Updated Management of Colorectal Cancer Liver Metastases: Scientific Advances Driving Modern Therapeutic Innovations

Colorectal cancer is the second leading cause of cancer-related deaths in the United States and accounts for an estimated 1 million deaths annually worldwide. The liver is the most common site of metastatic spread from colorectal cancer, significantly driving both morbidity and mortality. Although remarkable advances have been made in recent years in the management for patients with colorectal cancer liver metastases, significant challenges remain in early detection, prevention of progression and recurrence, and in the development of more effective therapeutics. In 2017, our group held a multidisciplinary state-of-the-science symposium to discuss the rapidly evolving clinical and scientific advances in the field of colorectal liver metastases, including novel early detection and prognostic liquid biomarkers, identification of high-risk cohorts, advances in tumor-immune therapy, and different regional and systemic therapeutic strategies. Since that time, there have been scientific discoveries translating into therapeutic innovations addressing the current management challenges. These innovations are currently reshaping the treatment paradigms and spurring further scientific discovery. Herein, we present an updated discussion of both the scientific and clinical advances and future directions in the management of colorectal liver metastases, including adoptive T-cell therapies, novel blood-based biomarkers, and the role of the tumor microbiome. In addition, we provide a comprehensive overview detailing the role of modern multidisciplinary clinical approaches used in the management of patients with colorectal liver metastases, including considerations toward specific molecular tumor profiles identified on next generation sequencing, as well as quality of life implications for these innovative treatments.

Colonic Microbial Abundances Predict Adenoma Formers

OBJECTIVE

We aimed to examine associations between the oral, fecal, and mucosal microbiome communities and adenoma formation.

SUMMARY BACKGROUND DATA

Data are limited regarding the relationships between microbiota and preneoplastic colorectal lesions.

METHODS

Individuals undergoing screening colonoscopy were prospectively enrolled and divided into adenoma and nonadenoma formers. Oral, fecal, nonadenoma and adenoma-adjacent mucosa were collected along with clinical and dietary information. 16S rRNA gene libraries were generated using V4 primers. DADA2 processed sequence reads and custom R-scripts quantified microbial diversity. Linear regression identified differential taxonomy and diversity in microbial communities and machine learning identified adenoma former microbial signatures.

RESULTS

One hundred four subjects were included, 46% with adenomas. Mucosal and fecal samples were dominated by Firmicutes and Bacteroidetes whereas Firmicutes and Proteobacteria were most abundant in oral communities. Mucosal communities harbored significant microbial diversity that was not observed in fecal or oral communities. Random forest classifiers predicted adenoma formation using fecal, oral, and mucosal amplicon sequence variant (ASV) abundances. The mucosal classifier reliably diagnosed adenoma formation with an area under the curve (AUC) = 0.993 and an out-of-bag (OOB) error of 3.2%. Mucosal classifier accuracy was strongly influenced by five taxa associated with the family Lachnospiraceae, genera Bacteroides and Marvinbryantia, and Blautia obeum. In contrast, classifiers built using fecal and oral samples manifested high OOB error rates (47.3% and 51.1%, respectively) and poor diagnostic abilities (fecal and oral AUC = 0.53).

CONCLUSION

Normal mucosa microbial abundances of adenoma formers manifest unique patterns of microbial diversity that may be predictive of adenoma formation.

Transcriptional and Cytotoxic Responses of Human Intestinal Organoids to IFN Types I, II, and III

The three types of IFN have roles in antimicrobial immunity and inflammation that must be properly balanced to maintain tissue homeostasis. For example, IFNs are elevated in the context of inflammatory bowel disease and may synergize with inflammatory cytokines such as TNF-α to promote tissue damage. Prior studies suggest that in mouse intestinal epithelial cells (IECs), type III IFNs are preferentially produced during viral infections and are less cytotoxic than type I IFN. In this study, we generated human IEC organoid lines from biopsies of ileum, ascending colon, and sigmoid colon of three healthy subjects to establish the baseline responses of normal human IECs to types I, II, and III IFN. We found that all IFN types elicited responses that were qualitatively consistent across intestinal biopsy sites. However, IFN types differed in magnitude of STAT1 phosphorylation and identity of genes in their downstream transcriptional programs. Specifically, there was a core transcriptional module shared by IFN types, but types I and II IFN stimulated unique transcriptional modules beyond this core gene signature. The transcriptional modules of type I and II IFN included proapoptotic genes, and expression of these genes correlated with potentiation of TNF-α cytotoxicity. These data define the response profiles of healthy human IEC organoids across IFN types, and they suggest that cytotoxic effects mediated by TNF-α in inflamed tissues may be amplified by a simultaneous high-magnitude IFN response.

Early Versus Late Recurrence in Rectal Cancer: Does Timing Matter?

BACKGROUND

The definition of early recurrence (ER) in rectal cancer is unclear, and the association of ER with post-recurrence survival (PRS) is poorly described. We therefore sought to identify if time to recurrence (TTR) is associated with PRS.

METHODS

We reviewed all curative-intent resections of nonmetastatic rectal cancer from 2003 to 2018 in our institutional registry within an NCI-Designated Comprehensive Cancer Center. Clinicopathologic data at diagnosis and first recurrence were collected and analyzed. ER was pre-specified at < 24 months and late recurrence (LR) at ≥ 24 months. PRS was evaluated by the Kaplan-Meier method and Cox proportional hazards modeling.

RESULTS

At a median follow-up of 53 months, 61 out of 548 (11.1%) patients undergoing resection experienced recurrence. Median TTR was 14 months (IQR 10-18) with 45 of 61 patients (74%) classified as ER. There were no significant baseline differences between patients with ER and LR. Most recurrences were isolated to the liver (26%) or lung (31%), and 16% were locoregional. ER was not associated with worse PRS compared to LR (P > 0.99). On multivariable analysis, detection of recurrence via workup for symptoms, CEA > 10 ng/mL at recurrence, and site of recurrence were independently associated with PRS.

CONCLUSION

ER is not associated with PRS in patients with resected rectal cancer. Symptomatic recurrences and those accompanied by CEA elevations are associated with worse PRS, while metastatic disease confined to the liver or lung is associated with improved PRS. Attention should be directed away from TTR and instead toward determining therapy for patients with treatable oligometastatic disease.

Are Surgical Guideline Changes in Diverticulitis Care Associated With Decreased Inpatient Healthcare Expenditure?

Objective

To examine possible associations in inpatient healthcare expenditure and guideline changes in the surgical management of diverticulitis, in terms of both cost per discharge and total aggregate costs of care.

Background

Medical costs throughout the healthcare system continue to rise due to increased prices for services, increased quantities of high-priced technologies, and an increase in the amount of overall services.

Methods

We used a retrospective case-control design using the Healthcare Cost and Utilization Project National Inpatient Sample to evaluate cost per discharge and total aggregate costs of diverticulitis management between 2004 and 2015. The year 2010 was selected as the transition between the pre and postguideline implementation period.

Results

The sample consisted of 450,122 unweighted (2,227,765 weighted) inpatient discharges for diverticulitis. Before the implementation period, inpatient costs per discharge increased 1.13% in 2015 dollars (95% confidence intervals [CI] 0.76% to 1.49%) per quarter. In the postimplementation period, the costs per discharge decreased 0.27% (95% CI -0.39% to -0.15%) per quarter. In aggregate, costs of care for diverticulitis increased 0.61% (95% CI 0.28% to 0.95%) per quarter prior to the guideline change, and decreased 0.52% (95% CI -0.87% to -0.17) following the guideline change.

Conclusions

This is the first study to investigate any associations between evidence-based guidelines meant to decrease surgical utilization and inpatient healthcare costs. Decreased inpatient costs of diverticulitis management may be associated with guideline changes to reduce surgical intervention for diverticulitis, both in regards to cost per discharge and aggregate costs of care.

Circulating Hybrid Cells: A Novel Liquid Biomarker of Treatment Response in Gastrointestinal Cancers

BACKGROUND

Real-time monitoring of treatment response with a liquid biomarker has potential to inform treatment decisions for patients with rectal adenocarcinoma (RAC), esophageal adenocarcinoma (EAC), and colorectal liver metastasis (CRLM). Circulating hybrid cells (CHCs), which have both immune and tumor cell phenotypes, are detectable in the peripheral blood of patients with gastrointestinal cancers, but their potential as an indicator of treatment response is unexplored.

METHODS

Peripheral blood specimens were collected from RAC and EAC patients after neoadjuvant therapy (NAT) or longitudinally during therapy and evaluated for CHC levels by immunostaining. Receiver operating characteristics (ROCs) and the Kaplan-Meier method were used to analyze the CHC level as a predictor of pathologic response to NAT and disease-specific survival (DSS), respectively.

RESULTS

Patients with RAC (n = 23) and EAC (n = 34) were sampled on the day of resection, and 11 patients (32%) demonstrated a pathologic complete response (pCR) to NAT. On ROC analysis, CHC levels successfully discriminated pCR from non-pCR with an area under the curve of 0.82 (95% confidence interval [CI], 0.71-0.92; P < 0.001). Additionally, CHC levels in the EAC patients correlated with residual nodal involvement (P = 0.026) and 1-year DSS (P = 0.029). The patients with RAC who were followed longitudinally during NAT (n = 2) and hepatic arterial infusion therapy for CRLM (n = 2) had CHC levels that decreased with therapy response and increased before clinical evidence of disease progression.

CONCLUSION

Circulating hybrid cells are a novel blood-based biomarker with potential for monitoring treatment response and disease progression to help guide decisions for further systemic therapy, definitive resection, and post-therapy surveillance. Additional validation studies of CHCs are warranted.

Relevance of circulating hybrid cells as a non-invasive biomarker for myriad solid tumors

Metastatic progression defines the final stages of tumor evolution and underlies the majority of cancer-related deaths. The heterogeneity in disseminated tumor cell populations capable of seeding and growing in distant organ sites contributes to the development of treatment resistant disease. We recently reported the identification of a novel tumor-derived cell population, circulating hybrid cells (CHCs), harboring attributes from both macrophages and neoplastic cells, including functional characteristics important to metastatic spread. These disseminated hybrids outnumber conventionally defined circulating tumor cells (CTCs) in cancer patients. It is unknown if CHCs represent a generalized cancer mechanism for cell dissemination, or if this population is relevant to the metastatic cascade. Herein, we detect CHCs in the peripheral blood of patients with cancer in myriad disease sites encompassing epithelial and non-epithelial malignancies. Further, we demonstrate that in vivo-derived hybrid cells harbor tumor-initiating capacity in murine cancer models and that CHCs from human breast cancer patients express stem cell antigens, features consistent with the potential to seed and grow at metastatic sites. Finally, we reveal heterogeneity of CHC phenotypes reflect key tumor features, including oncogenic mutations and functional protein expression. Importantly, this novel population of disseminated neoplastic cells opens a new area in cancer biology and renewed opportunity for battling metastatic disease.

A Distinct Innate Immune Signature of Early Onset Colorectal Cancer

Despite a decrease in the prevalence of colorectal cancer (CRC) over the last 40 y, the prevalence of CRC in people under 50 y old is increasing around the globe. Early onset (≤50 y old) and late onset (≥65 y old) CRC appear to have differences in their clinicopathological and genetic features, but it is unclear if there are differences in the tumor microenvironment. We hypothesized that the immune microenvironment of early onset CRC is distinct from late onset CRC and promotes tumor progression. We used NanoString immune profiling to analyze mRNA expression of immune genes in formalin-fixed paraffin-embedded surgical specimens from patients with early (n = 40) and late onset (n = 39) CRC. We found three genes, SAA1, C7, and CFD, have increased expression in early onset CRC and distinct immune signatures based on the tumor location. After adjusting for clinicopathological features, increased expression of CFD and SAA1 were associated with worse progression-free survival, and increased expression of C7 was associated with worse overall survival. We also performed gain-of-function experiments with CFD and SAA1 in s.c. tumor models and found that CFD is associated with higher tumor volumes, impacted several immune genes, and impacted three genes in mice that were also found to be differentially expressed in early onset CRC (EGR1, PSMB9, and CXCL9). Our data demonstrate that the immune microenvironment, characterized by a distinct innate immune response signature in early onset CRC, is unique, location dependent, and might contribute to worse outcomes.

Early Postoperative Mortality Among Patients Aged 75 Years or Older With Stage II/III Rectal Cancer

BACKGROUND

Elderly patients with rectal cancer have been excluded from randomized studies, thus little is known about their early postoperative mortality, which is critical for informed consent and treatment decisions. This study examined early mortality after surgery in elderly patients with locally advanced rectal cancer (LARC).

METHODS

Using the National Cancer Database, we identified patients aged ≥75 years, diagnosed with clinical stage II/III rectal cancer who underwent surgery in 2004 through 2015. Descriptive analyses determined proportions and trends and multivariable logistic regression analyses were performed to determine factors associated with early mortality after rectal cancer surgery.

RESULTS

Among 11,794 patients with rectal cancer aged ≥75 years, approximately 6% underwent local excision and 94% received radical resection. Overall 30-day, 90-day, and 6-month postoperative mortality rates were 4.2%, 7.8%, and 11.5%, respectively. Six-month mortality varied by age (8.4% in age 75-79 years to 18.3% in age ≥85 years), and comorbidity score (10.1% for comorbidity score 0 to 17.7% for comorbidity score ≥2). Six-month mortality declined from 12.3% in 2004 through 2007 to 10.2% in 2012 through 2015 (Ptrend=.0035). Older age, higher comorbidity score, and lower facility case volume were associated with higher 6-month mortality. Patients treated at NCI-designated centers had 30% lower odds of 6-month mortality compared with those treated at teaching/research centers.

CONCLUSIONS

Six-month mortality rates after surgery among patients aged ≥75 years with LARC have declined steadily over the past decade in the United States. Older age, higher comorbidity score, and care at a low-case-volume facility were associated with higher 6-month mortality after surgery. This information is necessary for informed consent and decisions regarding optimal management of elderly patients with LARC.

Stem Cell Marker Expression in Early Stage Colorectal Cancer is Associated with Recurrent Intestinal Neoplasia

BACKGROUND

Colorectal cancer (CRC) ranks second in cancer deaths worldwide and presents multiple management challenges, one of which is identifying high risk stage II disease that may benefit from adjuvant therapy. Molecular biomarkers, such as ones that identify stem cell activity, could better stratify high-risk cohorts for additional treatment.

METHODS

To identify possible biomarkers of high-risk disease in early-stage CRC, a discovery set (n = 66) of advanced-stage tumors were immunostained with antibodies to stemness proteins (CD166, CD44, CD26, and LGR5) and then digitally analyzed. Using a second validation cohort (n = 54) of primary CRC tumors, we analyzed protein and gene expression of CD166 across disease stages, and extended our analyses to CD166-associated genes (LGR5, ASCL2, BMI1, POSTN, and VIM) by qRT-PCR.

RESULTS

Stage III and metastatic CRC tumors highly expressed stem cell-associated proteins, CD166, CD44, and LGR5. When evaluated across stages, CD166 protein expression was elevated in advanced-stage compared to early-stage tumors. Notably, a small subset of stage I and II cancers harbored elevated CD166 protein expression, which correlated with development of recurrent cancer or adenomatous polyps. Gene expression analyses of CD166-associated molecules revealed elevated ASCL2 in primary tumors from patients who recurred.

CONCLUSIONS

We identified a protein signature prognostic of aggressive disease in early stage CRC. Stem cell-associated protein and gene expression identified a subset of early-stage tumors associated with cancer recurrence and/or subsequent adenoma formation. Signatures for stemness offer promising fingerprints for stratifying early-stage patients at high risk of recurrence.

Benign Anal Disease: Implementation of an Educational Program Across Specialties

BACKGROUND

Benign anal diseases, including hemorrhoids, fissures, abscesses, fistulas, and anal condylomata, affect 10%-15% of our population. Most patients seen by nonsurgical providers experience delayed treatment. We examined at our institution whether an educational session on anorectal diseases would benefit trainees from medical and surgical specialties.

MATERIALS AND METHODS

The study took place at Oregon Health & Science University, a primary institutional practice with 130 resident participants. An exploratory study using a 10-point pretest and posttest regarding these diseases was designed and administered to medical subspecialties, including general surgery (GS), emergency medicine, internal medicine, and family medicine, obstetrics/gynecology, and pediatric residents. Intervention was a 50-min presentation highlighting anatomy, history and physical findings, and disease treatment. The posttest was repeated after 6 mo to evaluate retention and overall satisfaction, and differences were evaluated.

RESULTS

With the exception of GS, posttest scores improved. Internal medicine improved most significantly. GS residents scored better on the pretest than other specialties; their posttest scores, however, declined. The survey demonstrated residents with prior education scored better on the pretest. PGY-1 and PGY-2 residents improved most on their posttest. On 6-mo retest, 17.6% of residents responded and posttest performance was 72%.

CONCLUSIONS

Nonsurgical residents have limited knowledge about benign anal diseases but demonstrate improvement after educational intervention. Surgery residents performed well, but demonstrate regression to the mean, common in test taking, but may also require a more advanced lecture. Formal institutional, regional, and national educational interventions are needed to improve the understanding of these diseases.

Who Undergoes Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy for Appendiceal Cancer? An Analysis of the National Cancer Database

BACKGROUND

We sought to identify patterns of care for patients with appendiceal cancer and identify clinical factors associated with patient selection for multimodality treatment, including cytoreductive surgery and perioperative intraperitoneal chemotherapy (CRS/PIC).

MATERIALS AND METHODS

National Cancer Database (NCDB) data from 2004 to 2014 of all diagnoses of appendiceal cancers were examined. We examined treatment modalities, as well as demographic, tumor-specific, and survival data. A multivariate logistic regression analysis was performed to determine the patient cohort most likely to receive CRS/PIC. Kaplan-Meier was used to estimate survival for all treatment groups. Significance was evaluated at P ≤ 0.05.

RESULTS

We analyzed data on 18,055 patients. Nine thousand nine hundred ninety-two (55.3%) were treated with surgery only, 5848 (32.4%) received surgery and systemic chemotherapy, 1393 (7.71%) received CRS/PIC, 520 (2.88%) received chemotherapy alone, and 302 (1.67%) received neither surgery nor chemotherapy. Significant predictors of receiving CRS/PIC included male sex (OR 1.33, 95% CI: 1.11-1.59), white race (OR 2.00, 95% CI 1.40-2.86), non-Hispanic ethnicity (OR 1.92, 95% CI 1.21-3.05), private insurance (OR 1.52, 95% CI 1.26-1.84), and well-differentiated tumors (OR 4.25, CI: 3.39-5.32) (P < 0.05). Treatment with CRS/PIC was associated with a higher 5-year survival for mucinous malignancies, when compared to surgery alone (65.6% versus 62.4%, P < 0.01). Treatment with CRS/PIC was also associated with higher 5-year survival for well-differentiated malignancies, when compared to all other treatment modalities (74.9% versus 65.4%, P < 0.01).

CONCLUSIONS

Patients were more likely to undergo CRS/PIC if they were male, white, privately insured, and with well-differentiated tumors. CRS/PIC was associated with improved survival in patients with mucinous and low-grade tumors.

Review of Colorectal Studies Using the National Cancer Database

The National Cancer Database (NCDB) is a large clinical oncology database developed with data collected from Commission on Cancer (CoC)-accredited facilities. The CoC is managed under the American College of Surgeons, and is a multidisciplinary team that maintains standards in cancer care delivery in health care settings. This database has been used in multiple cancer-focused studies and reports on cancer diagnosis, hospital-level, and patient-related demographics. The focus of this review is to explore and discuss the use of NCDB in colorectal surgery research. Furthermore, our aim for this review is to formulate a guide for researchers who are interested in using the NCDB to complete colorectal research.

Clinical Research Using the National Inpatient Sample: A Brief Review of Colorectal Studies Utilizing the NIS Database

The National Inpatient Sample (NIS) is the largest collection of longitudinal hospital care data in the United States and is sponsored by the Agency for Healthcare Research and Quality. The data are collected from state organizations, hospital associations, private organizations, and the federal government. This database has been used in more than 400 disease-focused studies to examine health care utilization, access, charges, quality, and outcomes of care. The database has been maintained since 1988, making it one of the oldest on hospital data. The focus of this review is to explore and discuss the use of NIS database in colorectal surgery research and to formulate a simplified guide of the data captured for future researchers.

microRNA-451a regulates colorectal cancer proliferation in response to radiation

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related death. The biologic response of CRC to standard of care adjuvant therapies such as chemotherapy and radiation are poorly understood. MicroRNAs (miRs) have been shown to affect CRC progression and metastasis. Therefore, we hypothesized that specific miRs modulate CRC response to chemoradiation.

METHODS

In this study, we used miR expression profiling and discovered a set of microRNAs upregulated rapidly in response to either a single 2 Gy dose fraction or a 10 Gy dose of γ-radiation in mouse colorectal carcinoma models. We used gain and loss-of-function studies in 2D and 3Dcell proliferation assays and colony formation assays to understand the role of the top miR candidate from our profiling. We used Student's T-tests for simple comparisons and two-factor ANOVA for evaluating significance.

RESULTS

The most upregulated candidate at early time points in our signature, miR-451a inhibited tumor cell proliferation and attenuated surviving fraction in longer-term cultures. Conversely, inhibition of miR-451a increased proliferation, tumorsphere formation, and surviving fraction of tumor cells. Using a bioinformatics approach, we identified four genes, CAB39, EMSY, MEX3C, and EREG, as targets of miR-451a. Transfection of miR-451a decreased both mRNA and protein levels of these targets. Importantly, we found miR-451a expression was high and CAB39, EMSY levels were low in a small subset of rectal cancer patients who had a partial response to chemoradiation when compared to patients that had no response. Finally, analysis of a TCGA colorectal cancer dataset revealed that CAB39 and EMSY are upregulated at the protein level in a significant number of CRC patients. Higher levels of CAB39 and EMSY correlated with poorer overall survival.

CONCLUSIONS

Taken together, our data indicates miR-451a is induced by radiation and may influence colorectal carcinoma proliferation via CAB39 and EMSY pathways.

Travel distance influences readmissions in colorectal cancer patients-what the primary operative team needs to know

BACKGROUND

Many colorectal cancer patients receive complex surgical care remotely. We hypothesized that their readmission rates would be adversely affected after accounting for differences in travel distance from primary/index hospital and correlate with mortality.

MATERIALS AND METHODS

We identified 48,481 colorectal cancer patients in the Surveillance, Epidemiology and End Results (SEER)-Medicare database. Travel distance was calculated, using Google Maps, and SAS. Multivariate negative binomial regression was used to identify factors associated with readmission rates. Overall survival was analyzed, using Kaplan-Meier and Cox proportional hazard.

RESULTS AND CONCLUSIONS

Thirty-day readmissions occurred in 14.9% of the cohort, 27.5% of which were to a nonindex hospital. In the colon and rectal cancer cohorts, readmissions were 14.5% and 16.5%, respectively. Rectal cancer patients had an increase in readmission by 13% (incidence rate ratios [IRR] 1.13; 95% confidence interval [CI] 1.05-1.21). Factors associated with readmission were male gender, advanced disease, length of stay (LOS), discharge disposition, hospital volume, Charlson score, and poverty level (P < 0.05). Greater distance traveled increased the likelihood of readmission but did not affect mortality. Travel distance influences readmission rates but not mortality. Discharge readiness to decrease readmissions is essential for colorectal cancer patients discharged from index hospitals.

Prognosis of small bowel adenocarcinoma in Crohn's disease compares favourably with de novo small bowel adenocarcinoma

AIM

Limited data exist on Crohn's disease (CD)-associated small bowel adenocarcinoma (SBA). A large-scale retrospective cohort study was conducted comparing the clinical features and outcome of CD-associated SBA and de novo SBA.

METHOD

Data for patients with small bowel adenocarcinoma were gathered from the 1992-2010 United States Surveillance, Epidemiology and End Results cancer registry-Medicare linked database. We identified 2123 patients, of whom 179 had CD-associated and 1944 de novo SBA. The main outcome measures were overall survival (OS) and cancer-specific survival (CSS).

RESULTS

CD-associated SBA was most commonly located in the ileum (62% vs 31%, P < 0.0001). CD patients were diagnosed at an earlier stage (I/II), compared with de novo SBA (55% vs 32%, P < 0.0001), and were more likely to undergo surgery (81% vs 72%, P = 0.0016). Chemotherapy use was similar (25% vs 21%, P = 0.1886). Patients with CD-associated SBA had better 5-year OS (43% vs 34%, P = 0.0121) but a similar CSS (65% vs 64%, P = 0.77). There was no difference in the OS between the cohorts when stratified by stage. On multivariate analysis, CD was not significantly related to OS [hazard ratio (HR) 0.97, 95% CI: 0.79-1.20, P = 0.7889]. Surgery and the extent of lymphadenectomy improved OS for all SBA patients (HR 0.73, 95% CI: 0.60-0.88, P = 0.001), whereas chemotherapy did not (HR 1.13, 95% CI: 0.99-1.28, P = 0.0665).

CONCLUSION

Patients with CD-associated SBA present at an earlier stage than patients with de novo SBA, they receive more surgery but similar rates of chemotherapy, and have similar OS and CSS. The presence of CD does not worsen survival after treatment of SBA.

Colorectal Cancer Liver Metastasis: Evolving Paradigms and Future Directions

In patients with colorectal cancer (CRC) that metastasizes to the liver, there are several key goals for improving outcomes including early detection, effective prognostic indicators of treatment response, and accurate identification of patients at high risk for recurrence. Although new therapeutic regimens developed over the past decade have increased survival, there is substantial room for improvement in selecting targeted treatment regimens for the patients who will derive the most benefit. Recently, there have been exciting developments in identifying high-risk patient cohorts, refinements in the understanding of systemic vs localized drug delivery to metastatic niches, liquid biomarker development, and dramatic advances in tumor immune therapy, all of which promise new and innovative approaches to tackling the problem of detecting and treating the metastatic spread of CRC to the liver. Our multidisciplinary group held a state-of-the-science symposium this past year to review advances in this rapidly evolving field. Herein, we present a discussion around the issues facing treatment of patients with CRC liver metastases, including the relationship of discrete gene signatures with prognosis. We also discuss the latest advances to maximize regional and systemic therapies aimed at decreasing intrahepatic recurrence, review recent insights into the tumor microenvironment, and summarize advances in noninvasive multimodal biomarkers for early detection of primary and recurrent disease. As we continue to advance clinically and technologically in the field of colorectal tumor biology, our goal should be continued refinement of predictive and prognostic studies to decrease recurrence after curative resection and minimize treatment toxicity to patients through a tailored multidisciplinary approach to cancer care.

Colorectal Cancer Liver Metastasis: Evolving Paradigms and Future Directions

In patients with colorectal cancer (CRC) that metastasizes to the liver, there are several key goals for improving outcomes including early detection, effective prognostic indicators of treatment response, and accurate identification of patients at high risk for recurrence. Although new therapeutic regimens developed over the past decade have increased survival, there is substantial room for improvement in selecting targeted treatment regimens for the patients who will derive the most benefit. Recently, there have been exciting developments in identifying high-risk patient cohorts, refinements in the understanding of systemic vs localized drug delivery to metastatic niches, liquid biomarker development, and dramatic advances in tumor immune therapy, all of which promise new and innovative approaches to tackling the problem of detecting and treating the metastatic spread of CRC to the liver. Our multidisciplinary group held a state-of-the-science symposium this past year to review advances in this rapidly evolving field. Herein, we present a discussion around the issues facing treatment of patients with CRC liver metastases, including the relationship of discrete gene signatures with prognosis. We also discuss the latest advances to maximize regional and systemic therapies aimed at decreasing intrahepatic recurrence, review recent insights into the tumor microenvironment, and summarize advances in noninvasive multimodal biomarkers for early detection of primary and recurrent disease. As we continue to advance clinically and technologically in the field of colorectal tumor biology, our goal should be continued refinement of predictive and prognostic studies to decrease recurrence after curative resection and minimize treatment toxicity to patients through a tailored multidisciplinary approach to cancer care.

Endoluminal Therapy in Colorectal Cancer

Appropriate endoscopic resection for colorectal polyps can present a challenge to endoscopists, as these lesions may harbor malignancy. With recent advances in endoscopy, however, we are now entering an exciting frontier of endoscopic therapy for gastrointestinal lesions. These techniques include endoluminal mucosal resection and endoscopic submucosal dissection, which may be utilized on several colonic lesions. This article will discuss these principle endoscopic techniques, their outcomes, and briefly highlight their influence on endoscopic interventions, including transanal endoscopic microsurgery and natural orifice transluminal endoscopic surgery.

Psychiatric Illness is a Disparity in the Surgical Management of Rectal Cancer

BACKGROUND

Psychiatric disorders are common in the US and represent a major health disparity but little is known about their impact on surgical management and outcomes in cancer.

OBJECTIVE

The aim of this study was to determine whether rectal cancer patients with psychiatric diagnoses have fewer sphincter-preserving procedures and higher postoperative complications.

METHODS

Overall, 23,914 patients from the Nationwide Inpatient Sample (NIS) who underwent surgery for rectal cancer from 2004 to 2011 were identified. Patients with comorbid common psychiatric diagnoses were identified by International Classification of Diseases, Ninth Revision (ICD-9) codes. Main outcomes were measured by operation performed, length of stay (LOS), postoperative complications, and discharge disposition.

RESULTS

Twenty percent of patients had a psychiatric diagnosis, with substance use being the most common psychiatric disorder (63 %). Patients with psychiatric diagnoses were more likely to be younger, White, have lower income, and have Medicaid insurance (p < 0.001) than those without. In a logistic regression model, patients with any psychiatric diagnosis were less likely to have sphincter-sparing surgery, controlling for patient sociodemographics, Charlson score, hospital procedure volume, and year (odds ratio 0.77; 95 % CI 0.72-0.83). LOS and postoperative complications were similar among the cohorts. Patients with psychiatric disorders were more likely to have home health care at discharge (p < 0.001).

CONCLUSIONS

Fewer sphincter-sparing procedures were performed on rectal cancer patients with psychiatric diagnoses. However, no significant differences in postoperative complications were observed.

Strictureplasty for Treatment of Crohn's Disease: an ACS-NSQIP Database Analysis

INTRODUCTION

Strictureplasty is an alternative to resection for treatment of Crohn's disease (CD) strictures. It preserves bowel length, and specialized centers report favorable outcomes. Strictureplasty rates, however, are thought to be low, and it was recently removed from required cases for colon and rectal surgery residents. We examined operative characteristics, and trends in its use using a large national database.

MATERIALS AND METHODS

We examined the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2005 to 2012, identifying patients with CD who underwent strictureplasty. We identified patient characteristics, outcome variables, and trends in utilization of strictureplasty.

RESULTS

A total of 9172 patients underwent surgery for CD. Two hundred fifty-six (2.8 %) underwent strictureplasty. Median preoperative albumin was 3.6. Preoperative steroid use and weight loss rates were 39 and 8 %. Rates of wound infection and organ space infection were 11 and 4 %. Rate of reoperation was 6 %. Outcomes did not change significantly over time (all p = NS). The proportion of CD operations that included a strictureplasty decreased from 5.1 to 1.7 % (OR 0.902 with each additional year, 95 % CI (0.852, 0.960), p < 0.001).

CONCLUSION

Strictureplasty as treatment for CD is decreasing in the ACS-NSQIP database. Infectious complications and reoperation rates following strictureplasty are low and have not changed over time.

A virtual reality endoscopic simulator augments general surgery resident cancer education as measured by performance improvement

Colorectal cancer is the second most common cause of death in the USA. The need for screening colonoscopies, and thus adequately trained endoscopists, particularly in rural areas, is on the rise. Recent increases in required endoscopic cases for surgical resident graduation by the Surgery Residency Review Committee (RRC) further emphasize the need for more effective endoscopic training during residency to determine if a virtual reality colonoscopy simulator enhances surgical resident endoscopic education by detecting improvement in colonoscopy skills before and after 6 weeks of formal clinical endoscopic training. We conducted a retrospective review of prospectively collected surgery resident data on an endoscopy simulator. Residents performed four different clinical scenarios on the endoscopic simulator before and after a 6-week endoscopic training course. Data were collected over a 5-year period from 94 different residents performing a total of 795 colonoscopic simulation scenarios. Main outcome measures included time to cecal intubation, "red out" time, and severity of simulated patient discomfort (mild, moderate, severe, extreme) during colonoscopy scenarios. Average time to intubation of the cecum was 6.8 min for those residents who had not undergone endoscopic training versus 4.4 min for those who had undergone endoscopic training (p < 0.001). Residents who could be compared against themselves (pre vs. post-training), cecal intubation times decreased from 7.1 to 4.3 min (p < 0.001). Post-endoscopy rotation residents caused less severe discomfort during simulated colonoscopy than pre-endoscopy rotation residents (4 vs. 10%; p = 0.004). Virtual reality endoscopic simulation is an effective tool for both augmenting surgical resident endoscopy cancer education and measuring improvement in resident performance after formal clinical endoscopic training.

Cancer and age related colonic crypt deficiencies in cytochrome c oxidase I

AIM: To investigate whether deficiency of expression of cytochrome c oxidase I (CcOI) in colonic crypts is associated with colon cancer.

METHODS: The pattern and level of expression of CcOI in non-neoplastic colonic crypts, and in dysplastic tissues, was assessed using standard immunohistochemical methods. Biopsies were obtained from individuals undergoing colonoscopies for screening purposes or for a medically indicated reason. Tissue samples were also obtained from surgical colonic resections. Samples from resections were taken from colonic mucosa 1 and 10 cm from tumors and from the tumors themselves. Samples were evaluated for frequency of crypts with reduced or absent expression of CcOI. In most crypts the loss was apparent throughout the entire crypt, while in a small minority the loss was segmental. The strong immunoreactivity using this monoclonal antibody makes the scoring unambiguous. The percent of crypts with reduced or absent expression of CcOI or (infrequent) segmented loss of expression was then calculated. Data analyses were performed using SPSS statistical package 17.0.

RESULTS: The average frequency of CcOI deficient crypts (CcOI-DC) is low in individuals between 20 and 39 years of age, with 0.48% ± 0.40% CcOI-DC for women and 1.80% ± 0.35% for men. CcOI-DC increases after age 40 years, so that between the ages of 40 and 44 years the average frequency of CcOI-DC goes up to 5.89% ± 0.84% in women and 2.15% ± 1.27% in men. By 80-84 years of age, the average frequency of CcOI-DC goes up in women to 15.77% ± 0.97% and in men to 22.6% ± 0.65%. The increases in CcOI-DC from ages 40-44 years compared to 80-84 years in women and men are significantly different with P < 0.01. For women over age 60 years, deficiency of CcOI expression is greater in those women who have had a cancer in their colon. The frequency of CcOI-DC, measured in men, increased in tissues adjacent to colon cancer, being 4.03% ± 0.27% in individuals free of neoplasia in the age range 55-64 years and 14.13% ± 0.35% in resected histologically normal tissue of men with cancer in the same age range, P < 0.001. Similar significant differences were noted in older age ranges. The frequency of CcOI-DC crypts in the cecum and sigmoid colon of an individual are significantly correlated, with an R² = 0.414 for women and R² = 0.528 for men, P < 0.001. This suggests that the factors determining the level of CcOI deficiency act throughout the colon. Most defective crypts are in clusters of two or more, a likely consequence of crypt fission. In the non-neoplastic margins of cancers, crypts are frequently deficient for CcOI, and such crypts may appear in large clusters, some containing more than 100 deficient crypts. CcOI deficiency is also apparent in colon cancers and sometimes involves a large section of the tumor. Overall, CcOI deficient cells can be visualized in segments of crypts, in whole crypts that increase in frequency with age, in crypts undergoing fission, in clusters of crypts where the clusters increase in size with age, in increased frequency near tumors, in large clusters in the intimate margins of tumors, and in the tumors themselves. There is no clear dividing line between early stages that can be considered aspects of aging and later stages that can be considered aspects of the progression to cancer. This ambiguity may reflect a rather general situation leading to adult cancer where the early stages of cellular change appear to be relatively innocuous features of the aging process but over decades may evolve into malignancy.

CONCLUSION: CcOI deficient crypts increase in frequency with age, and clusters of deficient crypts are associated with, and may give rise to, colon cancer.

Deficient Pms2, ERCC1, Ku86, CcOI in field defects during progression to colon cancer

In carcinogenesis, the "field defect" is recognized clinically because of the high propensity of survivors of certain cancers to develop other malignancies of the same tissue type, often in a nearby location. Such field defects have been indicated in colon cancer. The molecular abnormalities that are responsible for a field defect in the colon should be detectable at high frequency in the histologically normal tissue surrounding a colonic adenocarcinoma or surrounding an adenoma with advanced neoplasia (well on the way to a colon cancer), but at low frequency in the colonic mucosa from patients without colonic neoplasia.

Using immunohistochemistry, entire crypts within 10 cm on each side of colonic adenocarcinomas or advanced colonic neoplasias were found to be frequently reduced or absent in expression for two DNA repair proteins, Pms2 and/or ERCC1. Pms2 is a dual role protein, active in DNA mismatch repair as well as needed in apoptosis of cells with excess DNA damage. ERCC1 is active in DNA nucleotide excision repair. The reduced or absent expression of both ERCC1 and Pms2 would create cells with both increased ability to survive (apoptosis resistance) and increased level of mutability. The reduced or absent expression of both ERCC1 and Pms2 is likely an early step in progression to colon cancer.

DNA repair gene Ku86 (active in DNA non-homologous end joining) and Cytochrome c Oxidase Subunit I (involved in apoptosis) had each been reported to be decreased in expression in mucosal areas close to colon cancers. However, immunohistochemical evaluation of their levels of expression showed only low to modest frequencies of crypts to be deficient in their expression in a field defect surrounding colon cancer or surrounding advanced colonic neoplasia.

We show, here, our method of evaluation of crypts for expression of ERCC1, Pms2, Ku86 and CcOI. We show that frequency of entire crypts deficient for Pms2 and ERCC1 is often as great as 70% to 95% in 20 cm long areas surrounding a colonic neoplasia, while frequency of crypts deficient in Ku86 has a median value of 2% and frequency of crypts deficient in CcOI has a median value of 16% in these areas. The entire colon is 150 cm long (about 5 feet) and has about 10 million crypts in its mucosal layer. The defect in Pms2 and ERCC1 surrounding a colon cancer thus may include 1 million crypts. It is from a defective crypt that colon cancer arises.