Haroon A. Choudry

Comparative Effectiveness of Minimally Invasive and Open Distal Pancreatectomy for Ductal Adenocarcinoma

IMPORTANCE Multicenter studies indicate that outcomes of open (ODP) and minimally invasive distal pancreatectomy (MIDP) are equivalent for benign lesions. However, data for pancreatic carcinoma are limited. OBJECTIVE To compare outcomes of ODP and MIDP for early-stage pancreatic ductal carcinoma to determine relative safety and oncologic efficacy. DESIGN Retrospective analysis of 62 consecutive patients undergoing ODP or MIDP for pancreatic ductal carcinoma by intention to treat with propensity scoring to correct for selection bias. SETTING A high-volume university center for pancreatic surgery. PARTICIPANTS Sixty-two patients at a single institution. INTERVENTIONS Patients underwent ODP or MIDP. MAIN OUTCOME MEASURES Perioperative mortality, morbidity, readmission, postoperative complications, disease progression, and overall survival. RESULTS Thirty-four patients underwent ODP, and 28 underwent MIDP with 5 conversions to ODP. No significant differences in age, body mass index, performance status, tumor size, or radiographic stage were identified. High rates of margin-negative resection (ODP, 88%; MIDP, 86%) and median lymph node clearance (ODP, 12; MIDP, 11) were achieved in both groups with equal rates and severity of postoperative complications (ODP, 50%; MIDP, 39%) and pancreatic fistula (ODP, 29%; MIDP, 21%). Despite conversions, intended MIDP was associated with reduced blood loss (P = .006) and length of stay (P = .04). Conversion was associated with a poor histologic grade and positive nodes. Median overall survival for the entire cohort was 19 (95% CI, 14-47) months. Minimally invasive distal pancreatectomy was performed increasingly in later study years and for patients with a higher Charlson-Age Comorbidity Index. Overall survival after ODP or intended MIDP was equivalent after adjusting for comorbidity and year of surgery (relative hazard, 1.11 [95% CI, 0.47-2.62]). CONCLUSIONS AND RELEVANCE We detected no evidence that MIDP was inferior to ODP based on postoperative outcomes or overall survival. This conclusion was verified by propensity score analysis with adjustment for factors affecting selection of operative technique.

The learning curve for robotic distal pancreatectomy: an analysis of outcomes of the first 100 consecutive cases at a high‐volume pancreatic centre

BACKGROUND Robotic distal pancreatectomy (RDP) is performed increasingly, but knowledge of the number of cases required to attain procedural proficiency is lacking. The aim of this study was to identify the learning curve associated with RDP at a high-volume pancreatic centre. METHODS Metrics of perioperative safety and efficiency for all consecutive RDPs were evaluated. Outcomes were followed to 90 days. Cumulative sum (CUSUM) analysis was used to identify inflexion points corresponding to the learning curve. RESULTS Between 2008 and 2013, 100 patients underwent RDP. There was no 90-day mortality. In two patients (2.0%), surgery was converted to laparotomy. Thirty procedures were performed for pancreatic adenocarcinoma. Precipitous operative time reductions from an initial operative time of 331 min were observed after the first 20 and 40 cases to 266 min and 210 min, respectively (P < 0.0001). The likelihood of readmission was significantly lower after the first 40 cases (P = 0.04), and non-significant reductions were observed in incidences of major (Clavien-Dindo Grade II or higher) morbidity and Grade B and C leaks, and length of stay. CONCLUSIONS In this experience, RDP outcomes were optimized after 40 cases. Familiarity with the platform and dedicated training are likely to contribute to significantly shorter learning curves in future adopters.

Clinicopathologic and molecular analysis of disseminated appendiceal mucinous neoplasms: identification of factors predicting survival and proposed criteria for a three-tiered assessment of tumor grade

Previous studies have demonstrated that the prognosis of disseminated mucinous appendiceal neoplasms is highly dependent upon tumor grade. Reflecting this, the 7th edition of the American Joint Committee on Cancer (AJCC) staging system now incorporates a three-tier grading system for prognostic staging of mucinous appendiceal tumors. However, the grading criteria are not well described. In order to address this issue, we evaluated clinicopathologic and molecular features of 219 cases from 151 patients with widely disseminated appendiceal mucinous neoplasia treated at our institution between 2004 and 2012. We identified histologic features that were associated with worse overall survival on univariate analysis: destructive invasion, high cytologic grade, high tumor cellularity, angiolymphatic invasion, perineural invasion, and signet ring cell component (all with P<0.0001). We used these morphologic characteristics to classify neoplasms into three grades: AJCC grade G1 lacked all adverse histologic features; AJCC grade G2 had at least one adverse histologic feature (except a signet ring cell component); and AJCC grade G3 were defined by the presence of a signet ring cell component. Patients with AJCC grade G2 and grade G3 adenocarcinomas had a significantly worse prognosis compared with AJCC grade G1 (P<0.0001 for each). A trend toward worse overall survival was identified for patients with AJCC grade G3 adenocarcinomas compared with AJCC grade G2 adenocarcinomas (P=0.07). Our multivariate analysis found that this three-tier grading system was a significant predictor of outcome (P=0.008), independent of other prognostic variables. After controlling for other prognostic variables, AJCC grade G2 was associated with a 2.7-fold increased risk of death (95% confidence interval (CI), 1.2–6.2) and AJCC grade G3 was associated with a 5.1-fold increased risk of death (95% CI, 1.7–14) relative to grade G1 tumors. Our results indicate that evaluation of a limited set of adverse histologic features allows for the separation of disseminated mucinous neoplasms of appendiceal origin into three morphologically defined and prognostically relevant grades as advocated by the AJCC.

The prognostic significance of BAP1, NF2, and CDKN2A in malignant peritoneal mesothelioma.

Cytoreductive surgery and hyperthermic intraperitoneal chemoperfusion for patients with malignant peritoneal mesothelioma has resulted in improved disease control and increased survival. Despite these results, there are significant perioperative risks associated with this aggressive procedure that necessitate consideration of prognostic markers during patient selection. The molecular pathogenesis of peritoneal mesothelioma remains relatively unknown, but extrapolation of findings from their pleural counterpart would suggest frequent alterations in CDKN2A, NF2, and BAP1. Homozygous deletions in CDKN2A portend a worse overall survival in peritoneal mesothelioma. However, the prevalence and prognostic significance of NF2 and BAP1 abnormalities has not been studied. Dual-color fluorescence in situ hybridization using CDKN2A and NF2 locus-specific probes and BAP1 immunohistochemistry identified homozygous CDKN2A deletions (n=25, 29%), hemizygous NF2 loss (n=30, 35%), and/or loss of BAP1 protein expression (n=49, 57%) in 68 of 86 (79%) peritoneal mesotheliomas. Homozygous CDKN2A deletions or hemizygous NF2 loss correlated with shorter progression-free survival (P<0.02) and poor overall survival (P<0.03). Moreover, the significance of these findings was cumulative. Patients harboring both homozygous CDKN2A deletions and hemizygous NF2 loss had a 2-year progression-free survival rate of 9% with a median of 6 months (P<0.01) and overall survival rate of 18% with a median of 8 months (P<0.01). By multivariate analysis, combined homozygous CDKN2A deletions and hemizygous NF2 loss was a negative prognostic factor for both progression-free survival and overall survival, independent of patient age, peritoneal cancer index, completeness of cytoreduction, and extent of invasion. In contrast, loss of BAP1 was not associated with clinical outcome. In summary, homozygous deletions in CDKN2A and hemizygous loss of NF2 as detected by fluorescence in situ hybridization would confer a poor clinical outcome and may guide future treatment decisions for patients with peritoneal mesothelioma.

GNAS is frequently mutated in both low-grade and high-grade disseminated appendiceal mucinous neoplasms but does not affect survival

We analyzed a series of 55 disseminated appendiceal mucinous neoplasms treated at our institution for GNAS and KRAS mutations in an attempt to correlate mutation status with clinicopathological findings and patient survival. GNAS mutations (p.R201H, c.602G>A and p.R201C, and c.602C>T) were identified in 17 (31%) of 55 of disseminated mucinous neoplasms and were found in 8 (35%) of 23 low-grade mucinous neoplasms, 7 (37%) of 19 high-grade mucinous adenocarcinomas lacking a signet ring cell component, and 2 (15%) of 13 high-grade mucinous adenocarcinomas with a signet ring cell component. All 7 mucinous adenocarcinomas composed of pure (>95%) signet ring cells harbored wild-type GNAS. There was no significant association between GNAS mutations and sex and age (both with P > .05) or between GNAS mutations and individual adverse histologic features including cytologic grade, destructive invasion, tumor cellularity, angiolymphatic invasion, perineural invasion, and signet ring cells (all with P > .05). KRAS mutations were identified in 22 (40%) of 55 disseminated mucinous neoplasms. GNAS-mutated disseminated appendiceal mucinous neoplasms more frequently harbored concurrent KRAS mutations compared with GNAS wild-type tumors (65% versus 29%, P = .018). GNAS mutations were not significantly associated with overall survival (both with P > .05). Only overall tumor grade was an independent predictor of overall survival in the multivariate analysis (P = .01). Our results indicate that GNAS mutations are frequently identified in both low-grade and high-grade disseminated appendiceal mucinous neoplasms indicating that GNAS mutation status cannot be used to distinguish between low-grade from high-grade appendiceal mucinous neoplasms.

Aggressive locoregional management of recurrent peritoneal sarcomatosis.

and Objectives Peritoneal sarcomatosis responds poorly to systemic chemotherapy and demonstrates high rates of recurrence after resection. We sought to determine perioperative and oncologic outcomes after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemoperfusion (HIPEC) for recurrent sarcomatosis.

Mucin as a therapeutic target in pseudomyxoma peritonei.

Pseudomyxoma peritonei (PMP) is characterized by intraperitoneal dissemination of mucinous ascites. This malignancy frequently recurs despite aggressive locoregional therapies, demonstrates chemo‐insensitivity and lacks targeted therapies. This review addresses some intriguing questions in PMP; what role does mucin play in this malignancy?; what genetic alterations and dysregulated signaling pathways lead to a putative goblet cell‐lineage differentiation or mucin overexpression?; are targeted therapies against known transcriptional pathways for mucin production a novel therapeutic strategy in this malignancy? J. Surg. Oncol. 2012; 106:911–917.

Chronic Anti-inflammatory Drug Therapy Inhibits Gel-Forming Mucin Production in a Murine Xenograft Model of Human Pseudomyxoma Peritonei

BackgroundIntraperitoneal accumulation of mucinous ascites in pseudomyxoma peritonei (PMP) promotes an inflammatory/fibrotic reaction that progresses to bowel obstruction and eventual patient demise. Cytokines and inflammation-associated transcription factor binding sites, such as glucocorticoid response elements and COX-2, regulate secretory mucin, specifically MUC2, production. We hypothesized that anti-inflammatory drugs targeting inflammation-associated pathways may reduce mucin production and subsequent disease morbidity in PMP.MethodsThe effects of dexamethasone and Celebrex were assessed in mucin-secreting human colon cancer LS174T cells in vitro and murine xenograft models of LS174T and human appendiceal PMP in vivo by serial parametric measurements, MUC2 transcripts via real-time RT-PCR, and MUC2 protein expression via immunofluorescence assays.ResultsDexamethasone significantly inhibited basal MUC2 mRNA levels in LS174T cells, inhibited mucinous tumor accumulation in an intraperitoneal PMP xenograft model, and prolonged survival in a subcutaneous LS174T xenograft model. Celebrex significantly inhibited sodium butyrate-stimulated MUC2 mRNA levels in LS174T cells and demonstrated a statistically nonsignificant trend toward reduced mucinous tumor growth and prolonged survival in the xenograft models. MUC2 protein analysis by immunofluorescence demonstrated a dual effect of dexamethasone on mucin production and tumor cell count.ConclusionsInflammatory mediators are known to regulate mucin production and may promote overexpression of MUC2 by neoplastic cells with goblet cell phenotype in PMP. Anti-inflammatory drugs, dexamethasone and Celebrex, could inhibit extracellular mucin production in PMP by targeting inflammatory cascades and, therefore, may decrease compressive symptoms, increase the disease-free interval, and reduce the extent or frequency of morbid cytoreductive surgeries.

Signet ring cell colorectal carcinoma: a distinct subset of mucin-poor microsatellite-stable signet ring cell carcinoma associated with dismal prognosis.

We evaluated a consecutive series of signet ring cell colorectal carcinomas in an attempt to correlate the histopathologic pattern of infiltration with molecular alterations and prognosis. Of the 4760 primary colorectal carcinomas surgically resected between the years 2002 and 2012, 53 (1%) were composed of >50% signet ring cells. Of the 53 signet ring cell carcinomas, 40 (75%) were composed of >50% extracellular mucin with signet ring cells floating within pools of mucin and were subclassified as mucin-rich signet ring cell carcinomas. Thirteen (25%) carcinomas were characterized by diffusely infiltrating carcinomas with minimal to no extracellular mucin and were subclassified as mucin-poor signet ring cell carcinomas. All 13 mucin-poor signet ring cell carcinomas were either stage III or IV, whereas many cases of mucin-rich signet ring cell carcinoma were stage I or II (17 cases) (P=0.005). Compared with mucin-rich tumors, mucin-poor signet ring cell carcinomas more frequently demonstrated adverse histologic features such as lymphatic invasion (13/13, 100% vs. 22/40, 55%; P=0.002), venous invasion (6/13, 46% vs. 3/40, 8%; P=0.004), and perineural invasion (11/13, 85% vs. 9/40, 23%; P=0.0001). Twenty-three of 53 (43%) signet ring cell carcinomas demonstrated high levels of microsatellite instability (MSI-H). Twenty-two of 23 (96%) MSI-H signet ring cell carcinomas were mucin rich; only 1 MSI-H signet ring carcinoma was mucin poor (P=0.0033). Mucin-poor signet ring cell carcinoma had significantly reduced overall and recurrence-free survival compared with mucin-rich signet ring cell carcinomas (P=0.0035 and 0.0001, respectively), even when adjusting for tumor stage. Mucin-poor signet ring cell carcinoma had a higher propensity for peritoneal dissemination (5/13, 38%) compared with mucin-rich signet ring cell carcinoma (5/40, 12.5%), although this was not statistically significant (P=0.052). Finally, MSI-H and microsatellite-stable signet ring cell carcinomas had similar overall and recurrence-free survival (P=0.2266 and 0.1055, respectively), even when adjusting for tumor stage. In conclusion, we identified a unique subset of signet ring cell colorectal carcinoma with diffuse infiltration and minimal to no extracellular mucin (mucin-poor signet ring cell carcinoma), which lacks MSI-H and has a dismal prognosis with an aggressive clinical course often with peritoneal dissemination. Further, our results confirm that MSI does not affect survival in colorectal signet ring cell carcinomas.

Critical role of hyperthermic intraperitoneal chemoperfusion in the treatment of a patient with Pseudomyxoma peritonei.

The role of hyperthermic intraperitoneal chemoperfusion (HIPEC) in the treatment of Pseudomyxoma peritonei is debated by clinicians. We report the case of a patient who had multiple episodes of short‐interval disease recurrence following debulking surgery, and only achieved long‐term remission with the addition of HIPEC. A review of the relevant literature is presented. J. Surg. Oncol. 2012; 106:513–516.