ECOG is as independent predictor of the response to chemotherapy, overall survival and progression-free survival in carcinoma of unknown primary site.

The aim of the present study was to determine whether age, gender, functional status, histology, tumor location, number of metastases, and levels of the tumor markers, lactate dehydrogenase (LDH) and albumin, are poor prognostic factors for the response to chemotherapy in patients with carcinoma of unknown primary site. A total of 149 patients diagnosed with carcinoma of unknown primary site that was histologically confirmed, and treated with chemotherapy in the Oncology Hospital, National Medical Center, 'Century XXI' IMSS, Mexico City, Mexico during the period between January 2002 to December 2009, were carefully selected for the present study. The analysis of 149 patients diagnosed with carcinoma of unknown primary site revealed that the liver was the organ with the highest frequency of metastases (33.5%). The objective response rates to chemotherapy were ~30.2%. Notably, ECOG was an important predictor of response to chemotherapy (P=0.008). The median progression-free survival was 7.1 months. Upon multivariate analysis, the Eastern Cooperative Oncology Group (ECOG) Scale of Performance Status was observed as an independent predictor of progression (P<0.0001). The median overall survival was 14.2 months. The ECOG was also an independent predictor of mortality (P<0.0001). In conclusion, the data from the present study have demonstrated that ECOG is an independent predictor of a poor response to chemotherapy, lower overall survival and progression-free survival in carcinoma of unknown primary site.