RESUMO
Canine mammary tumors (CMTs) are the most diagnosed neoplasms in dogs; however, there are few studies analyzing the influence of epidemiological, clinicopathological, and histopathological data on cancer-specific survival (CSS), disease-free interval (DFI), and overall survival (OS) in a large cohort. To contribute to the understanding of the biological behavior of this neoplasm, 385 cases were analyzed, 89% malignant, 4% benign, and 7% non-neoplastic lesions. Among the dogs diagnosed with malignant neoplasms, 86% had early clinical stages (I-III), while 14% had regional or distant metastasis at the time of diagnosis. Carcinoma in a mixed tumor was the most frequent histological type with 44% of the cases and had the best prognosis. Analyzed factors such as the presence of pseudocyesis, previous history of the disease, advanced clinical stage (IV-V), and presence of ulceration obtained significant results for CSS, DFI, and OS through univariate analysis and had a negative impact on the survival of the patients. Multivariate analysis showed that histological grading and age proved to be the best independent parameters for the prognostic evaluation of CSS and DFI in this study. These factors were also significant in the overall survival analysis. Therefore, these parameters should be considered valuable risk and prognostic factors for CMTs.
RESUMO
Introduction: Bone healing depends on inflammation control and tissue repair time. Low-level laser therapy (LLLT) has been investigated to accelerate this process. Methylene blue (MB), together with LLLT, has been investigated for its antioxidant and anti-inflammatory potential; however, the effects of photosensitizers (photodynamic therapy, PDT) are controversial. This study aimed to verify whether the combination of MB and LLLT changes the course of the consolidation of experimental bone defects. Methods: Sixteen Wistar rats underwent femoral bone defects. In the control group (n=4), LLLT simulations were performed without MB. The MB group (n=4) received MB and simulation of LLLT. The LLLT group (n=4) was exposed to LLLT. The PDT+LLLT group (n=4) received MB and LLLT. At the end of 7 or 14 days, the animals were euthanized, and samples were collected. Results: PDT and LLLT induced osteogenic formation with cellularity (after seven days) and union of bony edges (14 days). On the seventh day, LLLT combined with PDT induced an increase (P<0.05) of 484% in the area of bone neoformation compared to the control. On the fourteenth day, LLLT combined with PDT or alone increased (P<0.05) the area of bone neoformation by 214% and 240% respectively, compared to the control group. The PDT/LLLT combination was associated with increased radiopacity (P<0.038). Conclusion: The combined use of MB with LLLT initiated during the transoperative phase may stimulate the bone repair process in rats.