Nipun B. Merchant

Left-sided pancreatectomy: a multicenter comparison of laparoscopic and open approaches.

Objectives:To compare perioperative outcomes of laparoscopic left-sided pancreatectomy (LLP) with traditional open left-sided pancreatectomy (OLP) in a multicenter experience. Summary and Background Data:LLP is being performed more commonly with limited data comparing results with outcomes from OLP. Methods:Data from 8 centers were combined for all cases performed between 2002–2006. OLP and LLP cohorts were matched by age, American Society of Anesthesiologists, resected pancreas length, tumor size, and diagnosis. Multivariate analysis was performed using binary logistic regression. Results:Six hundred sixty-seven LPs were performed, with 159 (24%) attempted laparoscopically. Indications were solid lesion in 307 (46%), cystic in 295 (44%), and pancreatitis in 65 (10%) cases. Positive margins occurred in 51 (8%) cases, 335 (50%) had complications, and significant leaks occurred in 108 (16%). Conversion to OLP occurred in 20 (13%) of the LLPs. In the matched comparison, 200 OLPs were compared with 142 LLPs. There were no differences in positive margin rates (8% vs. 7%, P = 0.8), operative times (216 vs. 230 minutes, P = 0.3), or leak rates (18% vs. 11%, P = 0.1). LLP patients had lower average blood loss (357 vs. 588 mL, P < 0.01), fewer complications (40% vs. 57%, P < 0.01), and shorter hospital stays (5.9 vs. 9.0 days, P < 0.01). By MVA, LLP was an independent factor for shorter hospital stay (P < 0.01, odds ratio 0.33, 95% confidence interval 0.19–0.56). Conclusions:In selected patients, LLP is associated with less morbidity and shorter LOS than OLP. Pancreatic fistula rates are similar for OLP and LLP. LLP is appropriate for selected patients with left-sided pancreatic pathology.

Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

Objective:Our aims were to (1) determine the long-term oncologic outcome for patients with rectal cancer treated with preoperative combined modality therapy (CMT) followed by total mesorectal excision (TME), (2) identify factors predictive of oncologic outcome, and (3) determine the oncologic significance of the extent of pathologic tumor response. Summary Background Data:Locally advanced (T3–4 and/or N1) rectal adenocarcinoma is commonly treated with preoperative CMT and TME. However, the long-term oncologic results of this approach and factors predictive of a durable outcome remain largely unknown. Methods:Two hundred ninety-seven consecutive patients with locally advanced rectal adenocarcinoma at a median distance of 6cm from the anal verge (range 0–15 cm) were treated with preoperative CMT (radiation: 5040 centi-Gray (cGy) and 5-fluorouracil (5-FU)-based chemotherapy) followed by TME from 1988 to 2002. A prospectively collected database was queried for long-term oncologic outcome and predictive clinicopathologic factors. Results:With a median follow-up of 44 months, the estimated 10-year overall survival (OS) was 58% and 10 year recurrence-free survival (RFS) was 62%. On multivariate analysis, pathologic response >95%, lymphovascular invasion and/or perineural invasion (PNI), and positive lymph nodes were significantly associated with OS and RFS. Patients with a >95% pathologic response had a significantly improved OS (P = 0.003) and RFS (P = 0.002). Conclusions:Treatment of locally advanced rectal cancer with preoperative CMT followed by TME can provide for a durable 10-year OS of 58% and RFS of 62%. Patients who achieve a >95% response to preoperative CMT have an improved long-term oncologic outcome, a novel finding that deserves further study.

Experimentally Derived Metastasis Gene Expression Profile Predicts Recurrence and Death in Patients With Colon Cancer

BACKGROUND & AIMS Staging inadequately predicts metastatic risk in patients with colon cancer. We used a gene expression profile derived from invasive, murine colon cancer cells that were highly metastatic in an immunocompetent mouse model to identify patients with colon cancer at risk of recurrence. METHODS This phase 1, exploratory biomarker study used 55 patients with colorectal cancer from Vanderbilt Medical Center (VMC) as the training dataset and 177 patients from the Moffitt Cancer Center as the independent dataset. The metastasis-associated gene expression profile developed from the mouse model was refined with comparative functional genomics in the VMC gene expression profiles to identify a 34-gene classifier associated with high risk of metastasis and death from colon cancer. A metastasis score derived from the biologically based classifier was tested in the Moffitt dataset. RESULTS A high score was significantly associated with increased risk of metastasis and death from colon cancer across all pathologic stages and specifically in stage II and stage III patients. The metastasis score was shown to independently predict risk of cancer recurrence and death in univariate and multivariate models. For example, among stage III patients, a high score translated to increased relative risk of cancer recurrence (hazard ratio, 4.7; 95% confidence interval, 1.566-14.05). Furthermore, the metastasis score identified patients with stage III disease whose 5-year recurrence-free survival was >88% and for whom adjuvant chemotherapy did not increase survival time. CONCLUSION A gene expression profile identified from an experimental model of colon cancer metastasis predicted cancer recurrence and death, independently of conventional measures, in patients with colon cancer.

A Multicenter Analysis of Distal Pancreatectomy for Adenocarcinoma: Is Laparoscopic Resection Appropriate?

BACKGROUND As compared with open distal pancreatectomy (ODP), laparoscopic distal pancreatectomy (LDP) affords improved perioperative outcomes. The role of LDP for patients with pancreatic ductal adenocarcinoma (PDAC) is not defined. STUDY DESIGN Records from patients undergoing distal pancreatectomy (DP) for PDAC from 2000 to 2008 from 9 academic medical centers were reviewed. Short-term (node harvest and margin status) and long-term (survival) cancer outcomes were assessed. A 3:1 matched analysis was performed for ODP and LDP cases using age, American Society of Anesthesiologists (ASA) class, and tumor size. RESULTS There were 212 patients who underwent DP for PDAC; 23 (11%) of these were approached laparoscopically. For all 212 patients, 56 (26%) had positive margins. The mean number of nodes (+/- SD) examined was 12.6 +/-8.4 and 114 patients (54%) had at least 1 positive node. Median overall survival was 16 months. In the matched analysis there were no significant differences in positive margin rates, number of nodes examined, number of patients with at least 1 positive node, or overall survival. Logistic regression for all 212 patients demonstrated that advanced age, larger tumors, positive margins, and node positive disease were independently associated with worse survival; however, method of resection (ODP vs. LDP) was not. Hospital stay was 2 days shorter in the matched comparison, which approached significance (LDP, 7.4 days vs. ODP, 9.4 days, p = 0.06). CONCLUSIONS LDP provides similar short- and long-term oncologic outcomes as compared with OD, with potentially shorter hospital stay. These results suggest that LDP is an acceptable approach for resection of PDAC of the left pancreas in selected patients.

Factors influencing readmission after pancreaticoduodenectomy: a multi-institutional study of 1302 patients.

Objective and Background:Morbidity, mortality, and length of hospital stay after pancreaticoduodenectomy (PD) have significantly decreased over recent decades. Despite this progress, early readmission rates after PD have been reported as high as 50%. Few reports have delineated factors associated with readmission after PD. Methods:The medical records of 6 high-volume institutions were reviewed for patients who underwent PD between 2005 and 2010. Data collection included patient characteristics, medical comorbidities, and perioperative factors. Analysis included readmissions up to 90 days after PD. Results:A total of 1302 patients underwent PD across all institutions. The 30-day and 90-day readmission rates were 15% and 19%, respectively. The most common reasons for 30-day readmission included infectious complications (n = 65) and delayed gastric emptying (n = 29). The most common reasons for readmission after 90 days included wound infections and intra-abdominal abscess (n = 75) and failure to thrive (n = 38). On multivariate analysis, factors associated with higher readmission rates included a preoperative diagnosis of chronic pancreatitis, higher transfusion requirements, and postoperative complications including intra-abdominal abscess and pancreatic fistula (all P < 0.02). Factors not associated with higher readmission rates included advanced age, body mass index, cardiovascular/pulmonary comorbidities, diabetes, steroid use, Whipple type (standard vs pylorus preserving PD), preoperative endobiliary stenting, and vascular reconstruction. Conclusions:These multi-institutional data represent a large experience of PD without the biases typically of single center studies. Factors related to infection, nutritional status, and delayed gastric emptying were the most common reasons for readmission after PD. Postoperative complications including pancreatic fistula predicted higher rates of readmission.

Proposed revision of the esophageal cancer staging system to accommodate pathologic response (PP) following preoperative chemoradiation (CRT)

Objective:To determine the impact of pathologic response following preoperative chemoradiation (CRT) on the AJCC esophageal cancer staging system. Summary Background Data:Increasing numbers of locoregionally advanced esophageal cancer patients are treated with preoperative CRT prior to surgical resection. Methods:Five hundred ninety-three pts from 1985 to 2003 with esophageal cancer who underwent surgery with (n = 239) or without CRT (n = 354) were reviewed. Resected esophageal tumors were assessed for pathologic response by determining extent of residual tumor following CRT (P0, 0% residual; P1, 1%–50% residual; P2, >50% residual). Results:After CRT down-staging, pTNM specific survival was similar, irrespective of treatment group (P = 0.98). The pTNM stage distribution was more favorable in the CRT group (P < 0.001) despite a more advanced initial cTNM stage distribution (P < 0.001). Following CRT, the pathologic response (pP) at the primary tumor as defined by extent of residual tumor predicted overall survival (3 years: P0, 0% residual = 74%; P1, 1%–50% residual = 54%; P2, >50% residual = 24%, P < 0.001) and stage specific survival with greater accuracy than pTNM stage alone. Conclusions:Our analyses demonstrate that following CRT, pTNM continues to predict survival. The extent of pathologic response following CRT is an independent risk factor for survival (pP) and should be incorporated in the pTNM esophageal cancer staging system to better predict patient outcome in esophageal cancer.

Full-Dose Gemcitabine With Concurrent Radiation Therapy in Patients With Nonmetastatic Pancreatic Cancer: A Multicenter Phase II Trial

PURPOSE Gemcitabine is effective in the treatment of pancreatic cancer and is a potent radiosensitizer. This study assessed safety and efficacy of full-dose gemcitabine administered before and during concurrent three-dimensional conformal radiation (3D-CRT) in patients with nonmetastatic pancreatic cancer. PATIENTS AND METHODS During cycles 1 and 3, patients received gemcitabine at 1,000 mg/m(2) on days 1 and 8 of each 21-day cycle. Cycle 2 included the same dose of gemcitabine on days 1, 8, and 15 of a 28-day cycle with concurrent 3D-CRT at 36 Gy, administered in 15 fractions of 2.4 Gy, over 3 weeks. Resectable patients underwent surgery 4 to 6 weeks after treatment. The primary objective was evaluation of toxicity. Tumor response, CA 19-9, and 1-year survival were also assessed. RESULTS Forty-one patients enrolled at six institutions between April 2002 and October 2003. Among the 39 treated patients, the most common toxicities were grade 3 neutropenia (12.8%), grade 3 nausea (10.3%), and grade 3 vomiting (10.3%). The response rate was 5.1% and disease control rate was 84.6%. Mean post-treatment CA 19-9 levels (228 +/- 347 U/mL) were significantly (P = .006) reduced compared with pretreatment levels (1,241 +/- 2,124 U/mL). Thirteen (81%) of 16 patients initially judged resectable, three (33%) of nine borderline-resectable patients, and one (7%) of 14 unresectable patients underwent resection after therapy. One-year survival rates were 73% for all patients, 94% for resectable patients, 76% for borderline-resectable patients, and 47% for unresectable patients. CONCLUSION Full-dose gemcitabine with concurrent radiotherapy was well tolerated and active. Evaluation of this regimen in a larger, randomized trial for patients with resectable or borderline-resectable disease may be warranted.

T3N0 rectal cancer: results following sharp mesorectal excision and no adjuvant therapy☆

Adjuvant chemoradiation therapy following resection of T3N0 rectal cancer is recommended in order to reduce the incidence of local recurrence and improve survival. However, recent experience with rectal cancer resection utilizing sharp dissection and total mesorectal excision has resulted in a reduction in local recurrence rates to as low as 5% without adjuvant treatment. The purpose of this study was to determine if rectal cancer resection utilizing sharp mesorectal excision alone is adequate treatment for local control of T3N0 rectal cancer. Between July 1986 and December 1993, 95 patients with T3N0M0 rectal cancer underwent resection with sharp mesorectal excision and did not receive any adjuvant therapy. Various prognostic factors were analyzed for their association with local recurrence and survival. Seventy-nine patients had a low anterior resection, 10 of whom had a coloanal anastomosis, and 16 had an abdominoperineal resection. The median follow-up was 53.3 months. Six patients had local recurrence, 12 had distant recurrence, and three had local and distant recurrences. The overall local recurrence rate was 9% crude and 12% 5-year actuarial. The overall crude recurrence rate was 22%. The 5-year disease-specific survival rate was 86.6% with an overall survival of 75%. Postoperative complications occurred in 18 patients (19%). Five patients (6%) had a documented anastomotic leak. Perioperative mortality was 3%. No technical factors, including type of resection (low anterior vs. abdominoperineal), location of tumor, or extent of resection margin, were significant for determining local recurrence. The only histopathologic marker significant for determining local recurrence was lymphatic invasion (P <0.04). Sharp mesorectal excision with low anterior resection or abdominoperineal resection for T3N0M0 rectal cancer results in a local recurrence rate of less than 10% without the use of adjuvant therapy. Therefore, in select patients with T3N0M0 rectal cancer, the standard use of adjuvant therapy for local control may not be justified.

Pancreatic ductal adenocarcinoma radiology reporting template: Consensus statement of the society of abdominal radiology and the american pancreatic association

Pancreatic ductal adenocarcinoma is an aggressive malignancy with a high mortality rate. Proper determination of the extent of disease on imaging studies at the time of staging is one of the most important steps in optimal patient management. Given the variability in expertise and definition of disease extent among different practitioners as well as frequent lack of complete reporting of pertinent imaging findings at radiologic examinations, adoption of a standardized template for radiology reporting, using universally accepted and agreed on terminology for solid pancreatic neoplasms, is needed. A consensus statement describing a standardized reporting template authored by a multi-institutional group of experts in pancreatic ductal adenocarcinoma that included radiologists, gastroenterologists, and hepatopancreatobiliary surgeons was developed under the joint sponsorship of the Society of Abdominal Radiologists and the American Pancreatic Association. Adoption of this standardized imaging reporting template should improve the decision-making process for the management of patients with pancreatic ductal adenocarcinoma by providing a complete, pertinent, and accurate reporting of disease staging to optimize treatment recommendations that can be offered to the patient. Standardization can also help to facilitate research and clinical trial design by using appropriate and consistent staging by means of resectability status, thus allowing for comparison of results among different institutions.

Overexpression of OATP1B3 confers apoptotic resistance in colon cancer

Organic anion transporting polypeptide 1B3 (OATP1B3, SLCO1B3) is normally expressed in hepatocytes. In this study, we showed frequent overexpression of OATP1B3 in colorectal adenocarcinomas. Quantitative reverse transcription-PCR analysis of 17 colon tumors indicated tumoral overexpression of OATP1B3 by approximately 100-fold, compared with 20 normal colon samples (P < 0.0001). Using immunohistochemistry on a tissue microarray containing 93 evaluable colon tumor specimens, we detected immunostaining of OATP1B3 in 75 colon adenocarcinomas (81%) and no immunostaining in normal samples. To determine the functional effects of OATP1B3 expression on drug-induced apoptosis, we used camptothecin and oxaliplatin on a panel of colorectal cancer cell lines stably overexpressing OATP1B3. The results indicated that OATP1B3 overexpression enhanced cell survival in RKO, HCT-8, and HCT116(p53+/+) cells that harbor wild-type p53 but not in Caco-2 and HCT116(p53-/-) cells that lack p53, compared with the respective empty vector controls (P < 0.01). The terminal deoxynucleotidyl transferase-mediated nick-end labeling assay confirmed that HCT116(p53+/+) cells overexpressing OATP1B3 had significantly lower apoptotic levels compared with empty vector control (P < 0.001). The overexpression of OATP1B3 reduced the transcriptional activity of p53, with subsequent reductions in transcript and protein levels of its downstream transcription targets (P21WAF1 and PUMA). Overexpression of a point mutation (G583E) variant of OATP1B3 lacking transport activity did not confer an antiapoptotic effect or affect p53 transcriptional activity, suggesting that the antiapoptotic effect of OATP1B3 may be associated with its transport activity. Taken together, our results suggest that OATP1B3 overexpression in colorectal cancer cells may provide a survival advantage by altering p53-dependent pathways.