Injection Site Sarcomas Research Articles

INFLUENCE OF DIFFERENT CELL STORAGE/CULTURE CONDITIONS ON SPONTANEOUS PROLIFERATION AND LEVEL OF TYROSINE KINASE RECEPTOR INHIBITION IN TWO FELINE INJECTION-SITE SARCOMA CELL LINES

Optimizing cell culture conditions is important when studying cell proliferation and viability, particularly in response to cytotoxic compounds. Altered cell storage conditions can adversely impact proliferation and viability in mortal cell lines. However, little is known regarding the effects on immortal feline cell lines. In the present study, two feline injection-site sarcoma (ISS) cell lines were evaluated under standard culture conditions and three alternative storage/culture conditions for spontaneous proliferation rate and sensitivity to masitinib, a highly selective tyrosine kinase inhibitor with activity against primary and metastatic ISS cell lines. Cell viability was assessed by 7-aminoactinomycin D and cytology. Spontaneous proliferation did not significantly differ across the FBS concentrations (10% vs. 1%) for one cell line, however, with the other cell line spontaneous proliferation was significantly decreased in the 1% FBS 1-step technique, and the cold step technique at both 1% and 10% FBS. When normalized to untreated control cells, the IC50 values for masitinib were comparable across all culture techniques. Furthermore, apoptosis appeared to be the primary mechanism of this proliferation inhibition. Our preliminary findings suggest that select feline sarcoma cell lines cultured in 10% FBS yield comparable cytotoxicity data even when subjected to varying storage/culture conditions.

CLINICAL AND LOW‐FIELD MRI CHARACTERISTICS OF INJECTION SITE SARCOMA IN 19 CATS

Magnetic resonance imaging (MRI) has been recommended for staging and surgical planning in cats with injection site sarcomas (ISS). The purpose of this retrospective study was to describe low-field MRI characteristics of confirmed injection site sarcomas in a group of cats. Low-field MR images, thoracic radiographs, histopathology findings, and medical records of cats that fulfilled histological criteria of injection site sarcoma were retrieved and reviewed retrospectively. Presence or absence of tumor mineralization and pulmonary metastases were recorded from thoracic radiographs. Characteristics recorded from low-field MRI studies included tumor number, volume (ellipsoid method), intensity relative to surrounding musculature, homogeneity, regions of signal void (mineralization) or cavitation, degree and pattern of contrast enhancement, tumor margination, presence of a peripheral T2W hyperintense zone, and bone contact. A total of 19 cats met inclusion criteria. Cats with multiple tumors were more likely to have had previous excisional biopsy, and were less likely to undergo definitive surgery. All tumors were hyperintense relative to surrounding musculature on T1W and T2W images. Larger tumors were more likely to exhibit mineralization (P < 0.05). Tumor volume could not predict tumor-free margins at definitive surgery. The majority of tumors showed moderate to marked heterogeneous contrast enhancement. Infiltrative margins and the presence of a peripheral T2W hyperintense zone were more prevalent following excisional biopsy, while cavitation was more prevalent following incisional biopsy. Findings indicated that low-field MRI characteristics of injection site sarcoma may vary widely and may be affected by prior incisional or excisional biopsy.

Changes in γ-H2AX expression in irradiated feline sarcoma cells: An indicator of double strand DNA breaks

Feline injection site sarcoma (ISS) is a highly invasive soft tissue tumor that is commonly treated with radiation. Cellular deoxyribonucleic acid (DNA) is the principal target for the biologic effects of radiation with cell killing correlating to the number of double stranded DNA breaks (DSBs). The objective of this study was to determine if radiation-induced damage to feline ISS cells could be detected using a commercially available DNA DSB detection kit. Feline ISS cells were irradiated and evaluated for extent of DSB induction with a γ-H2AX chemiluminescent kit; results were validated by Western Blot analysis. Irradiated cells showed a significant increase in double strand break induction compared to control cells, which was supported by Western Blot. DNA damage in feline sarcoma cells following single exposure of radiation can be indirectly detected using a commercially available mouse anti-human monoclonal antibody for γ-H2AX.

Computed tomography characteristics of fibrosarcoma -- a histological subtype of feline injection-site sarcoma.

Feline injection-site sarcoma (FISS) may be a consequence of subcutaneous injection. In the present study, the medical records and the computed tomography (CT) features of 22 cats with a FISS, histopathological subtype fibrosarcoma, were used. The majority of the fibrosarcomas (45%) were located in the interscapular region. All fibrosarcomas, except one with mild enhancement, showed strong contrast uptake, characterised as ring (42%), heterogeneous (36%), homogeneous (9%), heterogeneous/ring (6.5%) or mixed heterogeneous/homogeneous enhancement (6.5%). The longest axis of the mass was in a cranio-caudal (68%) or dorso-ventral (32%) direction. The median volume calculated on CT was 7.57 cm(3). Common features were a marked local invasiveness of the musculature and heterogeneity of the tissue in the periphery of the neoplasia. When the fibrosarcoma was interscapular, performing an additional post-contrast scan with the forelimbs positioned caudally along the body, in addition to the standard protocol with the forelimbs extended cranially, allowed better evaluation of the actual relationship between the tumour and the surrounding tissues. The mean number of muscles involved with the tumour was 2.09 with extended and 1.95 with flexed forelimbs. When a lower number of structures was considered infiltrated through the double positioning, a less invasive surgical approach to underlying muscles and scapula was performed.

The incidence of feline injection site sarcomas in the United Kingdom

BackgroundFeline injection site sarcomas (FISS) are aggressive neoplasms that have been associated with vaccination. In North America the incidence estimates have varied from 1 case of FISS per 1,000-10,000 cats vaccinated. The aim of this study was to estimate the incidence of FISS in the United Kingdom (UK) in 2007. The ratio of FISS to vaccines sold in the UK was also estimated.Fourteen FISS were diagnosed by a convenience sample of 34 small animal veterinary practices in the United Kingdom in 2007 and were used as the numerator for the incidence estimates. Denominator data was obtained from the computer systems of each practice. Considering that a single cause relationship with vaccination is not proven, three different denominators (number of cats registered, the number of cat consultations undertaken and the number of vaccination visits for cats at the practices) were used to express the potential variation in risk.ResultsThe incidence risk of FISS per year was estimated to be 1/16,000 -50,000 cats registered by practices, 1/10,000-20,000 cat consultations and 1/5,000-12,500 vaccination visits.ConclusionWhen interpreting these findings, it needs to be taken into consideration that this sample of practices and their cats may not be representative of veterinary practices and cats at risk of FISS in the UK. However it can still be concluded with reasonable certainty that the incidence of FISS in the UK is very low.

Comparative vaccine-specific and other injectable-specific risks of injection-site sarcomas in cats

To compare associations between vaccine types and other injectable drugs with development of injection-site sarcomas in cats. Case-control study. 181 cats with soft tissue sarcomas (cases), 96 cats with tumors at non-vaccine regions (control group I), and 159 cats with basal cell tumors (control group II). Subjects were prospectively obtained from a large pathology database. Demographic, sarcoma location, basal cell tumor, and vaccine and other injectable history data were documented by use of a questionnaire and used to define case, control, and exposure status. Three control groups were included: cats with sarcomas at non-vaccine sites, cats with basal cell tumors, and a combined group of cats with sarcomas at non-vaccine sites and cats with basal cell tumors. χ(2) tests, marginal homogeneity tests, and exact logistic regression were performed. In the broad interscapular region, the frequency of administration of long-acting corticosteroid injections (dexamethasone, methylprednisolone, and triamcinolone) was significantly higher in cases than in controls. In the broad rear limb region, case cats were significantly less likely to have received recombinant vaccines than inactivated vaccines; ORs from logistic regression analyses equaled 0.1, with 95% confidence intervals ranging from 0 to 0.4 and 0 to 0.7, depending on control group and time period of exposure used. This case-control study measuring temporal and spatial exposures efficiently detected associations between administrations of various types of vaccines (recombinant vs inactivated rabies) and other injectable products (ie, long-acting corticosteroids) with sarcoma development without the need to directly measure incidence. These findings nevertheless also indicated that no vaccines were risk free. The study is informative in allowing practitioners to weigh the relative merits and risks of commonly used pharmaceutical products.

Lack of association between p53SNPand FISSin a cat population from Germany

One recent study indicates a significant association between certain single nucleotide polymorphisms (SNPs) in the genomic sequence of feline p53 and feline injection-site sarcoma (FISS). The aim of this study was to investigate the correlation between a specific nucleotide insertion in p53 gene and FISS in a German cat population. Blood samples from 150 German cats were allocated to a control group consisting of 100 healthy cats and a FISS-group consisting of 50 cats with FISS. All blood samples were examined for the presence of the SNP in the p53 gene. Results found the T-insertion at SNP 3 in 20.0% of the cats in the FISS-group and 19.2% of cats in the control-group. No statistically significant difference was observed in allelic distribution between the two groups. Further investigations are necessary to determine the association of SNPs in the feline p53 gene and the occurrence of FISS.

Suspected adverse events, 2011

Increase in injection site reactions after vaccination in horsesDecrease in injection site sarcomas in catsIncrease in human adverse reaction reportsThese are some of the results from the Suspected Adverse Reaction...

Feline vaccination practices and protocols used by veterinarians in the United Kingdom

Vaccination is an important aspect of disease control in the feline population, as it prevents disease or reduces its severity in individual cats. However the types of antigens that should be administered to cats, the frequency of administration of certain antigens and the anatomical location at which vaccines should be administered are controversial. Various groups have developed guidelines to help veterinarians decide vaccine protocols for cats in their care. The aim of this study was to survey veterinarians in the United Kingdom about the vaccination protocols used in 2007-2008. A questionnaire about aspects of feline vaccination was distributed to a 431 veterinary practices taking part in a case-control study of feline injection site sarcomas. A response rate of 72% was achieved. The majority of veterinarians who responded administered the commonly used antigens annually (84-96% of practices). Most of the veterinarians administered most vaccines in the interscapular region (90-96% of practices depending on the antigen). The vaccination practices of the veterinarians were not consistent with the published vaccination guidelines at that time.

Musculoskeletal neoplasia: an important differential for lumps or lameness in the cat.

Musculoskeletal neoplasia is an uncommon but Important differential diagnosis for cats presenting with lameness, pain or swellings associated with bones and/or soft tissues. The most common tumours of soft tissue origin are the sarcomas (in particular feline injection site sarcomas [FISSs]); the most common bone tumour of the cat is osteosarcoma (OSA). FISSs present a clinical challenge in terms of their local invasiveness, difficulty in obtaining complete surgical excision and high risk of local recurrence. Axial and extraskeletal OSAs pose similar challenges, whereas appendicular OSA is usually easy to remove via limb amputation and can, therefore, carry a good prognosis in many cases. Cats of any age, gender or breed may be affected, although bone tumours predominantly affect middle- to old-aged cats. Vaccination of cats is of global importance in preventing feline diseases; hence, any possible significant consequences of vaccination such as neoplasia, even of a low incidence, are of huge concern to cat owners and veterinarians alike. This review is based on current literature relating to pathogenesis, pathology, presentation, diagnosis, staging, treatment and prognosis. It aims to summarise feline musculoskeletal neoplasia for clinicians in general practice.

P53 Gene Alterations and Outcome in Feline Injection Site Sarcomas

P53 Gene Alterations and Outcome in Feline Injection Site Sarcomas

Development of an injection site sarcoma shortly after meloxicam injection in an unvaccinated cat

A single dose of a rapidly-absorbed non-steroidal anti-inflammatory drug (NSAID) was injected into the subcutaneous tissue of the interscapular region of a 12.5-year-old cat. A mild swelling was noticed at the injection site 6 weeks later. This progressed into a 5 cm diameter mass which was removed 6 months after the injection had been given. An injection site sarcoma (ISS) was diagnosed histologically. As the cat had not been vaccinated for at least 12 years, the previous NSAID injection was considered to be a possible cause of the ISS. Inflammation is thought to be important in the development of ISS. If injection of a rapidly-absorbed NSAID can stimulate sufficient inflammation to promote the development of an ISS, other non-vaccine injections may also have the potential to influence ISS development. This suggests that injection of both vaccines and non-vaccine medications should be minimised to reduce the risk of ISS development.

Masitinib demonstrates anti‐proliferative and pro‐apoptotic activity in primary and metastatic feline injection‐site sarcoma cells*

Dysregulation of platelet-derived growth factor receptor (PDGFR) may play a role in feline injection-site sarcoma (ISS) cell growth and viability. Masitinib, a tyrosine kinase inhibitor approved for treatment of canine mast cell tumours, is highly selective for the PDGFR signalling pathway and may offer a new therapeutic approach for this disease. The in vitro effects of masitinib on growth, apoptosis and PDGFR signalling in two novel ISS cell lines were investigated. PDGFR expression was confirmed by Western blot in cell lines derived from a primary ISS tumour (JB) and a corresponding, histologically confirmed ISS lung metastasis (JBLM). Masitinib inhibited cell growth and PDGFR phosphorylation in both cell lines. Higher drug concentrations were required to inhibit growth than to modulate ligand-induced autophosphorylation of PDGFR. These in vitro data suggest that masitinib displays activity against both primary and metastatic ISS cell line and may aid in the clinical management of ISS.

Radical excision with five-centimeter margins for treatment of feline injection-site sarcomas: 91 cases (1998–2002)

To evaluate outcomes of radical excision of feline injection-site sarcomas (ISS) via assessment of local recurrence and metastasis rates, survival times, and complications associated with surgery. Retrospective case series. 91 cats with ISS. Medical records of cats that had radical excision of ISS without adjunctive treatment were reviewed. Information extracted included sex, type of surgical procedure, histologic tumor grade, tumor diameter, time from tumor detection to definitive surgery, complications associated with surgery, whether tumors recurred locally or metastasized, and survival times. Diagnosis of ISS was histologically confirmed, and additional follow-up was performed. Overall median survival time was 901 days. Thirteen of 91 (14%) cats had local tumor recurrence; 18 (20%) cats had evidence of metastasis after surgery. Median survival time of cats with and without recurrence was 499 and 1,461 days, respectively. Median survival time of cats with and without metastasis was 388 and 1,528 days, respectively. Tumor recurrence and metastasis were significantly associated with survival time, whereas other examined variables were not. Major complications occurred in 10 cats, including 7 with incisional dehiscence. Radical excision of ISS resulted in a metastasis rate similar to rates reported previously; the local recurrence rate appeared to be substantially less than rates reported after less aggressive surgeries, with or without adjuvant treatment. Major complication rates were similar to rates reported previously after aggressive surgical resection of ISS. Radical excision may be a valuable means of attaining an improved outcome in the treatment of feline ISS.

Selected Case From the Arkadi M. Rywlin International Pathology Slide Seminar

A high-grade angiosarcoma with epithelioid features located in the buttock of an 87-year-old woman arose in an area of old, palpable fat necrosis at the site of several subcutaneous injections administered 20 years previously. The nature of the injected material is unknown, but is presumed to have been an iron compound. Two weeks before surgery, the buttock lesion started to enlarge and was excised. It consisted of 3 contiguous nodules of old, calcified fat necrosis associated with plentiful hemosiderin. One of the nodules was largely replaced by an angiosarcoma, which was invading the edges of the other 2 nodules. The patient died from wound sepsis 41 days postoperatively, with no clinically apparent metastases. Vaccination injection-site sarcomas are well known to occur in cats, whereas in humans, rare sarcomas associated with prostheses and foreign materials have been reported; however, human injection-site sarcomas are vanishingly rare. The Club members agreed with the diagnosis of angiosarcoma at an injection site, with the majority calling it an epithelioid angiosarcoma. Many accepted that the injected material was probably iron, but one cautioned about regarding the injections as the cause of the angiosarcoma.

Origins of injection-site sarcomas in cats: the possible role of chronic inflammation-a review.

The etiology of feline injection-site sarcomas remains obscure. Sarcomas and other tumors are known to be associated with viral infections in humans and other animals, including cats. However, the available evidence suggests that this is not the case with feline injection-site sarcomas. These tumors have more in common with sarcomas noted in experimental studies with laboratory animals where foreign materials such as glass, plastics, and metal are the causal agent. Tumors arising with these agents are associated with chronic inflammation at the injection or implantation sites. Similar tumors have been observed, albeit infrequently, at microchip implantation sites, and these also are associated with chronic inflammation. It is suggested that injection-site sarcomas in cats may arise at the administration site as a result of chronic inflammation, possibly provoked by adjuvant materials, with subsequent DNA damage, cellular transformation, and clonal expansion. However, more fundamental research is required to elucidate the mechanisms involved.

Reporting of injection‐site sarcomas in cats

THE recent Suspected Adverse Reaction Surveillance Scheme report for 2009 ( VR , July 24, 2010, vol 167, [pp 118-121][1]) records 40 reports of injection-site sarcomas in cats, compared with 42 reports in 2008. We are surprised at these numbers because, in our own database for the 18 months since

Changes in characteristics of feline injection-site sarcomas

Changes in characteristics of feline injection-site sarcomas

Feline injection-site sarcoma: Past, present and future perspectives

Feline injection-site sarcomas (FISS) have been known since the early 1990s. After an initial correlation with rabies and feline leukaemia virus vaccination, subsequent studies have demonstrated that an abnormal reaction of feline tissues to chronic inflammation was mainly responsible for the disease. The low incidence of FISS in the population is explained by its multifactorial aetiology, since individual genetic characteristics are also implicated. FISS is an infiltrative tumour with low metastatic potential but local recurrence is common. Multimodal treatment (extensive surgery, radiotherapy, chemotherapy) is recommended. The use of sophisticated imaging techniques can improve diagnosis and help in surgical planning. After the initial enthusiasm in understanding the disease, only few advances have been made in the last few years. New promising therapies may arise from a better knowledge of the molecular pathogenesis of FISS and the successful development of drugs modulating the immune system.

Proteasomes are not a Target for Doxorubicin in Feline Injection-Site Sarcoma

The potent anti-cancer agent doxorubicin (DOX) induces apoptosis of rapidly proliferating cells by inhibiting cellular proteasomes. The aim of the present study was to determine whether DOX modulates the level of expression and function of proteasomes in feline injection-site sarcoma (FISS). Tissue extracts from primary sarcoma lesions and the related healthy subcutis of 18 cats affected by FISS were investigated. Nine of these cats had received neoadjuvant DOX treatment and nine cats did not receive this therapy. There was enhanced proteasome expression in FISS, but this was not affected by administration of DOX. This finding may account for the low clinical effectiveness of DOX therapy in FISS and provides the rationale for developing new therapeutic protocols aimed at achieving better proteasomal inhibition in FISS and other tumours that respond poorly to DOX therapy.