Clinical utility of perioperative staging laparoscopy for advanced gastric cancer

Techniques of staging laparoscopy and peritoneal fluid assessment in gastric cancer: a systematic review

BACKGROUND

Staging laparoscopy for gastric cancer is recommended to assess the tumor's locoregional extension and exclude peritoneal disease. As there is no consensus on optimizing the procedure's diagnostic accuracy, we aimed to systematically review the literature on operative techniques, followed by peritoneal lavage fluid assessment in gastric cancer patients. Specifically, we sought to indicate the most common characteristics of the procedure and cytological evaluation.

METHODS

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The protocol for this systematic review was registered on PROSPERO database (CRD: 42022306746). On September 2022, a search was carried out using Embase, Medline ALL, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection.

RESULTS

The search identified 1632 studies on staging laparoscopy and 2190 studies on peritoneal fluid assessment. Some 212 studies were included. Open Hasson was the method of choice in accessing the peritoneal cavity in 65% of the studies, followed by establishing a pneumoperitoneum at 10-12 mmHg in 52% of reports. Most frequently, the patient was positioned supine (70%), while a 30° scope and three ports were used to assess the peritoneal cavity clockwise (72%, 77%, and 85%, respectively). Right and left upper abdomen quadrants were the predominant area of laparoscopic exploration (both 65%), followed by the primary tumor region (54%), liver and pelvis (both 30%), and small bowel and spleen (19% and 17%, respectively). Regions of peritoneal lavage and aspiration were limited to the pelvis (50%), followed by right and left upper abdomen quadrants (37.5% and 50%, respectively). No studies compared different methods of operative techniques or analysis of ascites/fluid.

CONCLUSIONS

This study indicates a high heterogeneity in the technique of staging laparoscopy and peritoneal fluid assessment in gastric cancer patients. Further research and initiatives to reach a consensus on the standardization of the procedure are warranted.

Does resection after neoadjuvant chemotherapy of docetaxel, oxaliplatin, and S-1 (DOS regimen) benefit for gastric cancer patients with single non-curable factor? a multicenter, prospective cohort study (Neo-REGATTA)

BACKGROUND

The Neo-REGATTA study evaluated the effectiveness and safety of Docetaxel, oxaliplatin, and S-1 (DOS regimen) followed by radical resection vs. chemotherapy in advanced gastric adenocarcinoma patients with single non-curable factor.

METHODS

This cohort study prospectively enrolled advanced gastric adenocarcinoma patients with single non-curable factor between November 2017 and June 2021. Patients without progression after four cycles of DOS were divided into resection group and chemotherapy group. The outcomes included overall survival (OS), progression-free survival (PFS) and safety. Effectiveness analysis was also performed by propensity score matching (PSM).

RESULTS

A total of 73 patients were enrolled and 13 patients were withdrawn due to disease progression after 4 cycles of DOS. Afterwards, 35 and 25 participants were in the resection and chemotherapy groups, respectively. After a median follow-up time of 30.0 months, the median PFS and OS were 9.0 months, and 18.0 months for the chemotherapy group, but not reached in the resection group. After PSM, 19 matched participants were in each group, and the median PFS and OS were longer in resection group than that in chemotherapy group. The most common grade 3 or 4 adverse events both in the resection group and chemotherapy groups were neutropenia (5.7%, 8.0%) and leukopenia (5.7%, 8.0%).

CONCLUSIONS

Radical resection might provide survival benefit compared with continuous chemotherapy alone in advanced gastric adenocarcinoma patients who had a disease control after DOS, with a good safety profile.

TRIAL REGISTRATION

The study protocol was registered on ClinicalTrial.gov (NCT03001726, 23/12/2016).

Global scientific trends in laparoscopy and gastric cancer in the 21st century: A bibliometric and visual mapping analysis

Aims

To use visual mapping and bibliometrics to analyze and summarize the valuable information on laparoscopic surgery for gastric cancer (GC) obtained in the last 20 years, so as to determine the research hotspots and trends in this field.

Methods

We screened all literature on laparoscopic surgery for GC in the Web of Science published from 2000 to 2022 and analyzed the research hotspots and trends in this field using VOSviewer.

Results

A total of 2796 reports from 61 countries and regions were selected. Japanese researchers published the most papers (n=946), followed by those from China (n=747) and South Korea (n=557). Papers from Japan also had the most citations (n=21,836). Surgical Endoscopy and Other Interventional Techniques published the most reports on laparoscopic surgery for GC (n=386) and also had the highest total number of citations (n=11,076), making this journal the most authoritative in this field. Among the institutions, researchers from Seoul National University in South Korea had the highest numbers of published papers and citations. The keywords of the articles could be divided into five categories: surgical methods for GC, short-term and long-term efficacy of laparoscopic surgery, guiding role of laparoscopy in the treatment of advanced GC, diagnosis and treatment of early gastric cancer (EGC), and lymph node dissection. Keywords such as "laparoscopic proximal gastrectomy", "surgical outcomes", and "esophagogastric junction" have emerged recently, and relevant studies on laparoscopic surgery for adenocarcinoma of esophagogastric junction(AEG)have gradually become a hot topic and trend.

Conclusion

This study adopted bibliometric analysis to identify the current research hotspots and research trends in the field of laparoscopic surgery for GC. Five main research hotspots of laparoscopic surgery for GC were also identified. Laparoscopic surgery for AEG may become an important research focus in the future.

Which gastric cancer patients could benefit from staging laparoscopy? A GIRCG multicenter cohort study

BACKGROUND

This study aimed to investigate which gastric cancer patients could benefit the most from staging laparoscopy.

METHODS

A retrospective cohort study was carried out, including 316 (216 cM- and 100 cM+) gastric cancer patients who had undergone staging laparoscopy between 2010 and 2020 in seven GIRCG centers. A model including easily-accessible clinical, biochemical and pathological markers was constructed to predict the risk of carcinomatosis. ROC curve and decision curve analyses were used to verify its accuracy and net benefit.

RESULTS

In the cM-population staging laparoscopy could detect 67 cases who had peritoneal carcinomatosis or positive cytology, for a yield of 30.5%. In cM-patients, intestinal type tumors (0.25, 0.12-0.51; p = 0.002), cT4 tumors (2.18, 1.11-4.28; p = 0.023) and cancers of the lower third (0.31, 0.14-0.70; p = 0.004) were associated with the presence of peritoneal carcinomatosis and/or positive cytology. The ROC curve analysis of the model including the three variables showed an AUC of 0.75 (0.68-0.81, p < 0.001). The decision curve analyses showed that the model had a higher net benefit than the treating all strategy between threshold probabilities of 15 and 50%.

CONCLUSIONS

Staging laparoscopy is a useful tool to address the patient with gastric cancer to the most adequate treatment. In cM-patients the assessment of the location of the tumor, the Lauren's histotype and the cT status may help in providing additional elements in indicating or not the use of staging laparoscopy.

Usefulness of Diagnostic Staging Laparoscopy for Advanced Gastric Cancer

BACKGROUND

For advanced gastric cancer (AGC), peritoneal metastasis is the most common determinant of unresectability, but accurate preoperative diagnosis for peritoneal metastasis is challenging. Staging laparoscopy (SL) can detect unsuspected peritoneal metastasis. This study retrospectively evaluated the utility of SL and its indication in patients with AGC.

METHODS

In this study, we enrolled 114 patients with pathologically diagnosed gastric adenocarcinoma who underwent SL.

RESULTS

Of the 114 patients, 43 (37.7%) had peritoneal metastasis (P1 or CY1). Higher age, larger tumor size, type 4 GC, deeper tumor depth, elevated CA125, and ascites findings in preoperative CT were found to be significant predictors of peritoneal metastasis. In multivariate analysis, peritoneal metastasis was associated with type 4 GC (odds ratio [OR]: 6.11; 95% confidence interval [CI]: 1.87-19.8; P < .01) and ascites in CT (OR: 4.25; 95% CI: 1.48-12.1; P < .01).

CONCLUSIONS

Staging laparoscopy is an effective tool to detect peritoneal metastasis from AGC. It can increase the curative resection rate and decrease unnecessary laparotomies.

Clinical TNM staging for esophageal, gastric, and colorectal cancers in the era of neoadjuvant therapy: A systematic review of the literature

AIM

Clinical staging is vital for selecting appropriate candidates and designing neoadjuvant treatment strategies for advanced tumors. The aim of this review was to evaluate diagnostic abilities of clinical TNM staging for gastrointestinal, gastrointestinal cancers.

METHODS

We conducted a systematic review of recent publications to evaluate the accuracy of diagnostic modalities on gastrointestinal cancers. A systematic literature search was performed in PubMed/MEDLINE using the keywords "TNM staging," "T4 staging," "distant metastases," "esophageal cancer," "gastric cancer," and "colorectal cancer," and the search terms used in Cochrane Reviews between January 2005 to July 2020. Articles focusing on preoperative diagnosis of: (a) depth of invasion; (b) lymph node metastases; and (c) distant metastases were selected.

RESULTS

After a full-text search, a final set of 55 studies (17 esophageal cancer studies, 26 gastric cancer studies, and 12 colorectal cancer studies) were used to evaluate the accuracy of clinical TNM staging. Positron emission tomography-computed tomography (PET-CT) and/or magnetic resonance imaging (MRI) were the best modalities to assess distant metastases. Fat and fiber mode of CT may be useful for T4 staging of esophageal cancer, CT was a partially reliable modality for lymph node staging in gastric cancer, and CT combined with MRI was the most reliable modality for liver metastases from colorectal cancer.

CONCLUSION

The most reliable diagnostic modality differed among gastrointestinal cancers depending on the type of cancer. Therefore, we propose diagnostic algorithms for clinical staging for each type of cancer.

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.

Peritoneal dissemination of breast cancer diagnosed by laparoscopy

The accuracy of modern imaging techniques for the diagnosis of peritoneal carcinomatosis is poor. A breast cancer patient with a high serum CA15-3 level did not receive a definitive diagnosis of peritoneal dissemination by imaging examination and then underwent laparoscopy. Pathological examination showed peritoneal dissemination of breast cancer, but the biological markers were different from the primary lesion: ER(−), PgR(−), and Her2:3 +. T-DM1 therapy was very effective, and her systemic symptoms disappeared. Since biomarkers of metastatic lesions may sometimes change, laparoscopic biopsy is very important and useful.

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.

Role of staging laparoscopy for gastric cancer patients

Staging laparoscopy (SL) is frequently carried out in patients with advanced gastric cancer. However, some clinical questions are being debated and consensus must be obtained. With this aim, a literature search of PubMed/MEDLINE was carried out using the keywords "gastric cancer," "SL," and "diagnostic laparoscopy". Articles published online up to February 2019 were analyzed, focusing on the following questions. (i) What is an adequate indication for SL? (ii) How do you carry out SL? (iii) Does SL provide accurate information about peritoneal dissemination? (iv) Is the yield of SL different by tumor location? (v) Is SL a safe procedure? (vi) Is "repeat SL" needed? (vii) Does SL provide oncological benefit? Results provided the following responses: (i) In Western countries, clinically resectable advanced tumor is an indication for SL. Terms to be introduced for adequate indication include "location," "type 4 (linitis feature)," "large tumor," "equivocal computed tomography (CT] findings," and "lymph node swelling". (ii) Exploration of the entire peritoneal cavity is preferable. (iii) Detection rate of peritoneal disease is 43%-52% in Japanese institutions and 7.8%-40% in other countries. False-negative findings during SL were 0%-17%, and 10%-13% when limited to cytology. (iv) Yield of SL was higher in gastric cancer compared with esophagogastric junctional tumor. (v) SL-related complications were estimated to occur in 0.4%. (vi) Repeat SL is important after treatment. (vii) If the efficacy of neoadjuvant chemotherapy for patients with P0CY1 is established, SL can provide oncological benefit. SL can be carried out safely and effectively. Considering the prevalence of neoadjuvant treatment, the role of SL will become more important.

Gastric Cancer: Recent Molecular Classification Advances, Racial Disparity, and Management Implications

Gastric adenocarcinoma remains an aggressive and poorly understood malignancy with a heterogeneous presentation and tumor biology. The current histologic and anatomic classification has been ineffective in guiding therapy, with only marginal improvement in outcome over time. Furthermore, the variation in presentation and disease among racial and ethnic groups amplifies the complexity of this cancer. An understanding of the clinical and molecular variability is important for effective treatment. Recent advances in molecular biology have better defined gastric cancer subtypes. We systematically review recent literature on the molecular classification of gastric adenocarcinoma and the associated management implications, with an emphasis on Hispanic and Native American populations.

Deep transfer learning methods for colon cancer classification in confocal laser microscopy images

PURPOSE

The gold standard for colorectal cancer metastases detection in the peritoneum is histological evaluation of a removed tissue sample. For feedback during interventions, real-time in vivo imaging with confocal laser microscopy has been proposed for differentiation of benign and malignant tissue by manual expert evaluation. Automatic image classification could improve the surgical workflow further by providing immediate feedback.

METHODS

We analyze the feasibility of classifying tissue from confocal laser microscopy in the colon and peritoneum. For this purpose, we adopt both classical and state-of-the-art convolutional neural networks to directly learn from the images. As the available dataset is small, we investigate several transfer learning strategies including partial freezing variants and full fine-tuning. We address the distinction of different tissue types, as well as benign and malignant tissue.

RESULTS

We present a thorough analysis of transfer learning strategies for colorectal cancer with confocal laser microscopy. In the peritoneum, metastases are classified with an AUC of 97.1, and in the colon the primarius is classified with an AUC of 73.1. In general, transfer learning substantially improves performance over training from scratch. We find that the optimal transfer learning strategy differs for models and classification tasks.

CONCLUSIONS

We demonstrate that convolutional neural networks and transfer learning can be used to identify cancer tissue with confocal laser microscopy. We show that there is no generally optimal transfer learning strategy and model as well as task-specific engineering is required. Given the high performance for the peritoneum, even with a small dataset, application for intraoperative decision support could be feasible.

A case of advanced gastric cancer achieved a pathological complete response by chemotherapy

BACKGROUND

Although chemotherapy is the first recommended treatment of unresectable gastric cancer, a pathological complete response is a rare event.

CASE PRESENTATION

A 58-year-old male was diagnosed as gastric cancer with a bulky tumor, lymphadenopathy, and suspicious peritoneal dissemination. The patient underwent chemotherapy with S-1 and cisplatin. After three courses of chemotherapy, a computed tomography showed dramatic improvements in gastric wall thickening, shrinkage of lymphadenopathy, and disappearance of disseminated peritoneal lesion. The patient underwent potentially curative resection by total gastrectomy with D2 lymph node dissection. Histological examination revealed the absence of malignant cells not only in the resected specimen but also in the harvested lymph nodes. At present, more than 7 years after the initial surgery, the patient is still alive without any recurrence.

CONCLUSIONS

We obtained a pathological complete response by chemotherapy with S-1 and cisplatin for advanced gastric cancer. Although a pathological complete response is a rare event, it would be associated with the long-term survival of patients with advanced gastric cancer.

The Yield of Staging Laparoscopy in Gastric Cancer is Affected by Racial and Ethnic Differences in Disease Presentation

BACKGROUND

Gastric cancer is a heterogeneous disease with variable presentation between racial and ethnic groups. Staging laparoscopy (SL) detects occult metastases not visible on cross-sectional imaging and therefore improves staging. It remains unclear how differences in race and ethnicity affect disease presentation and the yield of SL.

METHODS

We performed a retrospective review of a prospectively maintained database to identify patients with gastric cancer treated with curative intent at our institutions from 2008 to 2015.

RESULTS

Hispanic patients presented at an earlier mean age (55.5 ± 11.9 years) compared with Asian (59.8 ± 13.9 years), African American (61.0 ± 10.0 years), and white patients (61.7 ± 12.5 years; p = 0.046) and with more locally advanced disease (clinical stage T3/T4 or node positive; Hispanic 87%; African American 79%; white 68%, Asian 55%; p = 0.03). SL identified 42 patients (34%) with occult metastatic disease. Hispanics were more likely to have a positive SL (44%) than white patients (21%; p = 0.04). On univariate analysis, Hispanic ethnicity, clinical T3/T4, positive nodal disease, signet ring cells, and poor differentiation were predictors of a positive SL. On multivariable analysis, clinical T3/T4, signet ring cells, and poor differentiation independently predicted radiographically occult disease.

CONCLUSIONS

Hispanic patients presented with more locally advanced disease and were more likely to have occult disease found on SL compared with white patients. Laparoscopy should be used routinely as part of the pretreatment staging evaluation for patients with locally advanced disease as it alters the management in a significant proportion of patients.

Cytomorphological changes induced by intraperitoneal chemotherapy present important diagnostic pitfalls in peritoneal fluid cytology

OBJECTIVE

Intraperitoneal chemotherapy (IP ChT) is an emerging modality in the treatment of advanced gastric adenocarcinoma with peritoneal disease. Cytological evaluation of peritoneal fluid specimens from patients undergoing IP ChT is important in clinical management. However, direct intraperitoneal exposure to chemotherapeutic agents induces cytomorphological changes in benign constituents of peritoneal fluid, presenting particular challenges to accurate cytological interpretation. These morphological changes have not been well characterised in the literature. We systematically reviewed the cytomorphological features in immunocytochemically-confirmed positive and negative IP ChT peritoneal fluid samples to elucidate the degree of morphological overlap between malignant and reactive cells.

METHODS

We reviewed 39 peritoneal fluid samples of patients treated with IP ChT, and scored specific cytomorphological parameters of both benign and malignant cells with the aid of relevant immunocytochemical interrogation.

RESULTS

The present findings show a significant degree of morphological overlap between reactive and malignant cells. Abnormal, "exploding" mitotic figures, nuclear membrane irregularities, multi-nucleation and cytoplasmic vacuolation were commonly observed in negative fluid specimens. The most helpful feature that favoured malignant cells was the increased nuclear-to-cytoplasmic ratio. A background inflammatory milieu of eosinophils and/or neutrophils was seen in 45-58% of post IP ChT peritoneal fluid specimens. The presence of pseudoparakeratotic cells, a novel observation in post IP ChT fluid specimens is also described.

CONCLUSIONS

The extent of reactive cytomorphological anomalies arising from treatment with IP ChT poses unique diagnostic challenges and may prompt a malignant or 'atypical' diagnosis in benign reactive samples.

Detection value of free cancer cells in peritoneal washing in gastric cancer: a systematic review and meta-analysis

Intraperitoneal free cancer cells in gastric adenocarcinoma are associated with a poor outcome. However, the true prognostic value of intraperitoneal free cancer cells is still unclear, leading to a lack of consensus in the management of gastric cancer. The aim of the present study is to perform a systematic review and meta-analysis to analyze intraperitoneal free cancer cells-positive patients with regard to tumor oncologic stage, recurrence, grade of cellular differentiation, and survival rates and to analyze the clinical significance of intraperitoneal free cancer cells with regard to prognosis. Databases were searched up to January 2016 for prognostic factors associated with intraperitoneal free cancer cells, including oncologic stage, depth of neoplasm invasion, lymph nodal spread, differentiation grade of the tumor, and recurrence and survival rates. A total of 100 studies were identified. Meta-analysis revealed a clear association between intraperitoneal free cancer cells and a poor prognosis. intraperitoneal free cancer cells -positive patients had higher rates of nodal spread (risk difference: 0.29; p<0.01), serosal invasion (risk difference: 0.43; p<0.01), recurrence (after 60 months of follow-up, risk difference: 0.44; p<0.01), and mortality (after 60 months of follow-up, risk difference: 0.34; p<0.01). Intraperitoneal free cancer cells are associated with a poor outcome in gastric cancer. This surrogate biomarker should be used to guide therapy both prior to and after surgery.

A case report of curative distal gastrectomy for stage IV gastric cancer after chemoradiotherapy in a patient with a gastrojejunal gastric bypass

Background

Advanced gastric cancer in the lower third of the stomach often results in stricture of the gastric cavity and digestive symptoms. Gastrojejunostomy has been suggested to improve such symptoms, and the advent of new anticancer agents for gastric cancer has improved the response rate of the disease, which makes it possible to perform R0 gastrectomy in part of patients with stage IV gastric cancer. We experienced a rare case in which a patient with stage IV gastric cancer and cancerous pyloric stenosis was treated with R0 surgery after undergoing a gastrojejunal bypass procedure and multidisciplinary treatment. There have not been any previous reports about cases in which a previous gastrojejunostomy was utilized as a reconstruction route during distal gastrectomy in a patient with gastric cancer that had been treated with chemotherapy and/or CRT.

Case presentation

An 80-year-old female with advanced gastric cancer and pyloric stenosis was admitted to Kagoshima University Hospital. As peritoneal washing cytology produced a positive result, laparoscopic gastrojejunostomy (modified Devine procedure) was performed to improve food passage, and S-1 (100 mg/body, days 1–14) plus paclitaxel (120 mg/body, days 1 and 15) was administered. Although the tumor was temporarily reduced in size, an abdominal computed tomography scan obtained after four courses of chemotherapy showed progressive disease. Thus, chemoradiotherapy (56 Gy, S-1: 60 mg/body, CDDP: 5 mg/body, days 1–5) was indicated. Marked tumor shrinkage and negative peritoneal washing cytological results were achieved. Curative gastrectomy with D2 lymphadenectomy was performed. We carried out distal gastrectomy and lymph node dissection, and the gastrojejunostomy produced as a gastric bypass in the previous operation was preserved. The patient has not suffered a tumor relapse in 4 years since the surgery.

Conclusions

We surgeons increase a chance to perform R0 gastrectomy for stage IV gastric cancer following intensive chemotherapy and/or CRT. We should choose proper position of gastrojejunostomy in producing alimentary bypass for stage IV gastric cancer patients to facilitate curative surgery.

Recent advances in photodynamic diagnosis of gastric cancer using 5-aminolevulinic acid

Photodynamic diagnosis based on 5-aminolevulinic acid-induced protoporphyrin IX has been clinically applied in many fields based upon its evidenced efficacy and adequate safety. In order to establish a personalized medicine approach for treating gastric cancer patients, rapid intraoperative detection of malignant lesions has become important. Feasibility of photodynamic diagnosis using 5-aminolevulinic acid for gastric cancer patients has been investigated, especially for the detection of peritoneal dissemination and lymph node metastasis. This method enables intraoperative real-time fluorescence detection of peritoneal dissemination, exhibiting higher sensitivity than white light observation without histopathological examination. The method also enables detection of metastatic foci within excised lymph nodes, exhibiting a diagnostic accuracy comparable to that of a current molecular diagnostics technique. Although several complicating issues still need to be resolved, such as the effect of tissue autofluorescence and the insufficient depth penetration of excitation light, this simple and rapid method has the potential to become a useful diagnostic tool for gastric cancer, as well as urinary bladder cancer and glioma.

National Trends in Utilization of Endoscopic Ultrasound for Gastric Cancer: a SEER-Medicare Study

INTRODUCTION

Accurate preoperative staging is important for patients with gastric cancer. This study identifies the rate of utilization of endoscopic ultrasound (EUS) and its associated factors in Medicare patients with gastric adenocarcinoma.

METHODS

The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare claims database was queried from 1996 to 2009 for patients with gastric cancer who underwent gastric resection. Analysis with univariate, multivariate, and Cochran-Armitage trend tests were performed.

RESULTS

In 5826 patients with gastric cancer with an average age of 76.9 ± 6.62 years, 59.1% had regionalized spread of cancer. EUS utilization increased significantly during the study period from 2.6% to 22% (p < 0.0001). EUS patients were more likely to be male, white, married, have higher education and income quartiles, and live in large metropolitan areas compared to non-EUS patients (p < 0.0001). Even after controlling for confounding factors, patients who underwent EUS were more likely to have >15 lymph nodes examined (odds ratio (OR) 1.26, 95% confidence interval (CI) 1.04-1.53) and have the administration of both pre- and postoperative chemotherapy (OR 1.27, 95% CI 1.03-1.57).

CONCLUSION

EUS is currently under-utilized but increasing. Patients who underwent EUS (12.9%) were more likely to receive other NCCN-recommended care, including perioperative chemotherapy and adequate nodal retrieval.