Surgical and Ablative Treatment for Metastatic Adenocarcinoma to the Liver from Unknown Primary Tumor

Abstract

Metastatic adenocarcinoma to the liver from an unknown primary tumor (UPT) carries a poor prognosis, with a median survival of 5 months. Chemotherapy has not significantly improved outcome, and effective treatment is yet to be established in these patients. We examined our experience with surgical resection and ablation of this disease to determine clinico-pathologic characteristics and treatment outcomes. We undertook a retrospective chart review of 157 patients who were treated for metastatic disease to the liver with resection or radiofrequency ablation (RFA) between 1999 and 2003. Seven patients were identified with unknown primary malignancy. Evaluation of the seven patients included complete history and physical examination, complete blood count, routine chemistries, stool Hemoccult test, chest radiograph, and computed tomography (CT) of the abdomen and pelvis. In addition, the three female patients had breast examinations and mammography. Adenocarcinoma histology was determined via CT-guided liver biopsy in all patients. Other diagnostic tests, including whole-body positron emission tomography to the measurement of various serum tumor markers, were performed in the majority of the patients. There were nine total lesions treated; six with RFA and three with hepatic resection. Median diameter of the lesions was 5.4 cm (range, 1.3–15). Two patients were treated with adjuvant and three patients with neoadjuvant and adjuvant chemotherapy. Extrahepatic sites of metastases, adrenal and skeletal, were discovered in 1 patient prior to treatment. With a median follow-up of 9 months, 1 patient is currently alive with no evidence of disease, 4 patients are alive with disease, and 2 patients died of disease. Median disease-free-interval following treatment was 6.5 months. To date, optimal treatment for metastatic adenocarcinoma to the liver UPT remains unclear. Localized treatment involving RFA or hepatic resection may be a promising addition to chemotherapy in the management of this disease.