Endoscopic ultrasound can improve the selection for laparoscopy in patients with localized gastric cancer

Endoscopic Ultrasound Predicts Risk of Occult Intra-Abdominal Metastases in Localized Gastric Cancer: A Validation Study

Background

In gastric cancer (GC) patients without imaging evidence of distant metastasis, diagnostic staging laparoscopy (DSL) is recommended to detect radiographically occult peritoneal metastasis (M1). DSL carries a risk for morbidity and its cost-effectiveness is unclear. Use of endoscopic ultrasound (EUS) to improve patient selection for DSL has been proposed but not validated. We aimed to validate an EUS-based risk classification system predicting risk for M1 disease.

Methods

We retrospectively identified all GC patients without positron emission tomography (PET)/computed tomography (CT) evidence of distant metastasis who underwent staging EUS followed by DSL between 2010 and 2020. T1-2, N0 disease was EUS "low-risk"; T3-4 and/or N+ disease was "high-risk".

Results

A total of 68 patients met inclusion criteria. DSL identified radiographically occult M1 disease in 17 patients (25%). Most patients had EUS T3 tumors (n = 59, 87%) and 48 (71%) patients were node-positive (N+). Five (7%) patients were classified EUS "low-risk" and 63 (93%) were classified "high-risk". Of 63 "high-risk" patients, 17 (27%) had M1 disease. The ability of "low-risk" EUS to predict M0 disease at laparoscopy was 100% and DSL would have been avoided in five patients (7%). This stratification algorithm showed a sensitivity of 100% (95% confidence interval (CI): 80.5-100%) and a specificity of 9.8% (95% CI: 3.3-21.4%).

Conclusions

Use of an EUS-based risk classification system in GC patients without imaging evidence of metastasis helps identify a subset of patients at low-risk for laparoscopic M1 disease who may avoid DSL and proceed directly to neoadjuvant chemotherapy or resection with curative intent. Larger, prospective studies are needed to validate these findings.

Surgical Treatment for Gastric Cancer

Surgery is an essential component of curative-intent treatment strategies for gastric cancer. However, the care of each patient with gastric cancer must be individualized based on patient and tumor characteristics. It is important that all physicians who will be caring for patient with gastric cancer understand the current best practices of surgical management to provide patients with the highest quality of care. This article aims to provide this information while acknowledging areas of surgical management that are still controversial.

Lymph Node Involvement in Advanced Gastric Cancer in the Era of Multimodal Treatment-Oncological and Surgical Perspective

Simple Summary

Gastric cancer (GC) continues to be one of the major oncological challenges on a global scale. The role of neoadjuvant chemotherapy (NAC) in GC is to downstage primary tumour, eliminate potential micrometastases, and increase the chance for radical resection. Although systemic treatment prolongs the survival in advanced GC, persistent lymph node (LN) metastases indicate poor prognosis. Therefore, further identification of prognostic factors after NAC is urgent and could positively influence clinical outcomes. This article aimed to review the actual trends and future perspectives in multimodal therapy of advanced GC, with a particular interest in the post-neoadjuvant pathological nodal stage. Since downstaged and primarily node-negative patients show a similar prognosis, the main target for NAC in advanced GC should be nodal clearance. Adequate staging and personalised perioperative therapy seem to be of great importance in the multimodal treatment of GC.

Abstract

Gastric cancer (GC) continues to be one of the major oncological challenges on a global scale. The role of neoadjuvant chemotherapy (NAC) in GC is to downstage primary tumour, eliminate potential micrometastases, and increase the chance for radical resection. Although systemic treatment prolongs the survival in advanced GC, persistent lymph node (LN) metastases indicate poor prognosis. Further identification of prognostic factors after NAC is urgent and could positively influence clinical outcomes. This article aimed to review the actual trends and future perspectives in multimodal therapy of advanced GC, with a particular interest in the post-neoadjuvant pathological nodal stage. A favourable prognostic impact for ypN0 patients is observed, either due to truly negative LN before the start of therapy or because preoperative therapy achieved a pathologically complete nodal response. Ongoing trials investigating the extent of lymphadenectomy after neoadjuvant therapy will standardise the LN dissection from the multimodal therapy perspective. Since downstaged and primarily node-negative patients show a similar prognosis, the main target for NAC in advanced GC should be nodal clearance. Adequate staging and personalised perioperative therapy seem to be of great importance in the multimodal treatment of GC.

Current status and future perspectives on neoadjuvant therapy in gastric cancer

Gastric cancer, with high morbidity and mortality rates, is one of the most heterogeneous tumors. Radical gastrectomy and postoperative chemotherapy are the standard treatments. However, the safety and efficacy of neoadjuvant therapy (NAT) need to be confirmed by many trials before implementation, creating a bottleneck in development. Although clinical benefits of NAT have been observed, a series of problems remain to be solved. Before therapy, more contributing factors should be offered for choice in the intended population and ideal regimens. Enhanced computed tomography (CT) scanning is usually applied to evaluate effectiveness according to Response Evaluation Criteria in Solid Tumors (RECIST), yet CT scanning results sometimes differ from pathological responses. After NAT, the appropriate time for surgery is still empirically defined. Our review aims to discuss the abovementioned issues regarding NAT for GC, including indications, selection of regimens, lesion assessment and NAT-surgery interval time.

Multivisceral Resection for Locally Advanced Gastric Cancer

BACKGROUND

Locally advanced gastric cancer (LAGC) presents a therapeutic dilemma, particularly as it often involves adjacent organs through desmoplasia or true pathologic invasion. To obtain a margin-negative resection, these tumors require en bloc gastrectomy with multivisceral resection (G+MVR), and contention remains regarding its safety and oncologic benefit.

METHODS

We used the National Cancer Database to retrospectively evaluate the short- and long-term outcomes of patients with LAGC treated in the USA between 2004 and 2016. Associations with margin status and perioperative outcomes were calculated using logistic regression. Survival was estimated using Cox proportional hazards regression and the Kaplan-Meier method.

RESULTS

Overall, 785 pathologic stage T4b (pT4b) patients diagnosed with LAGC underwent gastrectomy (n = 438) or G+MVR (n = 347). There was no association between G+MVR and short- or long-term mortality. Positive resection margins (HR 1.68, 95% CI 1.40-2.03), the presence of nodal disease (HRs 1.46-1.50), treatment at a high-volume center (HR 0.76, 95% CI 0.68-0.85), and the receipt of adjuvant chemotherapy (HR 0.64, 95% CI 0.51-0.80) were independently associated with overall survival. Diffuse-type histology was associated with higher rates of an R1 resection (OR 3.60, 95% CI 2.20-5.87). Perioperative and long-term survival metrics were comparable between patients with pT4a and pT4b LAGC who underwent a margin-negative G+MVR. Undergoing a margin-negative G+MVR imparted a 6-month survival benefit over non-curative gastrectomy alone (p < 0.001).

CONCLUSIONS

Our study demonstrates the safety and long-term feasibility of G+MVR for disease clearance in well-selected patients with LAGC, and we advocate for their referral to high-volume centers for optimal care.

The role of laparoscopic staging for the management of gastric cancer

AİM Staging laparoscopy enables us to perform palliative treatment, neo-adjuvant therapy for curative resection or direct curative resection and making a decision with minimal morbidity by avoiding from unnecessary laparotomies. In the present study, the importance of staging lapafoscopy was retrospectively investigated by using clinical and pathologic data. METHODS Data of 70 out of 350 patients who underwent diagnostic laparoscopy due to gastric cancer at Surgical Oncology department between August 2013 and January 2020 were retrospectively analyzed. RESULTS Peritoneal biopsy was positive for malignity in 41 (58.5%) and negative in 29 (41.5%) of the patients who underwent SL. Peritoneal cytology (PC) results were negative in 32 (45.7%) patients and positive in 38 (54.3%) patients. Peritoneal biopsy and cytology results were concurrently positive in 35 patients and concurrently negative in 26 patients. CONCLUSİONS In conclusion, even the most developed imaging methods cannot provide 100% staging, therefore SL plays an important role in treatment of gastric cancer and laparoscopic staging is essential as a simple, inexpensive, safe and well tolerated method in patients who have the suspicion of peritoneal disease and who cannot be clearly evaluated with pre-operative methods.

Gastric Cancer with Radiographically Occult Metastatic Disease: Biology, Challenges, and Diagnostic Approaches

Gastric adenocarcinoma is an aggressive cancer that demonstrates heterogeneous biology depending on patient ethnicity, tumor location, tumor type, and genetic profile. It remains the third leading cause of cancer deaths worldwide and was estimated to result in 782,000 deaths in 2018. Challenges exist in accurately assessing the disease burden, as available radiological staging often underestimates metastatic disease. This diagnostic handicap, along with the poor understanding of the heterogeneous biology of gastric cancer, has hindered the development of effective therapeutic solutions and thus halted improvement in patient outcomes over the last few decades. The management of occult peritoneal disease is complicated, as most patients are understaged by standard imaging studies and therefore thought to have local diseases. In this article, we systematically review recent literature on the limitations that are associated with standard radiographic staging, discuss recent molecular biology advances to better identify and diagnose occult peritoneal disease, and propose possible management strategies to approach this complicated clinical problem.

Pre-operative laparoscopic staging of gastric cancer in patients who are candidates for neo-adjuvant chemotherapy: A Cross Sectional Study

Objective The aim of this study is to evaluate the laparoscopic method in gastric cancer staging before surgery in patients undergoing Neo-adjuvant chemotherapy. Methods This was a cross-sectional study on patients with T3-T4 and node positive non-metastatic gastric adenocarcinoma who was candidates for neo-adjuvant chemotherapy. The patients were excluded from the study when they were not in the condition to continue the study. All eligible patients underwent metastases work up by abdominal, pelvic and chest CT scans and then received neo-adjuvant chemotherapy. Pre-operative laparoscopy was performed before definitive surgery. The collected data was analyzed using SPSS software. The statistical significance, sensitivity, specificity and predictive values were calculated from this data. Results In this study, out of 50 patients, 26 (52%) were male. The mean age of the patients was 62.44 ± 12.136 years. Most tumors were located in one-third distal of stomach (21 patients, 42%). The accuracy of the laparoscopic method, to determine the degree of involvement of the lymph nodes, revealed that the method had a sensitivity of 84%, a specificity of 47.62%, a positive likelihood ratio (PLR) of 1.6, a negative likelihood ratio (NLR) of 0.33%, a positive predictive value of 65.62% and a negative predictive value of 71.43%. The accuracy of the laparoscopic method, regarding determining the presence or absence of metastasis, revealed that the method had a sensitivity, specificity, positive predictive value, and a negative predictive value of 100%. Conclusion Based on the evidence of this study, and other studies in this field, it seems that the use of a step-by-step combination methods in gastric cancer staging would be logical. Alone, no singular method would be sufficient in providing the physician with sufficient information to successfully stage the tumor and thus determine the appropriate treatment. Therefore, the combination of methods should be used which, in view of the economic constraints of health systems, would be recommended for high-risk patients for metastasis (N+/ T3-T4), diagnostic pre-operative laparoscopy.

Review and Update on the Role of Peritoneal Cytology in the Treatment of Gastric Cancer

BACKGROUND

Positive peritoneal cytology (Cyt+) even in the absence of macroscopic disease is associated with poor prognosis in patients with gastric cancer and deemed as M1 disease. Recent years have seen advancements in the evaluation strategies for peritoneal washings and management of patients with Cyt+. The aim of this review was to describe the newest paradigms in the management of patients with gastric cancer who have Cyt+ without macroscopic peritoneal metastases.

METHODS

A comprehensive literature review was performed to identify studies on the management of gastric cancer and thereby to summarize relevant information on the accuracy of various diagnostic tests and controversies involved in the treatment of patients with Cyt+.

RESULTS

Although conventional cytology remains the standard technique for assessment of peritoneal washings, it is limited by low sensitivity. The role of immunohistochemistry and molecular techniques for the assessment of peritoneal washings is evolving. Although systemic chemotherapy remains the standard of care for patients with Cyt+ disease, the role of gastrectomy, intraperitoneal chemotherapy, extensive intraperitoneal saline lavage, and hyperthermic intraperitoneal chemotherapy is being evaluated.

CONCLUSIONS

Clinical decision-making in patients with Cyt+ remains controversial given the seemingly technical resectable albeit biologically unresectable or aggressive disease that portends an overall poor prognosis. Current management strategies are evolving, and further studies are needed to develop an optimal treatment strategy for these patients.

Adipocytes fuel gastric cancer omental metastasis via PITPNC1-mediated fatty acid metabolic reprogramming

Omental metastasis occurs frequently in gastric cancer (GC) and is considered one of the major causes of gastric cancer-related mortality. Recent research indicated that omental adipocytes might mediate this metastatic predilection. Phosphatidylinositol transfer protein, cytoplasmic 1 (PITPNC1) was identified to have a crucial role in metastasis. However, whether PITPNC1 participates in the interaction between adipocytes and GC omental metastasis is unclear. Methods: We profiled and analyzed the expression of PITPNC1 through analysis of the TCGA database as well as immunohistochemistry staining using matched GC tissues, adjacent normal gastric mucosa tissues (ANTs), and omental metastatic tissues. The regulation of PITPNC1 by adipocytes was explored by co-culture systems. By using both PITPNC1 overexpression and silencing methods, the role of PITPNC1 in anoikis resistance and metastasis was determined through in vitro and in vivo experiments. Results: PITPNC1 was expressed at higher rates in GC tissues than in ANTs; notably, it was higher in omental metastatic lesions. Elevated expression of PITPNC1 predicted higher rates of omental metastasis and a poor prognosis. PITPNC1 promoted anoikis resistance through fatty acid metabolism by upregulating CD36 and CPT1B expression. Further, PITPNC1 was elevated by adipocytes and facilitated GC omental metastasis. Lastly, in vivo studies showed that PITPNC1 was a therapeutic indicator of fatty acid oxidation (FAO) inhibition. Conclusion: Elevated expression of PITPNC1 in GC is correlated with an advanced clinical stage and a poor prognosis. PITPNC1 promotes anoikis resistance through enhanced FAO, which is regulated by omental adipocytes and consequently facilitates GC omental metastasis. Targeting PITPNC1 might present a promising strategy to treat omental metastasis.

Gastric Adenocarcinoma: A Multimodal Approach

Despite its declining incidence, gastric cancer (GC) remains a leading cause of cancer-related deaths worldwide. A multimodal approach to GC is critical to ensure optimal patient outcomes. Pretherapy fine resolution contrast-enhanced cross-sectional imaging, endoscopic ultrasound and staging laparoscopy play an important role in patients with newly diagnosed ostensibly operable GC to avoid unnecessary non-therapeutic laparotomies. Currently, margin negative gastrectomy and adequate lymphadenectomy performed at high volume hospitals remain the backbone of GC treatment. Importantly, adequate GC surgery should be integrated in the setting of a multimodal treatment approach. Treatment for advanced GC continues to expand with the emergence of additional lines of systemic and targeted therapies.

Depth of tumor invasion and tumor-occupied portions of stomach are predictive factors of intra-abdominal metastasis

Objective

Diagnostic laparoscopy is recommended for the pretherapeutic staging of gastric cancer to detect any unexpected or unconfirmed intra-abdominal metastasis. The aim of this study was to evaluate the role and indications of diagnostic laparoscopy in the detection of intra-abdominal metastasis.

Methods

Standard diagnostic laparoscopy with peritoneal cytology examination was performed prospectively on patients who were clinically diagnosed with primary local advanced gastric cancer (cT≥2M0). We calculated the rate of intra-abdominal metastases identified by diagnostic laparoscopy, and examined the relationship between peritoneal dissemination (P) and cytology results (CY). Split-sample method was applied to find clinical risk factors for intra-abdominal metastasis. Multivariate logistic regression analysis and receiver-operator characteristic (ROC) analysis were performed in training set to find out risk factors of intra-abdominal metastasis, and then validate it in testing set.

Results

Out of 249 cM0 patients, 51 (20.5%) patients with intra-abdominal metastasis were identified by diagnostic laparoscopy, including 20 (8.0%) P1CY1, 17 (6.8%) P0CY1 and 14 (5.6%) P1CY0 patients. In the training set, multivariate logistic regression analysis and ROC analysis showed that the depth of tumor invasion on computer tomography (CT) scan ≥21 mm and tumor-occupied ≥2 portions of stomach are predictive factors of metastasis. In the testing set, when diagnostic laparoscopy was performed on patients who had one or two of these risk factors, the sensitivity and positive predictive value for detecting intra-abdominal metastasis were 90.0% and 32.1%, respectively.

Conclusions

According to our results, depth of tumor invasion and tumor-occupied portions of stomach are predictive factors of intra-abdominal metastasis.

Recent insights in the therapeutic management of patients with gastric cancer

Gastric cancer remains frequent and one of the most lethal malignancies worldwide. In this article, we aimed to comprehensively review recent insights in the therapeutic management of gastric cancer, with focus on the surgical and perioperative management of resectable forms, and the latest advances regarding advanced diseases. Surgical improvements comprise the use of laparoscopic surgery including staging laparoscopy, a better definition of nodal dissection, and the development of hyperthermic intraperitoneal chemotherapy. The best individualized perioperative management should be assessed before curative-intent surgery for all patients and can consists in perioperative chemotherapy, adjuvant chemo-radiation therapy or adjuvant chemotherapy alone. The optimal timing and sequence of chemotherapy and radiation therapy with respect to surgery should be further explored. Patients with advanced gastric cancer have a poor prognosis. Nevertheless, they can benefit from doublet or triplet chemotherapy combination, including trastuzumab in HER2-positive patients. Upon progression, second-line therapy can be considered in patients with good performance status. Although anti-HER2 (trastuzumab) and anti-VEGFR (ramucirumab) may yield survival benefit, anti-EGFR and anti-HGFR therapies have failed to improve outcomes. Nevertheless, combination regimens containing cytotoxic drugs and targeted therapies should be further evaluated; keeping in mind that gastric cancer biology is different between Asia and the Western countries.

Positive Peritoneal Lavage Cytology -Implications for Staging and Management of Gastric Cancer

The survival rates of gastric cancer patients with cytology-positive peritoneal lavage fluid without macroscopic dissemination (CY+/P-) is the same as that of patients with overt peritoneal metastasis.The 5-year survival rate of such patients is only 2%. The current study aims to highlight its significance in the staging of gastrointestinal malignancies and its implications for patient care. Prospective nonrandom analysis of peritoneal wash cytology in patients with gastrointestinal malignancies was conducted in the department of Surgical Gastroenterology, Nizams Institute of Medical Sciences, Hyderabad from January 2012 to June 2013. Descriptive statistics and ANOVA variance analysis was performed to estimate incidence, risk factors and the effect of surgery in causing peritoneal dissemination of malignancy. A total of 60 patients with operable gastric cancer underwent peritoneal lavage for evaluation of malignant cells. The incidence of Positive peritoneal lavage cytology was 8.3% (5/60).Four patients with positive lavage fluid belong to T3 stage (11.7%, p-0.309).Poorly differentiating and mucinous tumors had a higher incidence of positive cytology (18.1% and 25%).None of the patients with positive cytology had positive resection margin. Tumors with advanced T stage, lymph nodal involvement, lympho-vascular and perineural invasion have higher incidence of positive peritoneal cytology. Surgical handling has a negligible effect in peritoneal dissemination of tumor. Large scale studies are warranted to validate the findings and define it's role in management of gastric cancer.

Staging laparoscopy improves treatment decision-making for advanced gastric cancer

AIM: To evaluate the clinical value of staging laparoscopy in treatment decision-making for advanced gastric cancer (GC).

METHODS: Clinical data of 582 patients with advanced GC were retrospectively analyzed. All patients underwent staging laparoscopy. The strength of agreement between computed tomography (CT) stage, endoscopic ultrasound (EUS) stage, laparoscopic stage, and final stage were determined by weighted Kappa statistic (Kw). The number of patients with treatment decision-changes was counted. A χ² test was used to analyze the correlation between peritoneal metastasis or positive cytology and clinical characteristics.

RESULTS: Among the 582 patients, the distributions of pathological T classifications were T2/3 (153, 26.3%), T4a (262, 45.0%), and T4b (167, 28.7%). Treatment plans for 211 (36.3%) patients were changed after staging laparoscopy was performed. Two (10.5%) of 19 patients in M1 regained the opportunity for potential radical resection by staging laparoscopy. Unnecessary laparotomy was avoided in 71 (12.2%) patients. The strength of agreement between preoperative T stage and final T stage was in almost perfect agreement (Kw = 0.838; 95% confidence interval (CI): 0.803-0.872; P < 0.05) for staging laparoscopy; compared with CT and EUS, which was in fair agreement. The strength of agreement between preoperative M stage and final M stage was in almost perfect agreement (Kw = 0.990; 95% CI: 0.977-1.000; P < 0.05) for staging laparoscopy; compared with CT, which was in slight agreement. Multivariate analysis revealed that tumor size (≥ 40 mm), depth of tumor invasion (T4b), and Borrmann type (III or IV) were significantly correlated with either peritoneal metastasis or positive cytology. The best performance in diagnosing P-positive was obtained when two or three risk factors existed.

CONCLUSION: Staging laparoscopy can improve treatment decision-making for advanced GC and decrease unnecessary exploratory laparotomy.

Surgical Resection First for Localized Gastric Adenocarcinoma: Are There Adjuvant Options?

A 55-year-old male presented with upper abdominal bloating followed by modest hematemesis that led to the diagnosis of an ulcerated poorly differentiated (with signet ring cells) adenocarcinoma in the angularis of the stomach. A contrast-enhanced positron emission tomography (PET) with computed tomography (CT) scan showed higher-than-normal physiologic avidity (standardized uptake value, 4.3) in the proximal stomach but not in the lower stomach, and the CT scan vaguely suggested a polypoid lesion in the distal stomach. Nodes were normal in size, and there were no metastases. He underwent esophagoduodenoscopy with ultrasonography (EUS) that showed a 3- x 2-cm flat nodular mass with an 8-mm ulcer in the angularis. The tumor mass was demarcated well on narrow-band imaging, and with a 20-MHz EUS probe, it was designated eusT1bN0. His case was presented to our weekly Multidisciplinary Gastric Adenocarcinoma Conference, and the consensus was to offer surgery as primary therapy. He underwent a subtotal gastrectomy with Roux-en-Y gastrojejunostomy along with D2 nodal dissection. The surgical pathology showed a poorly differentiated adenocarcinoma with signet ring cells; the primary tumor measured 2.8 x 2.2 cm in diameter with infiltration through the muscularis propria and into the subserosal fat. Seven of 53 examined lymph nodes were malignant; therefore, his cancer was staged pT3N3M0 (a higher stage than designated clinically). He recovered well without complications, and the postoperative CT scans showed no metastases. His case was represented at the tumor board meeting, and adjuvant chemotherapy with oxaliplatin and capecitabine was recommended.

International comparison of the German evidence-based S3-guidelines on the diagnosis and multimodal treatment of early and locally advanced gastric cancer, including adenocarcinoma of the lower esophagus

BACKGROUND

Clinical guidelines are essential in implementing and maintaining nationwide stage-specific diagnostic and therapeutic standards. In 2011, the first German expert consensus guideline defined the evidence for diagnosis and treatment of early and locally advanced esophagogastric cancers. Here, we compare this guideline with other national guidelines as well as current literature.

METHODS

The German S3-guideline used an approved development process with de novo literature research, international guideline adaptation, or good clinical practice. Other recent evidence-based national guidelines and current references were compared with German recommendations.

RESULTS

In the German S3 and other Western guidelines, adenocarcinomas of the esophagogastric junction (AEG) are classified according to formerly defined AEG I-III subgroups due to the high surgical impact. To stage local disease, computed tomography of the chest and abdomen and endosonography are reinforced. In contrast, laparoscopy is optional for staging. Mucosal cancers (T1a) should be endoscopically resected "en-bloc" to allow complete histological evaluation of lateral and basal margins. For locally advanced cancers of the stomach or esophagogastric junction (≥T3N+), preferred treatment is preoperative and postoperative chemotherapy. Preoperative radiochemotherapy is an evidence-based alternative for large AEG type I-II tumors (≥T3N+). Additionally, some experts recommend treating T2 tumors with a similar approach, mainly because pretherapeutic staging is often considered to be unreliable.

CONCLUSIONS

The German S3 guideline represents an up-to-date European position with regard to diagnosis, staging, and treatment recommendations for patients with locally advanced esophagogastric cancer. Effects of perioperative chemotherapy versus chemoradiotherapy are still to be investigated for adenocarcinoma of the cardia and the lower esophagus.

Tumor regression and survival after perioperative MAGIC-style chemotherapy in carcinoma of the stomach and gastroesophageal junction

BACKGROUND

We assessed the effectiveness of perioperative MAGIC-style chemotherapy in our series focused on the tumor regression grade and survival rate.

METHODS

We conducted a retrospective study of 53 patients following a perioperative regimen of epirubicin, cisplatin, and fluorouracil or capecitabine (ECF/X). Forty-four (83 %) neoplasias were located in the stomach and 9 (17 %) were located at the esophagogastric junction. Perioperative chemotherapy completion, resection, TNM staging, the tumor regression grade (Becker's classification) and survival were analyzed.

RESULTS

Forty-five patients (85 %) completed the 3 preoperative cycles. R0 resection was achieved in 42 (79 %) patients. Thirty-five (66 %) patients completed the 3 postoperative cycles. Nine carcinomas (17 %) were considered major responders after preoperative chemotherapy. With multivariate analysis, only completion of perioperative chemotherapy (HR: 0.25; 95%CI: 0.08 - 0.79; p = 0.019) was identified as an independent prognostic factor for disease-specific survival. However, the protective effect of perioperative therapy was lost in patients with ypT3-4 and more than 4 positive lymph nodes (HR: 1.16; 95%CI: 1.02 - 1.32; p = 0.029). The tumor regression grade (major vs minor responders) was at the limit of significance only with univariate analysis. The 5-year overall and disease-specific survival rates were 18 % and 22 % respectively.

CONCLUSIONS

The percentage of major responder tumors after preoperative chemotherapy was low. Completion of perioperative ECF/X chemotherapy may benefit patients with gastric carcinomas that do not invade the subserosa with few positive lymph nodes.

Prognostic significance of peritoneal lavage cytology at three cavities in patients with gastric cancer

BACKGROUND

We sought to determine the prognostic significance of intraoperative peritoneal lavage cytology (CY) at 3 different abdominal cavities and establish the optimal treatment for gastric cancer patients with positive peritoneal cytology (CY1).

METHODS

A total of 1,039 patients with primary gastric adenocarcinoma who underwent CY at 3 cavities (Douglas' pouch, left subphrenic cavity, and right subhepatic cavity) were enrolled; 116 (11%) patients had at least one positive cavity. We retrospectively analyzed the clinicopathologic characteristics and survival of these 116 patients with CY1.

RESULTS

Seventeen (15%) of the patients had negative cytology at Douglas' pouch but positive cytology at one or both of the other cavities. The 116 patients' overall 2-year survival rate was 22.9%, with the median survival time of 11 months. The overall 2-year survival rates for the patients with positive cytology at 1, 2, and 3 cavities were 41.9%, 35.8%, and 15%, with median survival times of 17, 18, and 9 months, respectively (P < .01). A multivariate analysis revealed that macroscopic type 4 tumor, R2 resection, lymph node metastasis, and postoperative chemotherapy were independent prognostic factors. Among the CY1 patients with type 4 tumors, there was no substantial difference in survival between the patients who underwent R1 or R2 resection, although the statistical power of this subgroup analysis was low.

CONCLUSION

CY at 3 cavities might be a useful method to decrease the false-negative rate. Palliative gastrectomy for CY1 patients with type 4 tumors is still controversial.

Controversies in the treatment of local and locally advanced gastric and esophageal cancers

Despite overall progress in the therapy of local and locally advanced esophageal, gastroesophageal junction, and gastric adenocarcinomas, death as a result of these tumors remains a common outcome. Most randomized phase III trials on which level-one evidence has been built have included the heterogeneous histologies and locations associated with these tumors. However, the different etiologies, molecular biology, and recurrence patterns associated with gastroesophageal malignancies suggest the need to split rather than lump. Biologic and response differences exist between squamous and adenocarcinomas, as well as diffuse and intestinal histologies. This may be a cause behind conflicting outcomes in similar trials. The accepted standard of chemoradiotherapy for locally advanced esophageal and gastroesophageal junction cancers is based on a few positive trials, with the best chemotherapy and total dose of radiation remaining controversial. In the West, the staging evaluations of locally advanced gastric cancer are not uniform. Yet, these evaluations will inform the results of preoperative and perioperative treatments. Although postoperative chemoradiotherapy for gastric cancer has been an accepted treatment option for the last decade, more recent studies have called into question the need for radiotherapy. In perioperative strategies, it has yet to be determined whether histologic or molecular changes in the operative specimen should inform postoperative treatment. An appropriate place for targeted therapy needs to be found in preoperative and postoperative treatment regimens. Finally, because so much is lost when trials are forced to close for lack of accrual, it is imperative to build multidisciplinary consensus before they are launched.

Novel imaging strategies for upper gastrointestinal tract cancers

Accurate pretherapeutic imaging is the cornerstone of all cancer treatment. Unfortunately, modern imaging modalities have several unsolved problems and limitations. The differentiation between inflammation and cancer infiltration, false positive and false negative findings as well as lack of confirming biopsies in suspected metastases may have serious negative consequences in cancer patients. This review describes some of these problems and challenges the use of conventional imaging by suggesting new combined strategies that include selective use of confirming biopsies and complementary methods to detect microscopic cancer dissemination.

Diagnostic accuracy of endoscopic ultrasonography (EUS) for the preoperative locoregional staging of primary gastric cancer

BACKGROUND

Endoscopic ultrasound (EUS) is proposed as an accurate diagnostic device for the locoregional staging of gastric cancer, which is crucial to developing a correct therapeutic strategy and ultimately to providing patients with the best chance of cure. However, despite a number of studies addressing this issue, there is no consensus on the role of EUS in routine clinical practice.

OBJECTIVES

To provide both a comprehensive overview and a quantitative analysis of the published data regarding the ability of EUS to preoperatively define the locoregional disease spread (i.e., primary tumor depth (T-stage) and regional lymph node status (N-stage)) in people with primary gastric carcinoma.

SEARCH METHODS

We performed a systematic search to identify articles that examined the diagnostic accuracy of EUS (the index test) in the evaluation of primary gastric cancer depth of invasion (T-stage, according to the AJCC/UICC TNM staging system categories T1, T2, T3 and T4) and regional lymph node status (N-stage, disease-free (N0) versus metastatic (N+)) using histopathology as the reference standard. To this end, we searched the following databases: the Cochrane Library (the Cochrane Central Register of Controlled Trials (CENTRAL)), MEDLINE, EMBASE, NIHR Prospero Register, MEDION, Aggressive Research Intelligence Facility (ARIF), ClinicalTrials.gov, Current Controlled Trials MetaRegister, and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), from 1988 to January 2015.

SELECTION CRITERIA

We included studies that met the following main inclusion criteria: 1) a minimum sample size of 10 patients with histologically-proven primary carcinoma of the stomach (target condition); 2) comparison of EUS (index test) with pathology evaluation (reference standard) in terms of primary tumor (T-stage) and regional lymph nodes (N-stage). We excluded reports with possible overlap with the selected studies.

DATA COLLECTION AND ANALYSIS

For each study, two review authors extracted a standard set of data, using a dedicated data extraction form. We assessed data quality using a standard procedure according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. We performed diagnostic accuracy meta-analysis using the hierarchical bivariate method.

MAIN RESULTS

We identified 66 articles (published between 1988 and 2012) that were eligible according to the inclusion criteria. We collected the data on 7747 patients with gastric cancer who were staged with EUS. Overall the quality of the included studies was good: in particular, only five studies presented a high risk of index test interpretation bias and two studies presented a high risk of selection bias.For primary tumor (T) stage, results were stratified according to the depth of invasion of the gastric wall. The meta-analysis of 50 studies (n = 4397) showed that the summary sensitivity and specificity of EUS in discriminating T1 to T2 (superficial) versus T3 to T4 (advanced) gastric carcinomas were 0.86 (95% confidence interval (CI) 0.81 to 0.90) and 0.90 (95% CI 0.87 to 0.93) respectively. For the diagnostic capacity of EUS to distinguish T1 (early gastric cancer, EGC) versus T2 (muscle-infiltrating) tumors, the meta-analysis of 46 studies (n = 2742) showed that the summary sensitivity and specificity were 0.85 (95% CI 0.78 to 0.91) and 0.90 (95% CI 0.85 to 0.93) respectively. When we addressed the capacity of EUS to distinguish between T1a (mucosal) versus T1b (submucosal) cancers the meta-analysis of 20 studies (n = 3321) showed that the summary sensitivity and specificity were 0.87 (95% CI 0.81 to 0.92) and 0.75 (95% CI 0.62 to 0.84) respectively. Finally, for the metastatic involvement of lymph nodes (N-stage), the meta-analysis of 44 studies (n = 3573) showed that the summary sensitivity and specificity were 0.83 (95% CI 0.79 to 0.87) and 0.67 (95% CI 0.61 to 0.72), respectively.Overall, as demonstrated also by the Bayesian nomograms, which enable readers to calculate post-test probabilities for any target condition prevalence, the EUS accuracy can be considered clinically useful to guide physicians in the locoregional staging of people with gastric cancer. However, it should be noted that between-study heterogeneity was not negligible: unfortunately, we could not identify any consistent source of the observed heterogeneity. Therefore, all accuracy measures reported in the present work and summarizing the available evidence should be interpreted cautiously. Moreover, we must emphasize that the analysis of positive and negative likelihood values revealed that EUS diagnostic performance cannot be considered optimal either for disease confirmation or for exclusion, especially for the ability of EUS to distinguish T1a (mucosal) versus T1b (submucosal) cancers and positive versus negative lymph node status.

AUTHORS' CONCLUSIONS

By analyzing the data from the largest series ever considered, we found that the diagnostic accuracy of EUS might be considered clinically useful to guide physicians in the locoregional staging of people with gastric carcinoma. However, the heterogeneity of the results warrants special caution, as well as further investigation for the identification of factors influencing the outcome of this diagnostic tool. Moreover, physicians should be warned that EUS performance is lower in diagnosing superficial tumors (T1a versus T1b) and lymph node status (positive versus negative). Overall, we observed large heterogeneity and its source needs to be understood before any definitive conclusion can be drawn about the use of EUS can be proposed in routine clinical settings.

Towards personalized perioperative treatment for advanced gastric cancer

Gastric cancer is one of the most frequently diagnosed cancers worldwide. Although the rate of gastric cancer has declined dramatically over the past decades in most developed Western countries, it has not declined in East Asia. Currently, a radical gastrectomy is still the only curative treatment for gastric cancer. Over the last twenty years, however, surgery alone has been replaced by a multimodal perioperative approach. To achieve the maximum benefit from the perioperative treatment, a thorough evaluation of the tumor must first be performed. A complete assessment of gastric cancer is divided into two parts: staging and histology. According to the stage and histology of the cancer, perioperative chemotherapy or radiochemotherapy can be implemented, and perioperative targeted therapies such as trastuzumab may also play a role in this field. However, perioperative treatment approaches have not been widely accepted until a series of clinical trials were performed to evaluate the value of perioperative treatment. Although multimodal perioperative treatment has been widely applied in clinical practice, personalization of perioperative treatment represents the next stage in the treatment of gastric cancer. Genomic-guided treatment and efficacy prediction using molecular biomarkers in perioperative treatment are of great importance in the evolution of treatment and may become an ideal treatment method.

The critical role of peritoneal cytology in the staging of gastric cancer: an evidence-based review

Positive peritoneal cytology (Cyt+) is an important staging tool for patients with locally advanced gastric cancer. The objective of this review is to evaluate the current literature regarding cytology evaluation in patients with gastric cancer and to provide recommendations on the inclusion of this powerful prognosticator in patients with this disease. A literature search was performed for recent and pertinent studies evaluating peritoneal cytology in patients with gastric adenocarcinoma. Peritoneal cytology as the only evidence for M1 disease is present in up to 10% of patients with locally advanced gastric cancer; survival in the setting of Cyt+ is dismal when gastrectomy is the first line of therapy. Improved survival is associated with response to chemotherapy indicated by conversion to negative cytology, good performance status, and antral tumors. Highly select patients with Cyt+ treated with gastrectomy show improved survival in only some of the available studies. There are high quality studies that support the routine practice of peritoneal cytology evaluation in patients with locally advanced gastric cancer. The role of gastrectomy remains unclear in patients with Cyt+ and clinical trials are needed to define the best treatment option for this select group of patients.

Can perioperative chemotherapy for advanced gastric cancer be recommended on the basis of current research? A critical analysis

PURPOSE

According to current guidelines, perioperative chemotherapy is an integral part of the treatment strategy for advanced gastric cancer. Randomized controlled studies have been conducted in order to determine whether perioperative chemotherapy leads to improved R0 resection rates, fewer recurrences, and prolonged survival. The aim of our project was to critically appraise three major studies to establish whether perioperative chemotherapy for advanced, potentially resectable gastric cancer can be recommended on the basis of their findings.

MATERIALS AND METHODS

We analyzed the validity of the three most important studies (MAGIC, ACCORD, and EORTC) using a standardized questionnaire. Each study was evaluated for the study design, patient selection, randomization, changes in protocol, participating clinics, preoperative staging, chemotherapy, homogeneity of subjects, surgical quality, analysis of the results, and recruitment period.

RESULTS

All three studies had serious shortcomings with respect to patient selection, homogeneity of subjects, changes in protocol, surgical quality, and analysis of the results. The protocols of the MAGIC and ACCORD-studies were changed during the study period because of insufficient recruitment, such that carcinomas of the lower esophagus and the stomach were examined collectively. In neither the MAGIC study nor the ACCORD study did patients undergo adequate lymphadenectomy, and only about half of the patients in the chemotherapy group could undergo the treatment specified in the protocol. The EORTC study had insufficient statistical power.

CONCLUSIONS

We concluded that none of the three studies was sufficiently robust to justify an unrestrained recommendation for perioperative chemotherapy in cases of advanced gastric cancer.

A prospective clinical trial of diagnostic peritoneal lavage for peritoneal cytology in patients with gastric cancer

AIM: To assess the safety and feasibility of diagnostic peritoneal lavage (DPL) in gastric cancer patients and determine whether DPL can be used to assess peritoneal cytology in patients with gastric cancer.

METHODS: Patients with gastric adenocarcinoma were prospectively enrolled to undergo DPL prior to diagnostic laparoscopy (DL). Saline was instilled through a percutaneous catheter and fluid was collected for cytology (DPL-cyt). Washings obtained during DL were used as controls (DL-cyt).

RESULTS: DPL was successful in 22 of 27 patients (81.5%). Among the 22 cases of successful DPL, 12 had positive cytology (54.5%). Positive DPL-cyt specimens were consistent with DL-cyt specimens in 12/12 cases (specificity = 100%).

CONCLUSION: DPL is a safe method for detecting positive cytology in patients with gastric cancer.

Surgical considerations in the treatment of gastric cancer

Gastric cancer is one of the most common malignancies in the world and is a leading cause of cancer death. Surgical treatment remains the best treatment option for potential cure and can be beneficial in the palliation of advanced disease. Several neoadjuvant chemotherapy regimens have been recently evaluated as potential adjuncts to surgery. This review describes the current role of surgical therapy in staging, resection, and palliation of gastric cancer.

Surgical considerations in the treatment of gastric cancer

Gastric cancer is one of the most common malignancies in the world and is a leading cause of cancer death. Surgical treatment remains the best treatment option for potential cure and can be beneficial in the palliation of advanced disease. Several neoadjuvant chemotherapy regimens have been recently evaluated as potential adjuncts to surgery. This review describes the current role of surgical therapy in staging, resection, and palliation of gastric cancer.

Prospective clinical trial of diagnostic peritoneal lavage to detect positive peritoneal cytology in patients with gastric cancer

BACKGROUND AND OBJECTIVES

Positive peritoneal cytology equates M1 disease in patients with gastric cancer. Diagnostic peritoneal lavage (DPL) is a proven test to detect occult visceral injury in trauma patients. The objective of this study is to determine whether DPL can be used to assess peritoneal cytology in patients with gastric cancer.

METHODS

Patients with gastric adenocarcinoma were prospectively enrolled to undergo DPL prior to diagnostic laparoscopy (DL). Saline was instilled through a percutaneous catheter and fluid was collected for cytology (DPL-cyt). Washings obtained during DL were used as controls (DL-cyt).

RESULTS

DPL was successful in 22/27 patients (81.5%). Among the 22 successful DPLs, 12 had positive cytology (54.5%). Positive DPL-cyt specimens matched DL-cyt specimens in 12/12 cases (specificity = 100%). One of 10 cases with negative DPL-cyt was positive on the final DL-cyt (sensitivity = 92%). There were six patients with negative DPL-cyt who had visible M1 disease diagnosed with DL (DPL evaluation of M1 disease, sensitivity 54.5%, specificity = 100%).

CONCLUSIONS

DPL is a safe method of detecting positive cytology in patients with gastric cancer, however gross M1 disease may be missed without visual inspection. The specific role of DPL in the staging workup of patients with gastric cancer remains to be determined.

Diagnostic bedside EUS in the intensive care unit: a single-center experience

BACKGROUND

The knowledge of bedside diagnostic EUS in critically ill patients is limited.

OBJECTIVE

To investigate the indications, feasibility, safety, and clinical utility of diagnostic EUS in the intensive care unit (ICU).

DESIGN

Retrospective.

SETTING

Tertiary-care referral teaching hospital.

PATIENTS

All consecutive patients who had EUS done in the ICU within a 6-year period.

INTERVENTION

Bedside EUS and EUS-guided FNA.

MAIN OUTCOME MEASUREMENTS

EUS indications, complications, and impact on management.

RESULTS

A total of 64 EUS procedures were performed in 63 patients (38 men, 25 women; age range 27-78 years); 1 patient underwent 2 separate EUS procedures. EUS was performed while the patients were mechanically ventilated in 70% (45/64) of cases. Indications for EUS included jaundice (n = 24), mass of unknown etiology (n = 25), unexplained pancreatitis (n = 7), and staging of known cancer (n = 3). In 5 cases, EUS was used as an alternative to other imaging modalities because of morbid obesity (n = 3) or contraindication to intravenous contrast material (n = 2). Complications included reversible oxygen desaturation (n = 4), nonsustained ventricular tachycardia (n = 1), and transient hypotension (n = 1). Overall, EUS influenced management in 97% (62/64) of cases.

LIMITATIONS

Retrospective, single-center study.

CONCLUSION

ICU-based EUS can be performed with few intraprocedural complications and can be a valuable diagnostic modality in the ICU setting. It appears to be particularly useful for determining the etiology of jaundice, masses of unknown etiology, and pancreatitis. It may have particular value as a diagnostic technique on selected patients with unstaged cancer and when morbid obesity or the inability to use intravenous contrast material precludes the use of other imaging modalities in the critically ill patient.

Laparoscopic gastrectomy for cancer

Gastric cancer is common worldwide. Tumor location and disease stage differ between Asian and Western countries. Western patients often have higher BMIs and comorbidities that may make laparoscopic resections challenging. Multiple trials from Asian countries demonstrate the benefits of laparoscopic gastrectomy for early gastric cancer while maintaining equivalent short-term and long-term oncologic outcomes compared with open surgery. The outcomes of laparoscopy seem to offer equivalent results to open surgery. In the United States, laparoscopic gastrectomy remains in its infancy and is somewhat controversial. This article summarizes the literature on the epidemiology, operative considerations and approaches, and outcomes for laparoscopic gastrectomy.

A systematic review of the accuracy and indications for diagnostic laparoscopy prior to curative-intent resection of gastric cancer

BACKGROUND

Despite improved preoperative imaging techniques, patients with incurable or unresectable gastric cancer are still subjected to non-therapeutic laparotomy. Diagnostic laparoscopy (DL) has been advocated by some to be essential in decision-making in gastric cancer. We aimed to identify and synthesize findings on the value of DL for patients with gastric cancer, in this era of improved preoperative imaging.

METHODS

Electronic literature searches were conducted using Medline, EMBASE, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 31, 2009. We calculated the change in management and avoidance of laparotomy based on the addition of DL and laparoscopic ultrasound (LUS). The accuracy, agreement (kappa), sensitivity, and specificity of DL in assessing tumor extent, nodal involvement, and the presence of metastases with respect to the gold standard (pathology) were also calculated.

RESULTS

Twenty-one articles were included. DL showed moderate to substantial agreement with final pathology for T stage, but only fair agreement for N stage. For M staging, DL had an overall accuracy, sensitivity, and specificity ranging from 85-98.9%, 64.3-94%, and 80-100%, respectively. The use of DL altered treatment in 8.5-59.6% of cases, avoiding laparotomy in 8.5-43.8% of cases. LUS provided additional benefit in 5.8-7.2% of cases.

CONCLUSIONS

Despite evolving preoperative imaging techniques, diagnostic laparoscopy continues to be of substantial value in staging patients with gastric cancer and in avoiding unnecessary laparotomy. The current data support DL for all patients with advanced gastric cancer.

Role of repeat staging laparoscopy in locoregionally advanced gastric or gastroesophageal cancer after neoadjuvant therapy

INTRODUCTION

Staging laparoscopy (SL) can identify occult, subradiographic metastatic (M1) disease in patients with gastric or gastroesophageal (G/GEJ) cancer who are unlikely to benefit from gastrectomy. The purpose of this study is to determine the yield of repeat SL following neoadjuvant therapy for G/GEJ adenocarcinoma after initial negative pretreatment SL.

METHODS

Retrospective review of a prospective database identified patients with locoregionally advanced (T3-4Nany or TanyN+) G/GEJ adenocarcinoma who underwent pretreatment SL. The yield of repeat SL following neoadjuvant therapy was determined.

RESULTS

From 1994 to 2010, 276 patients with locoregionally advanced G/GEJ adenocarcinoma were identified, of whom 244 proceeded to operation after neoadjuvant therapy, at a median time of 105 days. One hundred sixty-four patients (67 %) underwent repeat SL, and 80 patients (33 %) proceeded directly to laparotomy. Occult M1 disease was identified in 12 (7.3 %) and 6 (7.5 %) patients, respectively. In the repeat SL cohort, M1 disease was identified at laparoscopy in nine patients (5.5 %). M1 disease not identified by laparoscopy was discovered at laparotomy in three patients (1.8 %). The median follow-up for the study population was 31 months. For patients with M1 disease, median overall survival was 15 months, versus 41 months for patients resected without M1 disease (p < 0.0001).

CONCLUSIONS

Occult, subradiographic M1 disease develops in approximately 7 % of patients following neoadjuvant therapy for locoregionally advanced G/GEJ adenocarcinoma. These patients have poor prognosis, and repeat SL can be a valuable tool in selecting patients with locoregionally advanced G/GEJ tumors for potentially curative resection after neoadjuvant therapy.

[Current S3 guidelines on surgical treatment of gastric carcinoma]

The current S3 guidelines on the diagnosis and treatment of gastric carcinoma including those of the esophagogastric junction describe optimal clinical practice based on a high level of evidence and expert consensus from different medical disciplines. Endoscopy and performance of multiple biopsies is the standard approach to detect malignant tumors in the upper gastrointestinal tract. Further diagnostic procedures are necessary to evaluate the tumor stage. With the exception of mucosal carcinomas, surgical therapy is the cornerstone of curative treatment in all potentially resectable stages. In locally advanced carcinomas perioperative chemotherapy should be carried out and in high-seated tumors preoperative radiochemotherapy might be an alternative option. Palliative surgical resection should be avoided in disseminated asymptomatic stages. In a palliative situation complications of the tumor should primarily be treated by interventional or conservative procedures.

A prospective evaluation of the utility of 2-deoxy-2-[(18) F]fluoro-D-glucose positron emission tomography and computed tomography in staging locally advanced gastric cancer

BACKGROUND

The aim of this study was to examine prospectively the utility of adding preoperative [(18) F]fluorodeoxyglucose positron emission tomography (FDG-PET)/computed tomography (CT) to routine CT, endoscopic ultrasound (EUS), and laparoscopic staging of localized gastric cancer.

METHODS

Patients with locally advanced gastric/gastroesophageal cancer were screened for 2 institutional review board-approved Memorial Sloan-Kettering Cancer Center neoadjuvant chemotherapy protocols. Locally advanced disease was defined as T3 or T4, or lymph node-positive, based on EUS and high-resolution CT scan. All patients underwent both standard FDG-PET/CT and laparoscopy with cytological examination of washings. The sensitivity and specificity of FDG-PET/CT for the identification of metastatic disease not seen on CT was determined. An economic model using Medicare/Medicaid reimbursement charges was developed to assess the cost-effectiveness of these interventions.

RESULTS

A total of 113 patients were enrolled from 2003 to 2010. All patients were assessed as having locally advanced disease by CT/EUS. FDG uptake in the primary tumor was associated with male sex, proximal tumors, and nondiffuse Lauren's subtype. 31 (27%) patients had occult metastatic disease detected by PET/CT (n = 11, 10%) and/or laparoscopy (n = 21, 19%), with a single overlap. Economic modeling suggests that the addition of FDG-PET/CT to the standard staging evaluation of patients with locally advanced gastric cancer resulted in an estimated cost savings of ∼US $13,000 per patient.

CONCLUSIONS

FDG-PET/CT identifies occult metastatic lesions in approximately 10% of patients with locally advanced gastric cancer. Because of reduced morbidity from fewer futile surgeries and lower patient care costs, PET/CT should be considered as a component of the standard staging algorithm for localized gastric cancer.

Clinical trials in gastric cancer and the future

Following the first successful gastric resection for gastric cancer by Theodor Billroth in 1881 surgery has made tremendous progress leading to improved surgical mortality and morbidity. However, while treatment of early gastric cancer is frequently curative, 5-year survival rates for advanced gastric cancer remain dismal despite the application of perioperative multimodal treatment concepts. In this article we will outline key clinical trials that have lead to an improvement in treatment of gastric cancer patients with specific emphasis on the last 20 years. We will then outline recent concepts and key clinical trials that are currently being conducted in the field. Finally we will outline open questions that remain to be elucidated in the future.

Laparoscopic resection for gastric carcinoma: Western experience

There has been much speculation regarding differences in outcome for patients who have gastric cancer in the Eastern versus Western world. Among other factors, these differences have contributed to a unique cohort of patients and experience in the Western staging/evaluation of gastric cancer and in the application of minimally invasive approaches for treatment. This review summarizes the current state of laparoscopic approaches for the staging and treatment of gastric adenocarcinoma for patients presenting in Western countries, with their associated unique presentation, comorbidities, and outcomes.

Role of (18F) 2-fluoro-2-deoxyglucose positron emission tomography in upper gastrointestinal malignancies

The role of whole-body FDG [(¹⁸F) 2-fluoro-2-deoxyglucose] positron emission tomography (PET) scanning as an imaging modality in the management of patients with malignancy has evolved enormously over the past two decades. FDG-PET has demonstrated significant efficacy in the staging, prognostication and detection of occult metastatic disease in malignancies of the gastrointestinal tract, in addition to assessment of the response to cytotoxic chemotherapy in a more timely manner than has traditionally been possible by more conventional imaging tools. The sensitivity and specificity of FDG-PET for the detection and staging of malignancy depend not only on the site and size of the primary tumor and metastases, but also on histological cell type, reflecting underlying disparities in glucose metabolism. The metabolic response to neo-adjuvant chemotherapy or to chemo-radiotherapy in cancers of the gastro-esophageal junction or stomach has been demonstrated in several prospective studies to correlate significantly with both the histological tumor response to treatment and with consequent improvements in overall survival. This may offer a future paradigm of personalized treatment based on the PET response to chemotherapy. FDG-PET has been less successful in efforts to screen for and detect recurrent upper gastrointestinal malignancies, and in the detection of low volume metastatic peritoneal disease. Efforts to improve the accuracy of PET include the use of novel radiotracers such as (¹⁸F) FLT (3-deoxy-3-fluorothymidine) or ¹¹C-choline, or fusion PET-CT with concurrent high-resolution computed tomography. This review focuses on the role of FDG-PET scanning in staging and response assessment in malignancies of the upper gastrointestinal tract, specifically gastric, esophageal and pancreas carcinoma.

An evidence-based review of the surgical treatment of gastric adenocarcinoma

The management of gastric adenocarcinoma continues to evolve. Chemotherapy is being increasingly used in both the neoadjuvant and adjuvant setting. Surgical resection of the stomach and regional lymph nodes remains the mainstay of potentially curative therapy, but significant regional differences persist in the surgical management. This review provides an update on the current literature regarding the preoperative evaluation and staging, extent of gastric resection, extent of lymph node resection, and adjuvant therapy for patients with gastric adenocarcinoma.

Lymph node metastasis of gastric cancer

Despite a decrease in incidence in recent decades, gastric cancer is still one of the most common causes of cancer death worldwide [1]. In areas without screening for gastric cancer, it is diagnosed late and has a high frequency of nodal involvement [1]. Even in early gastric cancer (EGC), the incidence of lymph node (LN) metastasis exceeds 10%; it was reported to be 14.1% overall and was 4.8 to 23.6% depending on cancer depth [2]. It is important to evaluate LN status preoperatively for proper treatment strategy; however, sufficient results are not being obtained using various modalities. Surgery is the only effective intervention for cure or long-term survival. It is possible to cure local disease without distant metastasis by gastrectomy and LN dissection. However, there is no survival benefit from surgery for systemic disease with distant metastasis such as para-aortic lymph node metastasis [3]. Therefore, whether the disease is local or systemic is an important prognostic indicator for gastric cancer, and the debate continues over the importance of extended lymphadenectomy for gastric cancer. The concept of micro-metastasis has been described as a prognostic factor [4-9], and the biological mechanisms of LN metastasis are currently under study [10-12]. In this article, we review the status of LN metastasis including its molecular mechanisms and evaluate LN dissection for the treatment of gastric cancer.