Influence of pretreatment tumor growth rate on objective response of hepatocellular carcinoma treated with transarterial chemoembolization.

BACKGROUND AND AIM

The study aims to assess the influence of pretreatment tumor growth rate (TGR) on modified response evaluation criteria in solid tumors (mRECIST) objective response (OR) after a first session of selective transarterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC).

METHODS

One hundred fifteen patients (101 men [88%], mean 65.1 ± 10.5 years [range 26-87]) with 169 tumors (mean 34.2 ± 29.3 mm [10-160]), undergoing a first session of selective TACE for the treatment of HCC between 2011 and 2016, were included. TGR was calculated as the percentage change in tumor volume per month (%/month) on imaging before treatment. TGR cut-off for prediction of OR was identified by receiver operating characteristic curve analysis.

RESULTS

Overall 88/189 (52%) and 46/189 (27%) tumors showed complete response (CR) and partial response (PR) (OR rate 79%), while 32/189 (19%) showed stable disease (SD), and 3/189 (2%) were progressive disease (PD) on computed tomography at 1-month post-TACE. The mean pretreatment TGR was 12.0 ± 15.4 (-3.2-90.4) %/month. TGR of tumors showing CR, PR, SD, and PD was a mean 13.2 ± 16.4%, 12.1 ± 15.1%, 5.3 ± 4.5%, and 44.8 ± 20.4%, respectively (P < 0.001). The three tumors showing PD had TGR values > 20%/month. TGR was significantly higher in tumors with OR (12.8 ± 15.9% vs 5.3 ± 4.5% in SD, P = 0.009). A cut-off value of 6.5%/month had the highest predictive value of OR (AUROC 0.65 ± 0.05, P = 0.009).

CONCLUSION

Pretreatment TGR is highly variable in HCC before TACE with a U-shaped distribution for the prediction of tumor response. It provides insight into tumor biology that may be used during pretreatment workup to help stratify patients.