Abstract
Background: Oxaliplatin-based chemotherapy can cause hepatic sinusoidal injury such as sinusoidal obstructive syndrome (SOS). Spleen size is correlated with sinusoidal damage, and serum hyaluronic acid is also a marker of SOS. The aim of the present study was to clarify the impact of the current chemotherapeutic regimen plus bevacizumab against oxaliplatin-associated hepatic damage with serum hyaluronic acid and spleen size. Patients and Methods: Sixteen adult patients with colorectal cancer and liver metastasis were evaluated retrospectively. In the bevacizumab-treated group (n=9), oxaliplatin-based chemotherapy with bevacizumab prior to hepatic resection was administered, while oxaliplatin-based chemotherapy-alone was administered prior to hepatic resection in the control group (n=7). Hepatic sinusoidal injury, change in spleen size and serum value of hyaluronic acid were evaluated. Results: The incidence and severity of sinusoidal dilation was lower in the bevacizumab group than in the control group (moderate or severe: 2/9 (22.2%) vs. 5/7 (71.4%), incidence of sinusoidal dialation: 5/9 (55.6%) vs. 7/7 (100%), both p<0.05). The change in spleen size and serum hyaluronic acid were significantly lower in the bevacizumab-treated group compared to the control group (change in spleen size: 110.3%±27.5% vs. 146.3%±34.2%, hyaluronic acid: 33.6±21.2 ng/ml vs. 124.5±34.0 ng/ml, both p<0.05). Conclusion: In the current study, bevacizumab reduced SOS in pathological findings and suppressed the elevation of hyaluronic acid, and splenomegaly. In addition, a change in spleen size and serum hyaluronic acid could serve as a biomarker for a predictive effect of bevacizumab against SOS.
In patients with colorectal cancer, liver metastasis is one of the most significant prognostic factors. Forty to fifty percent of patients undergoing resection of the primary colorectal tumor develop liver metastasis within three years (1, 2). Nowadays, with the introduction of new systemic preoperative chemotherapeutic regimens that combine fluoropyrimidines with irinotecan, a topoisomerase-1 inhibitor or oxaliplatin, the prognosis of patients with advanced colorectal carcinoma has improved dramatically. However, it is well-known that oxaliplatin-based chemotherapy may cause liver injury, such as sinusoidal obstructive syndrome (SOS) (3).
Recently, some biological agents such as bevacizumab, an antibody against vascular endothelial growth factor-A (VEGFA), and cetuximab, an antibody against epithelial growth factor receptor (EGFR), are being used with oxaliplatin-based chemotherapy to obtain further improvement of outcome (4). It has already been reported that bevacizumab reduced the severity, as well as the incidence of SOS. The mechanism of the protective effect following VEGF blockade by bevacizumab may lead to down-regulation of matrix metalloproteinase (MMP)-9 and possibly reduces sinusoidal lesions (5, 6).
The development of SOS leads to portal hypertension and the resulting clinical presentation of tender hepatomegaly, fluid retention, hyperbilirubinemia and splenomegaly. Spleen size is correlated with an increasing grade of hepatic sinusoidal injury (5). Histopathological changes are characterized by sinusoidal dilation and congestion and subsequently nodular regenerative hyperplasia.
In addition, serum hyaluronic acid is a marker for endothelial cell injury in patients with SOS, which is also termed veno-occlusive disease, following bone marrow transplantation (7). However, to the best of our knowledge, the protective effect of bevacizumab against SOS in oxaliplatin-based chemotherapy has been evaluated only through pathological findings (5, 6, 8). We hypothesized that the protective effect of bevacizumab would be correlated with a change in spleen size and hyaluronic acid levels.
The aim of the present study was to evaluate the effect of bevacizumab on oxaliplatin-based chemotherapy administered prior to hepatic resection for metastasis of colorectal cancer on the change of spleen size and serum hyaluronic acid.
Patients and Methods
Study design and enrolled patients. In this retrospective study, using a University of Tokushima colorectal cancer and hepatic resection database, we identified 16 adult patients who underwent preoperative fluoropyrimidine [5-fluorouracil (5-FU) or capecitabine] and oxaliplatinum-based chemotherapy with or without bevacizumab before hepatic resection for colorectal liver metastases between 2005 and 2012 at the Tokushima University Hospital were evaluated retrospectively. In the bevacizumab-treated group (n=9), oxaliplatin-based chemotherapy with bevacizumab prior to hepatic resection was administered, while oxaliplatin-based chemotherapy alone was administered to the control group (n=7).
Volume of the spleen. The computed tomography (CT) scans were performed in patients with oxaliplatinum-based chemotherapy. Spleen volume was calculated by the commercially available Synapse Vincent® (Fuji Film, Tokyo, Japan) software. Changes in spleen size were determined for each CT time point by comparing the spleen size to that of the pre-treatment study. Splenomegaly was defined as a 50% or greater increase in spleen size compared with the baseline size.
Pathological evaluation of SOS. Archival material (prepared from formalin-fixed paraffin-embedded tissue) was reviewed for all patients, and representative sections of non-cancer hepatic parenchyma were selected. Morphological analysis was based in all cases on hematoxylin and eosin (H&E) staining. Histological features reflecting parenchymal, stromal and vascular change were evaluated to define the presence and grade of sinusoidal dilation according to a previously reported standard 4-point scale on which 0 indicates the absence of sinusoidal dilation, 1 mild sinusoidal dilation (centrilobular involvement limited to approximately one-third of the lobular surface), 2 moderate sinusoidal dilation (centrilobular involvement extending in approximately two-thirds of the lobular surface), and 3 severe sinusoidal dilation (complete lobular involvement) (9) by gastrointestinal pathologists who were blinded to the treatment and imaging findings (Figure 1).
Liver tests. All patients were monitored using standard liver biological tests, including serum bilirubin, alanine aminotransferase, prothrombin time, albumin and platelet count. Indocyanine green (ICG) retention at 15 min was measured by traditional spectrophotometry following a venous injection of the bolus dose of 0.5 mg/kg of ICG.
The receptor index (LHL15) was measured using following methods. After the injection of 3 mg (185 MBq) of Tc-99m galactosyl human serum albumin (Tc-GSA) (Nihon Medi-Physics, Nishinomiya, Japan), dynamic imaging was performed using a large field-of-view gamma camera. The LHL15 was calculated by dividing the radioactivity of the liver Regions of interest (ROI) by the radioactivity of the ROIs of the liver plus the heart at 15 minutes following injection (10).
Serum hyaluronic acid was assessed using a sequential radiometric assay (HA-test; Pharmacia Diagnostics, Uppsala, Sweden) based on the use of specific hyaluronan-binding proteins isolated from bovine cartilage. Intra- and interassay coefficients of variation were <7% and <9%, respectively. Normal level of hyaluronic acid in serum determined in the laboratory from 30 healthy individuals was 27±29 μg/l (mean±SD) (11).
Statistical analysis. Statistical comparisons of mean values were conducted using one-way analysis of variance (ANOVA). All results are presented as the mean±standard deviation (SD). A p-value of less than 0.05 was considered to be statistically significant. Statistical analysis was performed using JMP(®) 7.0.2 statistical software (SAS Institute, Cary, NC, USA).
Results
Liver biological tests. There was no significant difference between groups in the liver function tests including prothrombin time and albumin. On the other hand, the value of alanine aminotransferase, ICGR15, LHL15 and platelet counts in the bevacizumab-treated group had a tendency to be better than those of the control group (Table I).
Incidence of SOS. In pathological evaluation of non-tumorous liver parenchyma, the incidence of sinusoidal dilation of any grade (five out of nine patients; 55.6%) was significantly higher in the bevacizumab-treated group than in the control group (all of seven patients; 100%) (Figure 2a). The incidence of moderate and severe sinusoidal dilation (2 of 9 patients; 22.2%) was also significantly higher in the control group (5 of 7 patients; 71.4%) (Figure 2b). These differences were independent of the duration of chemotherapy and time interval between completion of chemotherapy and surgery.
Volume of the spleen and hyaluronic acid. CT scans were performed a median of one month after the completion of adjuvant chemotherapy and before chemotherapy. The level of hyaluronic acid was significantly lower in the bevacizumab-treated group compared with the control group (33.6±21.2 ng/ml vs. 352.4±609.3 ng/ml) (p<0.05) (Figure 3a). The increase ratio in spleen size and frequency of splenomegaly in the bevacizumab group was considerably lower than those in the control group (110.3%±27.5% vs. 146.3%±34.2%, and 11.1% vs. 57.1%, respectively; p<0.05) (Figure 3b). The level of hyaluronic acid was significantly lower in the bevacizumab-treated group compared with the control group (33.6±21.2 ng/ml vs. 352.4±609.3 ng/ml, respectively; p<0.05) (Figure 3b).
Discussion
To the best of our knowledge, this is the first report to show that bevacizumab reduced splenomegaly and serum levels of hyaluronic acid in patients with SOS due to oxaliplatin-based chemotherapy. Previous studies have reported spleen size and hyaluronic acid as biomarkers for the development of SOS. A decrease in spleen size and hyaluronic acid can serve as a simple method for evaluating the protective effects of bevacizumab and predicting the risk for SOS before hepatectomy without any pathological findings.
SOS was initially described as a life-threatening complication in patients after bone marrow transplantation (12-15). The incidence varies around 50% across Institutions where hematopoietic stem cell transplantation has been performed. Mortality rates for regimens that contain cyclophosphamide may be higher than the mortality rates for patients treated with other alkylating agents (16). Recently, SOS has been well-recognized as one of the adverse effects of oxaliplatin-based chemotherapy, along with the development of adjuvant therapy for advanced colorectal cancer.
Several reports suggest that SOS in the non-tumor liver parenchyma could increase the risk of liver resection for colorectal liver metastases because of the increase in the risk of intraoperative bleeding and need for transfusion (3, 17). Therefore, it is essential to evaluate the degree of liver injury and predict such a risk.
In the current study, serum hyaluronic acid was correlated with the severity of sinusoidal injury. In addition to pathological findings, serum hyaluronic acid and spleen size have been reported as biomarkers of SOS (7, 18). Hyaluronic acid is a polysaccharide that is metabolized almost exclusively by hepatic sinusoidal endothelial cells (7). Serum hyaluronic acid is elevated in patients with chronic liver disease, such as primary biliary cirrhosis and viral hepatitis (19, 20). The mechanism of increased hyaluronic acid could be due to either reduced clearance of hyaluronic acid by injured sinusoidal endothelial cells, or from increased production of hyaluronic acid by injured sinusoidal endothelial cells. Fried et al. reported that serum hyaluronic acid levels were higher in patients after bone marrow transplantation with moderate or severe SOS compared to those with no or mild SOS (7).
On the other hand, splenomegaly was reported as one of the clinical manifestations of SOS after oxaliplatin-based chemotherapy due to portal hypertension. Overman et al. reported that 86% of patients treated with adjuvant oxaliplatin-based chemotherapy showed increase in spleen size, with more than a 50% increase in 24% of patients. In patients treated with oxaliplatin-based chemotherapy, increase in spleen size was a predictor of higher histological grade of sinusoidal injury (5).
Several pathologists documented that toxic liver injury due to sinusoidal endothelial cells might manifest as sinusoidal dilation with erythrocyte extravasation in the peri-sinusoidal space, and hepatocyte plate disruption, which were signs of a loss of sinusoidal wall integrity (21). Deleve et al. revealed that the pathophysiological mechanism of SOS involved depolymerization of F-actin in sinusoidal endothelial cells, the activation of MMP9 and -2 by endothelial cells, and the consequent induction of oxidative stress (16, 22). Bevacizumab can neutralize free VEGF and thus inhibit VEGF-mediated endotherial cell proliferation, survival and migration in vitro (23); as a result, it can protect against SOS in terms of pathological findings, such as sinusoidal dilation, peliosis, fibrosis and perisinusoidal hemorrhage (5, 6, 8).
The present is a retrospective study. As the number of patients in this study was relatively small, a larger cohort study is needed to confirm our findings. Furthermore, the same design of study should be applied to a different dataset that does not contain the original patient population in order to confirm the validity of these findings.
In conclusion, bevacizumab can reduce SOS and suppress splenomegaly and the elevation of hyaluronic acid. In addition, a change in spleen size and serum hyaluronic acid would serve as a biomarker for the protective effect of bevacizumab against SOS.
- Received January 24, 2014.
- Revision received February 18, 2014.
- Accepted February 19, 2014.
- Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved