P-297 Prognostic impact of primary tumor location on synchronous and metachronous colorectal liver metastases: A retrospective monocentric real-life analysis

Abstract

Many studies have investigated the impact of primary tumor location (PTL) on the prognosis of colorectal cancer (CRC) patients. Our analysis aimed to evaluate the prognostic implications of PTL among patients (pts) with synchronous liver metastases (SM) and metachronous (MM) colorectal liver metastases (CRLM). We retrospectively reviewed the data of pts affected by CLRM from 2016 to 2021 at our institute. Overall survival (OS) and Progression-free survival (PFS) were investigated. 109 pts were included, median age 70 yrs (35-91), M/F= 66/43, RAS wt 37.6%, RAS mt 34.9%, 57.7% with left-sided colon cancer (LCC), 42.2% with right-sided colon cancer (RCC), 50.4% with only liver metastases (mets), 49.5% with hepatic + other mets, 21.1% underwent CRLM resection (R0=73.9%), 42.2% with SM-LCC, 27.5% with SM-RCC, 15.5% with MM-LCC and 14.6% with MM-RCC. SM were prevalent (n=76, 69.7%). The median duration of follow-up was 14 mos (1-98). The 1-yr and 2-yrs survival rates were higher in MM, MM-LCC, and all liver resected pts as listed below namely, respectively: 70.4% and 60.8% in all pts; 74.6% and 61.2% in LCC vs 65% and 61.8% of RCC (p=0.57); 72.5% and 67.7% in MM pts vs 69.5% and 57.5% of SM pts (p=0.63); 71.5% and 53.6% in resected SM-LCC pts vs both 66.7% of resected SM-RCC pts (p=0.95); both 84.6% in resected MM-LCC pts vs 62.5% and 54.7% of resected MM-RCC pts (p=0.23); 100% and 93.8% in pts undergoing liver resection vs 62.7% and 50.6% of pts with unresected liver (p=0.004); 64.9% and 43.9% in unresected SM-LCC pts vs both 62.5% of unresected SM-RCC pts (p=0.90); both 71.4% in unresected MM-LCC pts vs 53.8% and 43.1% of unresected MM-RCC pts (p=0.35). PTL had no influence on 2-yrs survival in all pts and OS in SM-RCC pts. The mOS in liver resected pts was higher in SM-LCC pts (21 vs 18 mos) and in MM-LCC pts (18.5 vs 15 mos). The best PFS in no liver resected pts was observed in the MM, SM-LCC, and in MM-LCC groups as follows: 8 months (mos) (95%CI=4-12) in all pts; 8 mos (95%CI=1-18) in LCC vs 8 mos (95%CI=4-12) of RCC (p=0.82); 11 mos (95%CI=8-14) in MM vs 5 mos (95%CI=1-19) of SM (p=0. 42); 10 mos (95%CI=7-13) of SM-LCC vs 7 mos of SM-RCC (95%CI=2-11) (p=0.59); 12 mos (95%=1-31) of MM-LCC vs 5 mos (95%CI=1-11) of MM-RCC (p=0.34). Our real-life study identified the timing of liver metastases as a prognostic factor and showed that pts with LCC and especially MM-LCC have the higher survival.