609P - The impact of surgical invasiveness on the efficacy of mFOLFOX6 in resected colorectal liver metastasis: An exploratory analysis of JCOG0603

Background

In JCOG0603, the addition of mFOLFOX6 to hepatectomy provided no clear survival benefit over hepatectomy alone in patients with colorectal liver metastasis (CLM). Therefore, this study examined the impact of surgical invasiveness on the tolerability of chemotherapy and survival.

Methods

Among patients registered in JCOG0603, those who received mFOLFOX6 after hepatectomy were analyzed in this subgroup analysis. The associations of factors related to surgical invasion (e.g., extent of hepatectomy, operative time, blood loss, postoperative complications) with factors related to the tolerability to mFOLFOX6 (completion of nine cycles, dose intensity, and adverse events) and disease-free survival (DFS) were assessed. The Hx ratio (resected liver weight/body weight) was calculated to evaluate the relative resected liver wight for each patient.

Results

One hundred forty-one patients treated with mFOLFOX6 were analyzed. The Hx ratio was identified as a predictor of the completion of nine cycles of mFOLFOX6 (≥median vs. Surgical invasiveness mFOLFOX6 vs. hepatectomy alone HR (95% CI) p Hx ratio ≥Median 0.73 (0.48–1.10) 0.12 0.55 (0.31–0.950) 0.03 Extent of hepatectomy Major hepatectomy 0.93 (0.45–1.90), 0.84 Minor hepatectomy 0.65 (0.46–0.92) 0.015 Liver weight ≥300 g 0.81 (0.47–1.40) 0.44 <300 g 0.55 (0.37–0.83) 0.038

Conclusions

Surgical invasiveness, especially the relative resected liver weight, might affect both the tolerability and cytotoxic effect of mFOLFOX6. Adjuvant mFOLFOX6 should be cautiously administered when the extent of hepatectomy is large.

Clinical trial identification

UMIN000000653, jRCTs031180285.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

National Cancer Research and Development Funds (23-A19, 26-A-4, 29-A-3, and 2020-J-3), a Health and Labour Sciences Research Grant for Clinical Cancer Research (H19-024), and AMED under Grant No. JP16ck0106047 and JP19ck0106308.

Disclosure

All authors have declared no conflicts of interest.