Liver injury due to chemotherapy-induced sinusoidal obstruction syndrome is associated with sinusoidal capillarization.

BACKGROUND: Indocyanine green (ICG) retention is a validated test of hepatic function in patients with chronic liver disease. The underlying mechanism for the impairment of ICG retention in patients undergoing chemotherapy for colorectal liver metastases (CLM) remains unclear. We sought to elucidate the mechanism for impairment of ICG retention in patients with CLM.

METHODS: Clinicopathologic data of 98 patients with CLM undergoing hepatectomy were analyzed. The archived nontumoral liver parenchyma bearing no CLM were immunostained with CD34 antibody to determine the sinusoidal capillarization.

RESULTS: Of 98 patients, 80 received preoperative chemotherapy. Sinusoidal obstruction syndrome (SOS) occurred in 39 patients (39.8%). The development of SOS in patients receiving oxaliplatin-based chemotherapy was significantly higher compared to those receiving non-oxaliplatin-based chemotherapy (P=0.003). SOS was independently associated with abnormal ICG retention rate at 15 minutes (ICG-R15) (odds ratio 3.45, 95% confidence interval 1.31-9.04, P=0.012) and CD 34 overexpression (odds ratio 18.76, 95% confidence interval 4.58-76.81, P<0.001). ICG-R15 correlated with CD34 expression within the nontumoral liver parenchyma (r=0.707, P<0.001) and severity of SOS (r=0.423, P<0.001). CD34 positive areas were likely situated at the peripheral area of SOS, and both SOS score and number of cycles of oxaliplatin-based chemotherapy significantly correlated with CD34 expression (r=0.629, P<0.001 and r=0.522, P<0.001, respectively).

CONCLUSIONS: These results suggest that the deterioration of hepatic functional reserve due to SOS is associated with sinusoidal capillarization, indicated by CD34 overexpression within nontumoral liver parenchyma adjacent to SOS.