Management of Gastric Neuroendocrine Tumors: A Review

Gastric neuroendocrine tumors (G-NET) are rare tumors arising from enterochromaffin-like cells of the gastric mucosa. They belong to a larger group called gastroenteropancreatic neuroendocrine tumors and are classified as low, intermediate, or high-grade tumors based on their proliferative indices. They are further categorized into three subtypes based on their morphologic characteristics, pathogenesis, and behavior. Types 1 and 2 tumors are characterized by elevated serum gastrin and are usually multifocal. They typically occur in the setting of atrophic gastritis or MEN1/Zollinger Ellison syndrome, respectively. Type 2 tumors are associated with the most symptoms, such as abdominal pain and diarrhea. Type 3 tumors are associated with normal serum gastrin, are usually solitary, and occur sporadically. This type has the most aggressive phenotype and metastatic potential. Treatment and prognosis for G-NET is dependent on their type, size, and stage. Type 1 has the best prognosis, and Type 3 has the worst. This review discusses the presentation, workup, and surgical management of these tumors.

Simple Preoperative Imaging Measurements Predict Postoperative Pancreatic Fistula After Pancreatoduodenectomy

OBJECTIVE

Postoperative pancreatic fistula is a potentially devastating complication after pancreatoduodenectomy (PD). The purpose of this study was to identify features on preoperative computed tomography (CT) imaging that correlate with an increased risk of postoperative pancreatic fistula (POPF).

METHODS

Patients who underwent PD at our high-volume pancreatic surgery center from 2019 to 2021 were included if CT imaging was available within 8 weeks of surgical intervention. Pancreatic neck thickness (PNT), abdominal wall thickness (AWT), and intra-abdominal distance from pancreas to peritoneum (PTP) were measured by two board-certified radiologists who were blinded to the clinical outcomes. Radiographic measurements, as well as preoperative patient characteristics and intraoperative data, were assessed with univariate and multivariable analysis (MVA) to determine risk for clinically relevant POPF (CR-POPF, grades B and C).

RESULTS

A total of 204 patients met inclusion criteria. Median PTP was 5.8 cm, AWT 1.9 cm, and PNT 1.3 cm. CR-POPF occurred in 33 of 204 (16.2%) patients. MVA revealed PTP > 5.8 cm (odds ratio [OR] 2.86, p = 0.023), PNT > 1.3 cm (OR 2.43, p = 0.047), soft pancreas consistency (OR 3.47, p = 0.012), and pancreatic duct size ≤ 3.0 mm (OR 4.55, p = 0.01) as independent risk factors for CR-POPF after PD. AWT and obesity were not associated with increased risk of CR-POPF. Patients with PTP > 5.8 cm or PNT > 1.3 cm were significantly more likely to suffer a major complication after PD (39.6% vs. 22.3% and 40% vs. 22.1%, p < 0.008).

CONCLUSIONS

Patients with a thick pancreatic neck and increased intra-abdominal girth have a heightened risk of CR-POPF after pancreatoduodenectomy, and they experience more serious postoperative complications. We defined a simple CT scan-based measurement tool to identify patients at increased risk of CR-POPF.

The Gender Gap in Surgical Literature: Are We Making Progress?

INTRODUCTION

The percentage of women in surgical leadership roles is not commensurate with percent of women in field of surgery. Citation indexes are used as proxy for scholarly impact and may serve as an indicator of women's progress in academic surgery. We aimed to evaluate gender disparities in authorship of surgery manuscripts in high-impact journals.

METHODS

In this bibliometric analysis of original research articles from four high-impact surgical journals from 2008 to 2010 (period A) and 2018-2020 (period B), the gender of primary and senior authors was assigned by Genderize.io. Number of citations per article was identified via Web of Science. Number of citations by gender of authors was compared across time periods.

RESULTS

Of the 3575 articles (Period A = 1915; Period B = 1660), 962 (26.9%) had women as primary authors and 590 (17.2%) as senior authors. Over time, significant increases in women primary and senior authorship were noted from 22.8% to 31.7% (P < 0.001) and 13.9% (254/11,915) to 21% (336/1660), respectively (P < 0.001). Articles written with women primary authors had fewer median (interquartile range) citations than those by men as primary author in period A (39 [17-69.5] versus 42 [20.0-84.0]; P = 0.005). Gender parity was noted in period B (9 [4-19] versus 9 [4-20] citations; P = 0.307). In period A, articles written by women as both primary and senior authors had approximately 25% fewer median citations compared with those by men (34 [17-62] versus 44 [21-86]); P < 0.011), and this reached parity in period B (9 [4-20] versus 9 [4-21]); P < 0.658).

CONCLUSIONS

Overall, gender authorship and citations parity are improving in high-impact surgery journals.

Identifying the optimal treatment strategy in patients with resectable non-cardia gastric cancer

BACKGROUND

Multimodal treatment strategy including perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), and postoperative chemotherapy (POC) has been accepted as the standard of care in gastric cancer (GC). The ideal sequence and type of therapy remain undetermined.

METHOD

The National Cancer Database was examined from 2006 to 2016 to identify patients with resectable non-cardia gastric cancer. Patient outcomes were compared based on the receipt of PEC, POCR, and POC. This comparison was repeated in a sub-group of patients who received optimal treatment. Optimal treatment was defined as initial chemotherapy within 45 days of diagnosis, resection within 45 days of diagnosis, negative margins, adjuvant chemotherapy within 90 days of resection and standard radiation dose (45 Gy). Kaplan-Meier test, log-rank test, and multivariable analysis (MVA) were performed.

RESULTS

We identified 9589 patients. Median survival was greater in the PEC group followed by POCR and POC (60.6, 42.3, and 31.2 months, respectively). On MVA, factors associated with worse overall survival included age above median (≥ 63 years), Charlson-Deyo score of ≥ 1, non-academic/research program, poorly differentiated/undifferentiated grade, positive margins, and positive lymph nodes. Both PEC and POCR were associated with improved survival when compared to POC (HR 0.78 and 0.79; p < 0.001). When compared with PEC, no significant difference was noted with POCR (HR 1.01; p = 0.987). These results were maintained in optimally treated cohort (n = 3418).

CONCLUSION

In patients with resectable non-cardia gastric cancer, both perioperative chemotherapy and postoperative chemoradiation therapy were associated with improved survival when compared to postoperative chemotherapy. No difference was noted between perioperative chemotherapy and postoperative chemoradiation therapy. These results were maintained in the optimally treated cohort.

Does non-metastatic gastric cancer of the cardia warrant a different treatment strategy?

BACKGROUND

Multimodal treatment strategies with surgery as its centerpiece have been accepted as the standard of care in nonmetastatic cardia gastric cancer (CGC). There remains a lack of consensus regarding the optimal multimodal treatment strategy.

METHOD

We queried National Cancer Database from 2004 to 2016 to identify patients with resected nonmetastatic CGC who received perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), or postoperative chemotherapy (POC). A subgroup analysis was performed in optimally treated patients defined as initial chemotherapy within 45 days of diagnosis, resection within 45 days of diagnosis, negative margins, adjuvant chemotherapy within 90 days of resection, and standard radiation dose (45 Gy). Kaplan-Meier, Univariate analysis (UVA), and Multivariable analysis (MVA) were performed.

RESULTS

We identified 2387 patients. Median survival was 38.8 months in the PEC group, 36 months in the POCR group, and 32.3 months in the POC group (p = 0.1025). On UVA, patients treated with PEC had an association with improved survival (HR, 0.83; p = 0.037) when compared with POC. On MVA, no significant difference was noted in overall survival (OS) between PEC, POCR, and POC, similar to subgroup analysis of optimally treated cohort.

CONCLUSION

OS rate in nonmetastatic CGC is not significantly different between patients receiving PEC, POCR, or POC.

Impact of nodal status in determining multimodal treatment strategies in non-cardia gastric cancer

BACKGROUND

Patients with resectable noncardia gastric cancer may be subjected to perioperative chemotherapy (PEC), postoperative chemoradiation (POCR), or postoperative chemotherapy (POC). We analyzed these treatment strategies to determine optimal therapy based on nodal status.

METHOD

The National Cancer Database was used to identify patients with resected noncardia gastric cancer (2004-2016). Patients were stratified based on clinical nodal status-negative (cLN-), positive (cLN+) and pathological nodal status (pLN-, pLN+). In cLN- patients who underwent upfront resection and were upstaged to pLN+, POC, and POCR were compared. Overall survival (OS) with PEC, POCR, and POC were compared in cLN- and cLN+.

RESULTS

We identified 6142 patients (cLN-: 3831; cLN+: 2311). In cLN- patients who underwent upfront resection (N = 3423), 69% were upstaged to pLN+ disease (N = 2499; POCR = 1796, POC = 703). On MVA, POCR was associated with significantly improved OS when compared to POC (hazard ratio [HR]: 0.75; p < 0.001). In patients with cLN- disease (PEC = 408; POCR = 2439; POC = 984), PEC(HR: 0.77; p = 0.01) and POCR(HR: 0.81; p < 0.001) were associated with improved OS compared with POC. In cLN+ group (PEC = 452; POCR = 1284; POC = 575), POCR was associated with improved OS compared with POC (HR: 0.81; p < 0.01), and trend towards improved OS was noted when PEC(HR: 0.83; p = 0.055) was compared with POC.

CONCLUSION

Postoperative chemoradiation may be the preferred treatment strategy over postoperative chemotherapy in non-cardia gastric cancer patients who receive upfront resection and are upstaged from clinically node negative to pathologically node positive disease.

Early experience with robotic central pancreatectomy with patient-reported outcomes and comparison with open central pancreatectomy

BACKGROUND

Robotic central pancreatectomy (CP) has emerged in recent years as a noninferior approach to open CP and may offer improved patient-reported outcomes and reduction in incisional hernias.

METHODS

All patients who underwent open and robotic CP between (2013 and 2022) were selected, and perioperative outcomes were analyzed. Patients who underwent robotic CP were interviewed over the phone to assess patient-reported postoperative outcomes.

RESULTS

A total of 18 CP operations (56%-open vs. 44%-robotic) were identified. The overall median age was 67 years (interquartile range: 60-72), and 50% (n = 9) of patients were female. Median length of surgery was statistically longer for robotic CP (411 vs. 138 min, p = 0.002); all other intraoperative variables were similar. Postoperatively, a similar number of patients in the open and robotic cohorts developed clinically significant postoperative pancreatic fistulas (37.5% vs. 30%, p = 1) and major complications (37.5% vs. 20%, p = 0.60), respectively. No patients in the robotic cohort developed an incisional hernia, compared to 40% (n = 4) in open (p = 0.08). All patients returned to a baseline level of activity and reported a high quality of life.

CONCLUSION

With the exception of longer operative times, robotic CP is a noninferior, definitive resection technique for select lesions of the middle pancreas. Additionally, the robotic approach may result in a reduction in incisional hernia development.

A review of hepatic epithelioid hemangioendothelioma-Analyzing patient characteristics and treatment strategies

BACKGROUND

Hepatic epithelioid hemangioendothelioma (HEH) is a rare vascular tumor of unknown etiology and unpredictable natural history. To date, no large-scale studies have been published evaluating this disease due to its rare occurrence.

METHODS

The National Cancer Database was reviewed between 2004 and 2016 to identify patients with HEH. Univariate analysis with overall survival (OS) was performed by Cox proportional hazards model. Kaplan-Meier method was used to create OS curves and compared using the log-rank test.

RESULTS

We identified 229 patients with HEH. The majority of patients were female (61.1%), white (84.3%), and had a Charlson-Deyo score of 0 (75%). Chemotherapeutic intervention was seen in 26% of the patients while 33% received surgical intervention in the form of wedge/segmental liver resection (n = 27), hepatectomy lobectomy/extended lobectomy (n = 18), and liver transplant (n = 22). Five-year survival in surgical patients was 90.5%, 66.5% and 81%, respectively (p = 0.485). Age greater than 55 years (hazard ratio [HR], 2.78; p < 0.001), Asian ethnicity compared to white (HR, 2.84; p = 0.012), and a higher Charlson-Deyo score (score 1: HR, 2.28; p < 0.001 and score ≥2: HR, 2.76; p = 0.011) were associated with worse OS.

CONCLUSION

Treatment for HEH remains variable with only a third of the patients undergoing surgery. International collaboration is necessary to determine the optimal treatment for this rare disease.

Robotic Distal Pancreatectomy, a Novel Standard of Care? Benchmark Values for Surgical Outcomes from 16 International Expert Centers

BACKGROUND AND OBJECTIVE

Robotic distal pancreatectomy (DP) is an emerging attractive approach, but its role compared to laparoscopic or open surgery remains unclear. Benchmark values are novel and objective tools for such comparisons. The aim of this study was to identify benchmark cutoffs for many outcome parameters for DP with or without splenectomy beyond the learning curve.

METHODS

This study analyzed outcomes from international expert centers from patients undergoing robotic DP for malignant or benign lesions. After excluding the first 10 cases in each center to reduce the effect of the learning curve, consecutive patients were included from the start of robotic DP up to June 2020. Benchmark patients had no significant comorbidities. Benchmark cutoff values were derived from the 75th or the 25th percentile of the median values of all benchmark centers. Benchmark values were compared to a laparoscopic control group from four high-volume centers and published open DP landmark series.

RESULTS

Sixteen centers contributed 755 cases, whereof 345 benchmark patients (46%) were included the analysis. Benchmark cut-offs included: operation time ≤300min, conversion rate ≤3%, clinically relevant POPF ≤32%, 3 months major complication rate ≤26.7% and lymph node retrieval ≥9. The CCI® at 3 months was ≤8.7 without deterioration thereafter. Compared to robotic DP, laparoscopy had significantly higher conversion rates (5x) and overall complications, while open DP was associated with more blood loss and longer hospital stay.

CONCLUSION

This first benchmark study demonstrates that robotic DP provides superior postoperative outcomes compared to laparoscopic and open DP. Robotic DP may be expected to become the approach of choice in minimally invasive DP.

The aborted Whipple: Why, and what happens next?

BACKGROUND

For patients with periampullary adenocarcinoma (PAC), pancreatoduodenectomy (PD) provides the best survival. Surgery on a subset of patients is aborted during PD. We analyzed these patients.

METHODS

Patients who underwent laparotomy for planned PD for PAC were identified (2006-2019). From operative notes, we identified the subset with intraoperative decision to abort. Patient, treatment, and outcome data were analyzed. The subset with pancreatic ductal adenocarcinoma (PDAC) was analyzed for survival.

RESULTS

Only 6.7% (n = 55/819) of cases were aborted. Majority 78% (n = 43) had pathologically-confirmed diagnoses at time of surgery, and 18.2% (n = 10) received preoperative chemotherapy. Reasons for aborted PD included: distant metastases (65.5%, n = 36) and local invasion (34.5%, n = 19). Of patients with metastatic disease, 75% (n = 27) had liver metastases. Eighty-nine percent (n = 49) of patients underwent at least one palliative bypass procedure and 81.8% (n = 45) had both gastric and biliary bypass. Patients with computed tomography (CT) scans before surgery more commonly had missed metastatic disease (79.2% CT compared to 54.8% magnetic resonance imaging [MRI], χ²  = 3.54, p = 0.059). In PDAC, 61.4% (n = 27/44) were aborted for metastatic disease and 38.7% (n = 17/44) for local invasion. Median overall survival for all PDAC patients after aborted PD was 334 days.

CONCLUSION

Majority of pancreatoduodenectomies for periampullary adenocarcinoma are done to completion. Liver metastases is the most common reason for aborting. Preoperative MRI may help identify hepatic metastases.