Increased kinetic growth rate during late phase liver regeneration impacts the risk of tumor recurrence after colorectal liver metastases resection.

BACKGROUND: Although experimental data strongly support the pro-tumorigenic role of postoperative liver regeneration, this hypothesis has not been clinically investigated. We aimed to examine the impact of liver regeneration determined by volumetric imaging on recurrence following resection of colorectal liver metastasis (CRLM).

METHODS: Resected liver volume was subtracted from total liver volume (TLV) to define postoperative remnant liver volume (RLVp ). Early and late kinetic growth rates (KGR) were defined as the postoperative increases in liver volume within 2-3 and 8-10 months from surgery, respectively, divided by the corresponding time interval.

RESULTS: Median early and late KGR was 2.6%/month (IQR: -0.9 to 12.3) and 1.0%/month (IQR: -0.64 to 2.91), respectively. Late KGR predicted intrahepatic recurrence after 1 year from surgery (AUC 0.677, P = 0.011). Specifically, patients with a late KGR ≥1% had a higher cumulative risk of recurrence compared with patients with a KGR <1% (P = 0.038). In multivariate analysis, KGR ≥1% independently predicted recurrence (P = 0.027).

DISCUSSION: A KGR ≥1% during the late regeneration phase was associated with increased risk of intrahepatic recurrence. These data may inform the timing of adjuvant therapy administration and focus surveillance strategies for high-risk patients.