prescribed in 15.3% and 25.8% of cases respectively. An ANC cut-off of <0.75 × 10⁹ /l for antimicrobial prophylaxis appears to be well tolerated and minimizes the prescription of antimicrobials.

Evaluation of the Tolerability of Combination Chemotherapy with Mitoxantrone and Dacarbazine in Dogs with Lymphoma

Combination chemotherapy can be an effective option for treating resistant lymphoma in dogs. This retrospective study examined the tolerability and efficacy of the combination of 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide (dacarbazine) (DTIC) in a population of dogs with lymphoma resistant to a doxorubicin-containing chemotherapy protocol. Mitoxantrone was administered at 5 mg/m² IV over 10 min followed by DTIC at 600 mg/m² IV over 5 hr, every 3 wk. All dogs were treated with prophylactic trimethoprim-sulfadiazine and metoclopramide. The frequency of grade 4 neutropenia was 18%, and 5% of dogs were hospitalized from sepsis. Gastrointestinal toxicity was uncommon. The overall response rate was 34% (15 of 44; 95% confidence interval 20-48%) for a median duration of 97 days (range 24-636 days, 95% confidence interval 44-150 days). Fourteen of 15 dogs who received mitoxantrone and DTIC as first rescue responded to treatment. Dogs who achieved complete remission to their initial L-asparaginase, cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy protocol were more likely to respond to mitoxantrone and DTIC (23 versus 11%, P = .035). The combination of mitoxantrone and DTIC is a safe treatment option for resistant lymphoma in dogs.

Antibiotic prophylaxis in veterinary cancer chemotherapy: A review and recommendations

Bacterial infection following cancer chemotherapy-induced neutropenia is a serious cause of morbidity and mortality in human and veterinary patients. Antimicrobial prophylaxis is controversial in the human oncology field, as any decreased incidence in bacterial infections is countered by patient adverse effects and increased antimicrobial resistance. Comprehensive guidelines exist to aid human oncologists in prescribing antimicrobial prophylaxis but similar recommendations are not available in veterinary literature. As the veterinarian's role in antimicrobial stewardship is increasingly emphasized, it is vital that veterinary oncologists implement appropriate antimicrobial use. By considering the available human and veterinary literature we present an overview of current clinical practices and are able to suggest recommendations for prophylactic antimicrobial use in veterinary cancer chemotherapy patients.

Evaluation of information presented within soft tissue sarcoma histopathology reports in the United States: 2012-2015

Despite the existence of the American College of Veterinary Pathology guidelines for tumour biopsy specimens, anecdotally the authors' have seen inconsistency of reporting of information on the pathology report for canine soft tissue sarcomas (STSs). If crucial aspects are not reported this can result in slower or impeded patient care. This retrospective study evaluated 255 STS histopathology reports submitted from across the United States. Reports were evaluated by a single observer to assess for information contained in 5 main categories: patient history and signalment, gross and microscopic description, grading, histologic margins and the comments section. Inclusion criteria for histopathology reports included a final diagnosis of STS, having a microscopic description and resulting from the initial surgical resection. The majority of the reports stated the patient signalment (91.2%) and clinical history (90.8%). However, only 64.8% of the reports had a gross description of the specimen. Histologic margin description was present in 229 reports (91.6%), however, only 149 reports (59.6%) stated an objective measurement of these margins. Histologic classification was stated in 50.0% of the reports, while grade was given on 97.2% of the reports. Variability in histopathologic reporting including histologic margin description for resected canine STS was identified. Given surgical treatment is the mainstay for STS and histopathological assessment plays an important role in determination of whether additional surgery, radiation or chemotherapy is needed. Standardization or checklists like the American College of Pathology utilize may be helpful to ensure histopathologic characteristics are reported that may guide further treatment recommendations.

Novel hyperthermia applicator system allows adaptive treatment planning: Preliminary clinical results in tumour-bearing animals

Hyperthermia (HT) as an adjuvant to radiation therapy (RT) is a multimodality treatment method to enhance therapeutic efficacy in different tumours. High demands are placed on the hardware and treatment planning software to guarantee adequately planned and applied HT treatments. The aim of this prospective study was to determine the effectiveness and safety of the novel HT system in tumour-bearing dogs and cats in terms of local response and toxicity as well as to compare planned with actual achieved data during heating. A novel applicator with a flexible number of elements and integrated closed-loop temperature feedback control system, and a tool for patient-specific treatment planning were used in a combined thermoradiotherapy protocol. Good agreement between predictions from planning and clinical outcome was found in 7 of 8 cases. Effective HT treatments were planned and verified with the novel system and provided improved quality of life in all but 1 patient. This individualized treatment planning and controlled heat exposure allows adaptive, flexible and safe HT treatments in palliatively treated animal patients.

High dose lansoprazole combined with metronomic chemotherapy: a phase I/II study in companion animals with spontaneously occurring tumors

BACKGROUND

The treatment of human cancer has been seriously hampered for decades by resistance to chemotherapeutic drugs. A very efficient mechanism of tumor resistance to drugs is the proton pumps-mediated acidification of tumor microenvironment. Metronomic chemotherapy has shown efficacy in adjuvant fashion as well as in the treatment of pets with advanced disease. Moreover, we have shown in veterinary clinical settings that pre-treatment with proton-pumps inhibitors (PPI) increases tumor responsiveness to chemotherapeutics. In this study pet with spontaneously occurring cancer have been recruited to be treated by a combination of metronomic chemotherapy and high dose PPIs and their responses have been matched to those of a historical control of ten patients treated with metronomic chemotherapy alone.

METHODS

Single arm, non randomized phase II open study, with historical control group, evaluating safety and efficacy of the combination of metronomic chemotherapy and alkalization. Twenty-four companion animals (22 dogs and 2 cats) were treated adding to their metronomic chemotherapy protocol the pump inhibitor lansoprazole at high dose, and a water alkalizer. Their responses have been evaluated by clinical and instrumental evaluation and matched to those of the control group.

RESULTS

The protocol was overall well tolerated, with only two dogs experiencing side effects due to gastric hypochlorhydria consisting with vomiting and or diarrhea. In terms of overall response, in the alkalized cohort, 18 out of 24 had partial or complete responses (75%), two patients had a stable disease and the remaining patients experienced no response or progressive disease. On the other hand, only one patient in the control group experienced a complete response (10%) and three other experienced short lived responses. Median time to terminal event was 34 weeks for the experimental group versus 2 weeks in the controls (p= 0.042).

CONCLUSIONS

Patient alkalization has shown to be well tolerated and to increase tumor response to metronomic chemotherapy as well the quality of life in pets with advanced cancer. Further studies are warranted to assess the efficacy of this strategy in patients with advanced cancers in companion animals as well as in humans.

Tolerability of Lomustine in Combination with Cyclophosphamide in Dogs with Lymphoma

This retrospective study describes toxicity associated with a protocol of lomustine (CCNU) and cyclophosphamide (CTX) in dogs with lymphoma. CCNU was administered per os (PO) at a targeted dosage of 60 mg/m2 body surface area on day 0, CTX was administered PO at a targeted dosage of 250 mg/m2 divided over days 0 through 4, and all dogs received prophylactic antibiotics. Ninety treatments were given to the 57 dogs included in the study. Neutropenia was the principal toxic effect, and the overall frequency of grade 4 neutropenia after the first treatment of CCNU/CTX was 30% (95% confidence interval, 19–43%). The mean body weight of dogs with grade 4 neutropenia (19.7 kg ± 13.4 kg) was significantly less than the mean body weight of dogs that did not develop grade 4 neutropenia (31.7 kg ± 12.4 kg; P = .005). One dog (3%) developed hematologic changes suggestive of hepatotoxicity. No dogs had evidence of either renal toxicity or hemorrhagic cystitis. Adverse gastrointestinal effects were uncommon. On the basis of the findings reported herein, a dose of 60 mg/m2 of CCNU combined with 250 mg/m2 of CTX (divided over 5 days) q 4 wk is tolerable in tumor-bearing dogs.

VAC protocol for treatment of dogs with stage III hemangiosarcoma

Hemangiosarcomas (HSAs) are aggressive tumors with a high rate of metastasis. Clinical stage has been considered a negative prognostic factor for survival. The study authors hypothesized that the median survival time (MST) of dogs with metastatic (stage III) HSA treated with a vincristine, doxorubicin, and cyclophosphamide (VAC) chemotherapy protocol would not be different than those with stage I/II HSA. Sixty-seven dogs with HSA in different anatomic locations were evaluated retrospectively. All dogs received the VAC protocol as an adjuvant to surgery (n = 50), neoadjuvant (n = 3), or as the sole treatment modality (n = 14). There was no significant difference (P = 0.97) between the MST of dogs with stage III and stage I/II HSA. For dogs presenting with splenic HSA alone, there was no significant difference between the MST of dogs with stage III and stage I/II disease (P = 0.12). The overall response rate (complete response [CR] and partial response [PR]) was 86%). No unacceptable toxicities were observed. Dogs with stage III HSA treated with the VAC protocol have a similar prognosis to dogs with stage I/II HSA. Dogs with HSA and evidence of metastases at the time of diagnosis should not be denied treatment.

Aggressive local therapy combined with systemic chemotherapy provides long-term control in grade II stage 2 canine mast cell tumour: 21 cases (1999-2012)

This retrospective case series evaluates the outcome of 21 dogs with grade II stage 2 mast cell tumour (MCT) treated with adequate local therapy and adjuvant systemic chemotherapy (prednisone, vinblastine and CCNU). The median survival for all dogs was 1359 days (range, 188-2340). Median disease-free interval was 2120 days (149-2325 days). Dogs treated with surgery and chemotherapy had shorter survival (median, 1103 days; 188-2010 days) than those that underwent surgery, radiation therapy and chemotherapy as part of their treatment (median, 2056 days; 300-2340 days). Two patients had local recurrence in the radiation field and four patients had de novo MCT. Distant metastasis was not observed in any dogs. The results of this study suggest that, in the presence of loco-regional lymph node metastasis in grade II MCT, the use of prednisone, vinblastine and CCNU after adequate local-regional therapy can provide a median survival in excess of 40 months.

Extranodal lymphoma in the cat: prognostic factors and treatment options

PRACTICAL RELEVANCE

The majority of feline lymphoma is extranodal. While the gastrointestinal (GI) tract is the most commonly affected site, non-GI extranodal lymphomas, which are the focus of this review, account for a large proportion of lymphomas in cats. This article discusses prognostic factors for the most common of these extranodal lymphomas, both in general terms and specifically for individual sites.

CLINICAL CHALLENGES

Prognostic factors remain poorly defined for feline lymphoma. Many cats with extranodal lymphoma have stage I disease at an accessible site. A major question for patients with apparently localised extranodal lymphoma is whether the tumour can be treated with localised therapy alone or requires systemic treatment as well. Again there is often no specific information available for a particular site, such as a localised intramuscular lymphoma. Instead, reliance must be placed on careful patient staging, particularly if local therapy alone is planned.

EVIDENCE BASE

Until such time as further studies looking at stage, anatomic site, histological grade and immunophenotype are available to assist treatment decision making for an individual cat with extranodal lymphoma, it seems reasonable to draw inferences from other common extranodal sites for which more specific information exists, such as nasal lymphoma.

Use of epothilone B (patupilone) in refractory lymphoma and advanced solid tumors in dogs

BACKGROUND

The epothilones are microtubule-stabilizing agents with promising antitumor effect in refractory and metastatic tumors in humans. The toxicity profile is considered more favorable than in taxanes. The safety of epothilone B (patupilone) has not been evaluated in tumor-bearing dogs.

OBJECTIVES

To evaluate the inhibition of proliferation in canine tumor cells after patupilone treatment. To assess toxicity profile and maximally tolerated dose of patupilone in dogs with refractory tumors.

ANIMALS

Twenty client-owned dogs with various malignancies.

METHODS

Prospective clinical study. The inhibition of proliferation was assessed with a proliferation assay in vitro in canine hemangiosarcoma and lymphoma cell lines. Dogs received patupilone IV once a week for 2 treatments (= 1 treatment cycle). Dose was escalated with 3 dogs per cohort and 20% increments. Adverse effects were graded according to the VCOG-CTCAE v1.0.

RESULTS

Both canine cell lines were sensitive to patupilone with approximately 50% decrease in proliferative activity at 0.2-1 nM. In vivo, dose-limiting adverse effects occurred at 3.3 mg/m(2); main adverse effects were diarrhea, anorexia, vomiting, and nausea. Neither neutropenia nor peripheral neuropathy was observed. Maximally tolerated dose for 2 patupilone administrations once weekly IV is 2.76 mg/m(2). Three per 11 dogs receiving more than 1 treatment cycle showed partial remission in the short period of observation.

CONCLUSIONS AND CLINICAL IMPORTANCE

Canine tumor cells show inhibition of proliferation to patupilone in vitro. Clinically, a dose of 2.76 mg/m(2) IV is well tolerated in dogs with spontaneously occurring tumors.

Toxicity associated with epirubicin treatments in a large case series of dogs

Epirubicin is a stereoisomer of doxorubicin that is widely used in human oncology. The purpose of this study was to evaluate the toxicity associated with epirubicin administration in dogs. Three hundred and fifteen treatments were administered to 139 dogs. Patients received between one and seven doses. One hundred and sixteen treatments were associated with toxicity in 81 patients (50 episodes of lethargy, 49 of diarrhoea, 42 of vomiting, 40 of anorexia, 2 hypersensitivity reactions and 2 suspected extravasations). Thirty-six (11%) adverse events resulted in hospitalization in 33 (24%) patients, of which 15 were neutropenic and 9 pyrexic. Mean duration of hospitalization was 3.4 days and 33 patients recovered uneventfully. Owners of 11 patients declined further treatment after toxicity occurred. After 25 treatments associated with toxicity, dose reductions reduced toxicity. The use of prophylactic anti-emetics, gastroprotectants and antibiotics did not reduce the frequency of gastrointestinal toxicity.

Supporting the veterinary cancer patient on chemotherapy: neutropenia and gastrointestinal toxicity

The application of effective chemotherapy protocols in companion animals with sensitive tumors may result in return to a good quality of life and extended long-term survival. However, the potential for adding adverse events that impact overall quality of life in veterinary cancer patients is an important consideration. To ensure the experience is a positive one for our clients and patients alike, the practicing veterinary oncologist must ensure clients are appropriately educated as to the type and likelihood of adverse events that may occur in their companions and should plan for appropriate preventative and therapeutic protocols to manage them. Such attention to detail will help guarantee their clients' experience with medical treatment is positive and worthwhile, and will result in improvement in the well-being of their companion.