Surgery and angiogenesis

Surgical trauma-induced immunosuppression in cancer: Recent advances and the potential therapies

Surgical resection remains the mainstay treatment for solid cancers, especially for localized disease. However, the postoperative immunosuppression provides a window for cancer cell proliferation and awakening dormant cancer cells, leading to rapid recurrences or metastases. This immunosuppressive status after surgery is associated with the severity of surgical trauma since immunosuppression induced by minimally invasive surgery is less than that of an extensive open surgery. The systemic response to tissue damages caused by surgical operations and the subsequent wound healing induced a cascade alteration in cellular immunity. After surgery, patients have a high level of circulating damage-associated molecular patterns (DAMPs), triggering a local and systemic inflammation. The inflammatory metrics in the immediate postoperative period was associated with the prognosis of cancer patients. Neutrophils provide the first response to surgical trauma, and the production of neutrophil extracellular traps (NETs) promotes cancer progression. Activated macrophage during wound healing presents a tumor-associated phenotype that cancers can exploit for their survival advantage. In addition, the amplification and activation of myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs) or the elevated programmed death ligand-1 and vascular endothelial growth factor expression under surgical trauma, exacerbate the immunosuppression and favor of the formation of the premetastatic niche. Therapeutic strategies to reduce the cellular immunity impairment after surgery include anti-DAMPs, anti-postoperative inflammation or inflammatory/pyroptosis signal, combined immunotherapy with surgery, antiangiogenesis and targeted therapies for neutrophils, macrophages, MDSCs, and Tregs. Further, the application of enhanced recovery after surgery also has a feasible outcome for postoperative immunity restoration. Overall, current therapies to improve the cellular immunity under the special condition after surgery are relatively lacking. Further understanding the underlying mechanisms of surgical trauma-related immunity dysfunction, phenotyping the immunosuppressive cells, and developing the related therapeutic intervention should be explored.

Pterins as Diagnostic Markers of Mechanical and Impact-Induced Trauma: A Systematic Review

We performed a systematic review of the literature to evaluate pterins as biomarkers of mechanical and impact-induced trauma. MEDLINE and Scopus were searched in March 2019. We included in vivo human studies that measured a pterin in response to mechanical or impact-induced trauma with no underlying prior disease or complication. We included 40 studies with a total of 3829 subjects. Seventy-seven percent of studies measured a significant increase in a pterin, primarily neopterin or total neopterin (neopterin + 7,8-dihydroneopterin). Fifty-one percent of studies measured an increase within 24 h of trauma, while 46% measured increases beyond 48 h. Pterins also showed promise as predictors of post-trauma complications such as sepsis, multi-organ failure and mortality. Exercise-induced trauma and traumatic brain injury caused an immediate increase in neopterin or total neopterin, while patients of multiple trauma had elevated pterin levels that remained above baseline for several days. Pterin concentration changes in response to surgery were variable with patients undergoing cardiac surgery having immediate and sustained pterin increases, while gastrectomy, liver resection or hysterectomy showed no change. This review provides systematic evidence that pterins, in particular neopterin and total neopterin, increase in response to multiple forms of mechanical or impact-induced trauma.

Differential Expression of Vascular Endothelial Growth Factor-A165 Isoforms Between Intracranial Atherosclerosis and Moyamoya Disease

BACKGROUND

Vascular endothelial growth factor-A₁₆₅ (VEGF-A₁₆₅) has been identified as a combination of 2 alternative splice variants: proangiogenic VEGF-A₁₆₅a and antiangiogenic VEGF-A₁₆₅b. Intracranial atherosclerotic disease (ICAD) and moyamoya disease (MMD) are 2 main types of intracranial arterial steno-occlusive disorders with distinct capacities for collateral formation. Recent studies indicate that VEGF-A₁₆₅ regulates collateral growth in ischemia. Therefore, we investigated if there is a distinctive composition of VEGF-A₁₆₅ isoforms in ICAD and MMD.

METHODS

Sixty-six ICAD patients, 6 MMD patients, and 5 controls were enrolled in this prospective study. ICAD and MMD patients received intensive medical management upon enrollment. Surgery was offered to 9 ICAD patients who had recurrent ischemic events, 6 MMD patients, and 5 surgical controls without ICAD. VEGF-A₁₆₅a and VEGF-A₁₆₅b plasma levels were measured at baseline, within 1 week after patients having surgery, and at 1, 3, and 6 months after treatment.

RESULTS

A significantly higher baseline VEGF-A₁₆₅a/b ratio was observed in MMD compared to ICAD (P = .016). The VEGF-A₁₆₅a/b ratio increased significantly and rapidly after surgical treatment in ICAD (P = .026) more so than in MMD and surgical controls. In patients with ICAD receiving intensive medical management, there was also an elevation of the VEGF-A₁₆₅a/b ratio, but at a slower rate, reaching the peak at 3 months after initiation of treatment (baseline versus 3 months VEGF-A₁₆₅a/b ratio, P = .028).

CONCLUSIONS

Our study shows an increased VEGF-A₁₆₅a/b ratio in MMD compared to ICAD, and suggests that both intensive medical management and surgical revascularization elevate the VEGF-A₁₆₅a/b ratio in ICAD patients.

Testing an unusual in vivo vessel network model: a method to study angiogenesis in the colonial tunicate Botryllus schlosseri

Tunicates are the closest relatives to vertebrates and include the only chordate species able to reproduce both sexually and asexually. The colonial tunicate Botryllus schlosseri is embedded in a transparent extracellular matrix (the tunic) containing the colonial circulatory system (CCS). The latter is a network of vessels external to zooids, limited by a simple, flat epithelium that originated from the epidermis. The CCS propagates and regenerates by remodelling and extending the vessel network through the mechanism of sprouting, which typically characterises vertebrate angiogenesis. In exploiting the characteristics of B. schlosseri as a laboratory model, we present a new experimental and analysis method based on the ability to obtain genetically identical subclones representing paired samples for the appropriate quantitative outcome statistical analysis. The method, tested using human VEGF and EGF to induce angiogenesis, shows that the CCS provides a useful in vivo vessel network model for testing the effects of specific injected solutes on vessel dynamics. These results show the potentiality of B. schlosseri CCS as an effective complementary model for in vivo studies on angiogenesis and anticancer therapy. We discuss this potentiality, taking into consideration the origin, nature, and roles of the cellular and molecular agents involved in CCS growth.

Implanted neonatal human dermal fibroblasts influence the recruitment of endothelial cells in mice

The vascularization of new tissue within a reasonable time is a crucial prerequisite for the success of different cell- and material-based strategies. Considering that angiogenesis is a multi-step process involving humoral and cellular regulatory components, only in vivo assays provide the adequate information about vessel formation and the recruitment of endothelial cells. The present study aimed to investigate if neonatal human dermal fibroblasts could influence in vivo neovascularization. Results obtained showed that fibroblasts were able to recruit endothelial cells to vascularize the implanted matrix, which was further colonized by murine functional blood vessels after one week. The vessels exhibited higher levels of hemoglobin, compared with the control matrix, implanted without fibroblasts, in which no vessel formation could be observed. No significant differences were detected in systemic inflammation. The presence of vessels originated from the host vasculature suggested that host vascular response was involved, which constitutes a fundamental aspect in the process of neovascularization. Fibroblasts implanted within matrigel increased the presence of endothelial cells with positive staining for CD31 and for CD34 and the production of collagen influencing the angiogenic process and promoting the formation of microvessels. New strategies in tissue engineering could be delineated with improved angiogenesis using neonatal fibroblasts.

The "cavitary" type of angiogenesis by gastric cancer. Morphological characteristics and prognostic value

The "cavitary" type of angiogenesis in patients with gastric cancer (GC) is described for the first time.

MATERIAL AND METHODS

The samples of tumour and adjacent gastric mucosa (GM) in 73 patients with GC who had undergone radical surgery were being studied. The sections were stained with hematoxylin and eosin (H&E) and immunohistochemically (IGH) using antibodies to CD34.

RESULTS

А new type of vessel formation consists of the appearance of cavitary structures (CS) in tumours and the adjacent GM, which are then lined by endothelial cells and merged into the blood vessels of the organ. We believe that the CS can be formed by means: 1) of the abruption of layers of epithelial cells (both normal and tumoral) from their underlying foundation and their desquamation into the lumen of the "obliterated" gastric glands (GG); 2) of the dilatation of the GG and thinning of their walls; 3) of the formation of "cavity" directly in the lamina propria of GM or in the tumoral stroma. It was noted that only the presence of multiple "cavitary" vessels (CV) of type-1 had been associated with the decrease of 3-year overall survival (OR=15,0, 95%CI=2,96-76,31) and relapse-free survival (OR=14,93, 95%CI=4,34-51,38). We also observed the improvement of the long-term outcomes in patients with GC having received antibacterial therapy (AT) before surgery that can be associated with its influence on the formation of CV type-1.

CONCLUSION

The described new type of angiogenesis is of great clinical importance.

Population pharmacokinetics of bevacizumab in children with osteosarcoma: implications for dosing

PURPOSE

To describe sources of interindividual variability in bevacizumab disposition in pediatric patients and explore associations among bevacizumab pharmacokinetics and clinical wound healing outcomes.

EXPERIMENTAL DESIGN

Before tumor resection, three doses of bevacizumab (15 mg/kg) were administered to patients (median age, 12.2 years) enrolled in a multi-institutional osteosarcoma trial. Serial sampling for bevacizumab pharmacokinetics was obtained from 27 patients. A population pharmacokinetic model was fit to the data, and patient demographics and clinical chemistry values were systematically tested as predictive covariates on model parameters. Associations between bevacizumab exposure and wound healing status were evaluated by logistic regression.

RESULTS

Bevacizumab concentration-time data were adequately described by a two-compartment model. Pharmacokinetic parameter estimates were similar to those previously reported in adults, with a long median (range) terminal half-life of 12.2 days (8.6 to 32.4 days) and a volume of distribution indicating confinement primarily to the vascular space, 49.1 mL/kg (27.1 to 68.3 mL/kg). Body composition was a key determinant of bevacizumab exposure, as body mass index percentile was significantly (P < 0.05) correlated to body-weight normalized clearance and volume of distribution. Furthermore, bevacizumab exposure before primary tumor resection was associated with increased risk of major wound healing complications after surgery (P < 0.05).

CONCLUSION

A population pharmacokinetic model for bevacizumab was developed, which demonstrated that variability in bevacizumab exposure using weight-based dosing is related to body composition. Bevacizumab dosage scaling using ideal body weight would provide an improved dosing approach in children by minimizing pharmacokinetic variability and reducing likelihood of major wound healing complications.

Tanshinone IIA inhibits metastasis after palliative resection of hepatocellular carcinoma and prolongs survival in part via vascular normalization

BACKGROUND

Promotion of endothelial normalization restores tumor oxygenation and obstructs tumor cells invasion, intravasation, and metastasis. We therefore investigated whether a vasoactive drug, tanshinone IIA, could inhibit metastasis by inducing vascular normalization after palliative resection (PR) of hepatocellular carcinoma (HCC).

METHODS

A liver orthotopic double-tumor xenograft model in nude mouse was established by implantation of HCCLM3 (high metastatic potential) and HepG2 tumor cells. After removal of one tumor by PR, the effects of tanshinone IIA administration on metastasis, tumor vascularization, and survival were evaluated. Tube formation was examined in mouse tumor-derived endothelial cells (TECs) treated with tanshinone IIA.

RESULTS

PR significantly accelerated residual hepatoma metastases. Tanshinone IIA did not inhibit growth of single-xenotransplanted tumors, but it did reduce the occurrence of metastases. Moreover, it inhibited PR-enhanced metastases and, more importantly, prolonged host survival. Tanshinone IIA alleviated residual tumor hypoxia and suppressed epithelial-mesenchymal transition (EMT) in vivo; however, it did not downregulate hypoxia-inducible factor 1α (HIF-1α) or reverse EMT of tumor cells under hypoxic conditions in vitro. Tanshinone IIA directly strengthened tube formation of TECs, associated with vascular endothelial cell growth factor receptor 1/platelet derived growth factor receptor (VEGFR1/PDGFR) upregulation. Although the microvessel density (MVD) of residual tumor tissue increased after PR, the microvessel integrity (MVI) was still low. While tanshinone IIA did not inhibit MVD, it did dramatically increase MVI, leading to vascular normalization.

CONCLUSIONS

Our results demonstrate that tanshinone IIA can inhibit the enhanced HCC metastasis associated with PR. Inhibition results from promoting VEGFR1/PDGFR-related vascular normalization. This application demonstrates the potential clinical benefit of preventing postsurgical recurrence.

Use of S-100B to evaluate therapy effects during bevacizumab induction treatment in AJCC stage III melanoma

AIM

To investigate the feasibility of using bevacizumab to improve the survival of American Joint Committee on Cancer (AJCC) stage III melanoma patients, we investigated how a single bevacizumab treatment affected nodal disease and a panel of biomarkers in clinically fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT)-staged, stage III melanoma patients, prior to therapeutic lymph node dissection (TLND).

METHODS

Four weeks before TLND, nine patients (median age 50, range 28.8-62.1 years; two male, seven female) with palpable lymph node metastases received 7.5 mg/kg bevacizumab. Before and after this treatment, all patients were assessed by measurements of the maximum standardized uptake value (SUVmax) by FDG-PET scan, and serum S-100B and lactate dehydrogenase (LDH). After TLND, the dissection specimen was analyzed for number of removed lymph nodes, number of metastatic lymph nodes, and tumor necrosis.

RESULTS

Median follow-up was 15.5 (2.2-32.9) months. Histopathological analysis revealed tumor necrosis in six patients, of whom five had an S-100B decline and one had an unchanged S-100B level after bevacizumab. The other three patients showed an S-100B increase and no necrosis. Tumor necrosis was correlated with S-100B decrease (P = 0.048). No association was found between necrosis and the markers SUVmax and LDH. No wound healing disturbances were encountered.

CONCLUSION

Tumor necrosis in dissection specimens was associated with declining S-100B levels, while elevated S-100B was only found in cases with no necrosis. Bevacizumab might be useful in treating AJCC stage III melanoma patients prior to TLND, and S100-B appears to be a useful marker for assessment of treatment effects.

Technical solutions to ensure safe yttrium-90 radioembolization in patients with initial extrahepatic deposition of (99m)technetium-albumin macroaggregates

Purpose

To evaluate the incidence of extrahepatic deposition of technetium-99m–labeled albumin macroaggregates (^99mTc-MAA) after pretreatment angiography, before yttrium-90 radioembolizaton (⁹⁰Y-RE), and to report on technical solutions that can be used to ensure safe delivery of ⁹⁰Y-microspheres in patients with initial extrahepatic deposition.

Materials and Methods

A retrospective analysis of 26 patients with primary and secondary liver malignancies, who were scheduled for treatment with ⁹⁰Y-RE in our institution in 2009, was performed. The angiograms and single-photon emission computed tomography images of all patients were reviewed by an interventional radiologist and a nuclear medicine physician, respectively, to identify and localize extrahepatic deposition of ^99mTc-MAA when present. Subsequently, the technical solutions were used to successfully perform ⁹⁰Y-RE in these patients were evaluated and described.

Results

Extrahepatic deposition of ^99mTc-MAA was observed in 8 of 26 patients (31%). In 7 of 8 patients, a second pretreatment angiography was performed to detect the cause of extrahepatic deposition. The technical solutions to enable safe ⁹⁰Y microspheres delivery included more distal placement of the microcatheter in the proper/right hepatic artery in 4 of 7 (57%) patients; (super)selective catheterization of multiple segmental branches in 2 of 7 (29%); and additional coiling of a newly detected branch in the remaining patient (14%). This was confirmed by a second MAA procedure. ⁹⁰Y-RE was eventually performed in 25 of 26 (96%) patients. No procedure-related complications (<30 days) were observed.

Conclusion

Extrahepatic deposition of ^99mTc-MAA after pretreatment angiography did occur in 8 of 26 (31%) patients. The technical solutions as presented allowed safe ⁹⁰Y-RE delivery in 25 of 26 (96%) patients.

Perinecrotic hypoxia contributes to ischemia/reperfusion-accelerated outgrowth of colorectal micrometastases

Ischemia/reperfusion (I/R) is often inevitable during hepatic surgery and may stimulate the outgrowth of colorectal micrometastases. Postischemic microcirculatory disturbances contribute to I/R damage and may induce prolonged tissue hypoxia and consequent stabilization of hypoxia-inducible factor (HIF)-1alpha. The aim of this study was to evaluate the contribution of postischemic microcirculatory disturbances, hypoxia, and HIF-1alpha to I/R-accelerated tumor growth. Partial hepatic I/R attributable to temporary clamping of the left liver lobe induced microcirculatory failure for up to 5 days. This was accompanied by profound and prolonged perinecrotic tissue hypoxia, stabilization of HIF-1alpha, and massive perinecrotic outgrowth of pre-established micrometastases. Restoration of the microcirculation by treatment with Atrasentan and L-arginine minimized hypoxia and HIF-1alpha stabilization and reduced the accelerated outgrowth of micrometastases by 50%. Destabilization of HIF-1alpha by the HSP90 inhibitor 17-DMAG caused an increase in tissue necrosis but reduced I/R-stimulated tumor growth by more than 70%. In conclusion, prevention of postischemic microcirculatory disturbances and perinecrotic hypoxia reduces the accelerated outgrowth of colorectal liver metastases after I/R. This may, at least in part, be attributed to the prevention of HIF-1alpha stabilization. Prevention of tissue hypoxia or inhibition of HIF-1alpha may represent attractive approaches to limiting recurrent tumor growth after hepatic surgery.

Tumour angiogenesis: the relevance to surgeons

INTRODUCTION

Angiogenesis is the process of new blood vessel formation from pre-existing vessels, and is a key feature of malignant tumours. Surgeons involved in the management of patients with malignant disease need to be aware of angiogenic mechanisms and their surgical implications.

PATIENTS AND METHODS

A literature search was used to review recent developments in our understanding of the factors and processes involved in tumour angiogenesis, and how these will impact on the care of patients with malignant disease encountered by surgeons.

RESULTS

Angiogenesis is fundamental to all stages of the malignant process, and involves a complex interaction between mediators secreted by tumour cells and host cells. Intense investigation continues into therapies targeting components of the angiogenic cascade. Imaging modalities capable of measuring the angiogenic activity of a tumour are also being studied in order to predict prognosis and select suitable patients for anti-angiogenic therapy.

CONCLUSIONS

As the use of these anti-angiogenic therapies becomes more wide-spread, they may have implications on the healing rates of cutaneous wounds and intracorporeal anastomoses.

Surgical wound healing complications in metastatic colorectal cancer patients treated with bevacizumab

BACKGROUND

Bevacizumab (Avastin; rhuMab VEGF), a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), significantly prolongs survival when added to intravenous 5-fluorouracil-based chemotherapy in first-line metastatic colorectal cancer (CRC) treatment. Because antiangiogenic agents might inhibit wound healing, we assessed postoperative wound healing complications in two randomized trials of 5 mg/kg bevacizumab in CRC treatment.

METHODS

We assessed the wound healing complications in patients who: (1) underwent cancer surgery 28-60 days before study treatment and (2) underwent major surgery during study treatment. Cases were reviewed for wound healing complications occurring < or = 60 days after surgery.

RESULTS

With cancer surgery 28-60 days before study treatment, wound healing complications occurred in 3/230 (1.3%) bevacizumab-treated patients and 1/194 (0.5%) control patients. With major surgery during study treatment, 10/75 bevacizumab-treated patients (13%) and 1/29 control patients (3.4%) had wound healing complications. Bevacizumab-treated patients experienced complications with surgery < or = 30 and 31-60 days after the last dose.

CONCLUSIONS

Bevacizumab administered in combination with 5-fluorouracil/leucovorin-based chemotherapy 28-60 days after primary cancer surgery caused no increased risk of wound healing complications compared with chemotherapy alone. While wound healing complications were increased in patients who had major surgery during bevacizumab therapy, the majority of bevacizumab-treated patients experienced no complications.

Are There Downsides to Mammography Screening?

Most Americans clearly believe that routine screening mammography is beneficial. Given its widespread acceptance, it is useful to consider what the downsides of mammography screening are so that patients are fully informed in the decisions they make. This article lists some less well-recognized risks of mammography, such as false negatives and their accompanying false reassurance, as well as the direct and indirect costs to women and society. Three important downsides-radiation hazard, overdiagnosis of breast cancer, and the paradoxical increase in breast cancer mortality observed in screened women compared to controls age 40-49 years-are addressed. The article also considers the reasons that women are poorly informed about the downsides of mammography. There is, however, agreement that early diagnosis and treatment are important, and that new methods to reduce breast cancer deaths must be sought.