Department of Companion Animal Clinical Sciences, Norwegian School of Veterinary Science, Oslo, Norway.
J Vet Intern Med. 2013 Jul-Aug;27(4):935-42. doi: 10.1111/jvim.12110. Epub 2013 May 22.
Nonmalignant mammary tumors (NMT) are common in intact female dogs. Little is known about the clinical significance of these tumors, and the effect of ovariohysterectomy (OHE) on their development.
Ovarian hormone ablation through OHE decreases the risk of new tumors and thereby improves long-term prognosis for dogs with NMT.
Eighty-four sexually intact bitches with NMT.
Dogs were allocated to undergo OHE (n = 42) or not (n = 42) at the time of NMT removal in a randomized clinical trial. Tumor diagnosis was confirmed histologically in all subjects. Information about new tumor development was collected via follow-up phone calls and recheck examinations. Separate survival analyses were performed with the endpoints new tumor development and death. Cause of death was classified as related or unrelated to mammary tumor. In addition to OHE status, the influence of age, body weight, breed, tumor size, tumor number, tumor duration, type of surgery, and tumor histology was investigated.
New mammary tumor(s) developed in 27 of 42 (64%) intact dogs and 15 of 42 (36%) ovariohysterectomized dogs (hazard ratio 0.47, P = .022). Nine of the 42 dogs (21%) which developed new tumors were euthanized because of mammary tumor. Survival was not significantly different between the 2 treatment groups. In the intact group, nine dogs subsequently developed ovarian-uterine diseases.
Ovariohysterectomy performed at the time of mammary tumor excision reduced the risk of new tumors by about 50% among dogs with NMT. Survival was not significantly affected. Adjuvant OHE should be considered in adult dogs with mammary tumors.
非恶性乳腺肿瘤（NMT）在未绝育的雌性犬中较为常见。目前对于这些肿瘤的临床意义以及绝育手术（OHE）对其发展的影响知之甚少。
通过 OHE 消除卵巢激素可降低新发肿瘤的风险，从而改善患有 NMT 的犬的长期预后。
84 只患有 NMT 的未绝育母犬。
在一项随机临床试验中，这些犬在接受 NMT 切除时被分配接受或不接受 OHE（n = 42）。所有研究对象的肿瘤诊断均通过组织学确认。通过随访电话和复查收集新肿瘤发展的信息。使用新发肿瘤和死亡作为终点进行单独的生存分析。将死亡原因分为与乳腺肿瘤相关或不相关。除了 OHE 状态外，还研究了年龄、体重、品种、肿瘤大小、肿瘤数量、肿瘤持续时间、手术类型和肿瘤组织学对肿瘤发展的影响。
42 只未绝育犬中有 27 只（64%）和 42 只绝育犬中有 15 只（36%）出现新的乳腺肿瘤（风险比 0.47，P =.022）。在 42 只发展出新肿瘤的犬中，有 9 只因乳腺肿瘤而被安乐死。两组的生存情况无显著差异。在未绝育组中，有 9 只犬随后出现卵巢-子宫疾病。
在切除乳腺肿瘤时同时进行绝育手术可使患有 NMT 的犬新发肿瘤的风险降低约 50%。生存情况未受显著影响。对于患有乳腺肿瘤的成年犬，应考虑辅助 OHE。
