Peer-reviewed veterinary case report
Radiation treatment results for dogs with anal sac cancer spread
By Martin, Tiffany W et al.·Published in Veterinary and comparative oncology·2025·Department of Clinical Sciences, United States·View original on PubMed →
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Original publication title: Retrospective Study Evaluating the Outcome and Efficacy of Stereotactic Body Radiation Therapy for the Treatment of Metastatic Abdominal Lymph Nodes in Dogs With Apocrine Gland Anal Sac Adenocarcinoma.
- Species:
- dog
Plain-English summary
A group of 25 dogs with anal sac cancer that had spread to their lymph nodes received a type of radiation therapy called stereotactic body radiation therapy (SBRT) instead of surgery. The dogs showed varying responses to the treatment, with some experiencing complete or partial improvement. On average, the dogs lived about 451 days after starting SBRT, and many had stable disease for several months. However, some dogs did experience changes in their hind limb movement after treatment. Overall, SBRT was found to be a good option for dogs that couldn't have surgery, but more research is needed to understand the side effects better.
People also search for: dog anal sac cancer treatment · SBRT for dogs · dog hind limb weakness after radiation · anal sac adenocarcinoma prognosis · dog lymph node cancer survival time
Abstract
Local treatment for dogs with regional lymph node metastasis secondary to apocrine gland anal sac adenocarcinoma (AGASACA) includes nodal extirpation or radiotherapy. Stereotactic body radiation therapy (SBRT) may provide a definitive intent treatment option for macroscopic nodal disease when surgery is declined or the disease is deemed inoperable. Twenty-five dogs receiving SBRT to the metastatic sacroiliac lymph nodes were retrospectively evaluated. Dogs were staged according to the previously published TNM staging system with 3 stage IIIa, 14 stage 3b, and 8 stage IV. The overall median survival time (MST) was 451 days and the stage did not significantly impact survival (p = 0.31). The overall median event-free survival time was 246 days. Significant positive prognostic factors included male sex, higher dose per fraction, and higher total dose (p = 0.034, 0.0035, 0.0047). Dogs receiving 6-7.5 Gy per fraction with a total dose of 30-37.5 Gy outperformed dogs receiving other protocols. Twelve dogs experienced gait changes in the hind limbs during the late radiation effects period. Resolution of hypercalcemia in 5 dogs was inconsistent and transient. The best response was complete in 21%, partial in 58%, and stable disease in 17% at a median of 100 days. Three dogs (12%) developed progression of treated lymph nodes at 157, 498, and 644 day. Eight dogs (32%) had recurrence of their primary (untreated by radiation) anal sac masses. SBRT was determined to be an effective alternative to surgical excision; however, more investigation is needed to determine the cause of gait changes in the late toxicity period.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/40110661/