Objective: In patients with metastatic colorectal cancer (mCRC), several prognostic factors such as performance status (PS), number of metastatic sites, carcinoembryonic antigen (CEA), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) have been reported. The objective of this study was to clarify the prognostic impact of Baseline Sum of Longest Diameter (BSLD) of target lesions by Response Evaluation Criteria in Solid Tumor (RECIST) in patients with mCRC.
Methods: The subjects of this study were consecutive 103 patients with mCRC who had been received the first line systemic chemotherapy between September 2002 and March 2005.
Results: The chemotherapy regimens included leucovorin-modulated 5-fluorouracil (5-FU) (n = 27) and 5-FU plus irinotecan (n = 76). The median overall survival time was 547 days. The median BSLD was 14.3 cm (range, 1.1-54.7). In univariate analysis, identified prognostic variables on survival were PS (0, 1 versus 2), number of metastatic sites (1 versus >1), peritoneal dissemination (+ versus -), pleural effusion (PE) and/or ascites, white blood cell (> or = versus <10,000/mm(3)), ALP (> or = versus <300 IU), LDH (> or = versus <300 IU), CEA (> or = versus <5 ng/ml), chemotherapy regimen, presence of liver metastasis, and BSLD. In multivariate analysis with covariates of the above significant factors, BSLD (> or = versus <10 cm) (HR 0.431, 95% CI 0.237-0.785, P = 0.0059), PS (HR 0.248, 95% CI 0.107-0.577, P = 0.0012), PE and/or ascites (HR 0.402, 95% CI 0.228-0.708, P = 0.0016) were independent prognostic factors.
Conclusion: BSLD of target lesions by RECIST representing tumor volume might be an independent prognostic factor of patients with mCRC after systemic chemotherapy.