Birgit Gruenberger

Bevacizumab protects against sinusoidal obstruction syndrome and does not increase response rate in neoadjuvant XELOX/FOLFOX therapy of colorectal cancer liver metastases

AIM In patients suffering from colorectal cancer liver metastases, 5-fluorouracil-based chemotherapy plus oxaliplatin ensures superior response rates at the cost of hepatic injury. Knowledge about the consequences of bevacizumab on chemotherapy-induced hepatic injury and tumor response is limited. METHODS Resected liver specimens from patients of two prospective, non-randomized trials (5-fluorouracil/oxaliplatin+/-bevacizumab) were analyzed retrospectively. Hepatotoxicity to the non-tumor bearing liver was evaluated for sinusoidal obstruction syndrome, hepatic steatosis and fibrosis. Tumor response under chemotherapy was assessed according to Response Evaluation Criteria in Solid Tumors (RECIST). RESULTS Bevacizumab decreased the severity of the sinusoidal obstruction syndrome. Bevacizumab had no impact on hepatic steatosis and fibrosis. The addition of bevacizumab to chemotherapy had no effect on tumor response compared to combination chemotherapy alone. CONCLUSIONS This analysis shows that bevacizumab protects against the sinusoidal obstruction syndrome and thus provides the histological explanation of the safe use of bevacizumab prior to liver resection. Furthermore, we show that bevacizumab does not improve tumor response according to RECIST.

Lymph node ratio after curative surgery for intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is rare but its incidence is rising worldwide. The value of lymph node dissection for ICC is under discussion; the current staging systems do not differentiate between numbers of involved nodes.

Evidence for serotonin as a relevant inducer of liver regeneration after liver resection in humans

Liver regeneration (LR) involves a complex interplay of growth factors and antagonists. In this context, platelet‐derived serotonin (5‐HT) has been identified as a critical inducer of LR in mice. Clinical evidence for a role of 5‐HT in LR in humans is lacking. Accordingly, serum and plasma 5‐HT was monitored perioperatively in 60 patients undergoing liver resection, of which 35 served as exploration and 25 as validation sets. Intraplatelet (IP) levels of 5‐HT were calculated by subtraction of plasma 5‐HT from serum values. Serum markers of liver function were used to evaluate LR and liver dysfunction (LD). In the exploration setting, IP 5‐HT levels significantly decreased after liver resection (P < 0.001) and gradually recovered during the first week. IP 5‐HT measured before surgery specifically predicted LD in the subsequent 7 days (area under the curve: 0.721; P = 0.029). Patients suffering from postoperative LD and morbidity were found to have reduced IP 5‐HT levels during the entire perioperative period. Furthermore, we validated that reduced preoperative IP 5‐HT (<73 ng/mL) was associated with an increased incidence of postoperative LD and morbidity (P =0.045 and P = 0.021) and were able to demonstrate that IP 5‐HT levels were an independent predictor of poor clinical outcome. Conclusions: These findings provide evidence that IP 5‐HT correlates with LR in humans: Patients with low IP 5‐HT before liver resection suffered from delayed hepatic regeneration. Therefore, IP 5‐HT levels may prove a helpful clinical marker to predict postoperative LD and clinical outcome before hepatic resection and initiate suitable interventions. (Hepatology 2014;60:257‐266)

KRAS status and outcome of liver resection after neoadjuvant chemotherapy including bevacizumab

The prognostic value of KRAS mutation in patients with colorectal cancer liver metastases (CLM) receiving neoadjuvant chemotherapy including bevacizumab before liver resection is unclear.

Liver resection remains a safe procedure after neoadjuvant chemotherapy including bevacizumab: a case-controlled study.

Objective:This study was conducted to analyze if the combination of Bevacizumab with standard chemotherapy increases postoperative morbidity and mortality after resection of colorectal liver metastases as compared with resection after chemotherapy alone. Parameters contributing to an increased morbidity were evaluated. Summary Background Data:Most patients referred for colorectal liver metastases are treated with neoadjuvant chemotherapy before hepatic surgery. Targeted agents like the vascular endothelial growth factor—antagonist Bevacizumab are increasingly added to standard therapy to prolong survival; however, little is known about the consequences of this policy in the perioperative period. Methods:One hundred-two patients treated between 2005 and 2009, who received neoadjuvant chemotherapy combined with Bevacizumab (CHT + B) were identified. A cohort of 112 patients treated without chemotherapy alone before resection served as the control group (CHT). Complications were graded within an established staging system and the therapeutic consequences were laid down. Uni- and multivariate analysis of factors contributing to postoperative complications in the CHT + B group was performed using a logistic regression model. Results:Postoperative complications occurred in 45 (44%, CHT + B) and 38 (34%, CHT) patients, respectively (P = 0.216). The incidence of severe complications requiring surgical or radiologic intervention or leading to organ failure was 10.8% in the CHT + B group and 7.1% in the CHT group (P = 0.350). Increased age, low serum albumin, resection of more than 3 liver segments and synchronous bowel procedures requiring an anastomosis were associated with an increased morbidity rate in the multivariate regression analysis. No patient died in either group. Conclusions:The addition of Bevacizumab to standard chemotherapy before resection of colorectal liver metastases does not seem to increase postoperative morbidity. Caution should be given to extended resections >3 liver segments and synchronous bowel anastomoses.

Thrombospondin-1: a unique marker to identify in vitro platelet activation when monitoring in vivo processes.

Summary.  Background:  Measuring platelet activation in patients has become a potent method to investigate pathophysiological processes. However, the commonly applied markers are sensitive to detrimental influences by in vitro platelet activation during blood analysis.

Adequate preoperative staging rarely leads to a change of intraoperative strategy in patients undergoing surgery for colorectal cancer liver metastases

BACKGROUND Diagnostic tools used prior to hepatic surgery have significantly advanced during the last decade. We investigated the value of preoperative staging on detection of additional resectable hepatic lesions in metastatic colorectal cancer patients. METHODS One hundred ninety-four consecutive resections for colorectal liver metastases between January 2002 and December 2005 were prospectively analyzed. Data on imaging (multidetector computed tomography [MDCT] and magnetic resonance imaging [MRI]) were compared to intraoperative findings by intraoperative sonography and bimanual palpation together with histopathological examination. Univariate and multivariate analysis of factors influencing recurrence was performed. RESULTS In 16 (8.2%) resections, additional lesions were detected intraoperatively. In 11 cases (5.7%), these were small (<1 cm) and subcapsular. Detection of additional tumors was associated with shorter median recurrence free survival (5.4 vs. 13.4 months; P < .001) even though all lesions were resected and risk of recurrence was stratified by the Fong score. Patients treated with neoadjuvant chemotherapy did not generally have an increased risk of additional tumors; however, intraoperative detection of new lesions was associated with inferior outcome in this subgroup (median RFS 4.6 vs. 18.3 months in responders, P < .001). CONCLUSION Preoperative imaging with contrast-enhanced MDCT and MRI is efficient and very seldom leads to changes in intraoperative strategy. Patients exhibiting additional resectable hepatic lesions upon surgery have a high risk for early recurrence and should be monitored closely during follow-up.

Neoadjuvant Treatment of Colorectal Cancer with Bevacizumab: The Perioperative Angiogenic Balance Is Sensitive to Systemic Thrombospondin-1 Levels

Purpose: Colorectal cancer patients receiving neoadjuvant treatment with bevacizumab, a monoclonal antibody neutralizing vascular endothelial growth factor (VEGF), may suffer from wound healing complications after surgery as the antibody persists in patient blood. We characterized the systemic angiogenic balance in the perioperative period to evaluate its effect on physiologic angiogenesis. Experimental Design: Nineteen patients receiving combination chemotherapy and bevacizumab for six neoadjuvant cycles were compared with 14 patients receiving chemotherapy without bevacizumab. Plasma from perioperative days −1, +1, +7, and +21 was analyzed for VEGF, thrombospondin-1 (TSP-1), and PD-ECGF concentrations. The angiogenic capacity was further tested in an in vitro assay of endothelial cell proliferation and migration. Results: On day +1, the onset of wound healing was reflected in a change of balance, i.e., an increase of proangiogenic factors VEGF and platelet-derived endothelial cell growth factor compared with low TSP-1 inhibitor levels in both treatment groups. Patients with bevacizumab therapy showed significantly higher blood levels of total VEGF throughout the evaluation period. However, most VEGF molecules were inactive, i.e., complexed with antibody. Nevertheless, the capacity to stimulate endothelial growth was higher for these plasma samples and was reflected in low TSP-1 levels and an altered TSP-1 sensitivity. When purified TSP-1 protein was added, plasma samples of the bevacizumab but not the chemotherapy group showed reduced endothelial growth. Conclusions: Feedback mechanisms of bevacizumab therapy are not restricted to VEGF expression but seem to involve additional factors, such as TSP-1, which influences the systemic angiogenic balance and permits endothelial growth.

Plasma thrombospondin 1 as a predictor of postoperative liver dysfunction.

Liver regeneration following liver resection involves a complex interplay of growth factors and their antagonists. Thrombospondin 1 has recently been identified as a critical inhibitor of liver regeneration by the activation of transforming growth factor β1 in mice, and preliminary data seem to confirm its relevance in humans. This study aimed to confirm these observations in an independent validation cohort.

Clinical evidence for thrombospondin-1 as a relevant suppressor of liver regeneration

To the Editor: The most significant factor determining morbidity and mortality following hepatectomy is the ability of the remnant liver to regenerate. In this context, Hayashi et al. [1] recently reported on a previously unknown role of thrombospondin-1 (TSP-1) in liver regeneration (LR). During tissue remodeling, TSP-1 is released into the pericellular space to regulate cell survival and extracellular matrix remodeling [2]. A major TSP-1 function is the conversion of latent TGF-b1 (transforming growth factor-beta 1) to its active form [3]. Based on a mouse model of partial hepatectomy, Hayashi et al. [1] demonstrated that TSP-1 was rapidly released in response to liver resection and triggered TGF-b1 activation and signal transduction in hepatocytes as a mechanism to inhibit the proliferative hepatic response [4–5]. Accordingly, knockdown of TSP-1 expression resulted in a significant reduction of TGF-b1 signaling, which promoted the proliferation of hepatocytes and accelerated LR [1]. Thus, TSP-1 was proposed as an inhibitory element and a potential therapeutic target of LR. We are now able to present the first clinical data, which support the relevance of TSP-1 in LR based on a cohort of metastasized colorectal cancer (mCRC) patients undergoing hepatic resection of liver metastases. A total of 66 mCRC patients without preexisting liver disease were included. Blood was retrieved before surgery (pre OP) and on day 1 (POD1) or days 5–8 (POD5) after liver resection, and plasma was prepared with an optimized method [6–7]. Samples were assayed by ELISA for human TSP-1 (R&D Systems, Minneapolis, MN, USA) and TGF-b1 (eBioscience, San Diego, CA, USA). For statistical analysis, non-parametric tests (Mann–Whitney U test, Wilcoxon test and Spearman correlation) and the Fisher exact test were applied. A significant increase in TSP-1 (Fig. 1A) and TGF-b1 was observed on POD1 (p = 0.007 and p = 0.006, respectively), which dropped moderately until POD5 (p = 0.016 and p = 0.397). Circulating TSP-1 and TGF-b1 showed a highly significant correlation (k = 0.736, p <0.001). To further investigate whether a high postoperative release of TSP-1 or TGF-b1 was associated with delayed LR, we assessed the incidence of postoperative liver dysfunction (LD), based on the previously defined ‘‘50–50 criteria’’ [8], with a prothrombin time (PT) <50% and a serum bilirubin (SB) level >50 lmol/L (>2.9 mg/dl). Our classification referred to measurements of any day within the first postoperative week to identify patients with delayed postoperative hepatic recovery. TSP-1 concentrations were significantly elevated (Fig. 1B) in patients with LD (median TSP-1 for LD: 98.8 ng/ml; no LD: 44.6 ng/ml, p = 0.003). Comparably, circulating TGF-b1 tended to be increased in individuals with LD (median TGF-b1 for LD: 2266 pg/ml; no LD: 1726 pg/ml), but the difference was not statistically significant (p = 0.102). Of note, our analyses were restricted to total TGF-b1 in patient blood since activated TGF-b1 was below ELISA detection limit. This may explain the lack of association between TGF-b1 levels and postoperative LD. To further characterize the potential of TSP-1 to predict postoperative LD, a ROC analysis was performed (Fig. 1C), revealing a significant predictive value of circulating TSP-1 on POD1 (AUC: 0.870; p = 0.003). A cut-off level of 100 ng/ml TSP-1 on POD1 was deduced to determine the high-risk group for postoperative LD with 95% specificity. No statistically significant difference in age and sex distribution or the site of primary tumor, type of hepatic resection and preoperative liver function parameters was observed between the TSP-1 individuals (>100 ng/ml TSP-1) and patients with lower circulating TSP-1 levels on POD1. When biochemical markers of postoperative liver function were compared between these groups, the TSP-1 patients showed a significant elevation in SB (Fig. 1D) and c-glutamyltransferase (p <0.001; p = 0.011). Prothrombin time (Fig. 1E) was found to be significantly decreased in TSP-1 patients (p <0.001). A trend towards elevated alanine and aspartate