Blackwood Laura, Harper Aaron, Elliott James, Gramer Irina
Department of Small Animal Clinical Science, University of Liverpool, Neston, UK.
J Feline Med Surg. 2019 Feb;21(2):186-194. doi: 10.1177/1098612X18771772. Epub 2018 May 16.
Salivary gland carcinoma is uncommon in cats. We report the outcome of radiation therapy in six cases (four salivary gland adenocarcinomas, one tubulopapillary adenocarcinoma, one carcinoma). Five were treated after surgical excision of the primary tumour, but four had gross disease (primary or metastatic) at the time of starting radiotherapy. Exact progression-free interval from the start of radiotherapy in the two cats where this was known was 120 and 144 days, respectively. One cat was signed off at 766 days with no evidence of recurrence. Another cat was in remission at 202 days (when last seen by the referring practice) but subsequently developed recurrence (date uncertain). Survival time was known for three cats (55 days, 258 days and 570 days from initiation of radiotherapy, respectively). In two cases, locoregional progressive disease (PD) was confirmed, and the other presumed as the cause of death. Two cats, known to have developed PD, were alive at the time of writing (at 206 and 549 days, respectively). No cat died as a result of distant metastatic disease.
There is a paucity of information on the treatment of salivary gland tumours. In humans, as in cats, there is no optimised standard of care for malignant tumours. It is accepted that, for surgical candidates (even with large tumours), surgery and radiotherapy is superior to radiotherapy alone. However, the benefits of postoperative radiotherapy compared with surgery alone are only clear in patients with high-risk tumours (ie, those with large and invasive primary tumours, close or incomplete margins, high histopathological grade, histological evidence of neural or vascular invasion, or positive lymph nodes). This population is analogous to the population reported here, and likely to most cats presented in practice. Thus, radiation therapy may help improve locoregional control and survival in cats.
猫唾液腺癌并不常见。我们报告了6例猫唾液腺癌（4例唾液腺腺癌、1例管状乳头状腺癌、1例癌）的放射治疗结果。5例在原发肿瘤手术切除后接受治疗，但4例在开始放疗时已有肉眼可见的疾病（原发或转移）。已知开始放疗后，两只猫的无进展生存期分别为120天和144天。一只猫在766天时未发现复发迹象。另一只猫在202天时缓解（转诊诊所最后一次见到时），但随后复发（日期不详）。已知三只猫的生存时间（分别从放疗开始起55天、258天和570天）。在两例中，确认存在局部区域进展性疾病（PD），另一例推测为死亡原因。已知发生PD的两只猫在撰写本文时还活着（分别为206天和549天）。没有猫因远处转移疾病死亡。
关于唾液腺肿瘤治疗的信息匮乏。在人类和猫中，恶性肿瘤都没有优化的标准治疗方案。人们公认，对于适合手术的患者（即使肿瘤较大），手术和放疗优于单纯放疗。然而，与单纯手术相比，术后放疗的益处仅在高危肿瘤患者（即原发肿瘤大且具有侵袭性、切缘接近或不完整、组织病理学分级高、有神经或血管侵犯的组织学证据或淋巴结阳性的患者）中才明确。这一人群与本文报告的人群相似，可能也是实际中大多数就诊猫的情况。因此，放射治疗可能有助于改善猫的局部区域控制和生存。
