Electrochemotherapy increases local control after incomplete excision of a recurring penile fibrosarcoma in a stallion

An eleven-year-old stallion was referred for adjuvant treatment of an incompletely excised, recurring penile fibrosarcoma. The horse was bright, alert and responsive with a 15 x 12 cm ulcerated lesion on the ventral side of the penis. The lesion was the tumor bed of an incompletely excised fibrosarcoma. After complete staging procedures, the owner elected to treat the horse with electrochemotherapy (ECT) using cisplatin as chemotherapy agent. Two sessions of ECT were performed at two-week intervals using local cisplatin followed by trains of biphasic electric pulses applied using different electrodes until complete coverage of the area was achieved. The treatment was well tolerated, and the patient is still disease free after 12 months. ECT resulted in improved local control and should be considered among the available adjuvant treatments in equines carrying soft tissue tumors.

Electrochemotherapy as First Line Cancer Treatment: Experiences from Veterinary Medicine in Developing Novel Protocols

Tumor microenvironment is one of the major obstacles to the efficacy of chemotherapy in cancer patients. The abnormal blood flow within the tumor results in uneven drug distribution. Electrochemotherapy (ECT) is a tumor treatment that adopts the systemic or local delivery of anticancer drugs with the application of permeabilizing electric pulses having appropriate amplitude and waveforms. This allows the use of lipophobic drugs that frequently have a narrow therapeutic index maintaining at the same time a reduced patient morbidity and preserving appropriate anticancer efficacy. Its use in humans is addressed to the treatment of cutaneous neoplasms or the palliation of skin tumor metastases, and a standard operating procedure has been devised. On the other hand, in veterinary oncology this approach is gaining popularity, thus becoming a first line treatment for different cancer histotypes, in a variety of clinical conditions due to its high efficacy and low toxicity. This review summarizes the state of the art in veterinary oncology as a preclinical model and reports the new protocols in terms of drugs and therapy combination that have been developed.

A case of advanced second-degree atrioventricular block in a ferret secondary to lymphoma

A female ferret was referred as an emergency for severe respiratory distress symptoms. At presentation, the patient was listlessness, dyspnoeic, and hyper-responsive. The clinical examination evidenced dyspnea with cyanosis, altered cardiac rhythm, and hepatomegaly. Electrocardiography showed an advanced second-degree atrioventricular (AV) block. The liver aspirate was diagnostic for lymphoma. The patient did not respond to supportive therapy and rapidly died. Post-mortem exams confirmed the presence of lymphoma with hepatic involvement. Moreover, a pericardial lymphocytic infiltration and a widespread myocardial nodular localization of lymphoma were evidenced as well. This condition was probably the cause of the cardiac arrhythmia. To the best of our knowledge, ours is the first report of cardiac lymphoma causing heart block in ferrets.

Electroporation Enhances Bleomycin Efficacy in Cats with Periocular Carcinoma and Advanced Squamous Cell Carcinoma of the Head

Background

Advanced carcinoma of the head represents a substantial health problem in cats for local control and overall survival.

Objectives

Evaluate the capability of electrochemotherapy (ECT) to improve bleomycin efficacy in cats with periocular carcinoma and advanced carcinoma of the head.

Animals

Twenty‐one cats with periocular carcinoma (17 squamous cell carcinoma [SCC] and 4 anaplastic carcinoma) and 26 cats with advanced SCC of the head.

Methods

Nonrandomized prospective controlled study. Periocular carcinoma cohorts: 12 cats were treated with bleomycin (15 mg/m²IV) coupled with ECT under anesthesia; 9 cats were treated with bleomycin alone. Advanced head SCC cohorts: 14 cats were treated with bleomycin (15 mg/m²IV) coupled with ECT administered under sedation; 12 control cats were treated with bleomycin alone. ECT treatments (2–8) were performed every other week until complete remission (CR) or tumor progression occurred.

Results

Toxicities were minimal and mostly treated symptomatically. Overall response rate in the ECT treated animals was 89% (21 Complete Response [CR] and 2 Partial Response [PR]) whereas controls had response rate of 33% (4 CR and 3 PR). Median time to progression in ECT group was 30.5 months, whereas in controls it was 3.9 months (P < .0001). Median time to progression for ECT cohorts was 24.2 months for periocular cohort and 20.6 in advanced head SCC cohort, respectively.

Conclusions

Electrochemotherapy is well tolerated for advanced SCC of the head in cats; its use may be considered among loco‐regional strategies for cancer therapy in sensitive body regions such as periocular region.

Inhibition of p85, the non-catalytic subunit of phosphatidylinositol 3-kinase, exerts potent antitumor activity in human breast cancer cells

The phosphoinositide 3-kinases (PI3Ks) are heterodimers consisting of the catalytic subunit p110 and the regulatory subunit p85. The PI3K/Akt pathway is strongly deregulated in breast cancer (BC) representing one of the mechanisms of resistance to therapies. Therefore, the identification of inhibitors of PI3K components represents one of the main goals to produce therapeutic agents. Here, we evaluated the efficacy of a phosphopeptide 1257 (P-1257) that targeting p85 strongly inhibits PI3K activity. We tested the effects of P-1257 administration in vitro and in vivo using BC cells expressing different levels of ErbB-2 and resistant or responsive to Trastuzumab. We demonstrated that inhibition of p85 activity by P-1257 induces cell death and sensitizes JIMT-1 and KPL-4 ErbB-2-overexpressing BC cells to Trastuzumab treatment. It is noteworthy that P-1257 delivery in vivo by electroporation or liposomes significantly inhibits the proliferation of tumor cells engrafted at subcutaneous and visceral sites. Overall, our data indicate that the p85 subunit is a valid target for therapeutic approaches and suggest that the structure of the peptide used in our study could be utilized for the development of novel drugs to apply in combination with therapies that fail to cure BCs with high PI3K activity.

Differential accumulation of BPA in some tissues of offspring of Balb-C mice exposed to different BPA doses

Pregnant adult Balb-C mice were exposed daily to two different doses of Bisphenol A (BPA) by subcutaneous injection beginning on gestational day 1 through the seventh day after delivery. The mothers were sacrificed on postpartum day 21, and the offspring were sacrificed at 3 months of age. Control mice were subjected to the same experimental protocol but received saline injections. The liver, muscles, hindbrain and forebrain of the offspring were dissected and processed using HPLC to assess the level of BPA in the tissues and to determine its dependence on the exposure dose and gender. For comparison, the same tissues were dissected from the mothers and analysed. We report the following results: (1) the level of BPA that accumulated in a given tissue was dependent on the exposure dose; (2) the rank order of BPA accumulation in the various tissues was dependent on the gender of the offspring; (3) the average BPA concentrations in the liver and muscle of the female offspring were higher than in the males; and (4) the average BPA concentration in the central nervous system (i.e., the hindbrain and forebrain) of the male offspring was higher than in the females.

Evaluation of Cisplatin as an electrochemotherapy agent for the treatment of incompletely excised mast cell tumors in dogs

BACKGROUND

Electrochemotherapy (ECT) couples the administration of anticancer drugs with the delivery of electric pulses that increase the drug uptake through the cell membranes, resulting in an improved efficacy.

HYPOTHESIS

To evaluate the tolerability and efficacy of cisplatin (CDDP) as an ECT agent to prevent recurrence of incompletely resected mast cell tumors (MCTs).

ANIMALS

Thirty-seven dogs.

METHODS

Prospective study recruiting dogs with incompletely excised MCTs as confirmed by surgeon and pathology reports. After debulking, the tumor bed and margins were infiltrated with CDDP, and then exposed to trains of biphasic electrical pulses under sedation. Five minutes after the injection of the chemotherapy agent, sequences of 8 biphasic pulses lasting 50 + 50 μs each, were delivered in bursts of 1,300 V/cm for sclerosed and of 800 V/cm for exposed lesions, with caliper or needle array electrodes, respectively. A second session was performed 1 or 2 weeks later based on clinical considerations.

RESULTS

The treatment was well tolerated with minimal adverse effects. Twenty-nine dogs had no evidence of recurrence over the 6-year study period, 6 had tumor recurrence, 1 died of multiple cutaneous MCTs, and 1 died of unrelated causes. The estimated median time to recurrence was 1,200 days. Recurrence was not observed among the long-term (> 1 year) treated dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

ECT with CDDP appears effective in the treatment of incompletely resected MCT in dogs and could be a useful addition to the current options based on its low cost, limited toxicity, and ease of administration.

Biphasic pulses enhance bleomycin efficacy in a spontaneous canine perianal tumors model

Perianal tumors (adenoma and carcinoma of the hepatoid glands) are frequently reported in veterinary literature. They are locally aggressive tumors with a low tendency to metastatic spread. An hormonal ethiology has been identified for the development of perianal adenomas in male dogs, while the carcinomas are free from hormonal influence. Standard treatments include surgery, cryotherapy or, in selected cases, radiation therapy. In this article we describe the outcome of a small cohort of canine patients with perianal tumors treated with bleomycin selectively driven by trains of biphasic pulses (electrochemotherapy). Twelve canine patients, eight with adenoma and four with carcinoma of the perianal glands, entered the study and received two sessions of ECT under sedation. The pets had local injection ofbleomycin at the concentration of 1.5 mg/mg and five minutes after the chemotherapy, trains of 8 biphasic electric pulses lasting 50 + 50 micros each, with 1 ms interpulse intervals, were delivered by means of modified caliper and needle array electrodes or, for difficult districts, through paired needle electrode. The overall response rate was 91% with a 83% of complete response (10/12); one dog had a PR that lasted 12 months and another had progressive disease. Electrochemotherapy appears as a safe and efficacious modality for the treatment of perianal tumors and warrants further investigations.

Cell-cycle molecules in mesothelioma: an overview

Cell cycle progression is mediated by a group of proteins named cyclins that activate a highly conserved family of protein kinases, the cyclin-dependent kinases (CDKs). CDKs are also regulated by related proteins called cdk inhibitors, grouped into two families: the INK4 inhibitors (p16, p15, p19 and p18) and the Cip/Kip inhibitors (p21, p27). Moreover, several tumour suppressor genes (such as Retinoblastoma gene and p53 gene) are implicated in the regulation of the molecular mechanism of cell division. Several studies report the importance of cell cycle regulator proteins in the pathogenesis and the prognosis of mesothelioma. This article will review the most recent data from the literature about the expression and the diagnostic and prognostic significance of cell cycle molecules in mesothelioma.

Electrochemotherapy for localized lymphoma: a preliminary study in companion animals

Non Hogdkin's lymphoma is the commonest malignant neoplasm in humans and in pets. Treatments include systemic chemotherapy eventually combined with radiation therapy. Radiation therapy is also used as single agent for the treatment of localized lymphoma (LSA). Albeit efficacious, this modality is potentially associated with side effects. Purpose of this study was to preliminarily evaluate the feasibility and efficacy of electrochemotherapy (ECT) in companion animals with localized lymphoma. Six patients entered the study and received two sessions of ECT under sedation. The pets had local injection of bleomycin at the concentration of 1.5 mg/mg and five minutes after the chemotherapy, trains of 8 biphasic electric pulses lasting 50 + 50 micros each, with 1 ms interpulse intervals, were delivered by means of modified caliper electrodes or for difficult districts, through paired needle electrode. All the patients achieved complete responses (lasting 1 week through 3 years), one cat with nasal LSA had local recurrence and two others experienced spinal and intestinal relapse. Side effects were not noted with the exception of focal alopecia in a cat with retrobulbar LSA. Electrochemotherapy appears as a safe and efficacious modality for the treatment of localized lymphoma and warrants further investigations.

Lomustine for the treatment of gastrointestinal mast cell tumour in a dog

An eight-year-old, male boxer dog was referred for the treatment of a large (5.5 x 5 cm), unresectable visceral mast cell tumour. The dog had a surgical resection performed one month before referral, and it had widespread metastases to the abdominal lymph nodes. The patient was treated with lomustine and prednisone and showed a rapid improvement and increased level of activity, weight gain and consistent tumour reduction. The patient remained in partial remission (defined as a greater than 50 per cent reduction in tumour volume) for seven months. Toxicity was acceptable and was limited to moderate anaemia and two episodes of neutropenia. At the completion of the seven months of therapy, the dog experienced a chemotherapy-induced sepsis, and the owners elected for euthanasia due to financial concerns. At that time, the tumour was still in partial remission. This case report suggests that a combination of lomustine and prednisone is an effective protocol for the palliation of aggressive visceral mast cell tumours.

Oncology of companion animals as a model for humans. an overview of tumor histotypes

The need for more appropriate animal models in cancer research has led, over the past 20 years, to consider pets with spontaneously occurring neoplasms as a valuable and still under used resource. The role of companion animals in the struggle to eradicate cancer can be multiple: they may act as environmental sentinels, help in gaining insights on tumor biology and finally may be enrolled in therapeutic trials which might act as a bridge to the clinic applications. This paper will focus on the most valuable spontaneous neoplasms in companion animals and will analyze the potentials of each histotype as a model for basic research and for new therapeutic strategies. It is conceivable that in the next years comparative oncology will play a paramount role in translational medicine allowing a rapid flow of data from laboratories to clinical application in humans.

Cox and mesothelioma: an overview

Cyclooxygenases catalyze the rate limiting step in the production of prostanoids. Accumulating data demonstrate that overexpression of these enzymes, and in particular of cyclooxygenases-2, promotes multiple events involved in tumorigenesis; in addition, numerous studies show that inhibition of cyclooxygenases-2 can delay or prevent certain forms of cancer. Malignant mesothelioma is a lethal pleural, peritoneal and pericardial neoplasia that actually lacks valid therapies and in which cyclooxygenases-2 is recognized as an important adverse prognostic factor. Hence, there is an increasing interest in the development of new treatments based on cyclooxygenases-2 inhibitors, to prolong survival and even potentially cure this neoplasia.

COX-2 overexpression in canine tumors: potential therapeutic targets in oncology

Cyclooxygenases catalyze the initial, rate-limiting steps of prostaglandin synthesis from arachidonic acid. Two isoforms of this enzyme exist in mammalian and avian species: COX-1 and COX-2. COX-1 is constitutively expressed and is the major isoform of gastrointestinal tissue. COX-2 is induced in response to inflammatory stimuli. COX-2 has been implicated in carcinogenesis of several neoplasms. Furthermore, COX-2 over-expression has been noted in many solid tumours and has been correlated with a worse prognosis in colorectal cancer, non-small-cell lung cancer, mesothelioma and gastric cancer. In this review, the most recent findings on the mechanisms by which COX-2 promote tumorigenesis are discussed, with particular emphasis on the studies involving spontaneous canine neoplasms.

Rational design of new electrodes for electrochemotherapy

Electrochemotherapy associates the local delivery of anticancer drugs with the administration of permeabilizing electric pulses that support the antiblastic action. The basic instrumentation for this therapy is constituted by a pulse generator and various specific electrodes. While many efforts have been profuse by researchers in this field to obtain the standardization of the pulse generating equipment over the past 15 years, the delivery apparatus still needs refinements in order to reach most of the body districts, to control the homogeneity and stability of the electric fields and to further reduce morbidity. With the aim to develop innovative electrodes able to satisfy, at least partially, these requirements, extensive studies on pet patients with spontaneous neoplasms have been conducted, leading to the manufacturing of several different prototypes. In this paper we discuss the rationale of 11 different electrodes, briefly summarize the results obtained and their experimental validation, also presenting five paradigmatic clinical cases. In particular, it is shown that the caliper electrodes are more suited for the treatment of cutaneous and subcutaneous lesions, while the needle arrays are more efficacious in intraoperative settings. Furthermore, relevant peculiarities of unipolar electrodes are examined with a particular focus on the irregular current paths that they produce and on the potentialities of this feature. Remarkably, the decrease of the steric encumbrance turned out to be a stronger factor in electrode design than the containment of the total number of electric fields covered in serial ECT sessions. In the conclusions, perspectives and new challenges of electrode design for electrochemotherapy are illustrated.

Pet models in cancer research: general principles

Oncology has made great advancements in the past 50 years, moving from preliminary to complex studies and developing in the process numerous models. An important function in this development has been played by animal investigations that have displayed many aspects of cancer and led to the discovery of new therapies. Nevertheless, the debate about preclinical "tools" suited to predict efficacy as well as side effects of anticancer compounds and treatments is open. In this review we focus on the role of pet models in cancer research, whose continuously increasing importance is due to the disclosure of striking histopathological, anatomical, genetical, and biomolecular similarities among feline, canine, and human tumors. Remarkably, the improvement of clinical condition of companion animals, obtained by their enrolment in cancer trials, is generally perceived as an added value for the whole society. In the first paragraphs we examine crucial ethical, clinical, and financial issues that make up the framework of this area of translational research. Then we illustrate the new figures of researchers, namely experts in laboratory-clinic interface, who are needed in this field, and describe the relevant potentialities of pet cancer registries and genome projects. In the conclusions are summarized the principal arguments that support the adoption of pet models in tumor studies.

Potentiation of chemotherapy in companion animals with spontaneous large neoplasms by application of biphasic electric pulses

The objectives of this phase I/II study were: i) to determine whether electrochemotherapy (intralesional bleomycin + electric pulses) could be effective in companion animals with different, large neoplasms compared to chemotherapy (conventional intralesional bleomycin); ii) to identify potential toxicities; iii) to preliminarily assess the electric field requirements. Twenty-two patients received intralesional bleomycin + administration of permeabilizing electric pulses. Specifically, after the injection of the drug, sequences of 8 biphasic electric pulses lasting 50 + 50 micros each, with 1 ms interpulse intervals, were delivered in bursts of 1300 V/cm for cutaneous and soft tissue lesions, and of 800 V/cm for oral mucosal and exposed soft tissue neoplasms, using caliper electrodes. The treatment was well tolerated and side effects were infrequent. Nevertheless, two previously unreported toxicities (drug-induced vasculitis and pulmonary thromboembolism) have been identified. A high response rate (complete remission + partial remission: > 80%), often long lasting (> 40%) was obtained. Furthermore, results of this trial were compared to a subset of veterinary cancer patients treated with bleomycin single agent, observing a remarkable superiority of the combined treatment (p < 0.01). Altogether, results suggest that electrochemotherapy is a potentially advantageous rescue protocol for bulky, even relapsing neoplasms of companion animals. Further investigations in this field might allow developing improved protocols for the treatment of down-staged relapsing cancer in pets as well as in humans.

Extraskeletal osteosarcoma in a cat

A 7-year-old spayed female domestic shorthair cat was referred for evaluation of a localized growing mass on the left flank. Cytologic and histologic findings suggested that the mass was an extraskeletal osteosarcoma. Radiography failed to reveal any association between the lesion and the axial or appendicular skeleton. Because of the large size of the tumor, the cat was treated with carboplatin prior to and after surgery (hemipelvectomy) to ensure that surgical margins were free of neoplastic cells and to prevent systemic dissemination of malignant cells. The tumor has not recurred during a 2-year follow-up period.

Primary irradiation of canine intracranial masses

Twenty-nine dogs received primary radiation therapy for intracranial lesions and clinical signs suggestive of neoplasia. Presumptive diagnosis and tumor categorization was based on computed tomographic or magnetic resonance images. Meningioma was the most likely tumor type in 22 dogs and glioma or choroid plexus tumors were tentatively identified in 4 and 3 dogs, respectively. Cobalt-60 radiation was delivered in 3 Gy fractions on a daily, Monday-through-Friday basis for a total dose of 48 Gy (16 fractions) in 28 dogs; one dog received 54 Gy. Two of 29 dogs died during treatment of signs suggestive of progressive tumor growth but were included in the overall evaluation of response to treatment. Median overall survival was 250 days (range 21-804). Mild acute radiation effects on normal tissue developed and did not influence outcome in any dog. Late radiation effects could not be evaluated in this study. No significant predictive indicators were identified from the clinical or imaging data. Radiation therapy is superior to medical treatment of brain tumors in dogs with steroids, is useful for tumors that are not currently operable and may be preferable to surgical resection in dogs if the mass appears infiltrative. However, 22/29 (76%) dogs died of recurrent progressive neuropathy suggestive of tumor regrowth or progression. Thus, alternative methods for delivery of radiation to dogs with brain tumors or novel combinations of therapy should continue to undergo evaluation.

Seminoma with cutaneous metastases in a dog

A 10-year-old Great Pyrenees was presented for anorexia and weight loss. On physical examination, the dog was emaciated and showed a large ulcerated lesion on the right lower lip in addition to an enlarged right testicle. Fine-needle aspiration biopsy of the testicle and surgical biopsy of the lip lesion were performed; the histopathological report was consistent with metastatic seminoma. The diagnostic and therapeutic approach in this unusual metastatic seminoma is presented and compared to the previous literature. A multimodality therapy consisting of surgery and chemotherapy is proposed for the clinical management of metastatic seminoma in dogs.