Conditional Survival After Hepatectomy for Colorectal Liver Metastasis: Results from the Colorectal Liver Operative Metastasis International Collaborative (COLOMIC).

INTRODUCTION: Complete resection of colorectal liver metastasis (CLM) improves long-term survival in colorectal cancer. However, there is limited recent data on conditional survival (CS) as postoperative survival milestones are achieved post-hepatectomy. METHODS: A retrospective analysis was performed on the penta-institutional Colorectal Liver Operative Metastasis International Collaborative (COLOMIC), with 906 consecutive CLM hepatectomy cases. CS was calculated using Bayes' theorem and Kaplan-Meier analysis. Additional CS analyses were performed on additional clinicopathologic risk factors, including colon cancer laterality, KRAS mutation status, and extrahepatic disease. RESULTS: The 5-year CS was 40.6%, 45.3%, 52.8%, and 65.3% at 0, 1, 2, and 3 years postoperatively, with significant improvements each year (p < 0.005). CS was not significantly different between right-sided and left-sided colorectal cancers by 3 years postoperatively. Patients with KRAS mutations had worse CS at all timepoints (p < 0.001). Extrahepatic disease was a poor prognostic factor for OS and CS (p < 0.001). However, CS for patients with KRAS mutations or extrahepatic disease improved significantly as 2-year, postoperative survival was achieved (p < 0.05). CONCLUSIONS: Five-year CS after hepatectomy for CLM improved with each passing year of survival postoperatively. Although extrahepatic disease and KRAS mutations are poor prognostic factors for OS, these populations still had improved CS after 2 years postoperatively.

Machine Learning Models for Predicting the Outcomes of Surgical Treatment of Colorectal Liver Metastases.

BACKGROUND: Surgical intervention remains the cornerstone of a multidisciplinary approach in the treatment of colorectal liver metastases (CLM). Nevertheless, patient outcomes vary greatly. While predictive tools can assist decision-making and patient counseling, decades of efforts have yet to result in generating a universally adopted tool in clinical practice. STUDY DESIGN: An international collaborative database of CLM patients who underwent surgical therapy between 2000 and 2018 was used to select 1,004 operations for this study. Two different machine learning methods were applied to construct 2 predictive models for recurrence and death, using 128 clinicopathologic variables: gradient-boosted trees (GBTs) and logistic regression with bootstrapping (LRB) in a leave-one-out cross-validation. RESULTS: Median survival after resection was 47.2 months, and disease-free survival was 19.0 months, with a median follow-up of 32.0 months in the cohort. Both models had good predictive power, with GBT demonstrating a superior performance in predicting overall survival (area under the receiver operating curve [AUC] 0.773, 95% CI 0.743 to 0.801 vs LRB: AUC 0.648, 95% CI 0.614 to 0.682) and recurrence (AUC 0.635, 95% CI 0.599 to 0.669 vs LRB: AUC 0.570, 95% CI 0.535 to 0.601). Similarly, better performances were observed predicting 3- and 5-year survival, as well as 3- and 5-year recurrence, with GBT methods generating higher AUCs. CONCLUSIONS: Machine learning provides powerful tools to create predictive models of survival and recurrence after surgery for CLM. The effectiveness of both machine learning models varies, but on most occasions, GBT outperforms LRB. Prospective validation of these models lays the groundwork to adopt them in clinical practice.

Renalase is a novel tissue and serological biomarker in pancreatic ductal adenocarcinoma.

Dysregulated expression of the secretory protein renalase can promote pancreatic ductal adenocarcinoma (PDAC) growth in animal models. We characterized renalase expression in premalignant and malignant PDAC tissue and investigated whether plasma renalase levels corresponded to clinical PDAC characteristics. Renalase immunohistochemistry was used to determine the presence and distribution of renalase in normal pancreas, chronic pancreatitis, PDAC precursor lesions, and PDAC tissues. Associations between pretreatment plasma renalase and PDAC clinical status were assessed in patients with varied clinical stages of PDAC and included tumor characteristics, surgical resection in locally advanced/borderline resectable PDAC, and overall survival. Data were retrospectively obtained and correlated using non-parametric analysis. Little to no renalase was detected by histochemistry in the normal pancreatic head in the absence of abdominal trauma. In chronic pancreatitis, renalase immunoreactivity localized to peri-acinar spindle-shaped cells in some samples. It was also widely present in PDAC precursor lesions and PDAC tissue. Among 240 patients with PDAC, elevated plasma renalase levels were associated with worse tumor characteristics, including greater angiolymphatic invasion (80.0% vs. 58.1%, p = 0.012) and greater node positive disease (76.5% vs. 56.5%, p = 0.024). Overall survival was worse in patients with high plasma renalase levels with median follow-up of 27.70 months vs. 65.03 months (p < 0.001). Renalase levels also predicted whether patients with locally advanced/borderline resectable PDAC underwent resection (AUC 0.674; 95%CI 0.42-0.82, p = 0.04). Overall tissue renalase was increased in both premalignant and malignant PDAC tissues compared to normal pancreas. Elevated plasma renalase levels were associated with advanced tumor characteristics, decreased overall survival, and reduced resectability in patients with locally advanced/borderline resectable PDAC. These studies show that renalase levels are increased in premalignant pancreatic tissues and that its levels in plasma correspond to the clinical behavior of PDAC.

Clinical impact of underutilization of adjuvant therapy in node positive gastric adenocarcinoma.

BACKGROUND: Adjuvant therapy for gastric adenocarcinoma has shown a survival advantage, though it may be underutilized. The purpose of this study is to examine how infrequently adjuvant therapy is administered with curative intent gastrectomy for node positive gastric cancer and the long-term effects to patients. METHODS: The National Cancer Database was queried from 2006-2013 for patients with node positive gastric adenocarcinoma undergoing a potentially curative gastrectomy. Overall survival was compared between patients who received adjuvant chemotherapy or chemoradiation and those who did not. RESULTS: Of 2,565 patients, 793 (30.9%) patients did not receive any adjuvant chemotherapy or radiation therapy, while 147 (5.7%) received peri-operative chemotherapy and 723 (28.2%) received post-operative chemoradiation. From 2006-2013, the percentage of patients receiving peri-operative chemotherapy rose from 1.1% to 9.9%, while those receiving post-operative chemoradiation decreased from 39.7% to 21.6%. The adjusted restricted mean survival time over 5 years for no adjuvant therapy was 27.7 months, peri-operative chemotherapy was 39.6 months, and post-operative chemoradiation was 37.7 months (P<0.0001). CONCLUSIONS: Approximately one third of patients treated for node positive gastric cancer undergo surgical resection without adjuvant therapy. This is associated with poorer survival, highlighting the need for improvement in multimodality care and cancer outcomes.

Distinctive features of gastrointestinal stromal tumors arising from the colon and rectum.

BACKGROUND: Colon and rectal gastrointestinal stromal tumors (GISTs) are rare and poorly characterized. Because the majority of treatment guidelines for GISTs are extrapolated from tumors of gastric and small bowel origin, our aim was to better characterize the unique clinicopathologic features and prognostic factors of colon and rectal GISTs to guide clinical care. METHODS: The National Cancer Data Base (NCDB) was queried from 2006 to 2013 for cases of GISTs in the stomach, colon, and rectum. Patient demographics, clinical characteristics, and survival were compared. RESULTS: A total of 11,302 gastric GISTs were compared to 398 colon and 393 rectal GISTs. After propensity matching, compared to gastric GISTs, rectal GISTs had improved overall survival (HR =0.695, P=0.0264), while colon GISTs had worse overall survival (HR =1.6, P=0.0005). Surgical treatment for rectal GISTs was more likely to be local excision compared to colonic GISTs (51.1% vs. 8.4%, P<0.0001). Colon and gastric GISTs were less likely to receive systemic therapy compared to rectal GISTs (34.2% vs. 34.0% vs. 55.2%, P<0.0001). Adjuvant systemic therapy conveyed a survival advantage to rectal GISTs (HR =0.47, P=0.042) but not colon GISTs. There was a negative impact of adjuvant therapy on survival for colon GISTs <5 cm (HR =3.41, P=0.032). CONCLUSIONS: Patients with rectal GISTs live longer than those with colon and gastric GISTs, and adjuvant therapy prolongs their survival. Many patients with colon GISTs are treated with adjuvant therapy despite a detrimental effect on survival. Tumor biology of colon and rectal GISTs needs to be better studied to tailor treatment.

Final analysis of a phase II study of modified FOLFIRINOX in locally advanced and metastatic pancreatic cancer.

BACKGROUND: Modifications of FOLFIRINOX are widely used despite the absence of prospective data validating efficacy in metastatic disease (metastatic pancreatic cancer (MPC)) or locally advanced pancreatic cancer (LAPC). We conducted a multicentre phase II study of modified FOLFIRINOX in advanced pancreatic cancer to assess the impact of dose attenuation in MPC and efficacy in LAPC. METHODS: Patients with untreated MPC or LAPC received modified FOLFIRINOX (irinotecan and bolus 5-fluorouracil reduced by 25%). Adverse events (AEs) were compared with full-dose FOLFIRINOX. Response rate (RR), median progression-free survival (PFS) and median overall survival (OS) were determined. RESULTS: In total, 31 and 44 patients with LAPC and MPC were enrolled, respectively. In MPC, efficacy of modified FOLFIRINOX was comparable with FOLFIRINOX with RR 35.1%, OS 10.2 months (95% CI 7.65-14.32) and PFS 6.1 months (95% CI 5.19-8.31). In LAPC, efficacy was notable with RR 17.2%, resection rate 41.9%, PFS 17.8 months (95% CI 11.0-23.9) and OS 26.6 months (95% CI 16.7, NA). Neutropenia (P<0.0001), vomiting (P<0.001) and fatigue (P=0.01) were significantly decreased. [(18)F]-Fluorodeoxyglucose positron emission tomography imaging response did not correlate with PFS or OS. CONCLUSIONS: In this first prospective study of modified FOLFIRINOX in MPC and LAPC, we observed decreased AEs compared with historical control patients. In MPC, the efficacy appears comparable with FOLFIRINOX. In LAPC, PFS and OS were prolonged and support the continued use of FOLFIRINOX in this setting.

The novel tumor angiogenic factor, adrenomedullin-2, predicts survival in pancreatic adenocarcinoma.

BACKGROUND: Tumor angiogenesis has been demonstrated to have an important role in the development, progression, and metastasis of pancreas cancer. Adrenomedullin-2 (ADM2) is a calcitonin gene-related peptide that has recently been shown to be a novel tumor angiogenesis factor, acting via mitogen-activated protein kinase/extracellular signal-regulated kinase, phosphoinositide 3-kinase/Akt, and vascular endothelial growth factor/vascular endothelial growth factor-2 signaling pathways. Through the use of tissue microarray (TMA) technology, we hypothesize that ADM2 is an important tumor angiogenesis factor in pancreatic cancer. METHODS: Multiple TMAs were created using tissue from pancreatic cancer patients resected between January 1996 and December 2006. Core tissue samples of formalin-fixed, paraffin-embedded blocks of pancreatic cancer tissue were collected through an institutional review board-approved protocol and linked to available clinicopathologic data. Two TMAs consisting of 112 and 60 patients with pancreatic adenocarcinoma were studied for ADM2 protein expression using a quantitative, automated immunofluorescent microscopy system, a technology that removes potential observer bias in TMA analysis. The results were analyzed using independent Student t-test, chi-square, log-rank regression, and Kaplan-Meier methods. RESULTS: One hundred sixteen patients were identified for complete analysis, and 56 patients had complete survival data. Median follow-up for survivors was 14.5 mo. Total cellular levels of ADM2 were found to be a predictor of survival in pancreatic cancer. Low ADM2 levels were associated with a higher 5-y survival compared with high ADM2 levels (18% versus 6%, P = 0.05). Median survival was also worse in high ADM2 expressers (18.7 versus 8.6 mo). In accordance with prior-published pancreatic cancer data, a worse histologic grade (P = 0.001), tumor (T) stage (P = 0.009), and overall disease stage (P = 0.004), all portended a worse survival. CONCLUSIONS: For the first time, we have demonstrated that high levels of ADM2 expression predict a poorer survival in patients with pancreatic adenocarcinoma. This suggests a possible role of ADM2 in pancreas cancer and as a novel biomarker that predicts poorer survival. Additional study of ADM2 in pancreatic cancer will help reveal its true angiogenic role in pancreas cancer and its potential role as a novel therapeutic target.

Automated quantitative analysis of tissue microarray of 443 patients with colorectal adenocarcinoma: low expression of Bcl-2 predicts poor survival.

BACKGROUND: Bcl-2 has been implicated in the development and progression of a number of cancers including colorectal cancer. Reports of Bcl-2 expression in colorectal cancer and patient outcomes have been inconsistent due to small cohorts and semi-quantitative grading methods. STUDY DESIGN: We used a high throughput tissue microarray system (automated quantitative analysis [AQUA]), analyzing colorectal adenocarcinoma samples from 443 patients resected during the period of 1967 to 1986. This system uses fully quantitative, automated fluorescent microscopy to accurately assess Bcl-2 expression in colorectal cancer samples. Clinicopathologic variables were collected prospectively and were assessed using log-rank tests and Cox proportional hazards models. RESULTS: At a median follow-up of 54 months, the 5- and 10-year disease-specific survivals for all patients were 59.2% and 52.1%, respectively. Loss of Bcl-2 expression was seen in 70.4% of tumors and was associated with a decreased 5-year disease-specific survival (55.8% vs 75.6%, p = 0.001 and relative risk [RR] 1.8) and decreased 5-year overall survival (45.8% vs 56.5%, p = 0.046 and RR 1.2). On univariate analysis, T stage, N stage, and loss of Bcl-2 expression predicted poor disease-specific survival. On multivariate analysis, Bcl-2 expression was an independent prognostic factor for disease-specific survival (p = 0.034). CONCLUSIONS: Our results indicate that loss of Bcl-2 expression in colorectal cancer is associated with decreased disease-specific and overall survival. This finding may help identify a subset of patients with a more aggressive phenotype and guide adjuvant chemotherapy choices.

Hepatocellular carcinoma: a comprehensive overview of surgical therapy.

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, with a rising incidence in the United States. The increase in medical and locally ablative therapies have improved prognosis, however surgery, either liver resection or transplantation, remains the mainstay of therapy. An increased understanding of liver anatomy, improved imaging modalities and refinements of surgical technique have all led to improved outcomes after surgery. Both resection and transplantation may be used in a complementary manner. Resection remains the treatment of choice for HCC when feasible. Liver transplantation, which removes both the tumor and the underlying diseased liver offers excellent outcomes in patients that meet the Milan criteria. While both these modalities have relatively well defined roles, the treatment of these patients must be tailored individually, using a multidisciplinary approach, to maximize survival, quality of life and allocation of scarce organs.

Intermedin is overexpressed in hepatocellular carcinoma and regulates cell proliferation and survival.

Angiogenesis is one of the hallmarks of tumor growth and metastasis. Identification of tumor angiogenic factors has been a critical component in understanding cancer biology and treatment. Intermedin (IMD) has been reported to promote angiogenesis in a rat ischemic model and human umbilical vascular endothelial cells. Our study sought to determine the role of IMD in human hepatocellular carcinoma tumor progression. High IMD mRNA expression levels were observed in human hepatocellular carcinoma tumors, even in early stage disease, by real-time RT-PCR. Immunohistochemical analysis of hepatocellular carcinoma clinical samples demonstrated that the tumor regions were significantly more immunoreactive for IMD than adjacent benign liver. Inhibition of IMD expression using RNA interference reduced cell proliferation in SK-Hep-1 and SNU-398 cells. Blockage of IMD signaling using either an antagonist peptide or a neutralizing antibody inhibited growth in a dose-dependent manner with concomitant induction of apoptosis, causing cleavage of caspase-8 and downregulation of Gli1 and Bcl2. Conversely, addition of IMD active peptide increased the phosphorylation level of extracellular signal-regulated kinase. Thus, IMD might play an important role in cell proliferation and survival of hepatocellular carcinoma. Our data suggests that IMD is a potential biomarker and therapeutic target for hepatocellular carcinoma.

Laparoscopic repair of iatrogenic diaphragmatic hernia following radiofrequency ablation for hepatocellular carcinoma.

Radiofrequency ablation (RFA) is commonly used for treating unresectable hepatic malignancies. Some commonly associated complications of RFA include fever, symptomatic pleural effusion, abscess, hepatoma and hepatic insufficiency. Here, we report a case of diaphragmatic hernia in a patient following RFA for hepatic malignancy with cirrhosis.

Tissue microarray analysis of 560 patients with colorectal adenocarcinoma: high expression of HuR predicts poor survival.

The purpose of this study is to characterize the expression of HuR in colorectal carcinoma and determine its correlation with clinical outcome. Differential expression of HuR has been suggested to be of prognostic significance in carcinomas of the ovaries, stomach, and breast. HuR regulates the expression of a variety of proteins critical to carcinogenesis via the pathways of cell-cycle progress, invasion, and metastasis. Increasing evidence suggests that angiogenic pathways are involved. A tissue microarray consisting of tumors from 560 patients with colorectal adenocarcinoma was analyzed for HuR protein expression using a quantitative, automated immunofluorescent microscopy system (AQUA). Clinical data corresponding to each examined specimen collected through an institutional review board (IRB)-approved protocol were analyzed using chi-squared test, Cox regression, and Kaplan-Meier analysis. Median follow-up was 54 months. Along with tumor stage and overall tumor-node-metastasis (TNM) stage, HuR expression was found to be an independent predictor of survival. In patients in the highest quartile of total HuR expression, survival was 22.8 months less than those in the lower quartiles (40.6 versus 63.4 months, p = 0.04). Furthermore, HuR levels correlate positively with expression of vascular endothelial growth factor (VEGF) and CD31, a marker for vascular endothelium. We conclude that expression of high levels of HuR correlates with features of advanced disease and portends poorer survival in patients with colorectal adenocarcinoma. These results further suggest that HuR exerts its tumorigenic effects through VEGF-mediated angiogenesis and may be a novel therapeutic target in colorectal cancer.

A novel in vitro model of lymphatic metastasis from colorectal cancer.

INTRODUCTION: For many types of cancers, successful metastasis is critically dependent on tumor cell survival under flow conditions in the lymphatic system as well as attachment to the lymphatic endothelium at distal sites. In the lymphatic system, tumor cells are exposed to dynamic forces of laminar shear stress; however, there are currently no models to study the effects of these dynamic fluid forces on colorectal cancer metastasis. This study aims to establish the rudiments of an in vitro flow system that mimics the conditions to which tumor colorectal cancer cells (CRCCs) are exposed during lymphatic spread. METHODS: Human CRCCs (RKO and HCT-8) were cultured on collagen-1 coated glass slides in 10% fetal bovine serum, and grown until 50% confluence under static conditions. Subconfluent cells were then treated with laminar shear stress (1.2 dynes/cm(2)) using a Flexcell Streamer (Flexcell International Corp., Hillsborough, NC) parallel plate chamber for up to 48 h, in the continued presence of serum. Control conditions consisted of cells maintained under static conditions (0 dynes/cm(2)). Cells were examined with digital microscopy. Cell number was determined directly by cell count. Poly (ADP-ribose) polymerase-1, caspase-3, matrix metalloproteinase (MMP)-2, MMP-9, and vascular endothelial growth factor C levels were measured by Western blot. RESULTS: CRCCs survived under conditions of lymphatic flow (1.2 dynes/cm(2)), and were confluent by 48 h. Although a small number of cells (10% to 15%) initially detached upon exposure to shear stress, the majority of cells remained attached, and mitotic cells were observed. Cells demonstrated increased attachment and spreading under lymphatic flow compared with cells kept under control conditions. Cell number increased in cells treated with both lymphatic flow and static conditions by similar amounts until confluence was achieved. Cleaved products of poly (ADP-ribose) polymerase-1 and caspase-3 were not observed. MMP-2, MMP-9, and vascular endothelial growth factor C were expressed to similar degrees at all time points in cells exposed to lymphatic flow. CONCLUSIONS: Using a novel in vitro model of lymphatic flow, we describe colorectal tumor cell proliferation and expression of peptides critical to lymphatic spread under flow conditions. The ability to model lymphatic spread in vitro will allow additional studies to determine mechanisms of tumor cell survival in the lymphatic system.

Venous identity is lost but arterial identity is not gained during vein graft adaptation.

OBJECTIVES: Ephrin ligands and Eph receptors are signaling molecules that are differentially expressed on arteries and veins during development. We examined whether Eph-B4, a venous marker, and Ephrin-B2, an arterial marker, are regulated during vein graft adaptation in humans and aged rats. METHODS AND RESULTS: Eph-B4 transcripts and immunodetectable protein are downregulated in endothelial and smooth muscle cells of patent vein grafts in both humans and in aged rats, whereas Ephrin-B2 transcripts and protein are not strongly induced. Other markers of arterial identity, including dll4 and notch-4, are also not induced during vein graft adaptation in aged rats. Because VEGF-A is upstream of the Ephrin-Eph pathway, and expression of VEGF-A is induced only at early time points after exposure of the vein to the arterial environment, we inhibited VEGF-A in vein grafts using an siRNA-based approach. Vein grafts treated with siRNA directed against VEGF-A demonstrated a thicker intima-media containing alpha-actin, consistent with arterialization, but did not contain Eph-B4 or Ephrin-B2. CONCLUSIONS: Venous identity is preserved in the veins of aged animals, but is lost during adaptation to the arterial circulation; arterial markers are not induced. Markers of vessel identity are plastic in adults and their selective regulation may mediate vein graft adaptation to the arterial environment in aged animals and humans.

Assessing risk factors for adverse outcomes in emergent colorectal surgery.

BACKGROUND: A variety of factors influence the increased morbidity and mortality seen in patients undergoing emergent colon surgery. Understanding comorbid conditions and variations in preoperative laboratory values that effect both morbidity and mortality can influence clinical decision making. METHODS: During a 5-year period 185 patients underwent colon surgery at the Veterans Administration Hospital in West Haven, CT. Through a retrospective chart review patients were classified as having either emergent or elective surgery. Patient characteristics and postoperative outcomes were analyzed using Chi Square and logistic regression models. RESULTS: Differences existed in preoperative variables as well as postoperative outcomes when comparing emergent and elective paitents. In those patients undergoing emergent colorectal surgery, both morbidity and mortality were increased and overall survival decresed when compared to a non-emergent population. CONCLUSIONS: Through identification of preoperative variables such as a hematocrit <30, the use of steroids, an albumin <3.5, and a creatinine of >1.4, those patients at risk for postoperative morbidity and mortality can be identified and clinical decision making can be appropriately adjusted.

Liver resection for metastatic colorectal cancer in the age of neoadjuvant chemotherapy and bevacizumab.

Hepatic metastases from colorectal carcinoma (CRC) were once thought to portend a uniformly grim outcome; however, improvements in chemotherapeutic and surgical approaches have led to significant advances as well as new clinical challenges. Some 60% of the 150,000 patients diagnosed with CRC each year in the United States will develop hepatic metastases. Only a fraction of these metastases are resectable at the time of presentation, but an increasing number of patients are able to undergo resection after neoadjuvant chemotherapy. Additionally, recent trials have demonstrated the efficacy of using chemotherapy with bevacizumab as first-line therapy for metastatic CRC, but how this treatment will affect surgical resection is unknown. Herein, we review the recent literature regarding neoadjuvant chemotherapy for hepatic metastases from CRC, discuss key aspects of the basic science of hepatic regeneration with regard to angiogenic mediators, and outline the key problems to be solved so that a rational strategy can be developed to treat patients with hepatic colorectal metastases in the age of neoadjuvant chemotherapy and antiangiogenic drugs.

Post-transcriptional regulation of vascular endothelial growth factor: implications for tumor angiogenesis.

Vascular endothelial growth factor (VEGF) is a potent secreted mitogen critical for physiologic and tumor angiogenesis. Regulation of VEGF occurs at several levels, including transcription, mRNA stabilization, translation, and differential cellular localization of various isoforms. Recent advances in our understanding of post-transcriptional regulation of VEGF include identification of the stabilizing mRNA binding protein, HuR, and the discovery of internal ribosomal entry sites in the 5'UTR of the VEGF mRNA. Monoclonal anti-VEGF antibody was recently approved for use in humans, but suffers from the need for high systemic doses. RNA interference (RNAi) technology is being used in vitro and in animal models with promising results. Here, we review the literature on post-transcriptional regulation of VEGF and describe recent progress in targeting these mechanisms for therapeutic benefit.