title: Treatment of advanced canine anal sac adenocarcinoma with hypofractionated radiation therapy: 77 cases (1999-2013).
abstract: Currently no standard of care exists for advanced, inoperable or metastatic anal sac adenocarcinoma (ASAC). The objective of this retrospective study was to assess the role of hypofractionated radiation therapy (RT) in 77 dogs with measurable ASAC. A total of 38% of dogs experienced a partial response to RT. For dogs presenting with clinical signs related to the tumour, improvement or resolution of signs was noted in 63%. For dogs presenting with hypercalcemia of malignancy, resolution was noted in 31% with RT alone and an additional 46% with radiation, prednisone, and/or bisphosphonates. Median overall survival was 329 days (range: 252-448 days). Median progression free survival was 289 days (range: 224-469). There was no difference in survival based on radiation protocol, use of chemotherapy, previous surgery or advanced stage. Radiation toxicities were mild and infrequent. Hypofractionated RT is well tolerated and is applicable in the treatment of advanced primary, locoregional or metastatic ASAC.
authors.affiliation: Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA, USA.
authors.forename: B
authors.initials: B
authors.lastname: McQuown
authors.affiliation: Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Keyerleber
authors.affiliation: New England Veterinary Oncology Group (NEVOG), Waltham, MA, USA.
authors.forename: K
authors.initials: K
authors.lastname: Rosen
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: McEntee
authors.affiliation: Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA, USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Burgess
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000532:radiotherapy / Q000662:veterinary*; D000694:Anal Gland Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D000695:Anal Sacs; D000818:Animals; D004283:Dog Diseases / Q000401:mortality / Q000532:radiotherapy*; D004285:Dogs; D005260:Female; D008297:Male; D000069473:Radiation Dose Hypofractionation; D012189:Retrospective Studies
keywords: anal sac adenocarcinoma; hypofractionated; oncology; palliative; radiation oncology; radiation therapy; small animal