Lumpectomy May Negatively Impact Survival in Female Dogs with Mammary Carcinomas

Mammary tumors are the most common neoplasms in female dogs, with mastectomy being the primary treatment. The impact of mastectomy type on survival remains unclear. This study evaluated the effect of different surgical techniques on the survival of female dogs with mammary carcinomas. A total of 307 dogs with 734 mammary tumors were analyzed. Ages ranged from 1 to 17 years, with mixed breeds comprising 48.9%. Most tumors (92.9%) were malignant, predominantly carcinoma in a mixed tumor (30.2%). Unilateral mastectomy was the most common technique (65.8%). Lumpectomy showed the shortest mean survival (179 days) and was associated with a 4.9-fold increased risk of death (p = 0.009). There was no significant association between surgical technique and overall survival or recurrence of mammary carcinoma (p = 0.2). This study relied on owner-reported data for survival and tumor recurrence. Lumpectomy appears to be associated with shorter survival times in female dogs with mammary carcinoma. Therefore, it may be advisable to reconsider this technique as a primary treatment option.