Long-Term Results of Organ Preservation in Patients With Rectal Adenocarcinoma Treated With Total Neoadjuvant Therapy: The Randomized Phase II OPRA Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.To assess long-term risk of local tumor regrowth, we report updated organ preservation rate and oncologic outcomes of the OPRA trial (ClinicalTrials.gov identifier: NCT02008656). Patients with stage II/III rectal cancer were randomly assigned to receive induction chemotherapy followed by chemoradiation (INCT-CRT) or chemoradiation followed by consolidation chemotherapy (CRT-CNCT). Patients who achieved a complete or near-complete response after finishing treatment were offered watch-and-wait (WW). Total mesorectal excision (TME) was recommended for those who achieved an incomplete response. The primary end point was disease-free survival (DFS). The secondary end point was TME-free survival. In total, 324 patients were randomly assigned (INCT-CRT, n = 158; CRT-CNCT, n = 166). Median follow-up was 5.1 years. The 5-year DFS rates were 71% (95% CI, 64 to 79) and 69% (95% CI, 62 to 77) for INCT-CRT and CRT-CNCT, respectively (P = .68). TME-free survival was 39% (95% CI, 32 to 48) in the INCT-CRT group and 54% (95% CI, 46 to 62) in the CRT-CNCT group (P = .012). Of 81 patients with regrowth, 94% occurred within 2 years and 99% occurred within 3 years. DFS was similar for patients who underwent TME after restaging (64% [95% CI, 53 to 78]) and patients in WW who underwent TME after regrowth (64% [95% CI, 53 to 78]; P = .94). Updated analysis continues to show long-term organ preservation in half of the patients with rectal cancer treated with total neoadjuvant therapy. In patients who enter WW, most cases of tumor regrowth occur in the first 2 years.

Organ Preservation and Survival by Clinical Response Grade in Patients With Rectal Cancer Treated With Total Neoadjuvant Therapy: A Secondary Analysis of the OPRA Randomized Clinical Trial

Importance

Assessing clinical tumor response following completion of total neoadjuvant therapy (TNT) in patients with locally advanced rectal cancer is paramount to select patients for watch-and-wait treatment.

Objective

To assess organ preservation (OP) and oncologic outcomes according to clinical tumor response grade.

Design, Setting, and Participants

This was secondary analysis of the Organ Preservation in Patients with Rectal Adenocarcinoma trial, a phase 2, nonblinded, multicenter, randomized clinical trial. Randomization occurred between April 2014 and March 2020. Eligible participants included patients with stage II or III rectal adenocarcinoma. Data analysis occurred from March 2022 to July 2023.

Intervention

Patients were randomized to induction chemotherapy followed by chemoradiation or chemoradiation followed by consolidation chemotherapy. Tumor response was assessed 8 (±4) weeks after TNT by digital rectal examination and endoscopy and categorized by clinical tumor response grade. A 3-tier grading schema that stratifies clinical tumor response into clinical complete response (CCR), near complete response (NCR), and incomplete clinical response (ICR) was devised to maximize patient eligibility for OP.

Main Outcomes and Measures

OP and survival rates by clinical tumor response grade were analyzed using the Kaplan-Meier method and log-rank test.

Results

There were 304 eligible patients, including 125 patients with a CCR (median [IQR] age, 60.6 [50.4-68.0] years; 76 male [60.8%]), 114 with an NCR (median [IQR] age, 57.6 [49.1-67.9] years; 80 male [70.2%]), and 65 with an ICR (median [IQR] age, 55.5 [47.7-64.2] years; 41 male [63.1%]) based on endoscopic imaging. Age, sex, tumor distance from the anal verge, pathological tumor classification, and clinical nodal classification were similar among the clinical tumor response grades. Median (IQR) follow-up for patients with OP was 4.09 (2.99-4.93) years. The 3-year probability of OP was 77% (95% CI, 70%-85%) for patients with a CCR and 40% (95% CI, 32%-51%) for patients with an NCR (P < .001). Clinical tumor response grade was associated with disease-free survival, local recurrence-free survival, distant metastasis-free survival, and overall survival.

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial, most patients with a CCR after TNT achieved OP, with few developing tumor regrowth. Although the probability of tumor regrowth was higher for patients with an NCR compared with patients with a CCR, a significant proportion of patients achieved OP. These findings suggest the 3-tier grading schema can be used to estimate recurrence and survival outcomes in patients with locally advanced rectal cancer who receive TNT.

Trial Registration

ClinicalTrials.gov Identifier: NCT02008656.

Organ Preservation in Patients With Rectal Adenocarcinoma Treated With Total Neoadjuvant Therapy

PURPOSE

Prospective data on the efficacy of a watch-and-wait strategy to achieve organ preservation in patients with locally advanced rectal cancer treated with total neoadjuvant therapy are limited.

METHODS

In this prospective, randomized phase II trial, we assessed the outcomes of 324 patients with stage II or III rectal adenocarcinoma treated with induction chemotherapy followed by chemoradiotherapy (INCT-CRT) or chemoradiotherapy followed by consolidation chemotherapy (CRT-CNCT) and either total mesorectal excision (TME) or watch-and-wait on the basis of tumor response. Patients in both groups received 4 months of infusional fluorouracil-leucovorin-oxaliplatin or capecitabine-oxaliplatin and 5,000 to 5,600 cGy of radiation combined with either continuous infusion fluorouracil or capecitabine during radiotherapy. The trial was designed as two stand-alone studies with disease-free survival (DFS) as the primary end point for both groups, with a comparison to a null hypothesis on the basis of historical data. The secondary end point was TME-free survival.

RESULTS

Median follow-up was 3 years. Three-year DFS was 76% (95% CI, 69 to 84) for the INCT-CRT group and 76% (95% CI, 69 to 83) for the CRT-CNCT group, in line with the 3-year DFS rate (75%) observed historically. Three-year TME-free survival was 41% (95% CI, 33 to 50) in the INCT-CRT group and 53% (95% CI, 45 to 62) in the CRT-CNCT group. No differences were found between groups in local recurrence-free survival, distant metastasis-free survival, or overall survival. Patients who underwent TME after restaging and patients who underwent TME after regrowth had similar DFS rates.

CONCLUSION

Organ preservation is achievable in half of the patients with rectal cancer treated with total neoadjuvant therapy, without an apparent detriment in survival, compared with historical controls treated with chemoradiotherapy, TME, and postoperative chemotherapy.

Organ Preservation in Patients With Rectal Adenocarcinoma Treated With Total Neoadjuvant Therapy

PURPOSE

Prospective data on the efficacy of a watch-and-wait strategy to achieve organ preservation in patients with locally advanced rectal cancer treated with total neoadjuvant therapy are limited.

METHODS

In this prospective, randomized phase II trial, we assessed the outcomes of 324 patients with stage II or III rectal adenocarcinoma treated with induction chemotherapy followed by chemoradiotherapy (INCT-CRT) or chemoradiotherapy followed by consolidation chemotherapy (CRT-CNCT) and either total mesorectal excision (TME) or watch-and-wait on the basis of tumor response. Patients in both groups received 4 months of infusional fluorouracil-leucovorin-oxaliplatin or capecitabine-oxaliplatin and 5,000 to 5,600 cGy of radiation combined with either continuous infusion fluorouracil or capecitabine during radiotherapy. The trial was designed as two stand-alone studies with disease-free survival (DFS) as the primary end point for both groups, with a comparison to a null hypothesis on the basis of historical data. The secondary end point was TME-free survival.

RESULTS

Median follow-up was 3 years. Three-year DFS was 76% (95% CI, 69 to 84) for the INCT-CRT group and 76% (95% CI, 69 to 83) for the CRT-CNCT group, in line with the 3-year DFS rate (75%) observed historically. Three-year TME-free survival was 41% (95% CI, 33 to 50) in the INCT-CRT group and 53% (95% CI, 45 to 62) in the CRT-CNCT group. No differences were found between groups in local recurrence-free survival, distant metastasis-free survival, or overall survival. Patients who underwent TME after restaging and patients who underwent TME after regrowth had similar DFS rates.

CONCLUSION

Organ preservation is achievable in half of the patients with rectal cancer treated with total neoadjuvant therapy, without an apparent detriment in survival, compared with historical controls treated with chemoradiotherapy, TME, and postoperative chemotherapy.

Hepatic arterial infusion pump chemotherapy combined with systemic therapy for patients with advanced colorectal liver metastases: Outcomes in a newly established program

BACKGROUND AND OBJECTIVES

Colorectal liver metastasis (CRLM) is a leading cause of morbidity and mortality in patients with colorectal cancer. Hepatic arterial infusion (HAI) chemotherapy has been demonstrated to improve survival in patients with resected CRLM and to facilitate conversion of technically unresectable disease.

METHODS

Between 2016 and 2018, n = 22 HAI pumps were placed for CRLM. All patients received systemic chemotherapy concurrently with HAI floxuridine/dexamethasone. Overall survival (OS) and progression-free survival (PFS) were assessed using the Kaplan-Meier method.

RESULTS

HAI pumps were placed in seven patients with completely resected CRLM and 15 patients with unresectable disease. Twenty-one patients received HAI floxuridine with a median of 5 total HAI cycles (interquartile range: 4-7). Biliary sclerosis was the most common HAI-related complication (n = 5, 24%). Of the 13 patients treated to convert unresectable CRLM, 3 (23%) underwent hepatic resection with curative intent after a median of 7 HAI cycles (range: 4-10). For all HAI patients, the mean OS was 26.7 months from CRLM diagnosis, while the median PFS and hepatic PFS from pump placement were 9 and 13 months, respectively.

CONCLUSION

Concomitant HAI and systemic therapy can be utilized at multidisciplinary programs for patients with advanced CRLM, both in the adjuvant setting and to facilitate conversion of unresectable disease.

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.

Assessment of a circular powered stapler for creation of anastomosis in left-sided colorectal surgery: A prospective cohort study

BACKGROUND

Circular staplers perform a critical function for creation of anastomoses in colorectal surgeries. Powered stapling systems allow for reduced force required by surgeons to fire the device and may provide advantages for creating a secure anastomosis. The objective of this study was to evaluate the clinical performance of a novel circular powered stapler in a post-market setting, during left-sided colectomy procedures.

MATERIALS AND METHODS

Consecutive subjects underwent left-sided colorectal resections that included anastomosis performed with the ECHELON CIRCULAR™ Powered Stapler (ECP). The primary endpoint was the frequency in which a stapler performance issue was observed. Secondary endpoints included evaluation of ease of use of the device via a surgeon satisfaction questionnaire, and monitoring/recording of procedure-related adverse events (AEs).

RESULTS

A total of 168 anastomoses were performed with the ECP. Surgical approaches included robotic-assisted (n = 74, 44.0%), laparoscopic (n = 71, 42.3%), open (n = 20, 11.9%), and hand-assisted minimally invasive (n = 3, 1.8%) procedures. There were 22 occurrences of device performance issues in 20 (11.9%) subjects during surgery. No positive intraoperative leak tests were observed, and only 1 issue was related to a procedure-related AE or surgical complication, which was an instance of incomplete surgical donut necessitating re-anastomosis. Postoperative anastomotic leaks were experienced in 4 (2.4%) subjects. Clavien-Dindo classification of all AEs indicated that 92.0% were Grades I or II. Participating surgeons rated the ECP as easier to use compared to previously used manual circular staplers in 85.7% of procedures.

CONCLUSION

The circular powered stapler exhibited few clinically relevant performance issues, an overall favorable safety profile, and ease of use for creation of left-sided colon anastomoses.

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.

Preferential use of imaging modalities in staging newly diagnosed rectal cancer: a survey of US radiation oncologists

Background

Accurate staging is crucial for management of patients with newly diagnosed rectal cancer. Endorectal ultrasound (EUS) has been the standard modality in the United States for decades, with magnetic resonance imaging (MRI) now preferred by national guidelines. Positron emission tomography (PET), conversely, is not recommended. The current utilization of imaging modalities by American radiation oncologists in staging newly diagnosed rectal cancer is unknown.

Methods

American radiation oncologists completed an anonymous institutional review board-approved online survey probing their imaging preferences for initial staging of rectal cancer patients.

Results

We received 220 responses from American radiation oncologists, with 39% in academic centers and with 45% seeing more than 10 rectal cancer patients per year. Most respondents utilize all three imaging modalities for rectal cancer staging-EUS, MRI and positron emission tomography/computed tomography (PET/CT). Fifty-two percent and 38% of respondents are high utilizers of EUS and MRI, respectively, defined as ordering these tests at least 75% of the time. Forty seven percent were high PET utilizers. The latter was associated with practice in a private setting (P=0.015) and being within 10 years from residency training completion (P<0.01).

Conclusions

Our analysis reveals a dramatic discordance among national guidelines and the practice patterns among American radiation oncologists. More rely on PET for initial staging of rectal cancer patients than on pelvic MRI. Further research needs to determine the most effective imaging work-up of patients with an initial diagnosis of rectal cancer.

Does a fine line exist between regional and metastatic pelvic lymph nodes in rectal cancer-striking discordance between national guidelines and treatment recommendations by US radiation oncologists

Background

Management of rectal cancer with involved lateral pelvic lymph nodes (LPLNs) at the time of diagnosis-the stage we refer institutionally to as Stage 3.5-is controversial. The American Joint Committee on Cancer's 7^th edition classifies internal iliac lymph nodes (LNs) as regional (Stage III), but both external and common iliac LNs as metastatic (Stage IV). However, in many Asian countries all LPLNs are considered regional and patients are treated with curative intent, with literature supporting improved outcomes with LPLN dissection. Management patterns of these patients by US radiation oncologists (ROs) are unknown.

Methods

American ROs completed an anonymous institutional review board-approved online questionnaire regarding rectal cancer management.

Results

Among the 220 completed responses, 45% treat more than 10 patients annually and 39% work in academia. We found 10.5% and 34.2% recommend biopsy of clinically involved internal and common iliac LNs, respectively. The vast majority of responders-98.6% and 94.5%-treat involved internal and common iliac LNs with curative intent, respectively. Respondents recommend treatment intensification to involved internal iliac LNs by dissection of the nodal basin (88.2%) and radiation therapy (RT) boost (59.1%), and treatment intensification to involved common iliac LNs by LN dissection (76.4%) and RT boost (63.6%).

Conclusions

Our analysis reveals that the vast majority of US ROs approach patients with involved LPLNs, both regional (internal iliac) and metastatic (common iliac), with curative intent. They recommend treatment intensification with surgical resection and/or RT boost to involved nodes. Prospective clinical trials need to determine the appropriate management of patients with Stage 3.5 rectal cancer.

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.

Variation in the Use of Chemoradiotherapy for Stage II and III Anal Cancer: Analysis of the National Cancer Data Base

BACKGROUND

Treatment for anal canal cancer has evolved from radical operations to definitive chemoradiotherapy (CRT), which allows for sphincter preservation in most patients.

OBJECTIVE

The aim of this study was to examine the use of CRT for patients with stage II and III anal cancer, among different patient demographics, geographic regions, and facility types.

METHODS

Utilizing the National Cancer Data Base, we examined patients with stage II and III anal canal squamous cell carcinoma from 2003 to 2010. Via univariate analysis, we examined patterns of treatment by patient demographics, tumor characteristics, geographic region, and facility type (academic vs. community). A multivariable logistic regression model was built to evaluate differences in treatment patterns when adjusting by age, sex, race, comorbidities, and stage.

RESULTS

A total of 12,801 patients were analyzed, of which 11,312 (88 %) received CRT. After adjusting for confounders, CRT was less likely to be administered to males [odds ratio (OR) 0.61, 95 % confidence interval (CI) 0.54-0.69], Black patients (OR 0.70, 95 % CI 0.59-0.83), and those with multiple comorbidities (OR 0.60, 95 % CI 0.51-0.72). CRT was not as widely utilized in the West (OR 0.74, 95 % CI 0.59-0.93), and patients treated in academic-based centers were less likely to receive CRT (OR 0.81, 95 % CI 0.72-0.92). Improved median overall survival was observed when CRT was utilized (p = 0.008).

CONCLUSION

When controlling for age, sex, race, comorbidities, and stage, discrepancies in the use of CRT for anal cancer treatment exist between demographic subtypes, geographical regions, and facility types.

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.

Effect of adding mFOLFOX6 after neoadjuvant chemoradiation in locally advanced rectal cancer: a multicentre, phase 2 trial

BACKGROUND

Patients with locally advanced rectal cancer who achieve a pathological complete response to neoadjuvant chemoradiation have an improved prognosis. The need for surgery in these patients has been questioned, but the proportion of patients achieving a pathological complete response is small. We aimed to assess whether adding cycles of mFOLFOX6 between chemoradiation and surgery increased the proportion of patients achieving a pathological complete response.

METHODS

We did a phase 2, non-randomised trial consisting of four sequential study groups of patients with stage II-III locally advanced rectal cancer at 17 institutions in the USA and Canada. All patients received chemoradiation (fluorouracil 225 mg/m(2) per day by continuous infusion throughout radiotherapy, and 45·0 Gy in 25 fractions, 5 days per week for 5 weeks, followed by a minimum boost of 5·4 Gy). Patients in group 1 had total mesorectal excision 6-8 weeks after chemoradiation. Patients in groups 2-4 received two, four, or six cycles of mFOLFOX6, respectively, between chemoradiation and total mesorectal excision. Each cycle of mFOLFOX6 consisted of racemic leucovorin 200 mg/m(2) or 400 mg/m(2), according to the discretion of the treating investigator, oxaliplatin 85 mg/m(2) in a 2-h infusion, bolus fluorouracil 400 mg/m(2) on day 1, and a 46-h infusion of fluorouracil 2400 mg/m(2). The primary endpoint was the proportion of patients who achieved a pathological complete response, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00335816.

FINDINGS

Between March 24, 2004, and Nov 16, 2012, 292 patients were registered, 259 of whom (60 in group 1, 67 in group 2, 67 in group 3, and 65 in group 4) met criteria for analysis. 11 (18%, 95% CI 10-30) of 60 patients in group 1, 17 (25%, 16-37) of 67 in group 2, 20 (30%, 19-42) of 67 in group 3, and 25 (38%, 27-51) of 65 in group 4 achieved a pathological complete response (p=0·0036). Study group was independently associated with pathological complete response (group 4 compared with group 1 odds ratio 3·49, 95% CI 1·39-8·75; p=0·011). In group 2, two (3%) of 67 patients had grade 3 adverse events associated with the neoadjuvant administration of mFOLFOX6 and one (1%) had a grade 4 adverse event; in group 3, 12 (18%) of 67 patients had grade 3 adverse events; in group 4, 18 (28%) of 65 patients had grade 3 adverse events and five (8%) had grade 4 adverse events. The most common grade 3 or higher adverse events associated with the neoadjuvant administration of mFOLFOX6 across groups 2-4 were neutropenia (five in group 3 and six in group 4) and lymphopenia (three in group 3 and four in group 4). Across all study groups, 25 grade 3 or worse surgery-related complications occurred (ten in group 1, five in group 2, three in group 3, and seven in group 4); the most common were pelvic abscesses (seven patients) and anastomotic leaks (seven patients).

INTERPRETATION

Delivery of mFOLFOX6 after chemoradiation and before total mesorectal excision has the potential to increase the proportion of patients eligible for less invasive treatment strategies; this strategy is being tested in phase 3 clinical trials.

FUNDING

National Institutes of Health National Cancer Institute.

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.

Molecular markers for colon diagnosis, prognosis and targeted therapy

Colorectal adenocarcinoma (CRC), the second leading cancer-related death in the United States, remains a global public health issue. Sporadic CRC is considered the result of sequential mucosal changes from normal colonic mucosa to adenocarcinoma. Efforts in understanding the molecular pathways leading to CRC tumorigenesis may lead to identifying novel, individually tailored therapeutic targets for patients. In this review, we focus on well-published prognostic and predictive markers in CRC and examine their role in clinical practice.

Serrated polyposis syndrome

SUMMARY 

Serrated polyposis syndrome, also called hyperplastic polyposis, is a condition characterized by numerous neoplastic polyps throughout the colon and rectum. The polyps possess a distinct serrated morphology. The term serrated refers to the ‘saw-tooth’ pattern formed by epithelial cells in the colonic crypts on standard histologic preparations. Historically, serrated lesions have been lumped together under the term ‘hyperplastic polyps’, and were assumed to carry no malignant potential. Over the past decade, however, an increasing body of evidence suggests that serrated lesions exist along a spectrum and represent an alternative molecular pathway to the development of colorectal cancer in contrast to the traditional adenocarcinoma sequence. Although a hallmark genetic signature for serrated polyposis syndrome remains unidentified, this is an area of active investigation.

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.

Increasing the number of lymph nodes examined after colectomy does not improve colon cancer staging

BACKGROUND

Current quality initiatives call for examination of at least 12 lymph nodes in curative colon cancer resections. The aim of this study was to determine if the number of nodes harvested has increased, and if the increased number nodes correlates with improved staging or overall survival.

STUDY DESIGN

A review of the Surveillance, Epidemiology, and End Results program database from 2004-2010 was performed. All patients who underwent colon cancer resection during this date range were analyzed. Number of nodes retrieved, patient stage, overall survival, and overall survival by stage were examined. Multivariable analysis controlled for stage, cancer site, age, year of diagnosis, and number of nodes retrieved. Improved staging was defined as increased detection of stage III patients.

RESULTS

A total of 147,076 patients met inclusion criteria. Median number of nodes analyzed increased sequentially with each year examined, from 12 in 2004 to 17 in 2010. Despite greater number of total nodes obtained and analyzed, there was no increase in the percentage of patients with positive nodes (stage III disease). On multivariable analysis, after controlling for stage, site of disease, age, and year of diagnosis, there was a slight overall survival benefit with increasing nodal retrieval (hazard ratio = 0.987 for each additional node removed; 95% CI, 0.986-0.988; p < 0.001).

CONCLUSIONS

Since quality initiatives have been put in place, there has been an increase in the number of nodes examined in colon cancer resections, but no improvement in staging. The improved survival seen with higher node counts was independent of stage, site of disease, patient age, and year of diagnosis.

Care of the patient with anorectal trauma

Blunt and penetrating injuries to the anus and rectum are uncommon. Considerable debate remains regarding the optimal treatment of rectal injuries. Although intraperitoneal rectal injuries can be treated similarly to colonic injuries, treatment options for extraperitoneal injuries include fecal diversion with a colostomy, presacral drainage, repair of the rectal defect, and distal rectal washout. Perineal injuries resulting in anal sphincter disruption often occur with severe associated injuries. Small defects can be repaired primarily, but extensive injuries often require diversion and sphincter reconstruction.

Surgeon leadership enables development of a colorectal cancer biorepository

BACKGROUND

We hypothesized that surgeons can improve the collection of all necessary elements (tissue and clinical data) needed to build a complete, robust research biorepository.

METHODS

All colorectal cancer patients treated at a university medical center and its affiliates were eligible for inclusion. Data were collected from an 18-page personal and family health questionnaire, a prospectively maintained clinical database, and molecular testing. Tissues included serum, plasma and peripheral blood mononuclear cells, and tumor and normal tissue. We compared 2 groups: the surgeon-referred group and the other clinician-referred group. The primary outcome was the complete collection of data (ie, preoperative/staging clinical data, blood samples, and tissue collection). Statistical analysis was performed using the Student t test.

RESULTS

Since 2006, 452 patients were approached, and 430 (95%) have been enrolled. Of these, 124 were referred by their surgeon, and 306 were consented in a clinic or over the telephone. Of patients referred by their surgeon, tumor tissue, blood samples, and preoperative/staging clinical data were obtained in 119 patients; conversely, in patients referred by oncologists or other clinicians, only 133 patients had complete data (96% vs 43.5%, P < .05). A total of 257 tissue samples were obtained from all patients. Additional testing has been performed on 228 specimens including immunohistochemistry, microsatellite testing, and genotype mutational analysis.

CONCLUSIONS

Surgeon-directed enrollment in a biorepository improves the ability to collect blood and tissue samples. Surgeons should take a leadership role in the development of tumor biorepositories.

Anal canal squamous cell carcinoma: overview, surveillance after treatment and management of local recurrence

SUMMARY Anal canal cancer is an uncommon gastrointestinal malignancy, although the incidence is increasing. Current treatment employs definitive chemoradiation, 5-fluorouracil, mitomycin C and a radiation dosage of 54–59 Gy for T3/T4 tumors, but not for T1 and T2 disease. Surveillance after completion of treatment is required. One acceptable strategy includes physical examinations every 3–6 months for 5 years and serial CT scans to detect advanced disease. A total of 40% of patients with T4 disease or immunosuppressed status may recur within the first 2 years after completion of treatment. Salvage therapy includes radical abdominoperineal resection. The most significant prognosticator after salvage surgery is the resection margin. Generally, patients with anal cancer should be treated by a multidisciplinary physician team and be assigned to clinical research trials, if feasible.

Effect of surgical approach on 30-day mortality and morbidity after elective colectomy: a NSQIP study

PURPOSE

The aim of this study was to evaluate the laparoscopic approach and pre- and postoperative conditions as predictors of 30-day mortality and morbidity in elective colectomy.

METHODS

Elective colectomies were identified in the 2005-2008 American College of Surgeons National Surgical Quality Improvement Program database. Multivariate logistic regression was used to model 30-day mortality and morbidity following elective colectomy. Propensity scores were calculated to decrease selection bias.

RESULTS

During the period studied, 14,321 patients underwent open colectomy and 10,409 underwent laparoscopic colectomy. Factors that significantly influenced mortality included male gender [odds ratio (OR) 1.4, confidence interval (CI) 1.07-1.9]; age (OR 1.07, CI 1.05-1.08); comorbidities including dyspnea, ascites, congestive heart failure, dialysis, or disseminated cancer; and postoperative conditions including reintubation (OR 2.6, CI 1.6-4.0), renal failure (OR 3.8, CI 2.1-6.9), stroke (OR 6.44, CI 2.4-17.6), and septic shock (OR 13.1, CI 8.76-19.4). While laparoscopy was not independently associated with mortality, it was associated with decreased postoperative morbidity including reintubation (OR 0.74, CI 0.59-0.91), renal failure (OR 0.60, CI 0.4-0.91), septic shock (OR 0.74, CI 0.59-0.92), wound infection (OR 0.58, CI0.44-0.77), and pneumonia (OR 0.71, CI 0.59-0.86).

CONCLUSIONS

Based on this analysis, laparoscopy was associated with a decrease in 30-day postoperative morbidity for colectomy. However, after adjusting for preoperative comorbidities and postoperative morbidities, laparoscopy did not independently influence mortality after colectomy.

Use and outcomes of emergent laparoscopic resection for acute diverticulitis

BACKGROUND

The use and outcomes of laparoscopic sigmoid resection during emergency admissions for diverticulitis are unknown.

METHODS

The Nationwide Inpatient Sample was queried for colorectal resections performed for diverticulitis during emergent hospital admissions (2003-2007). Univariate and multivariate analyses including patient, hospital, and outcome variables were performed.

RESULTS

A national estimate of 67,645 resections (4% laparoscopic) was evaluated. The rate of conversion to open operation was 55%. Ostomies were created in 66% of patients, 67% open and 41% laparoscopic. Laparoscopy was not a predictor of mortality (odds ratio [OR] =.70; confidence interval [CI], .32-1.53). Laparoscopy predicted routine discharge (OR = 1.31; CI, 1.06-1.63) and a decreased length of stay (absolute days = -.78; CI, -1.19 to -.37). There was no difference in the cost of hospitalization between the 2 groups (P = .45).

CONCLUSIONS

In acute diverticulitis, urgent laparoscopic resection decreases the length of stay. However, it is associated with a high conversion rate, no cost savings, and no difference in mortality.

Loss of expression of the cancer stem cell marker aldehyde dehydrogenase 1 correlates with advanced-stage colorectal cancer

BACKGROUND

Colorectal cancer (CRC) progression is mediated by cancer stem cells (CSCs). We sought to determine if the expression of the CSC marker aldehyde dehydrogenase 1 (ALDH1) in CRC tumors varies by American Joint Committee on Cancer stage or correlates to clinical outcomes.

METHODS

Primary and metastatic CRC samples from 96 patients were immunostained with antibodies to ALDH1 and imaged to evaluate marker expression. The percentage of ALDH1(+) cells was correlated to clinical outcomes.

RESULTS

ALDH1 was overexpressed in CRC tumors compared with nonneoplastic tissue. Marker expression was highest in nonmetastatic tumors. The loss of expression was associated with advanced stage and metastatic disease. No significant correlation was found between ALDH1 expression and metastasis, recurrence, or survival.

CONCLUSIONS

ALDH1 was highly expressed in nonmetastatic CRC, but expression was lost with advancing stage. ALDH1 could be an effective therapeutic target in early CRC but not late-stage disease. No correlation was found between ALDH1 and disease prognosis.

Dramatic decreases in mortality from laparoscopic colon resections based on data from the Nationwide Inpatient Sample

OBJECTIVE

To determine the mortality rate and associated factors for laparoscopic and open colectomy as derived from the Nationwide Inpatient Sample database.

DESIGN

Retrospective cohort.

SETTING

Nationwide Inpatient Sample database.

PATIENTS

Between 2002 and 2007, the Nationwide Inpatient Sample estimated 1,314,696 patients underwent colectomy in the United States. Most (n = 1,231,184) were open, but 83,512 were laparoscopic. Patients who underwent a laparoscopic procedure that was converted to open were analyzed within the laparoscopic group on an intention-to-treat basis.

MAIN OUTCOME MEASURE

Mortality rate. Using a logistic regression model, patient and institutional characteristics were analyzed and evaluated for significant associations with in-hospital mortality.

RESULTS

In a multivariate analysis, significant predictors of increased mortality included older age, male sex, lower socioeconomic status, comorbidities, and emergency or transfer admission. Additionally, a laparoscopic approach was an independent predictor of decreased mortality when compared with open colectomy (relative risk, 0.51; P < .001).

CONCLUSION

Even when controlling for comorbidities, socioeconomic status, practice setting, and admission type, laparoscopy is an independent predictor of decreased mortality for colon resection.

Laparoscopic converted to open colectomy: predictors and outcomes from the Nationwide Inpatient Sample

BACKGROUND

Early in their learning curve, surgeons need to appropriately select patients to avoid conversion from laparoscopic to an open colectomy.

METHODS

Using the Nationwide Inpatient Sample, laparoscopic and laparoscopic converted to open colectomies performed between 2002 and 2007 were compared. We evaluated patient and institutional characteristics to find significant predictors and outcomes of conversion.

RESULTS

Between 2002 and 2007, the rate of conversion was high, ranging from 35.7% to 38.0%. Multivariate predictors of conversion included obesity, diverticulitis, inflammatory bowel disease, constipation, metastatic disease, nonelective admission, left or transverse colectomy, intraoperative complication, lower socioeconomic status, uninsured status, and rural hospital location. A colectomy for benign colon polyps was less likely to be converted. Conversion to an open colectomy did not increase inpatient mortality.

CONCLUSIONS

Predictors of conversion from open to laparoscopic colectomy were found from a national database reflecting all US laparoscopic colectomies. Conversion did not increase inpatient mortality.

Specialized practice reduces inpatient mortality, length of stay, and cost in the care of colorectal patients

OBJECTIVE

This study aimed to determine whether specialized surgeon practice improves clinical outcomes for major inpatient adult colorectal resections.

DESIGN

The Nationwide Inpatient Sample was queried for elective colorectal resections performed from 2001 through 2007. Specialization was determined by first identifying surgeons' procedures as either colorectal or noncolorectal. Surgeons were then stratified as either a specialized surgeon, if colorectal cases comprised more than 75% of their caseload, or a nonspecialized surgeon if colorectal cases comprised less than 75%.

MAIN OUTCOME MEASURES

The data points collected for these cases were: cost, length of stay, mortality, demographics, comorbidities, acuity of admission, hospital region, hospital location and teaching status, and primary payer information. Cost and length of stay were analyzed using a linear regression model with a log transformation for length of stay. A logistic regression analysis was performed for mortality. These models were adjusted for all other covariates including surgeon volume.

RESULTS

A total of 13,925 surgeons performing 115,540 procedures were analyzed. Specialized surgeons comprised 4.6% of surgeons and performed 17.0% of resections. In multivariate analysis, specialized surgeons had a lower risk of mortality (OR 0.72; CI 0.57-0.90, P = .0044), decreased length of stay (absolute difference in days 0.23; CI 0.11-0.49, P = .0022), and similar hospital cost (absolute cost difference $420 less; CI $238 more to $1079 less, P = .211) compared with nonspecialized surgeons. Although cost was not significant at a 75% specialization cutoff, a relationship exists between lower hospitalization cost and increased surgeon specialization even when controlled for surgeon volume.

CONCLUSIONS

Surgical specialization leads to reductions in mortality, hospital days, and cost for inpatient colorectal care.

Trends in the surgical treatment of ulcerative colitis over time: increased mortality and centralization of care

BACKGROUND

New medical therapies available to ulcerative colitis (UC) patients have influenced operative mortality for patients requiring colectomy. We sought to examine trends in treatment and outcome for UC patients treated surgically.

METHODS

A review of 36,447 UC patients from the Nationwide Inpatient Sample was performed, comparing the pre-monoclonal antibody era (1990-1996) to the present-day era (2000-2006). Patients treated with total colectomy with ileostomy or proctocolectomy with ileal pouch were reviewed for outcome measures and practice setting (rural, urban non-teaching, urban teaching). Our main outcome measures were in-hospital mortality, length of stay, and total charges.

RESULTS

Total colectomy (n = 30,362) was performed five times more often than proctocolectomy (n = 6,085). When comparing the two study periods, mortality after total colectomy increased 3.8% to 4.6% (p = 0.0003). This difference was primarily due to increasing mortality in later years; when 1995-1996 was compared to 2005-2006, mortality increased from 3.6% to 5.6% (p < 0.0001). There were no deaths in the proctocolectomy group (p < 0.0001). The distribution by practice setting shifted over the two study periods, decreasing in rural (7.0% to 4.8%) and urban non-teaching (43.7% to 28.4%) centers, and increasing in urban teaching centers (49.3% to 66.8%). The total inflation-adjusted charges per patient increased significantly ($34,638 vs. $43,621; p < 0.0001).

CONCLUSIONS

The mortality rate after total colectomy is increasing, and the difference is accentuated in the years since widespread use of monoclonal antibody therapy. The care of these patients is being shifted to urban teaching centers and is becoming more expensive.

Management of colonic injuries in the combat theater

PURPOSE

Combat injuries are more often associated with blast, penetrating, and high-energy mechanisms than civilian trauma, generating controversy about the management of combat colonic injury. Despite implementation of mandatory colostomy in World War II, recent civilian data suggest that primary repair without diversion is safe and feasible. This study describes the modern management of battle-related colonic injuries and seeks to determine whether management strategy affects early complications.

METHODS

Records from the combat theater (downrange) and tertiary referral center in Germany were retrospectively reviewed from 2005 to 2006. Patient characteristics, management strategy, treatment course, and early complications were recorded. Comparison groups by management strategy were as follows: primary repair, diversion, and damage control.

RESULTS

A total of 133 (97% male) patients sustained colonic injuries from penetrating (71%), blunt (5%), and blast (23%) mechanisms. Average injury severity score was 21 and length of stay in the referral center was 7.1 days. Injury distribution was 21% ascending, 21% descending, 15% transverse, 27% sigmoid, and 25% rectum. Downrange complications for primary repair, initial ostomy, and damage control groups were 14%, 15%, and 30%, respectively. On discharge from the center, 62% of patients had undergone a diversion. The complication rate was 18% overall and was unrelated to management strategy (P = .16). Multivariate analysis did not identify independent predictors of complications.

CONCLUSION

Early complications were similar by mechanism, anatomic location, severity of injury, and management strategy. More diversions were performed for rectosigmoid injury. Good surgical judgment allows for low morbidity and supports primary repair in selected cases. Damage control surgery is effective in a multinational theater of operations.

Anal fissure

Anal fissure is a common disorder that is effectively treated and prevented with conservative measures in its acute form, whereas chronic fissures may require medical or surgical therapy. This article discusses the nonoperative and operative management strategies, reviews the current literature on expected outcomes, and provides guidance on dealing with fissures in special situations, such as patients with inflammatory bowel disease or hypotonic sphincters.

Disparities in the treatment of colon cancer in octogenarians

BACKGROUND

Disparities in healthcare for the elderly are understudied, despite the increasing proportion of patients over 80 years of age. Advanced age is a principal risk factor for colorectal adenocarcinoma, but there are few data to guide treatment in the elderly patient population.

METHODS

We performed a retrospective review of prospectively gathered data on 10,433 patients diagnosed with primary colon tumors between 1998 and 2004. We compared demographics, stage at diagnosis, and initial treatment between patients younger than 80 years and those age 80 years or older.

RESULTS

Patients who were >or=80 years old made up 30% of the database. Older patients were less likely to have colectomy for advanced or metastatic disease than younger patients. Patients who were >or=80 years of age had fewer lymph nodes removed than younger patients (11 vs 10, P <.01). Older patients were significantly less likely to receive chemotherapy for every stage of colon cancer than younger patients. When older patients did get chemotherapy, it was more likely to be with a single agent. Multivariate analysis revealed that predictors of receiving chemotherapy for patients >or=80 years of age include living in an urban county, younger age, and worse stage at diagnosis.

CONCLUSIONS

Older patients make up a large portion of the patients treated for colon cancer and are treated less aggressively. While some of the treatment difference may be explained by medical factors, demographic factors affect treatment decisions as well.

Treatment strategies and outcomes for rectal villous adenoma from a single-center experience

OBJECTIVES

To analyze a 13-year, single-surgeon experience with villous adenoma of the rectum with respect to procedure, complications, recurrence, and cancer incidence.

DESIGN

Retrospective review of patient and tumor characteristics, procedure, recurrence, and complications.

SETTING

University hospital.

PATIENTS

Patients who underwent excision of rectal villous adenoma.

MAIN OUTCOME MEASURES

Complication, recurrence, and malignancy rates.

RESULTS

Thirty-six patients underwent 30 transanal and 10 transabdominal excisions. Mean age was 66 years (range, 41-86 years) and mean follow-up was 25 months (range, 0.5-132 months). Mean tumor size was 3.0 cm (range, 0.5-11 cm) and the mean distance of the tumor from the anal verge was 4.9 cm (range, 0-10 cm). Preoperatively, 18 (45%) lesions harbored low-grade dysplasia while 17 (43%) had high-grade dysplasia. Postoperative pathology was discordant in 50% of patients, including 5 of 40 lesions (13%) that were recategorized as invasive cancer. Tumor size did not correlate with malignancy. The complication rate was significantly lower in transanal compared with transabdominal excisions (3.6% vs 50%, P = .005). There were 4 (12.5%) benign recurrences, all after transanal excisions.

CONCLUSIONS

Complete excision is warranted for rectal villous adenomas, as biopsies were accurate only 50% of the time, and 1 in 8 patients had unsuspected cancer found after excision. Transanal excision with negative margins is associated with low recurrence and complication rates and is the preferred approach, even with large lesions.

Heparin and enoxaparin enhance endotoxin-induced tumor necrosis factor-alpha production in human monocytes

OBJECTIVE

To determine whether heparin or the low-molecular-weight heparin enoxaparin alter lipopolysaccharide (LPS)-induced monocyte activation.

SUMMARY BACKGROUND DATA

Heparin is widely used in clinical practice to inhibit the coagulation cascade. However, heparin also is a naturally occurring glucosaminoglycan and a pleiotropic immunomodulator that binds to a variety of proteins. LPS is a component of gram-negative bacteria and is thought to be responsible for many of the deleterious effects seen in sepsis. The binding of LPS to CD14 induces a signaling cascade that results in the release of many inflammatory mediators, including tumor necrosis factor-alpha (TNF-alpha).

METHODS

Monocytes from healthy volunteers were isolated and cultured in the presence of saline, LPS (10 ng/ml), heparin (0.1 to 1000 microg/ml), or enoxaparin (0.1 to 1000 microg/ml). In blocking experiments, cells were pretreated for 60 minutes with the monoclonal anti-CD14 antibody MY4 (10 microg/ml) or with isotype-matched control IgG2 (10 microg/ml). TNF-alpha values were measured with enzyme-linked immunosorbent assay. Significance was assessed with analysis of variance.

RESULTS

Heparin (10 to 1000 microg/ml) and enoxaparin (1000 microg/ml) significantly enhanced LPS-induced TNF-alpha release. Heparin (1000 microg/ml) or enoxaparin (1000 microg/ml) did not produce TNF-alpha in the absence of LPS. Blockade of CD14 abrogated both LPS-induced TNF-alpha release and the effect of heparin or enoxaparin to enhance LPS-induced TNF-alpha release.

CONCLUSIONS

The effect of heparin to enhance LPS-induced TNF-alpha release is a biologic phenomenon that reveals a novel and potentially important host defense mechanism during endotoxemia and sepsis. Binding of LPS to CD14 is necessary to induce this phenomenon, suggesting that both heparin and enoxaparin induce signaling mechanisms that are downstream from the initial binding of LPS on CD14.

Phagocytosis and oxidative-burst response of planktonic Staphylococcus epidermidis RP62A and its non-slime-producing variant in human neutrophils

The ability of bacterial organisms to produce an extracellular polysaccharide matrix known as slime has been associated with increased virulence and delayed infections in various prosthetic implants. Within a biofilm, this slime may protect the embedded bacteria from host defense mechanisms, especially phagocytosis by polymorphonuclear leukocytes. To determine whether planktonic Staphylococcus epidermidis is protected in a similar way, a novel flow cytometric assay was performed, measuring ingestion and adherence during phagocytosis and the production of superoxide during oxidative burst. Hydrophobicity was determined by hydrophobic interaction chromatography. Slime-producing S. epidermidis RP62A and its phenotypic variant, non-slime-producing RP62A-NA, were compared. The results showed increased phagocytosis of RP62A at 2, 5, 10, and 30 min; increased adherence of RP62A at 30 s and 30 min; and increased superoxide production of RP62A after 2 min. Decreased hydrophobicity of RP62A over RP62A-NA was correlated with a hydrophilic slime coat. The data argue that the host aggressively combats slime-producing S. epidermidis. This biological phenomenon is potentially important during bacteremia to prevent further adhesion, accumulation, and the genesis of a bacterial biofilm on implants or tissue surfaces.