Background: In this retrospective study, we aimed to evaluate the clinicopathological characteristics of the patients presenting with liver metastases from unknown primary site besides survival rates, treatment outcomes, and prognostic factors.
Methods: In all, 68 patients followed-up at our center with adenocarcinoma of unknown primary (ACUP) metastatic to the liver between 2005 and 2013 were enrolled. All of the liver metastases were proven by liver biopsy and all yielded diagnosis of adenocarcinoma.
Results: Median age was 61 years (29-90) and most of the patients were male (male/female: 43/25). The liver was the only metastatic site in 2 (3%) patients whilst 66 patients (97%) had extrahepatic metastases. The most common extrahepatic metastatic sites were lymph nodes (89.7%), lungs (32.4%), bones (25%), peritoneum (11.8%), brain (4.4%), and adrenal glands (2.9%). Of all 68 patients, 39 (57.4%) were treated with chemotherapy. Median overall survival (OS) was significantly higher in ACUP patients treated with chemotherapy [12.5 months (95% CI 8.3-16.7) vs. 4 months (95% CI 1.2-6.8), (p = 0.026), respectively]. In multivariate analysis, ECOG (Eastern Cooperative Oncology Group) performance status (p = 0.009), chemotherapy (p = 0.024), serum albumin (p = 0.012), and serum CA 19-9 level (p = 0.026) at initial diagnosis were identified as independent prognostic factors influencing survival for the patients with liver metastases from ACUP.
Conclusion: Patients with liver metastases from ACUP have poor prognosis and chemotherapy improves survival. Decreased serum albumin level, increased CA 19-9 level and poor performance status are independent poor prognostic factors.
Keywords: Adenocarcinoma; Liver metastases; Survival; Unknown primary.