Impact of Hospital Volume on Utilization of Minimally Invasive Surgery for Gastric Cancer

BACKGROUND

Minimally invasive surgery (MIS) for gastric cancer is increasingly performed. The purpose of this study is to evaluate trends in utilization of laparoscopic and robotic techniques compared to open surgery as well as utilization based on hospital volume.

METHODS

We used the National Cancer Database to query patients who underwent gastrectomy from 2010 to 2017 for adenocarcinoma. Regression analyses were used to determine associations between MIS and clinical factors, the trend of MIS over time, and survival.

RESULTS

A total of 18,380 patients met inclusion criteria. The annual rates of MIS increased for all hospital volumes, though lower volume centers were less likely to undergo MIS. MIS was associated with a shorter length of stay compared to open, and robotic gastrectomy had a higher rate of obtaining at least 15 lymph nodes and lower rate of having a positive margin.

CONCLUSIONS

MIS utilization for resection of gastric cancer increased over time, with robotic surgery increasing at a higher rate than laparoscopic surgery. Importantly, this occurred without increased in mortality or sacrificing adequate oncologic outcomes.

Patient Comorbidities Drive High Mortality Rates Associated with Major Liver Resections Irrespective of Hospital Volume

INTRODUCTION

Major hepatectomies are utilized to manage primary hepatic malignancies. Reports from high-volume centers (HVCs) with minimal perioperative mortality focus on multiple aspects of perioperative care, although patient-specific factors remain unelucidated. We identified patient factors associated with outcomes and examined whether these contribute to survival differences.

METHODS

We queried the National Cancer Database (2006-2015) for patients with primary liver malignancies managed with major hepatectomy. Facilities were dichotomized by volume (high volume: >15 hepatectomies/year). Perioperative outcomes were compared based on patient demographic and clinical characteristics as well as center volume.

RESULTS

4263 patients were included with 78.5% receiving care in low-volume centers (LVCs). 90-day postoperative mortality was higher in LVCs vs. HVCs (12% vs. 7.5%; P < .001). Factors associated with undergoing surgery in LVCs included: living in areas with lower income (P = .006) and education (P < .001), having nonprivate insurance (P < .001), residing near the care center (P < .001), and having a comorbidity score (CDS) >1 (P = .014). Patients with CDS ≤ 1 had higher 90-day mortality in LVCs (11.3% vs. 6.6%; P < .001) and had similar outcomes in LVCs and HVCs (15.6% vs. 13.7% P = .6). Patients with CDS > 1 were more likely to receive care in LVCs (16.3% vs. 12.7%; P < .001).

CONCLUSION

Reduced perioperative mortality following major hepatectomy in HVCs is driven by optimal management of patients with low CDS. However, nearly 1 in 5 patients who undergo major hepatectomies have a high CDS and approximately 15% of them succumb in the perioperative period irrespective of the treating centers' experience.

Gallbladder squamous cell carcinoma: An analysis of 1084 cases from the National Cancer Database

BACKGROUND/OBJECTIVES

Gallbladder squamous cell carcinoma (SCC) is an uncommon malignancy whose rarity has made it particularly challenging to study. We utilized a national database to shed light on the clinicopathologic characteristics, management patterns, and survival associated with these tumors.

METHODS

Patients with gallbladder SCC were identified in the National Cancer Database. Clinicopathologic and treatment characteristics were recorded and compared with adenocarcinoma for context. Univariate and multivariable survival analyses were completed for patients who underwent resection.

RESULTS

Overall, 1084 patients with SCC and 23 958 patients with adenocarcinoma were identified. Compared with those with adenocarcinoma, patients with SCC had higher grade tumors (P < .001) and were diagnosed at a later stage (P < .001). Patients with SCC were more likely to undergo radical cholecystectomy (17% vs 9%; P < .001), but had a higher rate of margin positivity (36% vs 29%; P < .001). SCC histology was associated with worse survival compared with adenocarcinoma, even after adjusting for R0 resections (13 vs 29 months; P < .001). On multivariable analysis, SCC histology was independently associated with abbreviated survival (P = .003).

CONCLUSIONS

Gallbladder SCCs are aggressive cancers that often present at an advanced stage. Complete surgical extirpation should be pursued when feasible. However, prognosis is worse than that of adenocarcinoma, even after R0 resection.

Effect of Socioeconomic Status on Surgery for Pancreatic Adenocarcinoma

Survival for pancreatic cancer remains poor. Surgical resection remains the only chance for cure. The intent of this study was to investigate the role of socioeconomic status (SES) on resection rates for pancreatic adenocarcinoma. The National Cancer Institute's Surveillance, Epidemiology, and End results database was used to identify patients with pancreatic adenocarcinoma. Disease was deemed resectable or unresectable based on the extent of disease code. Median family income was used as a SES variable to compare patients who underwent resection with those who did not. Median family income was organized into three categories based on definitions from the national census: less than $34,680 (low income), $34,680 to $48,650 (middle), and greater than $48,650 (high income). A total of 5,908 patients with potentially resectable disease were included. A total of 3,331 patients did not have a surgical resection despite having resectable disease. Subgroup analysis of income status revealed that patients with a low or middle income were less likely to have a resection when compared with those with high income (33.0 vs 39.9 vs 45.8%, P = 0.0001). Multivariate analysis revealed that low and middle SES and race were significant predictors of resection. Ongoing study of access to health care may help define the means to eliminate the disparities in the care of patients with pancreatic adenocarcinoma.

Choledochoduodenostomy as the Biliary–Enteric Bypass of Choice for Benign and Malignant Distal Common Bile Duct Strictures

Choledochoduodenostomy (including hepaticoduodenostomy) for common bile duct (CBD) strictures has been underused because of concerns regarding postoperative duodenal fistula and cholangitis attending the so-called “sump syndrome.” An institutional retrospective review of 55 consecutive choledochoduodenostomy procedures for CBD strictures from 1995 to 2011 was performed to examine its suitability as the biliary–enteric bypass procedure of choice. There were 30 male (55%) and 25 female (45%) patients with a mean age of 49 years (range, 13 to 73 years). Thirty-seven (67%) patients had benign CBD strictures and 18 (33%) had unresectable periampullary adenocarcinomas. Forty-nine (89%) underwent choledochoduodenostomy and six (11%) underwent hepaticoduodenostomy. There were no 30-day postoperative deaths, anastomotic leaks, or intra-abdominal abscesses. Five patients (9%) sustained Clavien Grade III or IV complications. Over a mean long-term follow-up of 29 months (range, 1 to 162 months), there was one anastomotic stricture successfully managed by endoscopic dilation and temporary stenting. Liver function tests in all other patients returned to and remained within normal limits. We conclude that choledochoduodenostomy is the preferred biliary–enteric bypass for both benign and malignant distal CBD strictures because of its ease, safety, and durability. Persistent fears of duodenal fistula and the “sump syndrome” are not warranted by the empiric data and should be abandoned.

Primary Gallbladder Neuroendocrine Tumors: Insights into a Rare Histology Using a Large National Database

BACKGROUND

Primary gallbladder neuroendocrine tumors (NETs) are rare, poorly understood cancers infrequently encountered at even the largest of tertiary referral centers. We therefore sought to identify a large cohort of patients with gallbladder NETs using a national database, with the aim of defining treatment modalities employed and survival associated with these uncommon malignancies.

METHODS

Patients with primary gallbladder NETs were identified in the National Cancer Database, and clinicopathologic characteristics were recorded. A univariate log-rank survival analysis was completed for patients who underwent resection. Parameters found to be significant were entered into a multivariate accelerated failure time analysis. For context, survival comparisons were included for patients who underwent resections for NETs at any gastrointestinal site and for gallbladder adenocarcinoma.

RESULTS

Overall, 754 patients with gallbladder NETs were identified. Patients were predominantly female (n = 518, 69%), White (n = 503, 67%), presented with stage IV disease (n = 295, 39%) and had high-grade lesions (n = 312, 41%). The majority underwent resection (n = 480, 64%), primarily simple cholecystectomy (n = 431, 90%), whereas a minority received multimodal therapy (n = 145, 21%). Among patients who underwent resection, older age (p = 0.001), large cell histology (p = 0.012), and positive margins (p = 0.030) were independently associated with worse overall survival. Patients with gallbladder NETs had improved survival relative to those with gallbladder adenocarcinoma (p = 0.001), but significantly worse survival than patients with NETs from other gastrointestinal sites (p < 0.001).

CONCLUSIONS

Primary gallbladder NETs are aggressive lesions that carry a worse prognosis than NETs of other gastrointestinal sites. Older age, positive margins, and large cell histology are associated with abbreviated survival after resection.

Identification of nonalcoholic fatty liver disease following pancreatectomy for noninvasive intraductal papillary mucinous neoplasm

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) following pancreatectomy is a potential cause of long term morbidity in patients undergoing pancreatic resection with curative intent. Prior studies have reported an incidence of NAFLD up to 30% following pancreatectomy but the investigated cohorts were typically a mix of benign and malignant disease. Here we examined the incidence of NAFLD in a homogenous cohort of patients following pancreatectomy for benign intraductal papillary mucinous neoplasm (IPMN).

METHODS

A retrospective review of patients who underwent pancreatic resection for IPMN from 2000 to 2016 was performed. Post pancreatectomy CT/MRI scans were obtained as standard surveillance. We investigated changes in the liver parenchymal density on post surgical imaging to estimate the frequency with which NAFLD occurred. Radiographic criteria for NAFLD included Hounsfield units less than 40 on CT or liver:spleen ratio <0.9 on CT or MRI. Fischer's exact test, Kruskal-Wallis test, and logistic regression were performed.

RESULTS

Our study cohort included 109 patients who underwent pancreatectomy for nonmalignant intraductal papillary mucinous neoplasm with no evidence of NAFLD preoperatively and at least 6 months follow-up. Mean follow-up was 52 months (range 8-130/months). The incidence of postoperative NAFLD was 17/109 (15.6%). Most cases occurred within 12 months of pancreatectomy. On multivariate analysis, proximal pancreatectomy (pancreaticoduodenectomy) and development of atrophy of the pancreas remnant were significant risk factors for development of hepatic steatosis (p < 0.05).

CONCLUSION

Patients undergoing pancreatectomy for benign disease have a significant risk of developing NAFLD but the frequency is lower than previously reported in cohorts that included individuals with malignant disease. Highest risk was observed in individuals who underwent pancreaticoduodenectomy or developed pancreatic atrophy. Further investigations to define the mechanisms that promote steatosis and interventions to prevent subsequent morbidity from NAFLD are warranted.

Endoscopic ultrasound staging for early esophageal cancer: Are we denying patients neoadjuvant chemo-radiation?

AIM

To evaluate the accuracy of endoscopic ultrasound (EUS) in early esophageal cancer (EC) performed in a high-volume tertiary cancer center.

METHODS

A retrospective review of patients undergoing esophagectomy was performed and patients with cT1N0 and cT2N0 esophageal cancer by EUS were evaluated. Patient demographics, tumor characteristics, and treatment were reviewed. EUS staging was compared to surgical pathology to determine accuracy of EUS. Descriptive statistics was used to describe the cohort. Student’s t test and Fisher’s exact test or χ² test was used to compare variables. Logistic regression analysis was used to determine if clinical variables such as tumor location and tumor histology were associated with EUS accuracy.

RESULTS

Between 2000 and 2015, 139 patients with clinical stageIorIIA esophageal cancer undergoing esophagectomy were identified. There were 25 (18%) female and 114 (82%) male patients. The tumor location included the middle third of the esophagus in 11 (8%) and lower third and gastroesophageal junction in 128 (92%) patients. Ninety-three percent of patients had adenocarcinoma. Preoperative EUS matched the final surgical pathology in 73/139 patients for a concordance rate of 53%. Twenty-nine patients (21%) were under-staged by EUS; of those, 19 (14%) had unrecognized nodal disease. Positron emission tomography (PET) was used in addition to EUS for clinical staging in 62/139 patients. Occult nodal disease was only found in 4 of 62 patients (6%) in whom both EUS and PET were negative for nodal involvement.

CONCLUSION

EUS is less accurate in early EC and endoscopic mucosal resection might be useful in certain settings. The addition of PET to EUS improves staging accuracy.

Does histology really influence gastric cancer prognosis?

Background

Gastric cancer (GC) is associated with poor survival despite curative-intent surgical resection and systemic therapy. Our objective is to examine the impact of histology on prognosis as well as the impact of linitis plastica (LP) on survival.

Methods

The GC database at a single institution was evaluated for patients who underwent resection from 2000 to 2015. Clinicopathologic characteristics were examined and descriptive statistics was used to analyze four groups of patients based on Lauren classification: intestinal (n=93), diffuse (n=20), diffuse with signet-ring cell features (n=57), and LP (n=40). LP patients had diffuse GC but also presented with circumferential infiltration of the gastric wall for at least a third of the stomach length on endoscopy or imaging. Fisher's exact test was used to compare groups; Cox regression was used for multivariate analysis and Kaplan-Meier method for survival.

Results

Of 210 patients who underwent gastric resection, 112 (53%) were male with mean age 65.3 years (SD ±14.6 years). Intestinal GC patients were older at diagnosis but other patient demographics were similar between all groups. LP patients had a higher rate of R1 resection despite higher rates of total gastrectomy (P<0.01). Rates of perineural invasion (PNI) and nodal metastasis were higher in LP (P<0.001). The majority of intestinal GC patients (79%) had stage I/II disease compared to 70% of LP patients with stage III disease. Median overall survival (OS) was 13.7 months for LP, 79 months for intestinal, 97 months for signet-ring cell, and not reached for diffuse GC (P<0.001). When stratified by stage, there were no significant differences in survival by histology for stage II and stage III patients. However, by Cox regression analysis, factors associated with worse survival included lymphovascular invasion (LVI), nodal disease, and presence of LP. Neutrophil-lymphocyte ratio (NLR), neoadjuvant and adjuvant therapy, and tumor regression grade did not influence survival on multivariate analysis.

Conclusions

Intestinal GC is thought to have a better prognosis. Interestingly, this study demonstrates similar outcomes in patients with intestinal, diffuse, and signet-ring cell GC. However, a subset of diffuse GC-LP was associated with an infiltrative pattern of disease characterized by PNI and LVI. Despite controlling for poor prognostic markers, LP was independently associated with a worse prognosis. More research is needed to identify methods of earlier diagnosis and effective systemic therapy to treat this aggressive disease.

Gastric linitis plastica: Have we moved beyond surgical palliation?

184

Background: Diffuse type gastric cancer (DGC), especially linitis plastica (LP), is associated with poor survival. Despite curative-intent surgical resection and improvement in perioperative therapy, doubt remains whether long term survival is possible in this aggressive disease. Methods: A retrospective review of the GC database at a comprehensive cancer center was reviewed from 2000 to 2016. Patient demographics, tumor characteristics, and treatment were evaluated. Patients with DGC were assessed. LP was defined as patients with DGC who had circumferential infiltration of the gastric wall for at least a third of the stomach length. Descriptive statistics were used to compare DGC and LP groups; survival was assessed by the Kaplan-Meier method. Results: Of 209 resected GC patients, 114 had diffuse histology; the majority were of the signet ring cell subtype. 38 (33.3%) had LP and 76 (66.7%) had DGC without linitis. LP patients were more likely to present at a later stage, with 27/38 patients (71%) with stage III and 4/38 patients (10.5%) with stage IV compared to 16/76 (21.1%) and 2/76 (2.6%) in the DGC group, respectively, p < 0.001. All patients underwent gastric resection with some for palliative intent including 6 patients found to have metastatic disease on exploration. R0 resection was achieved in 26 patients (68.4%) with LP. Median OS was 31.5 months for the cohort and 13.6 months for LP patients (p < 0.001); survival in LP patients did not improve with R0 resection. When survival was stratified by stage, patients with stage II LP still had a lower median OS than DGC (18.4 vs. 51.2 months, respectively, p = 0.015), though there was no survival differences in stage III and IV. Only half of patients with LP received preoperative chemotherapy or chemoradiation, perhaps due to need for surgical palliation of symptoms; receipt of preoperative therapy was not associated with survival in this subgroup. Conclusions: Gastric LP is associated with a poor prognosis. Early diagnosis and adherence to multimodal therapy may improve survival after surgical resection. Development of novel agents and improvement in neoadjuvant therapy is needed to improve outcomes in this aggressive disease.

Abstract B12: Immune checkpoint blockade to improve T cell infiltration and function in colorectal cancer

Adoptive transfer of tumor infiltrating lymphocytes (TIL) has emerged as a promising approach to induce effective anti-tumor immunity and tumor regression in various types of cancers. Current studies suggest that the presence of TIL play a role in patient outcomes and can predict tumor stage, node positivity, and in some reports, disease free and overall survival in patients with colorectal cancer. TIL may be inactivated in patients due to factors in the local tumor microenvironment, such as regulatory T cells, myeloid derived suppressor cells and the expression of a number of co-inhibitory immune checkpoints including PD-L1, BTLA, PD-1, CTLA-4, Lag-3 and Tim-3. We first examined the feasibility of expanding TIL from the tumors of three colorectal patients. Tumors were minced into fragments and cultured in media supplemented with 6000 IU IL2 / mL. TIL growth was observed in tumor fragments from each of the three patients with a total of 12 out of 41 fragments demonstrating TIL expansion. TIL grown out of these fragments were predominantly CD3+ with 32% CD4+T cells and 46% CD8+ T cells and 18.5% NK cells. Seven of the 12 fragments tested were tumor specific as demonstrated by IFN-gamma production in response to autologous tumor. CD8+ T cells within the patient TIL expressed PD-1, BTLA, Lag-3 and Tim-3 and a co-stimulatory molecule, 41BB. In addition, we found high levels of PD-L1 expression on tumors of colorectal patients and human colorectal cell lines. Since we observed high levels of immune checkpoints expression in colorectal patients, we wanted to develop a preclinical colorectal model to investigate the effect of immune checkpoint blockade on tumor growth and TIL function. A previous study from our lab has shown that TIL from our preclinical MC38 colorectal murine model express high levels of co-inhibitory checkpoints and that blockade of PD-L1 leads to enhanced infiltration and anti-tumor specificity of TIL. However, given the dynamic nature of immune responses to tumors and expression of multiple immune checkpoints, it may be necessary to block additional checkpoints to improve clinical efficacy. In this study, we examined whether blockade of the immune checkpoint receptor BTLA had an effect on TIL infiltration and tumor growth. Mice bearing MC-38 tumors treated with anti-BTLA antibody demonstrated a delay in tumor growth (150mm2, p&lt;0.01) on day 28 post tumor injection compared to isotype control (300mm2). We observed an increase in CD8+ T cell infiltration (30%, p&lt;0.001) in the tumors of anti-BTLA antibody treated mice compared to mice treated with isotype control (13%). TIL isolated from the anti-BTLA antibody treated mice demonstrated increased IFN-gamma and granzyme B secretion compared to isotype controls (p&lt;0.001). Dual immune checkpoint blockade with anti-PD-L1 and anti-BTLA antibodies had a synergistic effect in delaying tumor growth. We also measured a significant increase in CD8+CD107a+IFN-gamma+ secreting T cells (37%) compared to TIL from mice treated with anti-PD-L1 (27%) or anti-BTLA antibody alone (25%) (p&lt;0.002). These findings suggest that targeting immune checkpoint molecules can improve T cell infiltration and anti-tumor immunity in a preclinical model of colorectal cancer. In addition, we demonstrate that tumor-specific TIL can be expanded from the tumors of colorectal patients. This study presents a rationale for the potential synergy between blockade of multiple immune checkpoints and adoptive transfer of TIL for the treatment of colorectal cancer.

Citation Format: Krithika N. Kodumudi, James Charles, Carrie Luu, John Mullinax, Julie Li, MacLean Hall, Amy Weber, Amod A. Sarnaik, Shari Pilon-Thomas. Immune checkpoint blockade to improve T cell infiltration and function in colorectal cancer. [abstract]. In: Proceedings of the AACR Special Conference on Colorectal Cancer: From Initiation to Outcomes; 2016 Sep 17-20; Tampa, FL. Philadelphia (PA): AACR; Cancer Res 2017;77(3 Suppl):Abstract nr B12.

Accuracy of clinical staging with EUS for early stage esophageal cancer: Are we denying patients beneficial neoadjuvant chemo-radiation?

163

Background: Esophagectomy alone has been considered the standard of care for early stage esophageal cancer (EC) while neoadjuvant therapy is now standard for locally advanced disease. The choice of treatment therefore hinges on accurate locoregional staging by endoscopic ultrasound (EUS). Our objective is to evaluate the accuracy of EUS performed in a high-volume tertiary cancer center in clinical stage T1N0 (cT1N0) and T2N0 (cT2N0) esophageal cancer patients undergoing esophagectomy without neoadjuvant therapy. Methods: A retrospective review of the esophageal cancer database at a single institution was performed. Patients with cT1N0 and cT2N0 esophageal cancer based on EUS undergoing esophagectomy without neoadjuvant treatment were evaluated. Patient demographics, tumor characteristics, and treatment were reviewed. Surgical pathology was compared to EUS staging. Results: Between 2000 and 2015, 139 patients were identified. There were 25 (18%) female and 114 (82%) male patients. The tumor location included the middle 1/3 of the esophagus in 11 (8%) and lower 1/3 and gastroesophageal junction in 128 (92%) patients. Eighty-one percent of patients had adenocarcinoma, 9% had squamous cell carcinoma, 9% had Barrett’s dysplasia, and 1% had mixed histology. Clinical staging were as follows: 110 (79%) patients had cT1N0 and 29 (21%) patients had cT2N0 tumors. For the entire cohort, preoperative EUS matched the final surgical pathology in 76/139 patients for an accuracy rate of 53%. Twenty-nine patients (21%) were under-staged by EUS; of those, 19 (14%) had unrecognized nodal disease. This included 12/109 (11%) of cT1N0 and 7/29 (24%) of cT2N0 patients. Conclusions: The accuracy of preoperative EUS staging in early esophageal cancer remains sub-optimal. Interestingly, a significant proportion (24%) of cT2N0 EC patients were found to have positive lymph nodes on surgical pathology, and perhaps these patients could have benefitted from neoadjuvant therapy. In light of these findings, the current management of cT2N0 esophageal cancer should be reconsidered.

Impact of gastric cancer resection on body mass index

Major gastric resection alters digestive function and may lead to profound weight loss. The objective of our study was to evaluate trends in body weight loss after curative gastrectomy for malignancy. A review of patients who underwent gastrectomy from 1999 to 2012 at two institutions was conducted. Patient demographics and treatment were assessed. Student's t test and analysis of variance were used to compare groups. Of 168 patients, two patients (1.2%) were Stage 0, 73 (43.5%) Stage I, 46 (27.4%) Stage II, 45 (26.8%) Stage III, and two (1.2%) stage unknown. Fifty-eight patients (34.5%) underwent total gastrectomy with Roux-en-Y esophagojejunostomy and 110 patients (65.5%) underwent subtotal gastrectomy. The average per cent decreases in body mass index (BMI) postgastrectomy at one month, six months, 12 months, and 24 months were 7.6, 11.7, 11.5, and 11.1 per cent, respectively (P = 0.003). The decreases in BMI were the same for all time periods whether patients had subtotal or total gastrectomy. Weight loss after gastric cancer resection is an important measure of quality of life. By understanding patterns of weight change after gastrectomy, we can better counsel and prepare our patients for the long-term effects of gastric cancer surgery.

Impact of Gastric Cancer Resection on Body Mass Index

Major gastric resection alters digestive function and may lead to profound weight loss. The objective of our study was to evaluate trends in body weight loss after curative gastrectomy for malignancy. A review of patients who underwent gastrectomy from 1999 to 2012 at two institutions was conducted. Patient demographics and treatment were assessed. Student's t test and analysis of variance were used to compare groups. Of 168 patients, two patients (1.2%) were Stage 0, 73 (43.5%) Stage I, 46 (27.4%) Stage II, 45 (26.8%) Stage III, and two (1.2%) stage unknown. Fifty-eight patients (34.5%) underwent total gastrectomy with Roux-en-Yesophagojejunostomy and 110 patients (65.5%) underwent subtotal gastrectomy. The average per cent decreases in body mass index (BMI) post-gastrectomy at one month, six months, 12 months, and 24 months were 7.6, 11.7, 11.5, and 11.1 per cent, respectively ( P = 0.003). The decreases in BMI were the same for all time periods whether patients had subtotal or total gastrectomy. Weight loss after gastric cancer resection is an important measure of quality of life. By understanding patterns of weight change after gastrectomy, we can better counsel and prepare our patients for the long-term effects of gastric cancer surgery.

Timing of chemotherapy and survival in patients with resectable gastric adenocarcinoma

AIM: To evaluate the timing of chemotherapy in gastric cancer by comparing survival outcomes in treatment groups.

METHODS: Patients with surgically resected gastric adenocarcinoma from 1988 to 2006 were identified from the Los Angeles County Cancer Surveillance Program. To evaluate the population most likely to receive and/or benefit from adjunct chemotherapy, inclusion criteria consisted of Stage II or III gastric cancer patients > 18 years of age who underwent curative-intent surgical resection. Patients were categorized into three groups according to the receipt of chemotherapy: (1) no chemotherapy; (2) preoperative chemotherapy; or (3) postoperative chemotherapy. Clinical and pathologic characteristics were compared across the different treatment arms.

RESULTS: Of 1518 patients with surgically resected gastric cancer, 327 (21.5%) received perioperative chemotherapy. The majority of these 327 patients were male (68%) with a mean age of 61.5 years; and they were significantly younger than non-chemotherapy patients (mean age, 70.7; P < 0.001). Most patients had tumors frequently located in the distal stomach (34.5%). Preoperative chemotherapy was administered to 11.3% of patients (n = 37) and postoperative therapy to 88.7% of patients (n = 290). An overall survival benefit according to timing of chemotherapy was not observed on univariate or multivariate analysis. Similar results were observed with stage-specific survival analyses (5-year overall survival: Stage II, 25% vs 30%, respectively; Stage III, 14% vs 11%, respectively). Therefore, our results do not identify a survival advantage for specific timing of chemotherapy in locally advanced gastric cancer.

CONCLUSION: This study supports the implementation of a randomized trial comparing the timing of perioperative therapy in patients with locally advanced gastric cancer.

Increasing age and survival after orthotopic liver transplantation for patients with hepatocellular cancer

BACKGROUND

Orthotopic liver transplantation (OLT) is the gold standard treatment for patients with early hepatocellular carcinoma (HCC). There are concerns about the efficacy of OLT for HCC in older patients, who we hypothesized might have poorer outcomes. Therefore, we sought to examine advanced age and its impact on OLT outcomes.

STUDY DESIGN

The United Network for Organ Sharing database was queried for patients who underwent OLT for HCC from 1987 to 2009. Patients were divided into 3 age groups: 35 to 49 years old, 50 to 64 years old, and 65 years or older, and patient characteristics were compared. Univariate and multivariate analyses were performed to assess the impact of age on OLT outcomes.

RESULTS

Of 10,238 patients with OLT for HCC, 16.5% (n = 1,688) of patients were 35 to 49 years old, 67.8% (n = 6,937) were 35 to 49 years old, and 15.8% (n = 1,613) were 65 years and older. By Kaplan-Meier method, the 50- to 64-year-old age group had the highest overall survival, despite having one of the highest rates of hepatitis C positivity (70%), but this group also had the lowest rate of diabetes mellitus (8.7%). The lowest overall survival was observed in the 65-year or older age group (p < 0.001). Finally, there was no difference in disease-specific survival among the age groups (p = 0.858), and patients aged 65 years and older had the highest rate of death from nonhepatic causes (17.5%).

CONCLUSIONS

Although OS was prolonged in younger patients who underwent OLT for HCC, there was no observed difference in disease-specific survival among the age groups. Our results suggest that carefully selected patients 65 years of age and older can derive equal benefit from OLT for HCC when compared with their younger counterparts.

Choledochoduodenostomy as the biliary-enteric bypass of choice for benign and malignant distal common bile duct strictures

Choledochoduodenostomy (including hepaticoduodenostomy) for common bile duct (CBD) strictures has been underused because of concerns regarding postoperative duodenal fistula and cholangitis attending the so-called "sump syndrome." An institutional retrospective review of 55 consecutive choledochoduodenostomy procedures for CBD strictures from 1995 to 2011 was performed to examine its suitability as the biliary-enteric bypass procedure of choice. There were 30 male (55%) and 25 female (45%) patients with a mean age of 49 years (range, 13 to 73 years). Thirty-seven (67%) patients had benign CBD strictures and 18 (33%) had unresectable periampullary adenocarcinomas. Forty-nine (89%) underwent choledochoduodenostomy and six (11%) underwent hepaticoduodenostomy. There were no 30-day postoperative deaths, anastomotic leaks, or intra-abdominal abscesses. Five patients (9%) sustained Clavien Grade III or IV complications. Over a mean long-term follow-up of 29 months (range, 1 to 162 months), there was one anastomotic stricture successfully managed by endoscopic dilation and temporary stenting. Liver function tests in all other patients returned to and remained within normal limits. We conclude that choledochoduodenostomy is the preferred biliary-enteric bypass for both benign and malignant distal CBD strictures because of its ease, safety, and durability. Persistent fears of duodenal fistula and the "sump syndrome" are not warranted by the empiric data and should be abandoned.

Targeted therapies in colorectal cancer: surgical considerations

Colorectal cancer (CRC) is a leading worldwide health concern that is responsible for thousands of deaths each year. The primary source of mortality for patients with CRC is the development and subsequent progression of metastatic disease. The most common site for distant metastatic disease is the liver. Although patients with metastatic disease to the liver have several effective treatment options, the only one for cure remains surgical resection of the liver metastases. Historically, most patients with liver metastases have had unresectable disease, and only a small percentage of patients have undergone complete curative resection. However, improved systemic therapies have led to an evolution in strategies to treat metastatic CRC to the liver. Under most conditions the management of these patients remains complex; and as chemotherapy options and new targeted therapies continue to improve outcomes, it is clear that a multidisciplinary approach must be the foundation on which advanced surgical and medical techniques are employed. Here, in this review, we highlight the role of targeted therapies in the surgical management of patients with metastatic CRC to the liver.

TP53 and let-7a micro-RNA regulate K-Ras activity in HCT116 colorectal cancer cells

Recent reports have indicated that KRAS and TP53 mutations predict response to therapy in colorectal cancer. However, little is known about the relationship between these two common genetic alterations. Micro-RNAs (miRNAs), a class of noncoding RNA implicated in cellular processes, have been increasingly linked to KRAS and TP53. We hypothesized that lethal-7a (let-7a) miRNA regulates KRAS through TP53. To investigate the relationship between KRAS, TP53, and let-7a, we used HCT116 KRAS^mut human colorectal cancer cells with four different genotypic modifications in TP53 (TP53^−/−, TP53^+/−, TP53^mut/+, and TP53^mut/−). Using these cells we observed that K-Ras activity was higher in cells with mutant or knocked out TP53 alleles, suggesting that wild-type TP53 may suppress K-Ras activity. Let-7a was present in HCT116 KRAS^mut cells, though there was no correlation between let-7a level and TP53 genotype status. To explore how let-7a may regulate K-Ras in the different TP53 genotype cells we used let-7a inhibitor and demonstrated increased K-Ras activity across all TP53, thus corroborating prior reports that let-7a regulates K-Ras. To assess potential clinical implications of this regulatory network, we examined the influence of TP53 genotype and let-7a inhibition on colon cancer cell survival following chemoradiation therapy (CRT). We observed that cells with complete loss of wild-type TP53 alleles (^−/− or ^−/mut) were resistant to CRT following treatment with 5-fluorouracil and radiation. Further increase in K-Ras activity with let-7a inhibition did not impact survival in these cells. In contrast, cells with single or double wild-type TP53 alleles were moderately responsive to CRT and exhibited resistance when let-7a was inhibited. In summary, our results show a complex regulatory system involving TP53, KRAS, and let-7a. Our results may provide clues to understand and target these interactions in colorectal cancer.

Impact of medical and surgical intervention on survival in patients with cholangiocarcinoma

AIM: To examine surgical and medical outcomes for patients with cholangiocarcinoma using a population-based cancer registry.

METHODS: Using the California Cancer Registry’s Cancer Surveillance Program, patients with intrahepatic cholangiocarcinoma treated in Los Angeles County from 1988 to 2006 were identified and evaluated for clinical and pathologic factors and therapies received (surgery, radiation, and chemotherapy). The surgical cohort was further categorized into three treatment groups: patients who received adjuvant chemotherapy, adjuvant chemoradiation, or underwent surgery alone (no chemotherapy or radiation administered). Survival was assessed by Kaplan-Meier method; and Cox proportional hazard modeling was used in multivariate analysis.

RESULTS: Of 825 patients, 60.2% received no treatment. Of the remaining 328 patients, 18.5% chemotherapy only, 7.4% chemoradiation, and 13.8% underwent surgery. More male patients underwent surgical resection (P = 0.004). Surgical patients were younger than the patients receiving chemotherapy or chemoradiation (P < 0.001). Of the surgical cohort (n = 114), 60.5% underwent surgery alone while 39.5% underwent surgery plus adjuvant therapy (chemotherapy, n = 20; chemoradiation, n = 21) (P < 0.001). Median survival for all patients in the study was 6.6 mo. Median survival was highest for patients who underwent surgery (23 mo), whereas both chemotherapy (9 mo) and chemoradiation (8 mo) alone were each less effective (P < 0.001). By multivariate analysis, extent of disease, receipt of surgery, and administration of chemotherapy (with/without surgery) were independent predictors of overall survival.

CONCLUSION: This study demonstrates that surgery is a critical treatment modality. Multimodality treatment has yet to be standardized, but play a role in optimal therapy for cholangiocarcinoma.

Abstract 4009: CCL25-CCR9 axis mediates pancreatic cancer progression through beta-catenin activation

Background: Expression of the chemokine receptor CCR9 is elevated in select solid organ cancers; and may contribute to drug resistance. However, there is no data for the role of CCR9 in GI cancers, aside from our prior work which demonstrated elevated expression in pancreatic cancer. Our current studies have uncovered activation of a novel CCR9-mediated molecular pathway and suggest that CCR9 may play a critical role in cancer progression through the aberrant activation of β-catenin.

Methods: Immunohistochemistry and western blotting were used to assess CCR9 expression. We exposed human pancreatic cancer cell lines to CCL25 and evaluated levels of activated β-catenin and phosphorylated AKT via western blot. Proliferation and invasion were measured using an ATP-based assay and a Boyden chamber assay, respectively. IC50 of gemcitabine was determined using an acid phosphatase assay.

Results: We have previously shown that CCR9 is expressed in human and murine PanIN lesions and in a human pancreatic cancer cell line. Here we expand upon these findings to show CCR9 expression in human pancreatic cancer tissue samples and in multiple cell lines. We determined that stimulation of CCR9 by its ligand, CCL25, signals through AKT and β-catenin to increase cell proliferation and invasion in pancreatic cancer cell lines. Following treatment with CCL25, cell proliferation was increased by an average of 20% across all cell lines (p&lt;0.01). Pre-treatment with the PI3K inhibitor, LY294002, inhibited the CCL25-mediated increase in proliferation. We further show a CCL25-mediated increase in invasion. Using a modified Boyden chamber matrigel invasion assay, we determined that CCL25 as a chemoattractant heightened the invasive abilities of our pancreatic cancer cell lines by 3-fold. Inhibiting PI3K activation blocked this increase. In addition, exposure to CCL25 led to reduced gemcitabine sensitivity. Pre-treatment with CCL25 increased the IC50 of gemcitabine by 7-fold in PANC-1 cells, from 0.1μM to 0.77μM (p=0.005) and 5.5-fold in AsPC-1 cells from 17.7μM to 96.7μM (p=0.008), indicating a drastic decrease in the effectiveness of gemcitabine when CCL25 is present.

Conclusions: The current paucity of effective therapies for pancreatic cancer presents a significant clinical challenge. This highlights the need to identify and study mechanisms and pathways involved in pancreatic cancer progression. Determining the role of CC9R in pancreatic cancer and targeting the CCL25-CCR9-β-catenin pathway may therefore present an innovative, clinically significant therapeutic target for pancreatic cancer.

Citation Format: Eileen L. Heinrich, Jianming Lu, Wendy Lee, Carrie Luu, Joseph Kim. CCL25-CCR9 axis mediates pancreatic cancer progression through beta-catenin activation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4009. doi:10.1158/1538-7445.AM2013-4009

Assessment of macroscopic features in relation to tumor response to neoadjuvant chemoradiation therapy in rectal cancer

507

Background: Several studies show locally advanced rectal cancer patients with clinical complete response (cCR) have comparable oncologic outcomes to pathologic complete response (pCR) to neoadjuvant chemoradiation therapy (NCRT). Thus, total mesorectal excision (TME) could potentially be avoided. Our objective was to validate macroscopic features of cCR. Methods: 164 patients with stage II/III rectal cancer were previously enrolled in a phase II trial and treated by NCRT and TME. Tumor response in the surgical specimens was assessed according to AJCC guidelines. A pCR was defined as absence of viable tumor cells. Gross macroscopic features by the pathologist were tabulated and our cohort was applied to previously published cCR criteria. Results: 25.0% (n = 41) had pCR; 75.0% (n = 123) had non-pCR. Descriptors were condensed into 14 macroscopic features by combining terms and excluding those rarely mentioned. Several reports affirm that scarring signifies cCR, while others suggest that fibrosis, edema, ulceration and nonpalpable tumor to be consistent with cCR. In our study, scarring was found in 6.1% of patients, 16.7% of which had pCR. We found that hyperemia, scarring, flat, smooth, and tan-pink mucosa were significantly associated with pCR (p < 0.05). In contrast, a firm lesion and ulceration were frequently observed in patients with non-pCR (p = 0.02 and 0.05 respectively). Conclusions: Our study suggests that macroscopic pathologic features do correlate with pCR. Although cCR has comparable oncologic outcomes as pCR with favorable outcomes, standard criteria of cCR should first be defined so NCRT patients can safely be selected for observation only. [Table: see text]

Effectiveness of capecitabine plus oxaliplatin for advanced colon cancer: A public hospital experience

570

Background: Adjuvant chemotherapy has been shown to improve disease-free survival (DFS) and overall survival (OS) in advanced colon cancer (CC). 5-fluorouracil (5-FU)/leucovorin and oxaliplatin is the first line therapy for stage II and III CC. Due to systematic and financial constraints imposed by administering infusional 5-FU, this agent is not available at our institution. Capecitabine plus oxaliplatin (CAPOX) has been studied by others as a possible alternative. We report our experience with CAPOX in the adjuvant treatment of CC patients in a large, public hospital. Methods: A retrospective study of 142 patients with CC who received CAPOX from 2005 to 2011 was performed. Data on patient demographics, treatment, disease recurrence, and survival were analyzed. Survival was assessed by the Kaplan-Meier method. The Cox regression model was used for multivariate analysis. Results: There were 60 female and 82 male patients with a mean age of 54 years (range 21-80). 57 patients were diagnosed with stage II CC and 85 with stage III CC. All patients with stage II and stage III disease underwent curative-intent surgical resection, except for one patient, who refused surgery. 14/141 operations (10%) were performed emergently. Mean follow-up was 36 months (range 2-85 months). The 3-year OS rates were 91% and 81% for stages II and III, respectively. The 3-year DFS rate was 74% for stage II and 66% for stage III. By multivariate analysis, only cancer stage was predictive of overall survival. Conclusions: CAPOX is an effective treatment for stage II and III CC in the adjuvant setting. Our study supports recent evidence demonstrating the efficacy of CAPOX in CC. Ease of administration and improved utilization of resources make it an ideal regimen for public hospital facilities.

Evaluating malignant intraductal papillary mucinous neoplasm: A population-based study

324

Background: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas has been increasingly recognized. Due to a paucity of evidence, the management and treatment of IPMN is still under debate. We hypothesize that with increased awareness, the incidence and resection rates for IPMN would increase. Using a population-based cancer registry, we examined incidence, prognostic factors, and survival for IPMN. Methods: Patients diagnosed with invasive IPMN from 1988 to 2009 were identified by the Surveillance, Epidemiology, and End Results (SEER) database. Patient demographics, clinical and pathologic factors, and therapies received (surgery and/or radiation) were analyzed. Survival was assessed by Kaplan-Meier method; Cox proportional hazard modeling was used for multivariate analysis. Results: 2,987 patients were identified. Over the study period, there was a decrease in age-adjusted incidence. The overall resection rate was 20.6% with an increase in annual rates of resection. On univariate analysis, age greater than 65 years, tumor location, poorly differentiated tumor grade, higher T stage, and positive lymph nodes predicted worse survival; more recent diagnosis, higher number of lymph nodes examined, and surgery were indicators of improved survival. On multivariate analysis, curative surgery remained predictive of survival. Patients who underwent surgery had median survival rates of 87, 18, and 14 months compared to 6, 7, and 5 months in the no surgery group for stages I, II, and III, respectively. Conclusions: Although recent reports show increasing incidence of IPMN, our study involving a population-based cohort demonstrates decreasing incidence of malignant IPMN. This may be accounted for by increased detection of non-malignant disease. It is imperative that we identify patients with invasive IPMN early so that they may benefit from the survival advantage conferred by curative resection.

Effect of socioeconomic status on surgery for pancreatic adenocarcinoma

Survival for pancreatic cancer remains poor. Surgical resection remains the only chance for cure. The intent of this study was to investigate the role of socioeconomic status (SES) on resection rates for pancreatic adenocarcinoma. The National Cancer Institute's Surveillance, Epidemiology, and End results database was used to identify patients with pancreatic adenocarcinoma. Disease was deemed resectable or unresectable based on the extent of disease code. Median family income was used as a SES variable to compare patients who underwent resection with those who did not. Median family income was organized into three categories based on definitions from the national census: less than $34,680 (low income), $34,680 to $48,650 (middle), and greater than $48,650 (high income). A total of 5,908 patients with potentially resectable disease were included. A total of 3,331 patients did not have a surgical resection despite having resectable disease. Subgroup analysis of income status revealed that patients with a low or middle income were less likely to have a resection when compared with those with high income (33.0 vs 39.9 vs 45.8%, P=0.0001). Multivariate analysis revealed that low and middle SES and race were significant predictors of resection. Ongoing study of access to health care may help define the means to eliminate the disparities in the care of patients with pancreatic adenocarcinoma.

Tissue loss secondary to extrinsic compression of common iliac artery from uterine leiomyoma: a case report and review of the literature

BACKGROUND

Uterine leiomyomas are commonly reported to cause deep venous thrombosis and rarely arterial compression.

CASE

A 48-year-old woman was transferred to our institution with acute right lower limb ischemia and tissue loss. She underwent urgent iliac thrombectomy and was subsequently found to have right common iliac artery compression by a large uterine leiomyoma. She underwent successful resection of the tumor followed by endovascular iliac stent placement.

CONCLUSION

This case emphasizes the importance of preoperative imaging when possible in the setting of acute arterial ischemia to evaluate for sources of extrinsic compression. Management requires correction of the etiology of extrinsic compression.

Integrated hydroxyapatite implant and non-integrated implants in enucleated Asian patients

INTRODUCTION

This study compares the outcome and complications of integrated hydroxyapatite implant and non-integrated orbital implants following enucleation in Asian patients.

MATERIALS AND METHODS

This is a retrospective study of enucleated patients with coralline hydroxyapatite implants versus non-integrated implants (acrylic, glass and silicone) at the Singapore National Eye Centre from January 1991 to December 2000. The outcomes measured were implant migration, extrusion, socket infection, conjunctival dehiscence and implant exposure. Statistical analysis was done using the 2-sample t-test.

RESULTS

Twenty-one patients had the hydroxyapatite implant and 38 non-integrated implants (27 acrylic, 9 glass and 2 silicone). The mean duration of follow-up was 2.7 years and 4 years for the hydroxyapatite implant and non-integrated implants respectively. Three patients with pre-existing severe socket contracture before enucleation surgeries were excluded from the study. Four cases of implant migration, 4 cases of implant extrusion and 3 cases of socket infection were encountered; all were sockets fitted with non-integrated implants. There was a higher rate of conjunctival dehiscence for sockets with hydroxyapatite implants (6 out of 21) compared to sockets with non-integrated implants (3 out of 35). This was statistically significant (P = 0.048).

CONCLUSIONS

Implant complications of migration, extrusion and socket infection were found in non-integrated implants and none in coralline hydroxyapatite implants, which had a significantly higher rate of conjunctival dehiscence. Most of these were easily managed with only a small number progressing to implant exposure.

Ozone potentiates vitamin E depletion by ultraviolet radiation in the murine stratum corneum

As the outermost layer of the skin, the stratum corneum is exposed to environmental oxidants. To investigate putative synergisms of environmental oxidative stressors in stratum corneum, hairless mice were exposed to ultraviolet radiation (UV) and ozone (O(3)) alone and in combination. Whereas a significant depletion of alpha-tocopherol was observed after individual exposure to either a 0.5 minimal erythemal dose of UV or 1 ppm O(3) for 2 h, the combination did not increase the effect of UV alone. However, a dose of 0.5 ppm O(3) x 2 h, which had no effect when used alone, significantly enhanced the UV-induced depletion of vitamin E. We conclude that concomitant exposure to low doses of UV and O(3) at levels near those that humans can be exposed to causes additive oxidative stress in the stratum corneum.

Decreased anterior cingulate gyrus metabolic rate in schizophrenia

OBJECTIVE

This study examined glucose metabolism in the anterior and posterior cingulate cortex in schizophrenia.

METHOD

Fifty unmedicated male schizophrenic patients and 24 normal men were studied with positron emission tomography.

RESULTS

Compared with the normal men, the schizophrenic patients had lower relative metabolic rates in the anterior cingulate and higher rates in the posterior cingulate.

CONCLUSIONS

The findings suggest hypofunction in the anterior cingulate cortex in schizophrenia.

Ventricular enlargement associated with linkage marker for schizophrenia-related disorders in one pedigree

We previously obtained evidence indicating a genetic linkage marker for schizophrenia and related disorders (two-point lod score = 3.72, P = 0.01) on the short arm of chromosome 5(5p14.1-13.1) in one large pedigree. Automated computer algorithms were used to edge the brain and measure the volume of the ventricles, regional sulcal atrophy, and skull size and shape in the original nuclear family members. Of the 11 subjects who underwent computed tomography, six (three schizophrenic, two with schizotypal personality disorder, and one unaffected) carried the marker allele that co-segregated with schizophrenia-related disorders, while five (all unaffected) did not. The family members with the marker allele linked to schizophrenia-related disorders (n = 6) had significantly (P < 0.05) larger ventricle-brain ratios (VBRs) and more fronto-parietal atrophy (controlling for age) than the family members lacking the schizophrenia-related marker allele (n = 5). The three individuals with the largest VBRs all carried the marker, although they received diagnoses of no schizophrenia-related disorder, schizotypal personality disorder, and schizophrenia. Regional cortical values indicative of cerebrospinal fluid content were higher in the frontal and parietal regions of family members carrying the marker. The hypothesis that genetic linkage is associated with structural brain pathology is difficult to test because of all the potential compounding factors. Our findings suggest the possibility that, in this family, relatively enlarged VBR and fronto-parietal atrophy, as determined by computed tomograph, may be associated with a schizophrenia-related gene and present susceptibility to schizophrenia-related disorders. In addition to a replication of these findings in other similarly linked families yet to be identified, further studies using higher resolution structural and functional neuroimaging techniques will be required.