Environmental risk factors for the development of oral squamous cell carcinoma in cats

Background: Risk factors for oral squamous cell carcinoma (OSCC) in cats are derived from a single study dated almost 20 years ago. The relationship between inflammation of oral tissues and OSCC is still unclear. Objectives: To investigate previously proposed and novel potential risk factors for OSCC development, including oral inflammatory diseases. Animals: Hundred cats with OSCC, 70 cats with chronic gingivostomatitis (CGS), 63 cats with periodontal disease (PD), and 500 controls. Methods: Prospective, observational case-control study. Cats with OSCC were compared with an age-matched control sample of client-owned cats and cats with CGS or PD. Owners of cats completed an anonymous questionnaire including demographic, environmental and lifestyle information. Results: On multivariable logistic regression, covariates significantly associated with an increased risk of OSCC were rural environment (OR: 1.77; 95% CI: 1.03-3.04; P =.04), outdoor access (OR: 1.68; 95% CI: 1.07-2.63; P =.02), environmental tobacco smoke (OR: 1.77; 95% CI: 1.05-3; P =.03), and petfood containing chemical additives (OR: 1.98; 95% CI: 1.04-3.76; P =.04). Risk factors shared with CGS and PD were outdoor access and petfood containing chemical additives, respectively. A history of oral inflammation was reported in 35% of cats with OSCC but did not emerge as a risk factor. Conclusions and Clinical Importance: The study proposes novel potential risk factors for OSCC in cats. Although a history of inflammatory oral disease was not significantly more frequent compared with random age-matched controls, OSCC shared several risk factors with CGS and PD

A retrospective study on prophylactic regional lymphadenectomy versus nodal observation only in the management of dogs with stage I, completely resected, low-grade cutaneous mast cell tumors

Background: While lymphadenectomy of metastatic lymph nodes (LNs) has been associated with improved outcome, the clinical utility of prophylactic lymphadenectomy in dogs with stage I cutaneous mast cell tumors (cMCTs) remains a controversial topic. To assess the therapeutic role of lymphadenectomy of uninvolved regional LNs, the long-term outcome of cMCT-bearing dogs with cytologically negative and surgically unresected regional LNs (observation only, OO) was compared with that of dogs with surgically resected and histologically negative regional LNs (prophylactic regional lymphadenectomy, PRL). Results: A retrospective analysis of 64 dogs with a low-grade, completely resected stage I cMCT was performed: 35 (54.7%) dogs were subjected to OO and 29 (45.3%) underwent PRL. Dogs were monitored for a median of 813 and 763 days in the OO group and PRL group, respectively. The number of dogs undergoing MCT progression was significantly higher in the OO group (P = 0.028) and curve comparison revealed a tendency to a better time to progression in the PRL group (P = 0.058). No significant difference in survival time (P = 0.294) was observed between dogs in the OO and PRL groups. Conclusions: Our results showed that lack of immediate lymphadenectomy was associated with a higher risk for tumor progression. This preliminary judgement, reinforced by the findings that lymphadenectomy was well tolerated in all cases, and that histopathology provides the definitive assessment of the nodal pathological status, may suggest that prophylactic lymphadenectomy is indicated in the management of stage I MCTs. Larger prospective studies are warranted for generating clinical evidence of this latter hypothesis