VEGF and endostatin levels in wound fluid and plasma after breast surgery

Contemporaneous Perioperative Inflammatory and Angiogenic Cytokine Profiles of Surgical Breast, Colorectal, and Prostate Cancer Patients: Clinical Implications

Surgery-induced tumor growth acceleration and synchronous metastatic growth promotion have been observed for decades. Surgery-induced wound healing, orchestrated through growth factors, chemokines, and cytokines, can negatively impact patients harboring residual or metastatic disease. We provide detailed clinical evidence of this process in surgical breast, prostate, and colorectal cancer patients. Plasma samples were analyzed from 68 cancer patients who had not received treatment before surgery or adjuvant therapy until at least four weeks post-surgery. The levels of plasma cytokines, chemokines, and growth factors were simultaneously quantified and profiled using multiplexed immunoassays for eight time points sampled per patient. The immunologic processes are induced immediately after surgery in patients, characterized by a drastic short-term shift in the expression levels of pro-inflammatory and angiogenic molecules and cytokines. A rapid and significant spike in circulating plasma levels of hepatocyte growth factor (HGF), interleukin-6 (IL-6), placental growth factor (PLGF), and matrix metalloproteinase-9 (MMP-9) after surgery was noted. The rise in these molecules was concomitant with a significant drop in transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF-AB/BB), insulin-like growth factor-1 (IGF-1), and monocyte chemoattractant protein-2 (MCP-2). If not earlier, each plasma analyte was normalized to baseline levels within 1-2 weeks after surgery, suggesting that surgical intervention alone was responsible for these effects. The effects of surgical tumor removal on disrupting the pro-inflammatory and angiogenic plasma profiles of cancer patients provide evidence for potentiating malignant progression. Our findings indicate a narrow therapeutic window of opportunity after surgery to prevent disease recurrence.

Ethanol Sclerotherapy for Postoperative Seroma of the Breast and Axilla

OBJECTIVE

Evaluate the effectiveness of alcohol sclerotherapy in postoperative breast and axillary seromas.

METHODS

This was an IRB-approved retrospective review of consecutive patients from 2017 to 2021. The procedure involves aspiration of seroma fluid, injection of ethanol for 15 to 30 minutes, and then aspiration of the injected ethanol. Following review of the medical record, patient and procedure data were recorded. Success was defined as no recurrence of seroma. Statistical analysis was performed using a chi-square or t-test, as appropriate.

RESULTS

Twenty seromas were treated in 19 patients (mean age, 63 years; range, 49-79) following mastectomy (9/20, 45%), lumpectomy (25%, 5/20), axillary nodal dissection (5/20, 25%), or chest wall surgery (1/20, 5%). The mean seroma volume was 146 ± 165 mL. There was a mean of 1.4 prior aspiration attempts (range, 0-3). Mean injected ethanol volume was 39 mL (range, 8-60 mL) for a mean of 26 ± 5 minutes. Seromas recurred in 85% (17/20) of cases, and repeat aspiration was performed in 35% (6/17). The mean recurrence time was 34 ± 29 days. The recurrent seromas were 31% smaller (mean, 80 ± 48 mL). Only a smaller pre-ablation seroma was associated with successful ablation (P < 0.01), as the mean pre-ablation volume was 36 ± 24 mL for successful ablations and 119 ± 56 mL for unsuccessful ablations. There were no post-procedural complications.

CONCLUSION

Single-treatment ethanol sclerotherapy is typically unsuccessful in ablating breast and axillary seromas. Only a smaller pre-ablation seroma size was associated with successful ablation.

Osteopontin Levels Are Persistently Elevated for 4 weeks Following Minimally Invasive Colorectal Cancer Resection

INTRODUCTION

Osteopontin (OPN) is an integrin binding phosphorylated glycoprotein secreted by macrophages and leukocytes that is found in extracellular fluids and sites of inflammation; various forms of CD44 serve as receptors. Osteopontin, expressed by numerous cancers, enhances tumor progression and angiogenesis via the PI3K/AKT and ERK mediated pathways in concert with Vascular Endothelial Growth Factor (VEGF); OPN also plays a role in wound healing. The impact of minimally invasive colorectal resection (MICR) for colorectal cancer (CRC) on plasma OPN levels is unknown. This study's goal was to assess blood levels during the first month after MICR.

METHOD

Patients undergoing MICR for CRC who were enrolled in an IRB approved tissue/prospective data bank for whom preoperative, postop Day (POD) 1, POD 3, and at least 1 late postop plasma sample (POD 7-34) were available were studied. Osteopontin levels were determined in duplicate via enzyme linked immunosorbent assay (ELISA) (results reported as mean ± SD). The Wilcoxon signed rank test was used for analysis (significance P < .05).

RESULTS

A total of 101 CRC patients (63% colon and 37% rectal) met study criteria. The mean preop OPN level was 89.2 ± 36.8 (ng/ml) for the entire group. Significantly elevated (P < .001) mean plasma levels were detected, vs preop, on POD1 (198.0 ± 67.4; n = 101), POD 3 (186.0 ± 72.6, n = 101), POD 7-13 (154.1 ± 70.2, n = 70), POD14-20 (146.7 ± 53.4, n=32), and POD 21-27 (123.0 ± 56.9, n = 25). No difference was noted at the POD 27-34 timepoint (P > .05).

CONCLUSION

Plasma OPN levels are significantly elevated over baseline for a month after MICR for CRC. The early rise in OPN levels may be related to the postop acute inflammatory response. The persistent elevation noted in weeks 2-4, however, may be a manifestation of wound healing in which OPN plays a role. Similar persistent plasma elevations of VEGF, angiopoietin 2 (ANG 2), and 11 other proangiogenic proteins have been noted and, collectively, may promote angiogenesis in residual tumors.

Dose-time and Source-dependent Analysis of Intraoperative Radiotherapy-treated Seroma on Breast Cancer Cell Types: A Pilot Study

Background: Intraoperative radiation therapy (IORT) is a novel approach to breast cancer (BC) treatment. Objectives: In this study, we compared the cellular and molecular effects of IORT-treated post-lumpectomy wound fluid (seroma) at the point of IOeRT versus IOxRT on the BC cell line. Methods: Immortalized human BC cell lines: MCF-7, MDA-MB-231, and MCF10 were incubated with seroma from 3 groups of patients (as a pilot study). The first group received Intraoperative electron radiation therapy (IOeRT, Boost dose=12Gy), the second one received IOeRT (Radical dose=21Gy), and the third group was prescribed Intraoperative x-ray radiation therapy (IOxRT, X-ray=20Gy). Cellular and molecular tests were used to investigate how cells are influenced by the IORT-treated seroma. Results: We evaluated the effects of dose-time and source-dependent IORT-treated seroma on BC cell lines. In this study, we observed that IOxRT-treated seroma has the most significant effects on the reduction of proliferation, induced cell cycle arrest, and apoptosis. Furthermore, inhibited migration and invasion of BC cell lines were compared to IOeRT -treated seroma. Conclusions: Although this is a pilot study, we suggest that at 24 h, the IORT (specifically IOxRT)-treated seroma may play an important protective role in the breast tumor bed, which is followed by local recurrence decreases.

Observation of Wound Healing Effect and Aesthetic Satisfaction of Patient with Second Degree Burn Wounds Treated by Kangfuxin Solution

Objective

To study the effect of wound healing and aesthetic satisfaction of patient with second degree burn wounds treated by Kangfuxin solution.

Methods

84 cases of burn plastic surgery in our hospital from October 2020 to October 2021 were included. All patients were randomly divided into observation group and control group with 42 cases in each group. Patients in both groups received basic treatment after admission, and patients in the control group received conventional treatment. Patients in the observation group were treated with Kangfuxin solution after admission. The clinical efficacy, wound healing time, secretion disappearance time, infection rate, and scar formation rate after treatment were compared between the two groups. The scores of patients and observer scar assessment scale (POSAS) before and after treatment were compared between the two groups, and the occurrence of adverse reactions during treatment was also compared between the two groups.

Results

The total effective rate of the observation group was 92.86%, which was significantly higher than that of the control group (61.90%) (P < 0.05).The time of wound healing and secretion disappearance in the observation group was significantly shorter than that in the control group (P < 0.05); the infection rate and scar formation rate in the observation group were significantly lower than those in the control group (P < 0.05).The scores of PSAs and OSAS in the observation group were significantly lower than those before treatment and after treatment in the control group (P < 0.05). There was no significant difference in the total incidence of adverse reactions between the observation group (7.14%) and the control group (9.52%) (P > 0.05).

Conclusion

The Kangfuxin solution has the advantages of fast wound healing, high patient satisfaction, better therapeutic effect, and high safety, which is worth clinical application.

Wound fluid sampling methods for proteomic studies: A scoping review

Understanding why some wounds are hard to heal is important for improving care and developing more effective treatments. The method of sample collection used is an integral step in the research process and thus may affect the results obtained. The primary objective of this study was to summarise and map the methods currently used to sample wound fluid for protein profiling and analysis. Eligible studies were those that used a sampling method to collect wound fluid from any human wound for analysis of proteins. A search for eligible studies was performed using MEDLINE, Embase and CINAHL Plus in May 2020. All references were screened for eligibility by one reviewer, followed by discussion and consensus with a second reviewer. Quantitative data were mapped and visualised using appropriate software and summarised via a narrative summary. After screening, 280 studies were included in this review. The most commonly used group of wound fluid collection methods were vacuum, drainage or use of other external devices, with surgical wounds being the most common sample source. Other frequently used collection methods were extraction from absorbent materials, collection beneath an occlusive dressing and direct collection of wound fluid. This scoping review highlights the variety of methods used for wound fluid collection. Many studies had small sample sizes and short sample collection periods; these weaknesses have hampered the discovery and validation of novel biomarkers. Future research should aim to assess the reproducibility and feasibility of sampling and analytical methods for use in larger longitudinal studies.

Effect of quilting on seroma formation in mastectomies: A meta-analysis

BACKGROUND

Seroma is the most common complication following mastectomy and can require several days of drainage and lead to delayed wound healing, longer hospital stays, and an increased financial and emotional burden. Seroma formation is not well understood and but there is good evidence that closing the dead space via quilting can help reduce seroma formation. This study assessed randomized controlled trials and reviewed current literature to elucidate if there is a strong association between quilting sutures and seroma formation.

METHODS

A systematic search of 5 databases using search terms similar to "seroma", "quilting", "flap fixation", "random", and "mastectomy". Data was extracted and Medcalc software used to perform a meta-analysis of the primary outcome: incidence of seroma formation, as well as secondary outcomes: volume and duration of drainage.

RESULTS

Eleven randomized controlled trials with 2009 patients were included. Quilting with sutures greatly reduced the incidence of seroma formation compared with conventional closure (p < 0.001, RR 0.367 [95% CI 0.25, 0.539]; I² = 63.56%) as well as duration of drainage (p = 0.015, SMD -1.657, SE 0.680 [95% CI -2.991, -0.324]; 8 studies, n = 1578; I² = 98.98%). Quilting did not significantly affect volume of drainage.

CONCLUSIONS

Quilting was found to be associated with lower seroma rates. Future studies should investigate the use of quilting in combination with other preventative techniques to search for a synergistic method that will further improve patient care.

Survival benefit of a combined surgical approach in patients with metastatic breast cancer

BACKGROUND

We previously reported survival benefit of surgery in patients with stage IV breast cancer (BC); prospective trials yielded inconclusive results.

METHODS

We sampled the National Cancer Database (2004-2016) for de novo stage IV BC patients undergoing both primary site resection and metastasectomy. A multivariate Cox-regression survival model investigated the overall survival (OS) of this surgical approach as compared to lumpectomy/mastectomy alone, metastasectomy alone, or no surgery. The Kaplan-Meier method was used to demonstrate the utility of surgery when metastasis were confined to 1 site stratifying by tissue type.

RESULTS

A total of n = 55,125 patients were included. As compared to lumpectomy/mastectomy alone (43 months), lumpectomy/mastectomy + metastasectomy exhibited the best OS (50 months, p = 0.012), metastasectomy alone showed slightly worse OS (30 months, p < 0.0001), and no surgery had the worst OS (21 months, p < 0.0001). In metastasis confined to 1 site, superior OS with combined lumpectomy/mastectomy and metastasectomy versus lumpectomy/mastectomy alone was observed with liver (72.8 vs. 48.1 months, p < 0.001) or lung (49.2 vs. 36.8 months, p < 0.001) metastasis but not bone (52.2 vs. 49.9 months, p < 0.001) or brain (16.2 vs. 15.5 months, p < 0.001).

CONCLUSION

Patients with metastatic BC undergoing primary site resection and metastasectomy exhibited optimal OS, particularly when metastasis involved only the liver or lung.

Local Anesthetic Lidocaine and Cancer: Insight Into Tumor Progression and Recurrence

Cancer is a leading contributor to deaths worldwide. Surgery is the primary treatment for resectable cancers. Nonetheless, it also results in inflammatory response, angiogenesis, and stimulated metastasis. Local anesthetic lidocaine can directly and indirectly effect different cancers. The direct mechanisms are inhibiting proliferation and inducing apoptosis via regulating PI3K/AKT/mTOR and caspase-dependent Bax/Bcl2 signaling pathways or repressing cytoskeleton formation. Repression invasion, migration, and angiogenesis through influencing the activation of TNFα-dependent, Src-induced AKT/NO/ICAM and VEGF/PI3K/AKT signaling pathways. Moreover, the indirect influences are immune regulation, anti-inflammation, and postoperative pain relief. This review summarizes the latest evidence that revealed potential clinical benefits of lidocaine in cancer treatment to explore the probable molecular mechanisms and the appropriate dose.

DNA aptamer immobilized hydroxyapatite for enhancing angiogenesis and bone regeneration

In this study, we developed aptamer-conjugated hydroxyapatite (Apt-HA) that promotes bone regeneration and angiogenesis. The 3R02 bivalent aptamer specific to vascular endothelial growth factor (VEGF) was grafted to the hydroxyapatite (HA) surface. Apt-HA was tested for its VEGF protein capture ability to determine the optimal aptamer concentration immobilized on the HA. Apt-HA showed higher VEGF protein capture ability, and faster growth of human umbilical vein endothelial cell (HUVEC) compared to a neat HA with no cytotoxic effects on human osteoblasts. To examine in vivo angiogenesis and bone regeneration, Apt-HA and HA were bilaterally implanted into rabbit tibial metaphyseal defects and analyzed after eight weeks using micro-CT, histology, and histomorphometry. Apt-HA showed significantly increased the volume of new bones, the percentage of bone, and the density of bone mineral in cortical bone. Apt-HA also exhibited the enhanced bone formation at the cortical region in a histomorphometric analysis. Finally, Apt-HA showed significantly increased blood vessel number compared to a neat HA. In summary, the engineered Apt-HA has potential as a bone graft material that may simultaneously promote bone regeneration and angiogenesis. STATEMENT OF SIGNIFICANCE: This work presents a functional hydroxyapatite bone graft using a DNA-based aptamer which overcomes the limitations of existing bone graft materials, which use bound signaling peptides. DNA aptamer immobilized hydroxyapatite enhances the in vitro proliferation of human umbilical vascular endothelial cells as well as in vivo angiogenesis and bone regeneration. DNA aptamer immobilized hydroxyapatite shows no cytotoxic effect on human osteoblasts.

Plasma and wound fluid levels of eight proangiogenic proteins are elevated after colorectal resection

BACKGROUND

Colorectal resection is associated with 3-5 wk long elevations in the plasma levels of at least 11 proangiogenic proteins that may stimulate tumor angiogenesis post-surgery. The increases during the first week after surgery may be related to the acute inflammatory response; the cause(s) of the week 2-5 increases is unknown. The wounds are a possible source because of the important role that angiogenesis plays in the healing process. The main hypothesis of the study is that wound fluid levels of the proteins studied will be elevated well beyond plasma levels which, in turn, are elevated from preoperative baseline levels.

AIM

To determine plasma and wound fluid levels of 8 proangiogenic proteins after colorectal resection for cancer and benign pathology.

METHODS

Blood and wound fluid samples were taken simultaneously on postoperative (postop) day 1, 3, and later time points until wound drain removal in 35 colorectal cancer patients and 31 benign disease patients undergoing colorectal resection in whom closed wound drains had been placed in either the pelvis or the subcutaneous space of the abdominal incision. Postop plasma levels were compared to preop plasma and postop wound fluid levels (separate analyses for cancer and benign groups).

RESULTS

Sixty-six colorectal disease patients were studied (35 cancer, 31 benign pathology). Most patients underwent minimally invasive surgery (open surgery in 11% of cancer and 6% of benign patients). The majority in the cancer group had rectal resections while in the benign group sigmoid or right colectomy predominated. Plasma levels of all 8 proteins were significantly elevated from baseline (P < 0.05) at all post-operative time points in the cancer group and at 90% of time points (29/32) in the benign group. Wound levels of all 8 proteins were 3-106 times higher (P < 0.05) than plasma levels at 87-90 percent of postop time points; of note, wound levels were more than 10 times higher at 47-50% of time points.

CONCLUSION

Plasma protein levels were elevated for 3 weeks after surgery; wound fluid levels were much greater than corresponding blood levels. Healing wounds may be the source of the plasma increases.

Plasma levels of the proangiogenic protein CXCL16 remains elevated for 1 month after minimally invasive colorectal cancer resection

BACKGROUND

Inflammation-induced endothelial precursor cell recruitment and angiogenesis are thought to be associated with CXCL16-CXCR6 pair activity. This study's main purpose was to determine plasma CXCL16 levels after minimally invasive colorectal resection (MICR) for colorectal cancer (CRC); an adjunct study assessed wound fluid (WF) and plasma CXCL16 levels in a separate group of CRC patients.

METHODS

CRC patients who had MICR and for whom plasma was available in a tissue bank were eligible. Plasma samples were collected preoperatively from all patients. Samples were also collected on postoperative days (POD) 1 and 3 and at various late postoperative time points (POD 7-34). In a separate study, blood and intra-abdominal wound fluid (WF) samples were collected from CRC MICR patients (pts). Samples were stored at - 80 °C. CXCL16 levels were determined via ELISA. The Wilcoxon signed-rank and Mann and Whitney tests were used for analysis.

RESULTS

Main study: 86 CRC pts. were included. The mean preoperative plasma CXCL16 level was 2.36 ± 0.57 ng/ml. Elevated mean plasma levels (p <  0.0001 × first 4 time points) were noted on POD 1 (2.82 ± 0.81, n = 86), POD 3 (3.12 ± 0.77, n = 82), POD 7-13 (3.28 ± 0.88, n = 64), POD 14-20 (3.03 ± 0.62, n = 24), POD 21-27 (3.06 ± 0.67, n = 20, p = 0.0003), and POD 28-34 (3.17 ± 0.43, n = 11, p = 0.001) vs. preop levels. WF study: In the adjunct study, plasma and WF CXCL16 levels were determined for 23 CRC MICR pts. WF levels at all time points were significantly elevated over plasma levels.

CONCLUSION

Plasma CXCL16 levels were elevated for 4 weeks after minimally invasive colorectal resection for cancer. Also, WF CXCL16 levels were 3-10 times greater than the corresponding plasma concentrations. The source of the late plasma elevations may be the healing wound. Increased plasma CXCL16 levels may promote tumor angiogenesis in the first month after MICR.

Potential impact of invasive surgical procedures on primary tumor growth and metastasis

Surgical procedures such as tumor resection and biopsy are still the gold standard for diagnosis and (determination of) treatment of solid tumors, and are prognostically beneficial for patients. However, growing evidence suggests that even a minor surgical trauma can influence several (patho) physiological processes that might promote postoperative metastatic spread and tumor recurrence. Local effects include tumor seeding and a wound healing response that can promote tumor cell migration, proliferation, differentiation, extracellular matrix remodeling, angiogenesis and extravasation. In addition, local and systemic immunosuppression impairs antitumor immunity and contributes to tumor cell survival. Surgical manipulation of the tumor can result in cancer cell release into the circulation, thus increasing the chance of tumor cell dissemination. To prevent these undesired effects of surgical interventions, therapeutic strategies targeting immune response exacerbation or alteration have been proposed. This review summarizes the current literature regarding these local, systemic and secondary site effects of surgical interventions on tumor progression and dissemination, and discusses studies that aimed to identify potential therapeutic approaches to prevent these effects in order to further increase the clinical benefit from surgical procedures.

Therapeutic Potential of Thymoquinone in Glioblastoma Treatment: Targeting Major Gliomagenesis Signaling Pathways

Glioblastoma multiforme (GBM) is one of the most devastating brain tumors with median survival of one year and presents unique challenges to therapy because of its aggressive behavior. Current treatment strategy involves surgery, radiotherapy, immunotherapy, and adjuvant chemotherapy even though optimal management requires a multidisciplinary approach and knowledge of potential complications from both the disease and its treatment. Thymoquinone (TQ), the main bioactive component of Nigella sativa L., has exhibited anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteract carcinogenesis, malignant growth, invasion, migration, and angiogenesis. TQ can specifically sensitize tumor cells towards conventional cancer treatments and minimize therapy-associated toxic effects in normal cells. Its potential to enter brain via nasal pathway due to volatile nature of TQ adds another advantage in overcoming blood-brain barrier. In this review, we summarized the potential role of TQ in different signaling pathways in GBM that have undergone treatment with standard therapeutic modalities or with TQ. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical level to delineate its implied utility as novel therapeutics to combat the challenges for the treatment of GBM.

Plasma interleukin-8 levels are persistently elevated for 1 month after minimally invasive colorectal resection for colorectal cancer

Minimally invasive colorectal resection (MICR) for colorectal cancer (CRC) is associated with elevated levels of seven proangiogenic proteins that persist for 2-4 weeks after surgery. The proangiogenic plasma may promote tumor growth postoperatively in patients with residual cancer. To the best of our knowledge, the impact of surgery on interleukin 8 (IL-8) levels is unknown. The aim of the present study was to evaluate plasma IL-8 levels after MICR for CRC. Patients with CRC enrolled in an institutional review board-approved plasma/data bank who underwent MICR were eligible. Blood samples were taken preoperatively (preop) and at multiple postoperative (postop) time points, and were stored at -80°C. Only patients for whom preop, postop day (POD) 1, POD 3 and at least 1 late postop plasma samples (POD7-34) available were enrolled. Clinical, demographical and pathological data were collected. IL-8 levels were determined via ELISA and results were reported as the mean and ± standard deviation. The Wilcoxon signed rank test was used for analysis with P<0.05 used as the significance threshold. A total of 73 CRC patients (colon, 62%; rectal, 38%) who underwent MICR (laparoscopic-assisted, 60%; hand-assisted, 40%) were studied. The mean preop IL-8 level was 20.4±10.6 pg/ml. Significant elevations in plasma IL-8 levels were noted compared with preop levels on POD1 (43.1±38.6; n=72; P<0.0001), POD 3 (33.0±30.1; n=71; P<0.0001), POD7-13 (29.9±21.9; n=50; P<0.0001), POD14-20 (33.1±18.3; n=24; P=0.002), and for the POD21-27 time point (24.0±9.2; n=16; P=0.002). In conclusion, plasma IL-8 levels were significantly elevated from baseline for 4 weeks after MICR for CRC. In conjunction with the other proangiogenic MICR-associated blood compositional changes, increased IL-8 levels may promote tumor angiogenesis and growth postop.

Thymoquinone as a Potential Adjuvant Therapy for Cancer Treatment: Evidence from Preclinical Studies

Thymoquinone (TQ), the main bioactive component of Nigella sativa, has been found to exhibit anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteracts carcinogenesis, malignant growth, invasion, migration, and angiogenesis. Moreover, TQ can specifically sensitize tumor cells toward conventional cancer treatments (e.g., radiotherapy, chemotherapy, and immunotherapy) and simultaneously minimize therapy-associated toxic effects in normal cells. In this review, we summarized the adjuvant potential of TQ as observed in various in vitro and in vivo animal models and discussed the pharmacological properties of TQ to rationalize its supplementary role in potentiating the efficacy of standard therapeutic modalities namely surgery, radiotherapy, chemotherapy, and immunotherapy. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical levels to delineate its implied utility as a novel complementary adjuvant therapy for cancer treatment.

Seroma in Prosthetic Breast Reconstruction

BACKGROUND

Seroma, as a complication of prosthetic breast reconstruction, results in patient distress, increased office visits, undesirable aesthetic outcomes, and--importantly--may escalate to infection and frank prosthesis loss. Herein, the authors review the pathophysiology and risk factors and attempt to collate published practices for avoidance and management of seroma.

METHODS

A systematic literature review was performed using MEDLINE, Web of Science, Embase, and Cochrane Library for studies published between 2000 and January of 2015. Random-effects meta-analysis was used to estimate the overall pooled incidence of seroma and to examine the effect of drain number and acellular dermal matrix use.

RESULTS

Seventy-two relevant primary articles and three systematic reviews were identified. Fifty-one citations met inclusion criteria, including two randomized controlled trials. The overall pooled incidence was 5.4 percent (95 percent CI, 4.1 to 6.7 percent). Obesity, acellular dermal matrix, and preoperative irradiation were cited risk factors. Pooled relative risk for acellular dermal matrix was 1.83 (95 percent CI, 1.28 to 2.62). Drain practices were collated from 34 articles.

CONCLUSIONS

Seromas following prosthetic breast reconstruction are complicated by the hypovascular, proinflammatory milieu of the mastectomy skin flap, the geometrically complex dead space, and the presence of a foreign body with potential contamination and biofilm. There is reasonable evidence to suggest that these factors contribute to a progression of seroma to infection and prosthesis loss. These findings have motivated this summary article on current practice guidelines and strategies to prevent and treat seromas.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

A Switch in the Dynamics of Intra-Platelet VEGF-A from Cancer to the Later Phase of Liver Regeneration after Partial Hepatectomy in Humans

Background

Liver regeneration (LR) involves an early inductive phase characterized by the proliferation of hepatocytes, and a delayed angiogenic phase distinguished by the expansion of non-parenchymal compartment. The interest in understanding the mechanism of LR has lately shifted from the proliferation and growth of parenchymal cells to vascular remodeling during LR. Angiogenesis accompanied by LR exerts a pivotal role to accomplish the process. Vascular endothelial growth factor (VEGF) has been elucidated as the most dynamic regulator of angiogenesis. From this perspective, platelet derived/Intra-platelet (IP) VEGF-A should be associated with LR.

Material and Methods

Thirty-seven patients diagnosed with hepatocellular carcinoma and undergoing partial hepatectomy (PH) were enrolled in the study. Serum and IP VEGF-A was monitored preoperatively and at four weeks of PH. Liver volumetry was determined on computer models derived from computed tomography (CT) scan.

Results

Serum and IP VEGF-A was significantly elevated at four weeks of PH. Preoperative IP VEGF-A was higher in patients with advanced cancer and vascular invasion. Postoperative IP VEGF-A was higher after major liver resection. There was a statistically significant correlation between postoperative IP VEGF-A and the future remnant liver volume. Moreover, the soluble vascular endothelial growth factor receptor-1 (sVEGFR1) was distinctly down-regulated suggesting a fine-tuned angiogenesis at the later phase of LR.

Conclusion

IP VEGF-A is overexpressed during later phase of LR suggesting its implications in inducing angiogenesis during LR.

Pre-Analytical Parameters Affecting Vascular Endothelial Growth Factor Measurement in Plasma: Identifying Confounders

Background

Vascular endothelial growth factor-A (VEGF-A) is intensively investigated in various medical fields. However, comparing VEGF-A measurements is difficult because sample acquisition and pre-analytic procedures differ between studies. We therefore investigated which variables act as confounders of VEGF-A measurements.

Methods

Following a standardized protocol, blood was taken at three clinical sites from six healthy participants (one male and one female participant at each center) twice one week apart. The following pre-analytical parameters were varied in order to analyze their impact on VEGF-A measurements: analyzing center, anticoagulant (EDTA vs. PECT / CTAD), cannula (butterfly vs. neonatal), type of centrifuge (swing-out vs. fixed-angle), time before and after centrifugation, filling level (completely filled vs. half-filled tubes) and analyzing method (ELISA vs. multiplex bead array). Additionally, intrapersonal variations over time and sex differences were explored. Statistical analysis was performed using a linear regression model.

Results

The following parameters were identified as statistically significant independent confounders of VEGF-A measurements: analyzing center, anticoagulant, centrifuge, analyzing method and sex of the proband. The following parameters were no significant confounders in our data set: intrapersonal variation over one week, cannula, time before and after centrifugation and filling level of collection tubes.

Conclusion

VEGF-A measurement results can be affected significantly by the identified pre-analytical parameters. We recommend the use of CTAD anticoagulant, a standardized type of centrifuge and one central laboratory using the same analyzing method for all samples.

A double-edged sword: the role of VEGF in wound repair and chemoattraction of opportunist pathogens

Wound healing is a complex process essential to repairing damaged tissues and preventing infection. Skin is the first line of defense, a chief physical barrier to microbe entry. Wound healing is a physical rebuilding process, but at the same time it is an inflammatory event. In turn, molecules for wound repair are secreted by fibroblasts and others present at the wound site. Vascular endothelial growth factor (VEGF) is a critical cytokine that exhibits chemoattractant properties, recruiting other immune cells to the site. Although generally beneficial, VEGF may also act as a chemoattractant for invading microorganisms, such as Pseudomonas aeruginosa.P. aeruginosa is problematic during wound infection due to its propensity to form biofilms and exhibit heightened antimicrobial resistance. Here, we explored the influence of VEGF gradients (in a microfluidic device wound model) on the motility and chemotactic properties of P. aeruginosa. At lower concentrations, VEGF had little effect on motility, but as the maximal concentration within the gradient increased, P. aeruginosa cells exhibited directed movement along the gradient. Our data provide evidence that while beneficial, VEGF, in excess, may aid colonization by P. aeruginosa. This highlights the necessity for the efficient resolution of inflammation. Understanding the dynamics of wound colonization may lead to new/enhanced therapeutics to hasten recovery.

Activation of latent metastases in the lung after resection of a metastatic lymph node in a lymph node metastasis mouse model

Iatrogenic induction of regional and distant cancer metastases is a risk associated with clinical resection of tumor-positive sentinel lymph nodes. However, there have been no studies of this risk in a mouse model of cancer metastasis. Here, we report that resection of a tumor-bearing subiliac lymph node (SiLN) enhanced lung metastasis in a mouse model of lymph node metastasis. Bioluminescence imaging revealed that metastatic tumor cells in the secondary lymph node continued to grow after resection of the SiLN, and that the probability of metastasis to the lungs was increased when the interval between SiLN inoculation and resection was reduced. Futhermore, histological analysis demonstrated that latents in the lung were stimulated to grow after resection of the SiLN. Fluorescence imaging indicated that the route of tumor cell dissemination from SiLN to the lung was the venous system located over the SiLN. We speculate that our mouse model will be useful for studying the mechanisms of tumor cell latency, with a view to improving the detection and treatment of latent metastases.

Minimally invasive colorectal resection is associated with significantly elevated levels of plasma matrix metalloproteinase 3 (MMP-3) during the first month after surgery which may promote the growth of residual metastases

INTRODUCTION

MMP-3, a member of the matrix metalloproteinase (MMP) family, is involved in the breakdown of the extracellular matrix in tissue remodeling and may also play a role in cancer progression and metastasis. Minimally invasive colorectal resection (MICR) may increase plasma MMP-3 levels directly via surgical trauma or indirectly due to surgery-associated elevations in TNF-α and IL1 which are regulators of MMP-3. This study's purpose was to evaluate plasma MMP-3 levels during the first month after MICR for colorectal cancer.

METHODS

Patients enrolled in an IRB approved data/plasma bank who underwent elective MICR for CRC. Blood plasma samples had been collected preoperatively, on postoperative day (POD) 1, 3 and at varying postoperative time points and were stored at -80 °C. The late samples (POD 7-41) were bundled into 7 day time blocks and considered as single time points. MMP-3 levels were analyzed in duplicate via ELISA and the results reported as mean ± SD. The paired t test was used for analysis (significance, p < 0.008 after Bonferroni's correction).

RESULTS

A total of 73 CRC patients who underwent MICR met the inclusion criteria. The mean PreOp MMP-3 level was 14.9 ± 7.8 ng/ml (n = 73). Significantly elevated mean plasma levels were noted on POD 1 (21.4 ± 14.7 ng/ml, n = 73, p < 0.0001), POD 3 (37.9 ± 21.5 ng/ml, n = 72, p < 0.0001), POD 7-13 (22.0 ± 13.0 ng/ml, n = 56, p < 0.0001), POD 14-20 (21.9 ± 10.3 ng/ml, n = 20, p = 0.003), and on POD 21-27 (21.9 ± 11.43 ng/ml, n = 20, p = 0.002) when compared to PreOp levels. Plasma levels returned to the PreOp baseline at the POD 28-41 time point (n = 16, p = 0.07).

CONCLUSION

Plasma MMP-3 levels remained significantly elevated from baseline for 4 weeks after MICR for CRC. The early postoperative increase in MMP-3 levels may be due to the surgery-related acute inflammatory response; the elevation noted during weeks 2-3 may be related to wound healing. Increased MMP-3 levels may promote metastases or the growth of residual cancer.

Minimally invasive colorectal resection for benign pathology is associated with persistent proangiogenic plasma compositional changes

BACKGROUND

Minimally invasive colorectal resection for cancer is associated with increased plasma levels of numerous proangiogenic proteins for 3 to 4 weeks postoperatively, and plasma from postoperative weeks 2 and 3 stimulates proangiogenic endothelial cell behavior in vitro. It is unknown if similar plasma changes occur after minimally invasive colorectal resection for benign pathology.

OBJECTIVE

The aim of this study is to assess 1) plasma levels of angiopoetin-2, placental growth factor, and soluble vascular cell adhesion molecule-1 after minimally invasive colorectal resection for benign pathology and 2) postoperative plasma's effects on in vitro endothelial cell proliferation (branch point formation), migration, and invasion.

DESIGN

Prospectively gathered plasma samples taken from patients undergoing colorectal resection who consented to participate in an institutional review board-approved plasma and data bank were used for ELISAs and in vitro endothelial cell studies.

SETTINGS

The plasma and clinical data used were collected at 3 hospitals.

PATIENTS

Patients undergoing minimally invasive colorectal resection for benign indications who were enrolled in a plasma/data bank and for whom adequate samples and volumes of plasma were available were included in the study.

MAIN OUTCOME MEASURES

Perioperative plasma levels of angiopoetin-2, placental growth factor, and soluble vascular cell adhesion molecule-1 were the primary outcomes measured. In vitro rates of endothelial cell branch point formation, migration, and invasion were determined after the addition of preoperative and postoperative plasma samples to endothelial cell cultures.

RESULTS

Plasma from 86 patients undergoing minimally invasive colorectal resection for benign indications was assessed (diverticulitis, 30; benign polyps, 56). Plasma levels of angiopoetin-2, placental growth factor, and soluble vascular cell adhesion molecule-1 were significantly increased for 3 to 4 weeks postoperatively compared with preoperative levels. In regard to the endothelial cell culture assays, significantly increased endothelial cell branch point formation, invasion, and migration results were noted with plasma from the second and third weeks postoperatively in comparison with preoperative culture results.

LIMITATIONS

The weaknesses of this study are the limited numbers of late postoperative plasma samples and the need to bundle late samples into 7- to 12-day time blocks.

CONCLUSIONS

Minimally invasive colorectal resection for benign pathology is associated with persistent proangiogenic plasma alterations similar to those found in patients who have cancer. Surgical trauma and not the indication is the likely cause.

The volume and duration of wound drainage are independent prognostic factors for breast cancer

Drain insertion is routinely done after breast cancer surgery. However, the prognostic value of suction drains in breast cancer is still unknown. This study aimed to reveal the prognostic value of drain insertion in breast cancer. A total of 296 female breast cancer patients undergoing surgery were retrospectively recruited. The correlation of drainage volume as well as drain duration with clinicopathological parameters and prognosis was assessed statistically. We found that breast cancer patients with a drainage volume of >240 ml had a better overall survival time. Breast cancer patients with more than 5 days postoperative drain duration would have better survival time. In addition, both the volume and duration of wound drainage are independent prognostic factors in multivariate analysis. Therefore, the volume of drainage as well as drain duration is a potential novel prognostic marker for breast cancer.

Does surgery for breast cancer induce angiogenesis and thus promote metastasis?

At the time of surgery for breast cancer, cancer cells released from the primary tumor have most likely entered blood or lymphatic vessels, leading to the development of micrometastases. Cancer cells directly produce angiogenesis stimulators, provoke the release of stimulators bound to the surrounding extracellular matrix and induce macrophages to secrete angiogenesis stimulators, thereby promoting angiogenesis. Metastasis dormancy is characterized by a balance between cell proliferation and apoptosis and is thought to be controlled by increased apoptosis, indirectly induced by angiogenesis inhibitors. Many patients with solid tumors already have micrometastases at the time of detection and surgical removal of their primary tumors. Primary tumor resection is believed to stimulate angiogenesis, initiating the proliferation of latent micrometastases. Latent micrometastases have already acquired angiogenic potential. The provision of additional therapy to inhibit angiogenesis after surgery is therefore considered a rational approach. The effectiveness of dormancy therapy should be evaluated in the prospective clinical trials of chemotherapy with drugs such as cyclophosphamide and UFT, which have been reported to inhibit angiogenesis as demonstrated by the numbers of circulating endothelial cells and circulating endothelial progenitors in peripheral blood before and after surgery in women with primary breast cancer.

Comparing scalpel, electrocautery and ultrasonic dissector effects: the impact on wound complications and pro-inflammatory cytokine levels in wound fluid from mastectomy patients

PURPOSE

Introducing the relationship between the surgical instruments used in modified radical mastectomy and wound complications is important for preventing and decreasing complications. This prospective randomized trial was designed to assess the impact of scalpel, electrocautery, and ultrasonic dissector usage on wound complications and tissue damage.

METHODS

Eighty-two consecutive patients operated with mastectomy were studied. The postoperative time period needed for hemovac drainage, the amount and duration of seroma, infection, flap ecchymosis and necrosis rates were compared. Tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) levels in drainage fluids were determined to confirm the inflammatory response and tissue damage.

RESULTS

The numbers of patients included in the scalpel, electrocautery and ultrasonic dissector groups were 27, 26, and 29, respectively. The groups were homogenous with respect to age, body mass index, stage, cormorbidities, breast volume and flap area. Operation time and the amount of bleeding were statistically higher in the scalpel group. The incidence of seroma was higher in the electrocautery group and arm mobilization had to be delayed in this group. There were no differences between groups with respect to hematoma, infection, ecchymosis, necrosis, hemovac drainage and the total and first 3 days of seroma volume. TNF-α and IL-6 levels were significantly higher in samples obtained from the drains of patients operated with electrocautery.

CONCLUSION

Ultrasonic dissector decreases operation time by decreasing the amount of bleeding without increasing the seroma incidence. High cytokine levels in drainage fluids from patients operated with elecrocautery indicates that electrocautery induces more tissue damage and acute inflammatory response. Therefore, seroma, due to acute inflammatory response, was seen more frequently in the electrocautery group. Ultrasonic dissector coagulates protein by breaking hydrogen bonds which may close vascular and lymphatic channels more precisely. But, its actual preventive effect on seroma formation might be related to diminished inflammatory response.

An evolutionary explanation for the perturbation of the dynamics of metastatic tumors induced by surgery and acute inflammation

Surgery has contributed to unveil a tumor behavior that is difficult to reconcile with the models of tumorigenesis based on gradualism. The postsurgical patterns of progression include unexpected features such as distant interactions and variable rhythms. The underlying evidence can be summarized as follows: (1) the resection of the primary tumor is able to accelerate the evolution of micrometastasis in early stages, and (2) the outcome is transiently opposed in advanced tumors. The objective of this paper is to give some insight into tumorigenesis and surgery-related effects, by applying the concepts of the evolutionary theory in those tumor behaviors that gompertzian and tissular-centered models are unable to explain. According to this view, tumors are the consequence of natural selection operating at the somatic level, which is the basic mechanism of tumorigenesis, notwithstanding the complementary role of the intrinsic constrictions of complex networks. A tumor is a complicated phenomenon that entails growth, evolution and development simultaneously. So, an evo-devo perspective can explain how and why tumor subclones are able to translate competition from a metabolic level into neoangiogenesis and the immune response. The paper proposes that distant interactions are an extension of the ecological events at the local level. This notion explains the evolutionary basis for tumor dormancy, and warns against the teleological view of tumorigenesis as a process directed towards the maximization of a concrete trait such as aggressiveness.

Randomized clinical trial comparing inflammatory and angiogenic response after open versus laparoscopic curative resection for colonic cancer

BACKGROUND

Several studies have suggested that laparoscopy might confer an oncological advantage in patients undergoing surgery for colonic cancer. A decreased inflammatory and angiogenic response has been proposed. This study compared the local and systemic inflammatory and angiogenic responses after open and laparoscopic surgery for colonic cancer.

METHODS

Some 122 patients with colonic cancer were randomized to open or laparoscopic colectomy. Levels of interleukin (IL) 6 and vascular endothelial growth factor (VEGF) were measured in serum and peritoneal fluid at baseline, then at 4, 12, 24 and 48 h and on day 4 after surgery. Samples obtained on day 4 were tested in an in vitro angiogenesis assay, with measurement of number of capillaries per field and capillary length.

RESULTS

The serum IL-6 level was lower in the laparoscopic group at 4 h (mean(s.d.) 124(110) versus 244(326) pg/dl after open colectomy; P = 0·027). The serum VEGF concentration was also lower in the laparoscopic group at 48 h and day 4 (430(435) versus 650(686) pg/dl; P = 0·001). Overall, local IL-6 and VEGF levels were significantly higher than serum levels but there were no differences between groups. In vitro, postoperative serum and peritoneal fluid samples were potently angiogenic but there were no differences between open surgery and laparoscopy. Rates of tumour recurrence and survival were similar in the two groups.

CONCLUSION

Despite differences in postoperative serum levels of IL-6 and VEGF after open and laparoscopic surgery in patients with colonic cancer, the angiogenic response is comparable in both surgical approaches.

REGISTRATION NUMBER

ISRCTN55624793 (http://www.controlled-trials.com).

Surgery triggers outgrowth of latent distant disease in breast cancer: an inconvenient truth?

We review our work over the past 14 years that began when we were first confronted with bimodal relapse patterns in two breast cancer databases from different countries. These data were unexplainable with the accepted continuous tumor growth paradigm. To explain these data, we proposed that metastatic breast cancer growth commonly includes periods of temporary dormancy at both the single cell phase and the avascular micrometastasis phase. We also suggested that surgery to remove the primary tumor often terminates dormancy resulting in accelerated relapses. These iatrogenic events are apparently very common in that over half of all metastatic relapses progress in that manner. Assuming this is true, there should be ample and clear evidence in clinical data. We review here the breast cancer paradigm from a variety of historical, clinical, and scientific perspectives and consider how dormancy and surgery-driven escape from dormancy would be observed and what this would mean. Dormancy can be identified in these diverse data but most conspicuous is the sudden synchronized escape from dormancy following primary surgery. On the basis of our findings, we suggest a new paradigm for early stage breast cancer. We also suggest a new treatment that is meant to stabilize and preserve dormancy rather than attempt to kill all cancer cells as is the present strategy.

Hypothesis: primary antiangiogenic method proposed to treat early stage breast cancer

BACKGROUND

Women with Down syndrome very rarely develop breast cancer even though they now live to an age when it normally occurs. This may be related to the fact that Down syndrome persons have an additional copy of chromosome 21 where the gene that codes for the antiangiogenic protein Endostatin is located. Can this information lead to a primary antiangiogenic therapy for early stage breast cancer that indefinitely prolongs remission? A key question that arises is when is the initial angiogenic switch thrown in micrometastases? We have conjectured that avascular micrometastases are dormant and relatively stable if undisturbed but that for some patients angiogenesis is precipitated by surgery. We also proposed that angiogenesis of micrometastases very rarely occurs before surgical removal of the primary tumor. If that is so, it seems possible that we could suggest a primary antiangiogenic therapy but the problem then arises that starting a therapy before surgery would interfere with wound healing.

RESULTS

The therapy must be initiated at least one day prior to surgical removal of the primary tumor and kept at a Down syndrome level perhaps indefinitely. That means the drug must have virtually no toxicity and not interfere meaningfully with wound healing. This specifically excludes drugs that significantly inhibit the VEGF pathway since that is important for wound healing and because these agents have some toxicity. Endostatin is apparently non-toxic and does not significantly interfere with wound healing since Down syndrome patients have no abnormal wound healing problems.

CONCLUSION

We propose a therapy for early stage breast cancer consisting of Endostatin at or above Down syndrome levels starting at least one day before surgery and continuing at that level. This should prevent micrometastatic angiogenesis resulting from surgery or at any time later. Adjuvant chemotherapy or hormone therapy should not be necessary. This can be continued indefinitely since there is no acquired resistance that develops, as happens in most cancer therapies.

Dormancy and surgery-driven escape from dormancy help explain some clinical features of breast cancer

To explain bimodal relapse patterns observed in breast cancer data, we have proposed that metastatic breast cancer growth commonly includes periods of temporary dormancy at both the single cell phase and the avascular micrometastasis phase. The half-lives of these states are 1 and 2 years respectively. We also suggested that surgery to remove the primary tumor often terminates dormancy resulting in accelerated relapses. These iatrogenic events are very common in that over half of all metastatic relapses progress in that manner. Assuming this is true, there should be ample and clear evidence in clinical data. We review here the breast cancer paradigm from early detection, through treatment and follow-up, and consider how dormancy and surgery-driven escape from dormancy would be observed. We examine mammography data, effectiveness of adjuvant chemotherapy, heterogeneity and aggressiveness, timing of surgery within the menstrual cycle and racial differences in outcome. Dormancy can be identified in these diverse data but most conspicuous is the sudden escape from dormancy following primary surgery. These quantitative findings provide linkage between experimental studies of tumor dormancy and clinical efforts to improve patient outcome.

The effects of surgery on tumor growth: a century of investigations

A few clinical investigations suggest that while primary breast cancer surgical removal favorably modifies the natural history for some patients, it may also hasten the metastatic development for others. The concepts underlying this disease paradigm, i.e. tumor homeostasis, tumor dormancy and surgery-driven enhancement of metastasis development, have a long history that is reviewed. The review reveals the context in which these concepts were conceived and structured to explain experimental data and shows that they are not so new and far fetched. The idea that surgical cancer resection has both beneficial and adverse effects upon cancer spread and growth that result from the modulation of tumor dormancy by the resection should be considered a potentially fruitful working hypothesis.

Where is VEGF in the body? A meta-analysis of VEGF distribution in cancer

Vascular endothelial growth factor (VEGF) is a major target for the inhibition of tumour vascularisation and the treatment of human cancer. Many tumours produce large quantities of VEGF, and as a result, diagnosis and prognosis of cancer may be predicted by measuring changes in VEGF concentrations in blood. In blood, the VEGF may be located in the plasma, or in the blood-borne cells and formed elements, in particular, platelets and leukocytes. In this study, we collate the measurements of VEGF in platelets, leukocytes, plasma and serum for breast, prostate, colorectal and other cancers. In addition, we analysed the concentration of VEGF in tumour tissue itself, as well as for other tissues in the human body. Although the concentration of VEGF in tumours is high, the size of tumours is small compared to other tissues, in particular, skeletal muscle. Thus, the total quantity of VEGF in tumours and in blood is small compared to the quantity in muscles. This large reservoir of VEGF may have important implications for the treatment of cancer.

Where is VEGF in the body? A meta-analysis of VEGF distribution in cancer

Vascular endothelial growth factor (VEGF) is a major target for the inhibition of tumour vascularisation and the treatment of human cancer. Many tumours produce large quantities of VEGF, and as a result, diagnosis and prognosis of cancer may be predicted by measuring changes in VEGF concentrations in blood. In blood, the VEGF may be located in the plasma, or in the blood-borne cells and formed elements, in particular, platelets and leukocytes. In this study, we collate the measurements of VEGF in platelets, leukocytes, plasma and serum for breast, prostate, colorectal and other cancers. In addition, we analysed the concentration of VEGF in tumour tissue itself, as well as for other tissues in the human body. Although the concentration of VEGF in tumours is high, the size of tumours is small compared to other tissues, in particular, skeletal muscle. Thus, the total quantity of VEGF in tumours and in blood is small compared to the quantity in muscles. This large reservoir of VEGF may have important implications for the treatment of cancer.

Clinical Significance of Circulating Vascular Endothelial Growth Factor in Dogs with Mammary Gland Tumors

Increase in circulating vascular endothelial growth factor (VEGF) is suggested as a prognostic indicator in human patients with malignant tumors. The purpose of this study was to evaluate the clinical significance of circulating VEGF in dogs with mammary gland tumors (MGT). Both plasma and serum VEGF were significantly higher in dogs with MGT when compared with those in the healthy dogs. In dogs with MGT, the plasma and serum VEGF of the malignant group increased significantly compared with those of the benign group. Additionally, there was a significant difference between the plasma and serum VEGF in the groups with postoperative metastasis and no metastasis. Circulating VEGF is expected to be clinically available for the determination of prognosis in canine MGT.

Flaxseed and its components reduce metastasis after surgical excision of solid human breast tumor in nude mice

This study determined the effect of 10% flaxseed (FS) and its components, secoisolariciresinol diglycoside (SDG) and flaxseed oil (FO) alone or in combination (SDG+FO), on the metastasis and recurrence of human breast tumor after excision in nude mice. Mice were injected orthotopically with human breast cancer cells (MDA-MB-435) and fed basal diet (BD). When the tumors reached an average size of 110 mm(2) (0.9 g), surgical excisions were performed, and the mice were assigned to one of five diet groups for 7 weeks. The total incidence of metastasis was significantly lower in the FS, SDG, and SDG+FO groups. Reduced lung and lymph node metastases were observed in the FS and SDG+FO groups. In the FS and FO groups, a greater reduction in lung and total metastases was found when excised tumors were <or=0.9 versus >0.9 g. There was no significant difference in tumor recurrence among groups. In conclusion, FS and its components inhibited tumor metastasis but not tumor recurrence after surgical excision of the primary tumor.

Pathophysiology of seroma in breast cancer

PURPOSE

Seroma is the most common complication of mastectomy. The aim of this systematic review is to clarify the pathophysiology of seroma.

MATERIALS AND METHODS

A computer-assisted MEDLINE search was conducted, and additional references were found in the bibliographies of these articles. The reference terms ''breast cancer'', ''mastectomy'', ''seroma'', ''lymphocele'' and ''lymphocyst'' were used as both keyword and subject terms. The search was limited to studies published in English.

RESULTS

The definition of seroma was highly variable across studies, but was most commonly a seroma large enough to be noticed by the patient or medical staff and affecting the patient's satisfaction in the immediate or acute postoperative period. So far, only limited data are available on the severity of seroma. With respect to the pathophysiology of seroma, the data indicated that several anatomical factors, especially dead space, likely contribute to seroma formation. However, it was obscure whether seroma was due to lymph-like fluid or exudate.

CONCLUSION

There is considerable variability in the way seroma is defined across studies, and its pathophysiology remains uncertain.