Effect of surgical site infection on survival after limb amputation in the curative‐intent treatment of canine appendicular osteosarcoma: a Veterinary Society of Surgical Oncology retrospective study

Combination of CT-Guided Microwave Ablation and Cementoplasty as a Minimally Invasive Limb-Sparing Approach in a Dog with Appendicular Osteosarcoma

Image-guided microwave ablation and cementoplasty are minimally invasive techniques that have been used as part of a limb-sparing approach in the treatment of appendicular bone tumors in humans. The objective of this case report was to describe the feasibility and result of microwave ablation (MWA) and cementoplasty in a dog with stage-1 osteoblastic appendicular osteosarcoma of the right distal radius. A microwave antenna was inserted in the osteolytic area using computed tomography (CT) guidance. Three ablation cycles of 5 min at 60 watts were performed. Immediately after the MWA procedure, a tricalcium phosphate-based cement was injected through the bone trocar to consolidate the ablated zone. Adjuvant chemotherapy with six sessions of carboplatin was performed, without major complication. Response to the treatment was evaluated according to RECIST criteria every 6 weeks. Twenty-four hours after MWA, the dog was pain-free and had excellent mobility. Based on CT measurements, a reduction of the size of the lytic area was observed at the 2-month and at the 7-month follow-up (from 13% to 25% of the longest diameter), classified as stable disease according to RECIST criteria. The dog died 18 months after the initial diagnosis due to distant metastases.

Tumor-associated macrophages: Prognostic and therapeutic targets for cancer in humans and dogs

Macrophages are ancient, phagocytic immune cells thought to have their origins 500 million years ago in metazoan phylogeny. The understanding of macrophages has evolved to encompass their foundational roles in development, homeostasis, tissue repair, inflammation, and immunity. Notably, macrophages display high plasticity in response to environmental cues, capable of a strikingly wide variety of dynamic gene signatures and phenotypes. Macrophages are also involved in many pathological states including neural disease, asthma, liver disease, heart disease, cancer, and others. In cancer, most tumor-associated immune cells are macrophages, coined tumor-associated macrophages (TAMs). While some TAMs can display anti-tumor properties such as phagocytizing tumor cells and orchestrating an immune response, most macrophages in the tumor microenvironment are immunosuppressive and pro-tumorigenic. Macrophages have been implicated in all stages of cancer. Therefore, interest in manipulating macrophages as a therapeutic strategy against cancer developed as early as the 1970s. Companion dogs are a strong comparative immuno-oncology model for people due to documented similarities in the immune system and spontaneous cancers between the species. Data from clinical trials in humans and dogs can be leveraged to further scientific advancements that benefit both species. This review aims to provide a summary of the current state of knowledge on macrophages in general, and an in-depth review of macrophages as a therapeutic strategy against cancer in humans and companion dogs.

Incidence of and risk factors for surgical site infection following canine limb amputation

OBJECTIVE

To determine the incidence of and risk factors for surgical site infection (SSI) following canine thoracic and pelvic limb amputations.

STUDY DESIGN

Retrospective, multicenter study.

ANIMALS

Dogs (n = 248).

METHODS

Medical records were reviewed for preoperative, intraoperative, and postoperative variables including indication for amputation, amputation type, method of muscle transection, duration of surgery and anesthesia, and wound classification. Follow up was ≥30 days or until SSI development. Logistic regression and Fisher's exact tests were used to compare SSI incidence to variables of interest.

RESULTS

The incidence of SSI was 12.5% for all procedures and 10.9% for clean procedures. Factors increasing odds of SSI were muscle transection with a bipolar vessel sealing device (P = .023 for all procedures, P = .025 for clean procedures), procedure classified as other than clean (P = .003), and indication for amputation of bacterial infection (P = .041) or traumatic injury (P = .003) compared to neoplasia.

CONCLUSION

Use of bipolar vessel sealing devices for muscle transection increased the odds of developing an SSI whereas use of electrosurgery and/or sharp transection did not. Dogs with surgical sites that were other than clean, or with bacterial infection and/or traumatic injury were also at increased odds of SSI.

CLINICAL SIGNIFICANCE

Use of electrosurgery or sharp transection for muscle transection should be considered rather than use of bipolar vessel sealing devices to decrease odds of SSI in dogs undergoing limb amputation. Further studies across a variety of procedures are needed to validate these findings given the increasing popularity of these devices in veterinary medicine.

Recent Advances in the Discovery of Biomarkers for Canine Osteosarcoma

Canine osteosarcoma (OSA) is an aggressive malignancy that frequently metastasizes to the lung and bone. Not only has there been essentially no improvement in therapeutic outcome over the past 3 decades, but there is also a lack of reliable biomarkers in clinical practice. This makes it difficult to discriminate which patients will most benefit from the standard treatment of amputation and adjuvant chemotherapy. The development of reliable diagnostic biomarkers could aid in the clinical diagnosis of primary OSA and metastasis; while prognostic, and predictive biomarkers could allow clinicians to stratify patients to predict response to treatment and outcome. This review summarizes biomarkers that have been explored in canine OSA to date. The focus is on molecular biomarkers identified in tumor samples as well as emerging biomarkers that have been identified in blood-based (liquid) biopsies, including circulating tumor cells, microRNAs, and extracellular vesicles. Lastly, we propose future directions in biomarker research to ensure they can be incorporated into a clinical setting.

Timing of adjuvant chemotherapy after limb amputation and effect on outcome in dogs with appendicular osteosarcoma without distant metastases

OBJECTIVE

To determine an optimal time interval between amputation and initiation of adjuvant chemotherapy (TI_amp-chemo) in dogs with appendicular osteosarcoma without distant metastases and whether TI_amp-chemo was associated with outcome.

ANIMALS

168 client-owned dogs treated at 9 veterinary oncology centers.

PROCEDURES

Data were collected from the dogs' medical records concerning potential prognostic variables and outcomes. Dogs were grouped as to whether they received chemotherapy within 3, 5, 7, 10, 15, 20, 30, or > 30 days after amputation of the affected limb. Analyses were performed to identify variables associated with time to tumor progression and survival time after limb amputation and to determine an optimal TI_amp-chemo.

RESULTS

Median TI_amp-chemo was 14 days (range, 1 to 210 days). Median time to tumor progression for dogs with a TI_amp-chemo ≤ 5 days (375 days; 95% CI, 162 to 588 days) was significantly longer than that for dogs with a TI_amp-chemo > 5 days (202 days; 95% CI, 146 to 257 days). Median overall survival time for dogs with a TI_amp-chemo ≤ 5 days (445 days; 95% CI, 345 to 545 days) was significantly longer than that for dogs with a TI_amp-chemo > 5 days (239 days; 95% CI, 186 to 291 days).

CONCLUSIONS AND CLINICAL RELEVANCE

Findings indicated that early (within 5 days) initiation of adjuvant chemotherapy after limb amputation was associated with a significant and clinically relevant survival benefit for dogs with appendicular osteosarcoma without distant metastases. These results suggested that the timing of chemotherapy may be an important prognostic variable.

Effectiveness of electroacupuncture for pain after osteosarcoma post surgery: A study protocol of systematic review of randomized controlled trial

BACKGROUND

This study will assess the effectiveness of electroacupuncture (EA) for pain in patients with osteosarcoma post surgery (OSPS).

METHODS

In this study, we will comprehensively search the following electronic databases from inception to the present without language restrictions: Cochrane Library, EMBASE, MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, the Allied and Complementary Medicine Database, and Chinese Biomedical Literature Database. Two authors will independently carry out study selection, data extraction, and methodological assessments. RevMan 5.3 software will be used for statistical analysis.

RESULTS

The primary outcome is pain intensity. The secondary outcomes consist of event-free survival, overall survival, quality of life, and adverse events.

CONCLUSION

The findings of this study will provide helpful evidence of EA treatment for patients with OSPS.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42019146696.

Analysis of outcome in dogs that undergo secondary amputation as an end-point for managing complications related to limb salvage surgery for treatment of appendicular osteosarcoma

Appendicular osteosarcoma (OSA) remains a prevalent musculoskeletal cancer in dogs and definitive local control followed by adjuvant cytotoxic chemotherapy is considered the gold standard approach. Several studies support surgical limb salvage as a means of local control with similar outcomes compared with limb amputation. Complications are well described for limb salvage but little is known of dogs that undergo secondary amputation as a result of complications and outcomes specific to this group. A retrospective analysis of dogs in an institutional primary bone tumour registry was performed to identify dogs diagnosed with histologically confirmed OSA treated with surgical limb salvage with a technique that required an implant to reconstruct the osseous defect. A total of 192 dogs were identified with 31 dogs undergoing secondary amputation representing a limb preservation rate of 84%. A total of 111 dogs were analysed: 31 secondary amputation cases and 80 controls were selected for comparison. The most common reasons for secondary amputation were local recurrence (LR) and surgical site infection (SSI), with odds ratios of 3.6 and 1.7, respectively. Dogs that underwent secondary amputation had a significantly (P = .05) longer median disease specific survival time (ST) (604 days) compared with the control group (385 days). Dogs lived for a median of 205 days beyond secondary amputation and 97% had good functional outcome. Significant independent factors that positively influenced ST were secondary amputation, moderate SSI, severe SSI and age.