Impact of bevacizumab on functional recovery and histology of the liver after resection of colorectal metastases.

BACKGROUND: The impact of bevacizumab on functional recovery and histology of the liver was evaluated in patients undergoing hepatic resection for colorectal liver metastases (CLM) following bevacizumab treatment. METHODS: Consecutive patients who had resection of CLM between July 2005 and July 2009 following preoperative chemotherapy were identified retrospectively from a prospectively collected database. Patients who had received bevacizumab before the last chemotherapy line were excluded. Postoperative liver function and histology were compared between patients with and without bevacizumab treatment. Recorded parameters included serum prothrombin time, total bilirubin concentration, and levels of aspartate and alanine aminotransferase and γ-glutamyltransferase. RESULTS: Of 208 patients identified, 67 had received last-line bevacizumab, 44 were excluded and 97 had not received bevacizumab. Most patients in the bevacizumab group (66 per cent) received a single line of chemotherapy. Bevacizumab was most often combined with 5-flurouracil/leucovorin and irinotecan (68 per cent). The median number of bevacizumab cycles was 8·6 (range 1-34). Bevacizumab administration was stopped a median of 8 (range 3-19) weeks before surgery. There were no deaths. Postoperative morbidity occurred in 43 and 36 per cent of patients in the bevacizumab and no-bevacizumab groups respectively (P = 0·353). The mean(s.d.) degree of tumour necrosis was significantly higher in the bevacizumab group (55(27) versus 32(29) per cent; P = 0·001). Complete pathological response rates were comparable (3 versus 8 per cent; P = 0·307). Postoperative changes in functional parameters and objective signs of hepatic toxicity were similar in both groups. CONCLUSION: Preoperative administration of bevacizumab does not seem to affect functional recovery of the liver after resection of CLM. Tumour necrosis is increased following bevacizumab treatment.

Utility or futility of prognostic scoring systems for colorectal liver metastases in an era of advanced multimodal therapy.

OBJECTIVES: To assess the general applicability of prognostic scores for colorectal liver metastases (CRLM). METHODS: Review of English language studies from 1980 to 2008 (Medline and Embase). Search keywords included "Colorectal neoplasms", "liver metastases", "liver resection", "prognostic scoring system". RESULTS: Six scoring systems and fourteen prognostic factors within these studies were identified. No prognostic factor was common in all scoring methods. Five scores retained the number of metastases as a prognostic factor. Size of metastases and time between the onset of the primary tumor and the discovery of metastases were present in four scores. Three scores predicted 5-year survival using carcinoembryonic antigen (CEA) and R1 resection. Only two scores were assessed preoperatively. Successive scoring methods had improved predictive accuracy compared to earlier systems. However, their applicability in general populations remains debatable. An evaluation of the scores applicability to different patient populations demonstrated that the models were minimally effective in predicting disease-specific survival and recurrence, suggesting that stratification of patients by clinical and pathologic factors alone, may be clinically unreliable and not applicable for selection of patients for surgery. CONCLUSION: The utility of prognostic models on general populations is inconsistent. Current clinicopathologic factors may be inadequate to determine disease prognosis in CRLM. Future attempts to develop prognostic scores should include additional biologic and clinical variables, and be validated in larger populations.

Silencing of TLR4 decreases liver tumor burden in a murine model of colorectal metastasis and hepatic steatosis.

BACKGROUND: The relationship between obesity and cancer has become of particular interest due to the rapidly growing prevalence of overweight individuals. Obesity predisposes individuals to the development of hepatic steatosis and is an independent risk factor for several neoplasms. Toll-like receptor 4 (TLR4) is the innate receptor for endotoxin, and steatotic livers are known to be sensitive to endotoxin. TLR4 signaling has been shown to have proneoplastic effects in vitro due to its effect on immune surveillance. Thus far, studies have predominantly focused on the effect of tumor-cell-derived TLR4 without regard to host TLR4 signaling. RESULTS: In the present study we show that steatotic livers have increased expression of TLR4. Obese animals developed higher metastatic tumor burden in the liver than lean controls regardless of the presence or absence of intact host TLR4. After silencing TLR4 expression using RNAi in the mouse colon cancer cell line MC38, there was a significant decrease in metastatic tumor burden within the liver of obese animals. CONCLUSIONS: These findings demonstrate that steatotic livers have increased susceptibility to metastatic tumor growth and that silencing tumor cell TLR4 reduces metastatic tumor burden in steatotic liver.

Vascular endothelial growth factor is increased in devascularized rat islets of Langerhans in vitro.

Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen with potent angiogenic and vascular permeability-inducing properties, both of which may be important for the function of islets of Langerhans. In this study, we have examined the expression of VEGF and its tyrosine kinase receptors (flt and flk-1) in isolated rat islets of Langerhans in vitro. When analyzed by in situ hybridization, islet tissue showed a significant 4.6-fold increase in VEGF mRNA expression over time in culture from 0 to 7 days. Islet tissue exposed to hypoxic/anoxic conditions for a period of 8 hr showed a 3.7-fold increase in VEGF mRNA when analyzed by Northern blot hybridization. Reverse transcriptase-polymerase chain reaction revealed the presence of both flt and flk-1 in freshly isolated islets, and two VEGF isoforms, namely VEGF120 and VEGF164. Three rodent beta-cell lines derived from insulinomas (RINm5F-2A, INS-1, and MIN6) were also found to express VEGF by Northern blot hybridization. However, neither hypoxia/anoxia nor low (0.3 g/L)- or high (3.0 g/L)-glucose culture conditions modulated their expression of VEGF. VEGF derived from RINm5F-2A cells was bioactive in a three-dimensional in vitro model of angiogenesis, which assays for endothelial cell invasion and capillary morphogenesis. These findings demonstrate, first, that devascularization increases VEGF expression in isolated islet tissue, and they point to VEGF as a potentially important endogenous angiogenic stimulus for subsequent revascularization in vivo. Second, our observations raise the possibility that survival of transplanted islets may be improved by increasing VEGF expression before transplantation.

Cell surface alteration in Epstein-Barr virus-transformed cells from patients with extreme insulin resistance.

An abnormality was detected in the morphology of the cell surface of Epstein-Barr virus-transformed lymphocytes of patients with genetic forms of insulin resistance. In cells from two patients with leprechaunism and two patients with type A extreme insulin resistance, scanning electron microscopy demonstrated a decrease in the percentage of the cell surface occupied by microvilli in cells from the patients with leprechaunism and type A insulin resistance compared with control cells. When cells from a healthy control subject and one of the patients with leprechaunism (Lep/Ark-1) were incubated with 125I-labeled insulin, there was a decrease in the percentage of 125I-insulin associated with microvilli on the cell surface. Thus, the decreased localization of insulin receptors with the microvillous region of the cell surface was in proportion to the decrease in microvilli.