Prognostic Value of Metabolic Parameters in Patients with Synchronous Colorectal Cancer Liver Metastasis Following Curative-Intent Colorectal and Hepatic Surgery

Synchronous colorectal cancer liver metastasis (SCLM) remains a clinical challenge, largely because of the limited availability of tools that use reliable prognostic indicators to guide treatment. This study assessed the prognostic ability of preoperative F-18-FDG PET/CT in patients with SCLM who had undergone curative-intent colorectal and liver surgery. Methods: All included patients had undergone simultaneous colorectal and hepatic surgery to treat SCLM. Cox regression for survival analysis was undertaken using clinicopathologic variables and metabolic parameters (metabolic tumor volume [MTV], total lesion glycolysis [TLG], and peak standardized uptake value [SUVpeak]) as covariates, with tumor recurrence and death used as endpoints. Results: One hundred twenty patients (82 men, 38 women; mean age +/- SD, 59.9 +/- 10.1 y) met the inclusion and exclusion criteria. Univariate analysis showed that MTV, TLG, and the size of hepatic metastases were significant indicators of both recurrence-free survival and overall survival, whereas those of primary colorectal tumors were not. Multivariate analysis revealed that the SUVpeak of primary tumors and hepatic metastases remained significant after adjusting for other clinicopathologic variables, whereas the MTV and TLG of hepatic metastases became insignificant after adjusting for differences in tumor size. The combination of a high SUVpeak of hepatic metastases and a low SUVpeak of primary tumors was related to poor prognosis under the multivariate model. Conclusion: In patients with SCLM who underwent curative-intent colorectal and liver surgery, metabolic parameters of hepatic metastases possess prognostic significance whereas those of primary colorectal tumors do not. For hepatic metastases, the SUVpeak is an independent prognostic factor, whereas MTV and TLG are surrogate measures of tumor size. Reduced recurrence-free survival rates are associated with higher SUVpeak for hepatic metastases and lower SUVpeak for primary tumors. Further studies are needed to elucidate the underlying mechanisms.