Canine Digital Tumors: A Veterinary Cooperative Oncology Group Retrospective Study of 64 Dogs

Abstract

We compared clinical characteristics and outcomes for dogs with various digital tumors. Medical records and histology specimens of affected dogs from 9 veterinary institutions were reviewed. Risk factors examined included age, weight, sex, tumor site (hindlimb or forelimb), local tumor (T) stage, metastases, tumor type, and treatment modality. The Kaplan-Meier product limit method was used to determine the effect of postulated risk factors on local disease-free interval (LDFI), metastasis-free interval (MFI), and survival time (ST). Outcomes were thought to differ significantly between groups when P Յ .003. Sixty-four dogs were included. Squamous cell carcinoma (SCC) accounted for 33 (51.6%) of the tumors. Three dogs presented with or developed multiple digital SCC. Other diagnoses included malignant melanoma (MM) (n ϭ 10; 15.6%), osteosarcoma (OSA) (n ϭ 4; 6.3%), hemangiopericytoma (n ϭ 3; 4.7%), benign soft tissue tumors (n ϭ 5; 7.8%), and malignant soft tissue tumors (n ϭ 9; 14%). Fourteen dogs with malignancies had black hair coats, including 5 of the 10 dogs with MM. Surgery was the most common treatment and, regardless of the procedure, had a positive impact on survival. None of the patient variables assessed, including age, sex, tumor type, site, and stage, had a significant impact on ST. Both LDFI and MFI were negatively affected by higher T stage, but not by type of malignancy. Although metastasis at diagnosis correlated with a shorter LDFI, it did not have a significant impact on ST. On the basis of these findings, early surgical intervention is advised for the treatment of dogs with digital tumors, regardless of tumor type or the presence of metastatic disease.

Diagnoses and Clinical Outcomes Associated with Surgically Amputated Feline Digits Submitted to Multiple Veterinary Diagnostic Laboratories

“…Affected digits in this study were primarily from the front limbs. A similar pattern is described in articles on neoplasia in the digits of dogs, 11,14 which speculate that possible reasons for this may be increased weight bearing on the front-versushind limbs and increased exposure to carcinogens during digging behavior. 11 No sex predilection for the development of neoplasia was present apart from adenocarcinoma, where females were overrepresented.…”

Skeletal–Extraskeletal Angiomatosis in a Dog

“…11 Melanoma is the second-most-common digital tumor in dogs, constituting 15.6% of these tumors, 6 and is less commonly associated with radiographic evidence of bone lysis. 11 Given the lack of osseous response in this case, osteosarcoma-which accounts for 6.3% of canine digital tumors 6 -was considered less likely.…”

“…11 Melanoma is the second-most-common digital tumor in dogs, constituting 15.6% of these tumors, 6 and is less commonly associated with radiographic evidence of bone lysis. 11 Given the lack of osseous response in this case, osteosarcoma-which accounts for 6.3% of canine digital tumors 6 -was considered less likely. Although digital metastasis from a primary bronchogenic carcinoma has been reported as one of the most frequently encountered digital tumors in cats, 16 a similar clinical syndrome has not been documented in dogs.…”

Leading the way: canine models of genomics and disease

“…Mammary (Taylor et al, 1976;Gilbertson et al, 1983) and squamous cell carcinomas (O'Brien, 1992;Henry et al, 2005) have also been reported in the dog. Many of these cancers exhibit an increased prevalence in particular breeds of dogs (Table 2), indicating a genetic predisposition (Cadieu and Ostrander, 2007).…”