Outcome and clinical, pathological, and immunohistochemical factors associated with prognosis for dogs with early-stage anal sac adenocarcinoma treated with surgery alone: 34 cases (2002–2013)

OBJECTIVE To determine survival time and metastatic rate for dogs with early-stage anal sac adenocarcinoma (ASACA) treated with surgery alone and assess whether specific clinical, pathological, or immunohistochemical factors were predictive of outcome for those dogs. DESIGN Retrospective case series. ANIMALS 34 dogs with early-stage, nonmetastatic ASACA that were treated with surgery only. PROCEDURES Medical record databases of 2 referral hospitals were searched to identify dogs examined between 2002 and 2013 that had a diagnosis of nonmetastatic ASACA that was < 3.2 cm at its largest diameter. Only dogs that received surgical treatment alone were included in the study. For each dog, information extracted from the medical record included signalment, clinical and diagnostic test findings, tumor characteristics, and outcome. When available, archived tumor specimens were histologically reviewed and tumor characteristics were described; Ki-67 and E-cadherin expressions were evaluated by use of immunohistochem...