Determination of Prognostic Factors Affecting 2-Year Survival Rate after Surgical Removal in Canine Mammary Gland Tumors

Canine mammary tumors are among the most common neoplasms in intact female dogs, ranging from benign lesions to highly malignant cancers.While various prognostic indicators have been proposed, published results have been inconsistent due to methodological differences and limited multivariable analyses.This retrospective cohort study aimed to identify clinicopathologic and hematologic factors associated with 2-year survival following the surgical removal of mammary tumors, focusing on tumor characteristics, reproductive status, and preoperative blood profiles.We reviewed the medical records of 135 bitches treated surgically at the Chungbuk National University Veterinary Medical Teaching Hospital from 2008 to 2022.Collected variables included breed, age, body weight, tumor size, histopathologic classification, metastasis, surgical procedure, ovariohysterectomy (OHE) status, and hematologic and biochemical parameters.Univariate analyses indicated that a tumor size of 3 cm, malignant histopathology, age 11.5 years, presence of metastasis, and absence of OHE were associated with a decreased likelihood of 2-year survival.While preoperative blood parameters were largely non-predictive, elevated platelet counts-potentially indicating tumor-related inflammatory or pro-thrombotic activity-showed a trend toward poorer outcomes.Multivariate logistic regression identified large tumor size (OR = 0.15), advanced age (OR = 0.23), and malignant tumor types-specifically carcinoma (OR = 0.05) and sarcoma (OR = 0.089)-as independent predictors of reduced survival.In contrast, OHE was associated with a significantly increased probability of 2-year survival (OR = 3.29), likely reflecting hormonal influences on tumor progression.In conclusion, tumor size, age at surgery, and histopathologic type are reliable prognostic indicators for dogs with mammary tumors, while OHE may provide a survival advantage.These findings highlight the clinical importance of early detection, timely surgical intervention, and consideration of reproductive status in therapeutic planning.