Size of the Largest Colorectal Liver Metastasis Is an Independent Prognostic Factor in the Neoadjuvant Setting

Up to 50% of patients diagnosed with colorectal cancer develop metastases during the course of their disease. Surgical resection remains the only curative treatment option for colorectal liver metastases (CRLM), frequently in conjunction with neoadjuvant chemotherapy. This study sought to determine if the pathologic size of the largest CRLM impacted disease-free survival (DFS) and disease-specific survival (DSS) in the setting of neoadjuvant chemotherapy.

All patients diagnosed with CRLM who underwent neoadjuvant chemotherapy for liver resection at the Massachusetts General Hospital between 2004 and 2016 were reviewed. The median size of the largest liver lesion was used as the cutoff for grouped evaluation.

A total of 214 patients were included. Median follow-up was 100.0 mo (interquartile range 68.9-133.8 mo). The median size of the largest lesion was 21 mm. Patients with lesions ≥21 mm exhibited significantly worse median DFS (12.5 mo versus 16.6 mo; P = 0.033) and median DSS (71.3 mo versus 103.5 mo; P = 0.038). CRLM lesions ≥21 mm were associated with poorer DFS on univariate analysis (hazard ratio (HR) = 1.42, 95% confidence interval (CI) 1.03-1.95 P = 0.033) and multivariable analysis (HR = 1.58, 95% CI 1.07-2.35, P = 0.023). CRLM lesions ≥21 mm were also independently associated with poorer DSS after liver resection on univariate analysis (HR = 1.51, 95% CI 1.02-2.24; P = 0.037) and multivariable analysis (HR = 1.98, 95% CI: 1.27-3.07; P = 0.002).

The size of the largest CRLM is an important prognostic factor for both DFS and DSS after neoadjuvant therapy and serves as a useful indicator of tumor biology.