Ramy Behman

Conditional Disease-Free Survival After Surgical Resection of Gastrointestinal Stromal Tumors A Multi-institutional Analysis of 502 Patients

IMPORTANCE Gastrointestinal stromal tumors (GISTs) are the most commonly diagnosed mesenchymal tumors of the gastrointestinal tract. The risk of recurrence following surgical resection of GISTs is typically reported from the date of surgery. However, disease-free survival (DFS) over time is dynamic and changes based on disease-free time already accumulated following surgery. OBJECTIVES To assess the comparative performance of established GIST recurrence risk prognostic scoring systems and to characterize conditional DFS following surgical resection of GISTs. DESIGN, SETTING, AND PARTICIPANTS A retrospective cohort study of 502 patients who underwent surgery for a primary, nonmetastatic GIST between January 1, 1998, and December 31, 2012, at 7 major academic cancer centers in the United States and Canada. MAIN OUTCOMES AND MEASURES Disease-free survival of the patients was classified according to 5 prognostic scoring systems, including the National Institutes of Health criteria, modified National Institutes of Health criteria, Memorial Sloan Kettering Cancer Center GIST nomogram, and American Joint Committee on Cancer gastric and nongastric categories. The concordance index (also known as the C statistic or the area under the receiver operating curve) of established GIST recurrence risk prognostic scoring systems. Conditional DFS estimates were calculated. RESULTS Overall 1-year, 3-year, and 5-year DFS following resection of GISTs was 95%, 83%, and 74%, respectively. All the prognostic scoring systems had fair prognostic ability. For all tumor sites, the American Joint Committee on Cancer gastric category demonstrated the best discrimination (C = 0.79). Using conditional DFS, the probability of remaining disease free for an additional 3 years given that a patient was disease free at 1 year, 3 years, and 5 years was 82%, 89%, and 92%, respectively. Patients with the highest initial recurrence risk demonstrated the greatest increase in conditional survival as time elapsed. CONCLUSIONS AND RELEVANCE Conditional DFS improves over time following resection of GISTs. This is valuable information about long-term prognosis to communicate to patients who are disease free after a period following surgery.

Surgical Management of Advanced Gastrointestinal Stromal Tumors: An International Multi-Institutional Analysis of 158 Patients

BACKGROUND Patients with advanced gastrointestinal stromal tumors (GIST) are at high risk for recurrence after surgery. The aim of this study was to characterize outcomes of advanced GIST treated with surgery from a large multi-institutional database in the tyrosine kinase inhibitor (TKI) era. STUDY DESIGN Patients who underwent surgery for an advanced GIST from 1998 through 2012 were identified. Demographic, clinicopathologic, perioperative, and survival data were collected and analyzed. RESULTS There were 87 patients with locally advanced GIST and 71 patients with recurrent/metastatic GIST. The vast majority (95%) of patients with locally advanced GIST required a multivisceral resection; most patients (87%) underwent a microscopically complete (R0) resection. Although 82% of patients had high-risk tumors according to modified NIH criteria or had recurrent/metastatic disease, only 56% of patients received adjuvant TKI therapy. Among patients with locally advanced GIST, 3-year recurrence-free survival and overall survival rates were 65% and 87%, respectively. In contrast, 3-year recurrence-free survival and overall survival rates among patients with recurrent/metastatic GIST were 49% and 82%, respectively. On multivariate analysis, predictors of worse outcomes included high mitotic rate and male sex for patients with locally advanced GIST, and age and lack of adjuvant TKI therapy were associated with adverse outcomes among patients with recurrent/metastatic GIST (all p < 0.05). CONCLUSIONS Resection of advanced GIST can be safely accomplished with high rates of R0 resection. Among patients with advanced GIST, TKI therapy was underused. Barriers to the use of TKI therapy in this population should be explored.

A nomogram to predict disease-free survival after surgical resection of GIST.

BackgroundGastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Adjuvant imatinib therapy has resulted in improved disease-free survival (DFS) following resection of primary GIST. The aim of our study was to create a nomogram to predict DFS following resection of GIST.MethodUsing a multi-institutional cohort of patients who underwent surgery for primary GIST at 7 academic hospitals in the USA and Canada between January 1998 and December 2012, a multivariable Cox proportional hazards model predicting DFS was created using backward stepwise selection. A nomogram to predict DFS following surgical resection of GIST was constructed with the variables selected in the multivariable model. We tested nomogram discrimination by calculating the C-statistic and compared the nomogram to four existing GIST prognostic stratification systems.ResultsA total of 365 patients who underwent surgery for primary GIST was included in the study. Using backward stepwise selection, sex, tumor size, tumor site, and mitotic rate were selected for incorporation into the nomogram. The nomogram demonstrated superior discrimination compared to the NIH criteria, modified NIH criteria, and Memorial Sloan-Kettering Nomogram and had similar discrimination to the Miettinen criteria (C-statistic 0.77 vs 0.73, 0.71, 0.71, and 0.78, respectively).ConclusionFour independent predictors of recurrence following surgery for primary GIST were used to create a nomogram to predict DFS. The nomogram stratified patients into prognostic groups and performed well on internal validation.

Laparoscopic Surgery for Adhesive Small Bowel Obstruction Is Associated With a Higher Risk of Bowel Injury: A Population-based Analysis of 8584 Patients

Objective: We set out to compare the incidence of bowel repair and/or resection in a large cohort of patients with adhesive small bowel obstruction (SBO) managed operatively. Background: Laparoscopic lysis of adhesions for adhesive SBO (aSBO) is becoming more common, yet might increase the risk of bowel injury given the distended and/or potentially compromised small bowel. Methods: We used administrative discharge data derived from a large geographic region, identifying patients who underwent surgery for their first episode of aSBO during 2005 to 2014. Procedure codes were used to determine the exposure: either an open approach or a laparoscopic approach (including procedures converted to open). The primary outcome was incidence of bowel intervention, defined as intraoperative enterotomy, suture repair of intestine, or bowel resection. We estimated the odds of bowel intervention after adjusting for patient and clinical factors. Results: A total of 8584 patients underwent operation for aSBO. Patients undergoing laparoscopic procedures were younger with fewer comorbid conditions. The rate of laparoscopic approaches increased more than 3-fold during the study period (4.3%–14.3%, P < 0.0001). The incidence of bowel intervention was 53.5% versus 43.4% in laparoscopic versus open procedures (P < 0.0001). After adjustment for potential confounders, the odds of bowel intervention among patients treated laparoscopically versus open was 1.6 (95% confidence interval: 1.4–1.9). Conclusions: Laparoscopic procedures for aSBO are associated with a greater likelihood of intervention for bowel injury and/or repair. This increase might be due to challenges inherent with laparoscopic approaches in patients with distended small bowel. Surgeons should approach laparoscopic lysis of adhesions with a higher level of awareness and use strategies to mitigate this risk.

Pasireotide for the Prevention of Pancreatic Fistula Following Pancreaticoduodenectomy: A Cost-effectiveness Analysis

Objective: To determine the cost-effectiveness of perioperative administration of pasireotide for reduction of pancreatic fistula (PF). Summary: PF is a major complication following pancreaticoduodenectomy (PD), associated with significant morbidity and healthcare-related costs. Pasireotide is a novel multireceptor ligand somatostatin analogue, which has been demonstrated to reduce the incidence of PF following pancreas resection; however, the drug cost is significant. This study sought to estimate the cost-effectiveness of routine administration of pasireotide to patients undergoing PD, compared with no intervention from the perspective of the hospital system. Methods: A decision-analytic model was developed to compare costs for perioperative administration of pasireotide versus no pasireotide. The model was populated using an institutional database containing all PDs performed 2002 to 2012 at a single institution, including data regarding clinically significant PF (International Study Group on Pancreatic Fistula Grade B or C) and hospital-related inpatient costs for 90 days following PD, converted to 2014

Medial open transversus abdominal plane catheter analgesia: a simple, safe, effective technique after open liver resection.

USD. Relative risk of PF associated with pasireotide was estimated from the published literature. Deterministic and probabilistic sensitivity analyses were performed to test robustness of the model. Results: Mean institutional cost of index admissions was

Open Versus Minimally Invasive Resection of Gastric GIST: A Multi-Institutional Analysis of Short- and Long-Term Outcomes

67,417 and

Impact of fluid resuscitation on major adverse events following pancreaticoduodenectomy

31,950 for patients with and without PF, respectively. Pasireotide was the dominant strategy, associated with savings of

Adherence to Guidelines for Adjuvant Imatinib Therapy for GIST: A Multi-institutional Analysis

1685, and a mean reduction of 1.5 days length of stay. Univariate sensitivity analyses demonstrated cost-savings down to a PF rate of 5.6%, up to a relative risk of PF of 0.775, and up to a drug cost of

Elevated Lactate is Independently Associated with Adverse Outcomes Following Hepatectomy

2817. Probabilistic sensitivity analysis showed 79% of simulations were cost saving. Conclusions: Pasireotide appears to be a cost-saving treatment following PD across a wide variation of clinical and cost scenarios.