Total Metastases Volume and Relative Volume Reduction After Neoadjuvant Therapy Predict Outcome After Liver Resection of Colorectal Liver Metastases.

Background: Established clinical risk scores (CRSs) can estimate the prognosis of patients with colorectal liver metastases (CLM) after hepatic resection. However, their ability to predict outcome for patients undergoing neoadjuvant chemotherapy is limited, mainly because most included variables do not reflect a biologic response to neoadjuvant chemotherapy (NAC). This study aimed to evaluate the prognostic value of total metastases volume (TMV) and relative volume reduction (RVR) for patients with CLM undergoing perioperative chemotherapy and surgery.

Methods: Liver metastases volume was semi-automatically measured on computed tomography images in 69 patients before and after NAC and compared to established CRS regarding progression-free survival (PFS) and overall survival (OS).

Results: Patients with a TMV smaller than 29.5 ml before NAC and 7.5 ml after NAC showed a significantly longer PFS than those with a larger TMV (median, 31.0 vs. 13.7 months [p = 0.005] and 22.6 vs. 9.1 months [p = 0.013], respectively). An RVR after NAC of at least 73% was a positive predictor of PFS (median, 38.0 vs. 9.4 months; p = 0.004) and OS (mean, 59.5 vs. 92.5 months; p = 0.002).

Conclusions: Total tumor volume and RVR of CLM seem to be superior to established CRS for patients undergoing neoadjuvant chemotherapy and surgery.