Research Update: Is surgery best for massive hepatocellular carcinoma in dogs?

In this retrospective study from a veterinary teaching hospital, the medical records of 48 dogs treated for massive hepatocellular carcinoma were reviewed to determine clinical features and prognostic factors. Forty-two dogs were treated surgically with liver lobectomy, and six had incisional biopsy only and were treated conservatively.

The dogs in the surgery group had a median age of 11 years and a median weight of 47.5 lb (21.6 kg). In the nonsurgery group, the dogs' median age was 12 years and median weight was 64 lb (29.1 kg). Numerous breeds were represented. Seventy-one percent of the dogs in the surgery group had clinical signs such as weight loss, inappetence, and lethargy with a median duration of 68 days.

An abdominal mass was palpated in 45% of the surgically treated dogs, and anemia was detected in 54% of the 41 dogs evaluated. A hepatic mass was identified by using radiography or ultrasonography in most of the dogs; pulmonary metastasis was not detected in any dog. A single, large hepatocellular carcinoma was found during exploratory celiotomy in all the dogs in the surgery group, and intraoperative complications (28.6%) were mostly related to variable amounts of hemorrhage. Intraoperative mortality was 4.8%.

In the surgery group, the median survival time was not reached by the end of the study and was greater than 1,460 days. Factors related to a poor prognosis in the surgery group included high serum alanine transaminase and aspartate transaminase activities and right-sided tumors. In the nonsurgery group, the median survival time was 270 days, which was significantly less than that of the surgery group.

The authors concluded that massive hepatocellular carcinoma in dogs should be treated with careful surgical resection to avoid intraoperative hemorrhage and provide prolonged survival time. The authors acknowledge the limitations of this retrospective review and the need for future studies involving standardized treatments and follow-up protocols.

COMMENTARY

Massive hepatocellular carcinoma, a large tumor affecting a single liver lobe, is the most common of all liver tumors. Despite the tumor's size and the disease's prolonged clinical course with varying degrees of morbidity, this study shows that patients can be successfully treated with surgical resection of the affected liver lobe. Clinicians should be alert to the subtle clinical abnormalities that patients with this tumor exhibit and recognize that using ultrasonography and radiography early in the course of the disease helps diagnose this condition. It is hoped that this early detection will reduce the technical challenges (i.e. hemorrhage) associated with resecting a large, vascular intra-abdominal mass.

Liptak JM, Dernell WS, Monnet E, et al. Massive hepatocellular carcinoma in dogs: 48 cases (1992-2002). J Am Vet Med Assoc 2004;225:1225-1230.

The information in "Research Updates" was provided by Veterinary Medicine Editorial Advisory Board member Joseph Harari, MS, DVM, DACVS, Veterinary Surgical Specialists, 21 E. Mission Ave., Spokane, WA 99202.

Joseph Harari, MS, DVM, DACVS