Faculty Bibliography

BACKGROUND:Recently, a tumor-burden "metro ticket" score (TBS) based on final pathology was proposed to predict outcome following resection of colorectal liver metastasis (CRLM). We sought to validate the TBS prognostic tool using preoperative radiologic cross-sectional imaging. METHODS:Imaging TBS was defined on a Cartesian plane that incorporated both maximum tumor size (x-axis) and lesion number (y-axis) assessed by pre-operative imaging. The discriminatory power (area under the curve [AUC]) and goodness-of-fit (Harrel's C statistic and Somer's D statistics) of the imaging TBS model was assessed. RESULTS:Imaging and pathologic TBS correlated strongly (r = 0.76, P < 0.01). Among patients treated with neoadjuvant therapy, the correlation was strongest among patients with progressive disease/stable disease (PD/SD) (r = 0.81). Discriminatory power of the imaging-based versus pathology-based TBS models were comparable (AUC 0.64 vs. 0.67, respectively P > 0.05). An incremental worsening of long-term survival was noted as the imaging TBS increased (5-year OS: Zone1, Zone2, and Zone3-61.3%, 46.7%, and 38.5%, respectively; P = 0.03). The imaging-based TBS model outperformed the "classic" pathology-based Fong score (Harrel's C-index: imaging TBS-0.56 vs. Fong score-0.53; Somers'D-index: imaging TBS-012 vs. Fong score-0.06). CONCLUSIONS:Imaging-based TBS was superior to traditional tumor size and number and was comparable to pathology-based TBS. Imaging-based TBS may have the potential to facilitate improved preoperative risk stratification of patients with CRLM.

BACKGROUND:Rates of superficial surgical site infection (SSI) following pancreaticoduodenectomy remain high. Following resection for cancer, complications such as SSI impact adjuvant therapy delivery and portend worse survival. An incisional negative pressure dressing (iVAC) has been demonstrated to reduce SSI in other high-risk cohorts. METHODS:Following a comprehensive effort to identify patients at high risk for SSI, the practice patterns at a single academic center shifted and iVAC use increased. SSI rates were tracked in a prospectively maintained database and are reported. RESULTS:394 patients underwent pancreaticoduodenectomy over 21 months. 120 patients (30.5%) had an iVAC applied. The overall rate of SSI was 19.8%. On multivariate analysis, increased risk for SSI was associated with neoadjuvant therapy, preoperative biliary interventions and prior abdominal surgery. iVAC use decreased the rate of SSI (OR 0.45, p = 0.015). In the highest-risk patients, SSI rate declined from 50% in patients without an iVAC to 19.1% with iVAC use (p = 0.015). CONCLUSION:The use of an iVAC following pancreaticoduodenectomy is associated with decreased SSI rates. This is particularly true for patients at highest risk as defined by a previously established risk scoring system in patients undergoing open pancreaticoduodenectomy.

BACKGROUND:Although experimental data strongly support the pro-tumorigenic role of postoperative liver regeneration, this hypothesis has not been clinically investigated. We aimed to examine the impact of liver regeneration determined by volumetric imaging on recurrence following resection of colorectal liver metastasis (CRLM). METHODS:). Early and late kinetic growth rates (KGR) were defined as the postoperative increases in liver volume within 2-3 and 8-10 months from surgery, respectively, divided by the corresponding time interval. RESULTS:Median early and late KGR was 2.6%/month (IQR: -0.9 to 12.3) and 1.0%/month (IQR: -0.64 to 2.91), respectively. Late KGR predicted intrahepatic recurrence after 1 year from surgery (AUC 0.677, P = 0.011). Specifically, patients with a late KGR ≥1% had a higher cumulative risk of recurrence compared with patients with a KGR <1% (P = 0.038). In multivariate analysis, KGR ≥1% independently predicted recurrence (P = 0.027). DISCUSSION:A KGR ≥1% during the late regeneration phase was associated with increased risk of intrahepatic recurrence. These data may inform the timing of adjuvant therapy administration and focus surveillance strategies for high-risk patients.

BACKGROUND:Although the prognostic role of surgical margin status after resection of colorectal liver metastasis (CRLM) has been previously examined, controversy still surrounds the importance of surgical margin status in patients with multiple tumors. METHODS:Patients who underwent curative-intent surgery for CRLM from 2000 to 2015 and who presented with multiple tumors were identified. Patients with R1 resection status determined by the closest resection margin of the non-largest tumor were classified as R1-Type 1; patients with R1 status determined by the resection margin of the largest tumor were defined as R1-Type 2. Data regarding surgical margin status, size of tumors, and overall survival (OS) were collected and assessed. RESULTS:A total of 251 patients met inclusion criteria; 156 patients (62.2%) had a negative margin (R0), 50 had an R1-type 1 (19.9%), and 45 had an R1-type 2 (17.9%) margin. Median and 5-year OS in the entire cohort was 56.4 months and 48.0%, respectively. When all R1 (Type 1 + Type 2) patients were compared with R0 patients, an R1 was not associated with worse prognosis (P = 0.05). In contrast, when R1-type 2 patients were compared with R0 patients, an R1 was strongly associated with worse OS (P = 0.009). On multivariate analysis, although the prognostic impact of all R1 was not associated with OS (hazard ratio [HR] 1.56; P = 0.08), R1-Type 2 margin status independently predicted a poor outcome (HR 1.93; P = 0.03). CONCLUSIONS:The impact of margin status varied according to the size of the tumor assessed. While R1 margin status defined according to the non-largest tumor was not associated with OS, R1 margin status relative to the largest index lesion was associated with prognosis.

BACKGROUND:Distal pancreatectomy (DP) is performed to treat tumors of the pancreatic body and tail. Traditionally, splenectomy is performed with a DP, however, laparoscopic spleen-preserving DP (SPDP) using Warshaw's (splenic vessels ligation) or Kimura's (splenic vessels preservation) techniques have been reported. The clinical benefits of using either technique remain unclear. In this study, we conducted a meta-analysis to compare the clinical outcomes of patients undergoing Warshaw's and Kimura SPDP. This is the first study to evaluate the geographical variation in outcomes of Warshaw's and Kimura SPDP. METHODS:Databases of PubMed, Embase, and Cochrane library were used to identify studies reporting Warshaw's and Kimura SPDP. Clinical outcomes were compared. Pooled odds risk and weighted mean difference with 95% confidence interval were calculated using random effect models. RESULTS:Fourteen non-randomized controlled studies involving 945 patients met our selection criteria. 301 (31.9%) patients underwent Warshaw's SPDP; 644 (68.1%) underwent Kimura SPDP. Compared to Warshaw's SPDP, patients undergoing Kimura SPDP had a lower incidence of post-operative complications including spleen infarction (OR = 9.64, 95% CI = 5.79 to 16.05, P < 0.001) and gastric varices (OR = 11.88, 95% CI = 5.11 to 27.66, P < 0.001). The length of surgery was significantly shorter for Warshaw's SPDP (WMD = -18.12, 95%CI = -26.52 to -9.72, p < 0.001). Decreased blood loss was reported for patients undergoing Warshaw's SPDP (WMD = -59.72, 95%CI = -102.01 to -17.43, p = 0.006). There were no differences between the two groups' rates of conversion to an open procedure (P = 0.35), postoperative pancreatic fistula (P = 0.71), need for reoperation (P = 0.25), and length of hospital stay (P = 0.38). CONCLUSION/CONCLUSIONS:Both Warshaw's and Kimura are safe SPDP techniques. These data suggest Kimura SPDP is the preferred technique due to less risk of splenic infarct and gastric varices. Despite evidence of regional variation in volume performed (between Kimura and Warshaw's), there are no statistically significant differences in outcomes between these techniques.

CEL-HYB is a hybrid allele that arose from a crossover between the 3' end of the Carboxyl ester lipase (CEL) gene and the nearby CEL pseudogene (CELP) and was recently identified as a risk factor for chronic pancreatitis. Since chronic pancreatitis is a risk factor for the development of pancreatic cancer, we compared the prevalence of the CEL-HYB allele in patients with pancreatic ductal adenocarcinoma to spousal controls and disease controls. The CEL-HYB allele was detected using Sanger and next generation sequencing. There was no significant difference in the prevalence of the CEL-HYB allele between cases with pancreatic ductal adenocarcinoma compared to controls; 2.6% (22/850) vs. 1.8% (18/976) (p=0.35). CEL-HYB carriers were not more likely to report a history of pancreatitis. Patients with pancreatic cancer are not more likely than controls to be carriers of the CEL-HYB allele.

OBJECTIVE:To evaluate the correlation between neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) values, and the presence of invasive carcinoma in patients with intraductal papillary mucinous neoplasm (IPMN). BACKGROUND:NLR and (PLR) are inflammatory markers that have been associated with overall survival in patients with invasive malignancies, including pancreatic cancer. METHODS:We retrospectively reviewed 272 patients who underwent surgical resection for histologically confirmed IPMN from January 1997 to July 2015. NLR and PLR were calculated and coevaluated with additional demographic, clinical, and imaging data for possible correlation with IPMN-associated carcinoma in the form of a predictive nomogram. RESULTS:NLR and PLR were significantly elevated in patients with IPMN-associated invasive carcinoma (P < 0.001). In the multivariate analysis, NLR value higher than 4 (P < 0.001), IPMN cyst of size more than 3 cm (P < 0.001), presence of enhanced solid component (P = 0.014), main pancreatic duct dilatation of more than 5 mm (P < 0.001), and jaundice (P < 0.001) were statistically significant variables. The developed statistical model has a c-index of 0.895. Implementation of the statistically significant variables in a predictive nomogram provided a reliable point system for estimating the presence of IPMN-associated invasive carcinoma. CONCLUSIONS:NLR is an independent predictive marker for the presence of IPMN-associated invasive carcinoma. Further prospective studies are needed to assess the predictive ability of NLR and how it can be applied in the clinical setting.

BACKGROUND:The current staging system for pancreatic ductal adenocarcinoma (PDAC) includes information about size and local extension of the primary tumor (T stage). The value of incorporating any local tumor extension into pancreatic staging systems has been questioned because it often is difficult to evaluate tumor extension to the peri-pancreatic soft tissues and because most carcinomas of the head of the pancreas infiltrate the intra-pancreatic common bile duct. This study sought to evaluate the prognostic implications of having PDAC with local tumor extension. METHODS:A single-institution, prospectively collected database of 1128 patients who underwent surgical resection for PDAC was queried to examine the prognostic significance of extra-pancreatic tumor involvement ("no involvement," "duodenal involvement," and "extensive involvement"; e.g., gastric, colon or major vein involvement). RESULTS:The median overall survival for the patients without extra-pancreatic involvement was 26 months versus 19 months for the patients with duodenal involvement and 16 months for the patients with extensive involvement (p < 0.001). In the multivariable analysis, duodenal and extensive involvement independently predicted increased risk of death compared with no involvement (hazard ratio [HR] 1.30; 95% confidence interval [CI] 1.08-1.57 and 1.78; 95% CI 1.25-2.55, respectively). A multivariable model combining duodenal and extensive extra-pancreatic involvement, tumor grade, lymph node ratio, and other prognostic features had the highest c-index (0.67). CONCLUSIONS:Inclusion of duodenal involvement in the staging of PDAC adds independent prognostic information.

BACKGROUND:We built a multinational retrospective database of patients with ampulla of Vater cancer to develop a reliable new staging system. METHOD/METHODS:This study included 841 patients with ampulla of Vater cancer after curative surgery at Seoul National University Hospital (n = 440) and Johns Hopkins University medical institutions (n = 401) between 1985 and 2013. RESULTS:American Joint Committee on Cancer staging system were 80.3%, 60.9%, 58.1%, 36.6%, 17.9%, and 25.0% for Stages IA (n = 140), IB (n = 194), IIA (n = 115), IIB (n = 348), III (n = 33), and IV (n = 4), respectively. Five-year OS rates were similar in patients with Stage IB (T2N0M0) and IIA (T3N0M0) tumors (P = 0.556), but differed significantly between other pairs of groups. The number of positive lymph nodes (PLN) enhanced prognosis when stratified as 0, 1-2 and ≥3 (P < 0.001). The revised staging system consisted of Stages I (T1, PLN 0), IIA (T2-T3, PLN 0), IIB (T1-T3, PLN 1-2), III (PLN ≥3 or any T4), and IV (any M1), with 5-year OS rates differing significantly in each pair of groups, including Stages I and IIA (P < 0.001). CONCLUSION/CONCLUSIONS:This new staging system has better discriminatory ability in stratifying 5-year OS rates based on a large multinational database.

OBJECTIVES:Circulating epithelial cells (CECs) are identified in the blood of patients with intraductal papillary mucinous neoplasms (IPMNs) despite the absence of malignancy. We assessed the blood of patients undergoing resection for IPMN or other benign pancreatic lesions for CECs. METHODS:Peripheral blood was collected from 26 patients prior to pancreatic resection and filtered by the ISET (Isolation by Size of Epithelial Tumor Cells) method. Circulating epithelial cells were identified with antibodies to cytokeratin and Pdx1 (pancreas and duodenal homeobox protein 1), a pancreas marker. RESULTS:Nineteen patients underwent resection of an IPMN without associated malignancy. Eleven patients (58%) had cytokeratin-positive CECs. Circulating epithelial cells were significantly more likely to be found in patients with IPMNs with high-grade dysplasia (P = 0.04). In addition, 10 of the 11 patients with cytokeratin-positive CECs also had separate populations of cytokeratin-positive, Pdx1-positive CECs, suggesting a pancreatic source. Dual-staining CECs were more frequently found in patients with high-grade dysplasia (P = 0.04). Patients with IPMNs were significantly more likely to have pan-cytokeratin CECs in the blood compared with those without IPMNs (P = 0.01). CONCLUSIONS:Circulating epithelial cells staining with potential pancreas-specific markers have been found in patients with IPMNs, even without malignancy. Circulating epithelial cells may help to differentiate patients with high-grade IPMN from lower grades of dysplasia and other pancreatic cysts.