529P - Evaluating metastatic disease sites as a prognostic marker in patients receiving sequential treatment with regorafenib and trifluridine/tipiracil for refractory colorectal cancer: Survival outcomes from the multicenter retrospective “ReTrITA” study

Background

Patients (pts) with colorectal cancer (CRC) who experience metastatic spread to many distant organs have been shown to have poorer survival rates. It is still unknown if the location of distant metastases impacts survival outcomes. The aim of this real-world substudy was to assess the survival differences by metastatic patterns in pts receiving sequential treatment with regorafenib (R) and trifluridine/tipiracil (T) and vice versa. The endpoints were median overall survival (mOS) and median progression-free survival (mPFS).

Methods

Clinical data on pts diagnosed with metastatic CRC who were treated with R and T from 2012 to 2023 have been collected retrospectively at 17 Italian cancer centers.

Results

1156 pts who were treated with sequential R and T (T/R, n=261; R/T, n=155) or T (n=427) or R (n=313) alone, were retrospectively enrolled. In this subgroups study, we focused on pts who received T/R or R/T sequences. We observed a statistically significant longer mOS in pts who were treated with R/T vs the reverse sequence: 17.6 vs 9.8 months (HR=0,55; p=0,0449) in pts with liver metastases only (n=47) and 16 vs 12 months (HR=0,61; p=0,0018) in pts with liver + other metastases (n=173), respectively. A similar result in mOS, albeit non statistically significant, was shown in pts with other than liver metastases (n=112) in R/T vs T/R group [16,6 vs 14,7 months (HR=0,85; p=0,4255)]. In terms of mPFS, we observed a statistically significant better outcome in R/T than T/R group: 11,3 vs 7.6 months (HR=0,53; p=0,0272) in pts with liver metastases only (n=55); 11,1 vs 8,5 months (HR=0,67; p=0,0090) in pts with liver + other metastases (n=195) and 11,5 vs 8,9 months (HR=0,57; p=0,0018) in pts with other than liver metastases (n=136), respectively.

Conclusions

According to this real-world subanalysis, the R/T sequence could improve survival outcomes in third-line treatment and beyond in CRC pts with any metastatic pattern. However, treatment choices should also take into account the patient's characteristics, including gender and ECOG PS. To validate our results, further prospective research is needed.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.