Salman Zaheer

Surgery for metastatic neuroendocrine tumors with occult primaries.

INTRODUCTION Neuroendocrine tumors (NETs) frequently metastasize prior to diagnosis. Although metastases are often identifiable on conventional imaging studies, primary tumors, particularly those in the midgut, are frequently difficult to localize preoperatively. MATERIALS AND METHODS Patients with metastatic NETs with intact primaries were identified. Clinical and pathologic data were extracted from medical records. Primary tumors were classified as localized or occult based on preoperative imaging. The sensitivities and specificities of preoperative imaging modalities for identifying the primary tumors were calculated. Patient characteristics, tumor features, and survival in localized and occult cases were compared. RESULTS Sixty-one patients with an intact primary tumor and metastatic disease were identified. In 28 of these patients (46%), the primary tumor could not be localized preoperatively. A median of three different preoperative imaging studies were utilized. Patients with occult primaries were more likely to have a delay (>6 mo) in surgical referral from time of onset of symptoms (57% versus 27%, P = 0.02). Among the 28 patients with occult primary tumors, 18 (64%) were found to have radiographic evidence of mesenteric lymphadenopathy corresponding, in all but one case, to a small bowel primary. In all but three patients (89%), the primary tumor could be identified intraoperatively. CONCLUSION The primary tumor can be identified intraoperatively in a majority of patients with metastatic NETs, irrespective of preoperative localization status. Referral for surgical management should not, therefore, be influenced by the inability to localize the primary tumor.

Blood Transfusion in Major Abdominal Surgery for Malignant Tumors: A Trend Analysis Using the National Surgical Quality Improvement Program

IMPORTANCE Blood transfusion can be a lifesaving treatment for the surgical patient, yet transfusion-related immunomodulation may underlie the association of allogeneic transfusion with increased perioperative morbidity and possibly poorer long-term oncologic outcomes. OBJECTIVE To evaluate trends in transfusion rates for major abdominal oncologic resections to assess changes in recent clinical practice (given the accumulating evidence of the deleterious effects of blood transfusion). DESIGN, SETTING, AND PARTICIPANTS Retrospective review of a population-based registry of all hospitals participating in the American College of Surgeons National Surgical Quality Improvement Project (2005-2013 Participant Use Data Files), which was queried for patients who underwent major resection of a pancreatic, hepatic, or gastric malignant tumor. Data analysis was performed from July to August 2015. MAIN OUTCOME AND MEASURES The primary outcome was the transfusion of any quantity of packed red blood cells. Transfusion rates were calculated for the perioperative period, which was defined as the time from the start of surgery to 72 hours after surgery. Secondary outcomes included wound infection, myocardial infarction, and renal insufficiency, and the rates of these complications were calculated as well. Trend analysis was performed for each year of data to evaluate for changes over the study period. RESULTS A total of 19 680 patients (median age, 65.0 years [interquartile range, 57.0-73.0 years]) were identified, of whom 5900 (30.0%) received a blood transfusion (of 13 657 patients who underwent a pancreatic resection, 4074 required transfusion [29.8%]; of 1605 patients who underwent a gastric resection, 378 required transfusion [23.6%]; and of 4418 patients who underwent a hepatic resection, 1448 required transfusion [32.8%]). There was a significant trend toward decreasing rates of transfusion during the study period (z = -7.89, P < .001), which corresponded to an absolute 6.1% decrease in the rate of transfusion of packed red blood cells from 2005 to 2013 (ie, from 32.8% to 26.7%). There was no significant change in the rates of postoperative wound infection or renal insufficiency during this time period, but there was an increased rate of perioperative myocardial infarction during the study period (0.33% absolute increase; z = 3.15, P = .002). CONCLUSIONS AND RELEVANCE Over 9 years of contemporary practice, a trend of less perioperative blood transfusions for oncologic abdominal surgery was observed. Further studies are needed to assess whether these trends reflect changes in operative techniques, hospital cohorts, or transfusion thresholds.

Addition of anti-estrogen therapy to anti-HER2 dendritic cell vaccination improves regional nodal immune response and pathologic complete response rate in patients with ERpos/HER2pos early breast cancer

ABSTRACT HER2-directed therapies are less effective in patients with ERpos compared to ERneg breast cancer, possibly reflecting bidirectional activation between HER2 and estrogen signaling pathways. We investigated dual blockade using anti-HER2 vaccination and anti-estrogen therapy in HER2pos/ERpos early breast cancer patients. In pre-clinical studies of HER2pos breast cancer cell lines, ERpos cells were partially resistant to CD4+ Th1 cytokine-induced metabolic suppression compared with ERneg cells. The addition of anti-estrogen treatment significantly enhanced cytokine sensitivity in ERpos, but not ERneg, cell lines. In two pooled phase-I clinical trials, patients with HER2pos early breast cancer were treated with neoadjuvant anti-HER2 dendritic cell vaccination; HER2pos/ERpos patients were treated with or without concurrent anti-estrogen therapy. The anti-HER2 Th1 immune response measured in the peripheral blood significantly increased following vaccination, but was similar across the three treatment groups (ERneg vaccination alone, ERpos vaccination alone, ERpos vaccination + anti-estrogen therapy). In the sentinel lymph nodes, however, the anti-HER2 Th1 immune response was significantly higher in ERpos patients treated with combination anti-HER2 vaccination plus anti-estrogen therapy compared to those treated with anti-HER2 vaccination alone. Similar rates of pathologic complete response (pCR) were observed in vaccinated ERneg patients and vaccinated ERpos patients treated with concurrent anti-estrogen therapy (31.4% vs. 28.6%); both were significantly higher than the pCR rate in vaccinated ERpos patients who did not receive anti-estrogen therapy (4.0%, p = 0.03). Since pCR portends long-term favorable outcomes, these results support additional clinical investigations using HER2-directed vaccines in combination with anti-estrogen treatments for ERpos/HER2pos DCIS and invasive breast cancer.

Role of adrenal vein sampling in primary aldosteronism: Impact of imaging, localization, and age

The role of adrenal vein sampling (AVS) has been debated, with some authorities advocating selective use in younger patients (≤40 years), and those localized by preoperative imaging. We examined our experience to determine the impact of AVS in patients who routinely underwent AVS with a high success rate.

Transected thin melanoma: Implications for sentinel lymph node staging

Indications for sentinel lymph node (SLN) biopsy in patients with thin melanoma (≤1 mm thick) are controversial. We asked whether deep margin (DM) positivity at initial biopsy of thin melanoma is associated with SLN positivity.

Predictors of false negative sentinel lymph node biopsy in trunk and extremity melanoma

Nodal recurrence following negative sentinel lymph node biopsy (SLNB) for melanoma is known as false‐negative (FN) SLNB. Risk factors for FN SLNB among patients with trunk and extremity melanoma have not been well‐defined.

Comparing International and United States Undergraduate Medical Education and Surgical Outcomes Using a Refined Balance Matching Methodology.

Objective: The aim of this study is to compare surgical outcomes of international medical graduates (IMGs) and United States medical graduates (USMGs). Summary of Background Data: IMGs represent 15% of practicing surgeons in the United States (US), and their training pathways often differ substantially from USMGs. To date, differences in the clinical outcomes between the 2 cohorts have not been examined. Methods: Using a unique dataset linking AMA Physician Masterfile data with hospital discharge claims from Florida and New York (2008–2011), patients who underwent 1 of 32 general surgical operations were stratified by IMG and USMG surgeon status. Mortality, complications, and prolonged length of stay were compared between IMG and USMG surgeon status using optimal sparse network matching with balance. Results: We identified 972,718 operations performed by 4581 surgeons (72% USMG, 28% IMG). IMG and USMG surgeons differed significantly in demographic (age, gender) and baseline training (years of training, university affiliation of training hospital) characteristics. USMG surgeons performed complex procedures (13.7% vs 11.1%, P < 0.01) and practiced in urban settings (79.4% vs 75.6%, P < 0.01) more frequently, while IMG surgeons performed a higher volume of studied operations (50.7 ± 5.1 vs 57.8 ± 8.4, P < 0.01). In the matched cohort analysis of 396,810 patients treated by IMG and USMG surgeons, rates of mortality (USMG: 2.2%, IMG: 2.1%; P < 0.001), complications (USMG: 14.5%, IMG: 14.3%; P = 0.032), and prolonged length of stay (pLOS) (USMG: 22.7%, IMG: 22.8%; P = 0.352) were clinically equivalent. Conclusion: Despite considerable differences in educational background, surgical training characteristics, and practice patterns, IMG and USMG-surgeons deliver equivalent surgical care to the patients whom they treat.

The influence of different training paradigms on surgical outcomes

METHODS: We selected all emergency admissions of open surgery performed in French hospitals between 2010 and 2012. After identifying mountain areas with increasing volume of surgical stays during winter, we considered seasonal variations in surgical outcomes using a difference-in-differences study design. We computed multilevel regressions to evaluate whether significant increase in emergency cases had an effect on surgical mortality, complications and length of stay. Clustering effect of patients within hospitals was integrated in analysis and surgical outcomes were adjusted for both patient and hospital characteristics.