Predicting factors of unexpected peritoneal seeding in locally advanced gastric cancer: indications for staging laparoscopy

STAGING LAPAROSCOPY IS STILL A VALUABLE TOOL FOR OPTIMAL GASTRIC CANCER MANAGEMENT

BACKGROUND

Complete surgical resection is the main determining factor in the survival of advanced gastric cancer patients, but is not indicated in metastatic disease. The peritoneum is a common site of metastasis and preoperative imaging techniques still fail to detect it.

AIM

The aim of this study was to evaluate the role of staging laparoscopy in the staging of advanced gastric cancer patients in a Western tertiary cancer center.

METHODS

A total of 130 patients with gastric adenocarcinoma who underwent staging laparoscopy from 2009 to 2020 were evaluated from a prospective database. Clinicopathological characteristics were analyzed to identify factors associated with the presence of peritoneal metastasis and were also evaluated the accuracy and strength of agreement between computed tomography and staging laparoscopy in detecting peritoneal metastasis and the change in treatment strategy after the procedure.

RESULTS

The peritoneal metastasis was identified in 66 (50.76%) patients. The sensitivity, specificity, and accuracy of computed tomography in detecting peritoneal metastasis were 51.5, 87.5, and 69.2%, respectively. According to the Kappa coefficient, the concordance between staging laparoscopy and computed tomography was 38.8%. In multivariate analysis, ascites (p=0.001) and suspected peritoneal metastasis on computed tomography (p=0.007) were statistically correlated with peritoneal metastasis. In 40 (30.8%) patients, staging and treatment plans changed after staging laparoscopy (32 patients avoided unnecessary laparotomy, and 8 patients, who were previously considered stage IVb by computed tomography, were referred to surgical treatment).

CONCLUSION

The staging laparoscopy demonstrated an important role in the diagnosis of peritoneal metastasis, even with current advances in imaging techniques.

Risk prediction model of peritoneal seeding in advanced gastric cancer: A decision tool for diagnostic laparoscopy

BACKGROUND

Selective diagnostic laparoscopy in gastric cancer patients at high risk of peritoneal metastasis is essential for optimal treatment planning. In this study available clinicopathologic factors predictive of peritoneal seeding in advanced gastric cancer (AGC) were identified, and this information was translated into a clinically useful tool.

METHODS

Totally 2833 patients underwent surgery for AGC between 2003 and 2013. The study identified clinicopathologic factors associated with the risk of peritoneal seeding for constructing nomograms using a multivariate logistic regression model with backward elimination. A nomogram was constructed to generate a numerical value indicating risk. Accuracy was validated using bootstrapping and cross-validation.

RESULTS

The proportion of seeding positive was 12.7% in females and 9.6% in males. Of 2833 patients who underwent surgery for AGC, 300 (10.6%) were intraoperatively identified with peritoneal seeding. Multivariate analysis revealed the following factors associated with peritoneal seeding: high American Society of Anesthesiologists score, fibrinogen, Borrmann type 3 or 4 tumors, the involvement of the middle, anterior, and greater curvature, cT3 or cT4cN1 or cN2 or cN3, cM1, and the presence of ascites or peritoneal thickening or plaque or a nodule on the peritoneal wall on computed tomography. The bootstrap analysis revealed a robust concordance between mean and final parameter estimates. The area under the ROC curve for the final model was 0.856 (95% CI, 0.835-0.877), which implies good performance.

CONCLUSIONS

This nomogram provides effective risk estimates of peritoneal seeding from gastric cancer and can facilitate individualized decision-making regarding the selective use of diagnostic laparoscopy.

Risk factors associated with peritoneal carcinomatosis of gastric cancer in staging laparoscopy: A systematic review and meta-analysis

Background

The optimal indications of staging laparoscopy in gastric cancer to detect peritoneal carcinomatosis are still controversial. We performed this systematic review and meta-analysis to quantify the relevance of the preoperative factors with peritoneal carcinomatosis to explore the indications of staging laparoscopy.

Materials and methods

Systematic searches were conducted using Medline, Embase, and the Cochrane Library in December 2021. On the basis of calculating the odds ratio (OR) of each factor, we quantified the association between the risk factors and peritoneal carcinomatosis such as clinical T/N stage, Borrmann type, and tumor markers, using meta-analysis with a random-effects model.

Results

A total of 21 case-control studies and one cohort study were obtained. T stage, N stage, and differentiation degree were most widely studied, with OR values of 2.96 (95% CI: 1.87–4.69), 1.22 (95% CI: 0.86–1.73), and 1.91 (95% CI: 1.42–2.56), respectively. Among all the factors, elevated CA125 (OR = 19.45, 95% CI: 4.71–80.30), Borrmann type IV (OR = 7.68, 95% CI: 3.62–16.27), and large tumor diameter (OR = 5.12, 95% CI: 2.55–10.31) had the highest OR. In particular, CA125 had the best predictability for peritoneal carcinomatosis but was only mentioned by three articles.

Conclusions

There was a cognitive gap between the awareness and importance of risk factors for peritoneal carcinomatosis. In addition to T4 stage, patients with factors with high OR, such as Borrmann type IV, large tumor diameter, and elevated CA125, should undergo staging laparoscopy.

Predicting peritoneal carcinomatosis of gastric cancer: A simple model to exempt low-risk patients from unnecessary staging laparoscopy

Background

Peritoneal carcinomatosis (PC) of gastric cancer indicates a poor outcome and is mainly diagnosed by staging laparoscopy (SL). This study was designed to develop a risk stratification model based on the number of risk factors to exempt low-risk patients from unnecessary SL.

Methods

This was a retrospective cohort study based on a single institution between January 2015 and December 2019. SL is indicated for patients of advanced locoregional stage, and clinicopathologic characteristics of 535 consecutive patients were included. PC-associated variables were identified by logistic regression analysis. A risk stratification model based on the number of risk factors was constructed, and we defined its predictive value with a receiver operating characteristic (ROC) curve and negative predictive value.

Results

In total, 15.9% of included patients were found to have PC during SL. Borrmann type IV, elevated CA125, and tumour diameter ≥5 cm were independent risk factors of PC. These three factors combined with cT4 were selected as predictive factors, and the number of predictive variables was significantly related to the possibility of PC (2.0%, 12.8%, 20.0%, 54.2%, and 100%, respectively). When the cutoff value is more than one predictive factor, the negative predictive value is 98.0%, with an area under the curve of 0.780. This model could exempt 29.8% of unnecessary SL compared to the indication of the current NCCN guideline.

Conclusions

We constructed a simple model to predict the probability of PC using the number of predictive factors. It is recommended that patients without any of these factors should be exempt from SL.

Novel CT based clinical nomogram comparable to radiomics model for identification of occult peritoneal metastasis in advanced gastric cancer

BACKGROUND

Occult peritoneal metastasis (OPM) in advanced gastric cancer (AGC) patients remains a major diagnostic challenge. The aim of this study was to develop novel predictive models for identification of OPM in AGCs.

METHOD

A total of 810 patients with primary AGCs from two hospitals were retrospectively selected and divided into training (n = 393), internal validation (n = 215) and external validation cohorts (n = 202). CT based machine learning models were built and tested to predict the OPM status in AGCs., which are 1) Radiomic signatures: using venous CT imaging features, 2) Clinical models: integrating tumor location, differentiation and extent of serosal exposure, and 3) Radiomics models: combining of radiomic signature, tumor location and tumor differentiation.

RESULT

Total incidence of OPM was 8.27% (67/810). Clinical models yielded comparable classification accuracy with the corresponding radiomics models with similar AUCs (0.902-0.969 vs. 0.896-0.975) while the radiomic signatures showed relatively low AUCs of 0.863-0.976. In the case where the specificity is higher than 90%, the overall sensitivity of clinical model and radiomics model for OPM positive cases was 76.1% (51/67) and 82.1% (55/67). A nomogram based on the logistic clinical model was drawn to facilitate the usage and verification of the clinical model.

CONCLUSION

Both the novel CT based clinical nomogram and radiomics model provide promising method to yield high accuracy in identification of OPM in AGC patients.

Comparison of clinical-computed tomography model with 2D and 3D radiomics models to predict occult peritoneal metastases in advanced gastric cancer

PURPOSE

To compare the ability of a clinical-computed tomography (CT) model vs. 2D and 3D radiomics models for predicting occult peritoneal metastasis (PM) in patients with advanced gastric cancer (AGC).

METHODS

In this retrospective study, we included 49 patients with occult PM and 49 control patients (without PM) who underwent preoperative CT and subsequent surgery between January 2016 and December 2018. Clinical information and CT semantic features were collected, and CT radiomics features were extracted. A predictive clinical-CT model was created using multivariate logistic regression. The least absolute shrinkage and selection operator algorithm and logistic regression were used for constructing 2D and 3D radiomics models. These models were validated with an external cohort (n = 30). Receiver operating characteristics curve with area under the curve (AUC), sensitivity, and specificity were used to evaluate predictive performance.

RESULTS

Tumor size, mild ascites, and serum CA125 were independent factors predictive of occult PM. The clinical-CT model of these independent factors showed better diagnostic performance than 2D and 3D radiomics models. In the external validation cohort, the AUCs of different models were as follows-clinical-CT model: 0.853 (sensitivity, 66.7%; specificity, 93.3%); 2D radiomics model: 0.622 (sensitivity, 80.0%; specificity, 46.7%); and 3D radiomics model: 0.676 (sensitivity, 60.0%; specificity, 86.0%). The clinical-CT model nomogram showed good clinical predictive efficiency to assess occult PM.

CONCLUSION

The clinical-CT model was better than the radiomics models in predicting occult PM in AGC.

Prognosis prediction model for a special entity of gastric cancer, linitis plastica

Background

Gastric linitis plastica (GLP) is characteristic by its poor prognosis and highly aggressive characteristics compared with other types of gastric cancer (GC). However, the guidelines have not yet been distinguished between GLP and non-GLP.

Methods

A total of 342 eligible patients with GLP identified in the Surveillance, Epidemiology, and End Results (SEER) dataset were randomly divided into training set (n=298) and validation set (n=153). A nomogram would be developed with the constructed predicting model based on the training cohort's data, and the validation cohort would be used to validate the model. Principal component analysis (PCA) was used to evaluate the differences between groups. Cox regression and LASSO (least absolute shrinkage and selection operator) were used to construct the models. Calibration curve, time-dependent receiver operating characteristic (ROC) curve, concordance index (C-index) and decision curve analysis (DCA) were used to evaluate the predicting performance. Restricted mean survival time (RMST) was used to analyze the curative effect of adjuvant therapy.

Results

For patients in training cohort, univariable and multivariable Cox analyses showed that age, examined lymph nodes (LN.E), positive lymph nodes (LN.P), lesion size, combined resection, and radiotherapy are independent prognostic factors for overall survival (OS), while chemotherapy can not meet the proportional hazards (PHs) assumption; age, race, lesion size, LN.E, LN.P, combined resection and marital status are independent prognostic factors for cancer-specific survival (CSS). The C-index of the nomogram was 0.678 [95% confidence interval (CI), 0.660-0.696] and 0.673 (95% CI, 0.630-0.716) in the training and validation cohort, respectively. Meanwhile, the C-index of the CSS nomogram was 0.671 (95% CI, 0.653-0.699) and 0.650 (95% CI, 0.601-0.691) in the training and validation cohort for CSS, respectively. Furthermore, the nomogram was well calibrated with satisfactory consistency. RMST analysis further determined that chemotherapy and radiotherapy might be beneficial for improving 1- and 3-year OS and CSS, but not the 5-year CSS.

Conclusions

We developed nomograms to help predict individualized prognosis for GLP patients. The new model might help guide treatment strategies for patients with GLP.

An Intraoperative Model for Predicting Survival and Deciding Therapeutic Schedules: A Comprehensive Analysis of Peritoneal Metastasis in Patients With Advanced Gastric Cancer

Background and Objective: No specialized prognostic model for patients with gastric cancer with peritoneal metastasis (GCPM) exists for intraoperative clinical decision making. This study aims to establish a new prognostic model to provide individual treatment decisions for patients with GCPM.

Method: This retrospective analysis included 324 patients with GCPM diagnosed pathologically by laparoscopy from January 2007 to January 2018 who were randomly assigned to different sets (227 in the training set and 97 in the internal validation set). A nomogram was established from preoperative and intraoperative variables determined by a Cox model. The predictive ability and clinical applicability of the PM nomogram (PMN) were compared with the 15th Japanese Classification of Gastric Carcinoma (JCGC) Staging Guidelines for PM (P1abc). Additional external validation was performed using a dataset (n = 39) from the First Affiliated Hospital of University of Science and Technology of China.

Results: The median survival time was 8 (range, 1–90) months. In the training set, each PMN substage had significantly different survival curves (P < 0.001), and the PMN was superior to the P1abc based on the results of time-dependent receiver operating characteristic curve, C-index, Akaike information criterion and likelihood ratio chi-square analyses. In the internal and external validation sets, the PMN was also better than the P1abc in terms of its predictive ability. Of the PMN1 patients, those undergoing palliative resection had better overall survival (OS) than those undergoing exploratory surgery (P < 0.05). Among the patients undergoing exploratory surgery, those who received chemotherapy exhibited better OS than those who did not (P < 0.05). Among the patients who received palliative resection, only PMN1 patients exhibited better OS following chemotherapy (P < 0.05).

Conclusion: We developed and validated a simple, specific PM model for patients with GCPM that can predict prognosis well and guide treatment decisions.

Radiologic serosal invasion sign as a new criterion of T4a gastric cancer on computed tomography: diagnostic performance and prognostic significance in patients with advanced gastric cancer

PURPOSE

To investigate the diagnostic performance and prognostic significance of a new criterion for radiologic T4a staging on computed tomography (CT) in patients with advanced gastric cancer (AGC).

METHODS

Between January 2010 and April 2019, 101 patients with pathologically confirmed gastric cancer were collected. Among them, 53 patients with pathologic T3 and T4a cancers were included in this study. Three reviewers assessed preoperative CT scans for radiologic T staging in two sessions, independently and in consensus at a 2-week interval, while blinded about the pathologic T stage. The radiologic serosal invasion sign was defined as a nodular extension from the outer gastric wall reaching beyond the perigastric vascular plane and adopted as a new CT criterion for T4a cancer. We evaluated the diagnostic performance, interobserver agreement, and prognostic significance of this sign for the postoperative recurrence.

RESULTS

There were 46 pathologic T3 cancers (86.7%) and seven pathologic T4a cancers (13.2%). The diagnostic performance of the radiologic serosal invasion sign in the differentiation between T3 and T4a cancers was as follows: sensitivity, 91.3%; specificity, 71.43%; and accuracy, 88.68% for R1 and sensitivity, 78.26%; specificity, 85.71%; and accuracy, 79.25% for R2. The k-value was 0.64. Among the clinical and pathologic variables, radiologic T4a sign [hazard ratio (HR): 7.96; 95% confidence interval (CI) 2.36-26.86, p = 0.001], pathologic T4a (HR 9.82, 95% CI 2.35-40.95, p = 0.002), tumor size (HR 1.18, 95% CI 1.02-1.35, p = 0.026), and lymphovascular invasion (HR 6.39, 95% CI 1.42-28.75, p = 0.015) were the significant factors for postoperative recurrence.

CONCLUSIONS

Radiologic serosal invasion sign is reliable as a new CT criterion for T4a cancer staging in patients with advanced gastric cancer, demonstrating 80% to 88% accuracy. Radiologic serosal invasion sign can also serve as a prognostic factor for postoperative recurrence as well as pathologic T4a stage.

Gastric cancer: development and validation of a CT-based model to predict peritoneal metastasis

BACKGROUND

The sensitivity of computed tomography (CT) for the detection of peritoneal metastasis (PM) of advanced gastric cancer (AGC) is relatively low.

PURPOSE

To develop a predictive model to improve the sensitivity of PM detection and to externally validate this model.

MATERIAL AND METHODS

We analyzed data from 78 patients with PM, who had undergone preoperative CT and subsequent surgery between January 2012 and December 2014, and 101 controls to form a derivation set, retrospectively. The following CT findings were evaluated: tumor size; Bormann type 4; enlarged lymph node; indirect findings of PM (peritoneal thickening, fat stranding, plaques or nodules on the peritoneum, and ascites); and definitive findings of PM (omental cake and rectal shelf). A predictive model was created using multivariate logistic regression. Receiver operating characteristic (ROC) analyses were performed to assess the diagnostic performance of the model. The accuracy was externally validated at other hospitals on 31 patients with PM and 48 patients without PM.

RESULTS

Tumor size >5.2 cm, Bormann type 4, enlarged lymph node, peritoneal plaques or nodules, and ascites were independently associated with PM. It was able to predict PM with a higher area under the ROC curve (AUC) and sensitivity than definitive findings of PM (AUC 0.903 vs. 0.647, sensitivity 92.3% vs. 38.3%). External validation confirmed the predictive power with good inter-observer agreement.

CONCLUSION

The CT-driven model shows higher AUC and sensitivity for prediction of PM and may help decision-making with the aim of improving care for patients with AGC.

Development and validation of an individualized nomogram to identify occult peritoneal metastasis in patients with advanced gastric cancer

Background

Occult peritoneal metastasis (PM) in advanced gastric cancer (AGC) patients is highly possible to be missed on computed tomography (CT) images. Patients with occult PMs are subject to late detection or even improper surgical treatment. We therefore aimed to develop a radiomic nomogram to preoperatively identify occult PMs in AGC patients.

Patients and methods

A total of 554 AGC patients from 4 centers were divided into 1 training, 1 internal validation, and 2 external validation cohorts. All patients’ PM status was firstly diagnosed as negative by CT, but later confirmed by laparoscopy (PM-positive n = 122, PM-negative n = 432). Radiomic signatures reflecting phenotypes of the primary tumor (RS1) and peritoneum region (RS2) were built as predictors of PM from 266 quantitative image features. Individualized nomograms of PM status incorporating RS1, RS2, or clinical factors were developed and evaluated regarding prediction ability.

Results

RS1, RS2, and Lauren type were significant predictors of occult PM (all P < 0.05). A nomogram of these three factors demonstrated better diagnostic accuracy than the model with RS1, RS2, or clinical factors alone (all net reclassification improvement P < 0.05). The area under curve yielded was 0.958 [95% confidence interval (CI) 0.923–0.993], 0.941 (95% CI 0.904–0.977), 0.928 (95% CI 0.886–0.971), and 0.920 (95% CI 0.862–0.978) for the training, internal, and two external validation cohorts, respectively. Stratification analysis showed that this nomogram had potential generalization ability.

Conclusion

CT phenotypes of both primary tumor and nearby peritoneum are significantly associated with occult PM status. A nomogram of these CT phenotypes and Lauren type has an excellent prediction ability of occult PM, and may have significant clinical implications on early detection of occult PM for AGC.

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.

Clinical Utility of Staging Laparoscopy for Advanced Obstructing Rectal Adenocarcinoma: Emerging Tool

The multimodal treatment for advanced rectal adenocarcinoma mandates accurate preoperative staging with contrast-enhanced computed tomography (CECT) of the thorax, abdomen, and pelvis, and magnetic resonance imaging (MRI) of the pelvis. Unlike gastric cancer, the role of staging laparoscopy (SL) in advanced colorectal cancer has not been evaluated. This study aims to evaluate the clinical value of SL in treatment decision-making for advanced rectal cancer (RC) with near or complete obstructing tumors. Observational review of colorectal database at Tata Memorial Hospital from January 2013 to December 2016 identified 562 patients diagnosed and treated for advanced RC. Of the 562 cases, 48.7% (274) were clinically and radiologically diagnosed of near or complete obstructing advanced RC. Medical records of 34% (94/274) who underwent SL with diversion stoma (DS) were analyzed. In the absence of ascites, extensive peritoneal deposits, and unresectable liver metastases on SL, a curative treatment was offered, which entailed neoadjuvant chemoradiation (NACTRT), whereas the cohort of patients with extensive peritoneal disease received palliative therapy. Of the 94 patients with advanced RC, conventional imaging studies staged 73.5% (69/94) cohort as non-metastatic locally advanced and 26.5% (25/94) had potentially resectable metastatic RC. Pre-therapeutic SL upstaged the disease by 26% (18/69) and 8% (2/25) in locally advanced and potentially resectable metastatic RC cohorts, respectively. Treatment decision changed in 21.2% (20/94) of the patients, and midline laparotomy was thus avoided. In our observational study, SL was found to be a safe and effective staging modality in RC; it detected occult peritoneal disease and prevented midline laparotomy in 21.2% of the cohort, which was of value to determine treatment strategy in patients with advanced RC before initiating NACTRT. SL and laparoscopic-assisted de-functioning stoma were associated with minimal morbidity and led to early initiation of NACTRT.

Cross-Sectional Location of Gastric Cancer Affects the Long-Term Survival of Patients as Tumor Invasion Deepens

BACKGROUND

The prognosis of gastric cancer is generally determined by tumor depth and lymph node metastasis, while the effect of cross-sectional tumor location on prognosis remains unclear.

METHODS

This study recruited patients who had been diagnosed with gastric cancer and who underwent gastrectomy from 1989 to 2012. The cross-sectional locations of the gastric cancers were classified into four regions: the lesser (LC) and greater curvatures (GC), and anterior (AW) and posterior walls (PW).

RESULTS

Overall, 4820 patients were enrolled in this study. The most common site of gastric cancer among the four cross-sectional locations was the LC (46.4%), while the proportions of PW (19.9%), AW (18.4%), and GC (15.4%) were similar. Overall survival differed statistically (p = 0.013) according to the cross-sectional location, and the 5-year overall survival of those with tumors with a GC location was significantly worse (p = 0.003) than for the other three locations. In subgroup multivariate analysis, GC location was an independent prognostic indicator for a worse clinical outcome at T stage 3-4b (hazard ratio 1.365, 95% confidence interval 1.150-1.620, p < 0.001). In addition, a GC gastric cancer had a higher recurrence rate in terms of peritoneal seeding compared with other locations.

CONCLUSIONS

The cross-sectional location of gastric cancer is associated with long-term survival. A GC location predicts a worse prognosis, especially in gastric cancer patients with deeper T stages.

Yield of Staging Laparoscopy for Incurable Factors in Chinese Patients with Advanced Gastric Cancer

BACKGROUND

Although the role of staging laparoscopy (SL) in detecting radiologically occult M1 disease has been widely recognized, it is seldom used in China and its clinical value based on Chinese population has been rarely reported. The aim of this study is to identify the yield of SL for Chinese patients with advanced gastric cancer (AGC) and determine the proportions of patients in whom treatment plan is altered.

MATERIALS AND METHODS

The clinical data were retrospectively collected from 879 AGC patients who underwent SL without any definite signs of disseminated disease on imaging examination. The primary outcomes were the proportions of patients whose laparoscopy identified incurable factors (including M1 diseases and unresectable T4b diseases), and who had their treatment plan altered.

RESULTS

SL revealed incurable factors in 130 (14.8%) patients, including macroscopic peritoneal metastasis (n = 92), positive peritoneal cytology (n = 10), liver metastasis (n = 12), para-aortic lymph node metastasis (n = 1), and unresectable T4b tumor (n = 18). After SL, treatment plans were altered in 123 (14.0%) patients, among which 82 (63.1%) patients were not offered any further procedure and referred for chemotherapy. Among 749 M0 patients who immediately proceeded to radical gastrectomy after SL, new incurable factors were found at subsequent operations in 21 (2.8%) patients. Multivariate analysis showed that tumor size ≥8 cm, Borrmann type III and IV, and tumor invasion of T4a and T4b in preoperative imaging examination were the predictive factors for peritoneal metastasis.

CONCLUSIONS

SL detects additional incurable factors in Chinese AGC patients with potentially resectable disease and optimizes their treatments. A systematic and painstaking inspection of the whole abdominal cavity, including routine entry into the bursa omentalis, is necessary for improving the yield of SL.

Impact of the Cross-Sectional Location of Multidetector Computed Tomography Scans on Prediction of Serosal Exposure in Patients with Advanced Gastric Cancer

BACKGROUND

The extent of serosal exposure varies depending on the cross-section of the stomach that is viewed, affected by the visceral peritoneum of the omentum. Although multidetector computed tomography (MDCT) is the most useful method to predict serosal exposure, the MDCT criteria for such exposure by cross-sectional location remain to be established.

METHODS

The MDCT of gastric cancer patients who underwent surgery, and for whom pathological reports were available, were reviewed by radiologists. The MDCT criteria for invasion depth were divided into five grades: (1) smooth margin; (2) undulating margin; (3) streaky margin within vessels; (4) nodular margin within perigastric vessels; and (5) streaky or nodular margin over the perigastric vessels. The five grades were compared in terms of pathological tumor depth by curvature and wall group.

RESULTS

A total of 125 patients of stage ≥ T2 were enrolled. The five MDCT grades correlated with tumor depth (P < 0.001). Exposed serosal lesions of grade 3 (P = 0.031) and 5 (P = 0.030) constituted significantly the largest proportion of wall and curvature cancers, respectively. The accuracy of MDCT in terms of T staging using the five grades was calculated by cross-sectional location. The highest accuracies were associated with curvature- and wall-located tumors (55.1 and 64.3%, respectively) when serosal exposure was graded 5 and 3, respectively. The highest overall accuracy for T staging was 59.2% when the various MDCT criteria were applied by reference to the cross-sectional location.

CONCLUSIONS

The MDCT criteria for serosal exposure vary by the cross-sectional location of the gastric cancer.

Effectiveness of laparoscopic stomach-partitioning gastrojejunostomy for patients with gastric outlet obstruction caused by advanced gastric cancer

BACKGROUND

Distal advanced gastric cancer (AGC) occasionally causes gastric outlet obstruction (GOO). We developed a laparoscopic stomach-partitioning gastrojejunostomy (LSPGJ) to restore the ability of food intake.

METHODS

This was a retrospective study performed at a single institution. Of consecutive 78 patients with GOO caused by AGC between 2006 and 2012, 43 patients who underwent LSPGJ were enrolled. The procedure was performed in an antiperistaltic Billroth II fashion, and the afferent loop was elevated and fixed along the staple line of the proximal partitioned stomach. Then, patients for whom R0 resection was planned received chemotherapy prior to laparoscopic gastrectomy. The primary end point was food intake at the time of discharge, which was evaluated using the GOO scoring system (GOOSS). Short- and long-term outcomes were assessed as secondary end points. Overall survival was estimated and compared between the groups who received neoadjuvant chemotherapy followed by surgery (NAC group), definitive chemotherapy followed by curative resection (Conversion group), and best supportive care (BSC group).

RESULTS

The median operative time was 92 min, blood loss did not exceed 30 g in any patient, and postoperative complications (Clavien-Dindo grade ≥2) were only seen in four patients (9.3 %). The median time to food intake was 3 days, and GOOSS scores were significantly improved in 41 patients (95.3 %). Chemotherapy was administered to 38 patients (88.4 %), of whom 11 later underwent radical resection, and 4 of 11 patients underwent conversion surgery following definitive chemotherapy. Median survival times were significantly superior in the NAC (n = 7; 46.8 months) and Conversion (n = 4; 35.9 months) groups than in the BSC group (n = 26; 12.2 months); however, the difference was not significant between the Conversion and NAC groups.

CONCLUSIONS

LSPGJ is a feasible and safe minimally invasive induction surgery for patients with GOO from surgical and oncological perspectives.

Limited significance of curative surgery in Borrmann type IV gastric cancer

Borrmann type IV advanced gastric cancer has a poor prognosis. Although surgical resection remains the only hope for a cure, the role of curative surgery is questionable in this type of cancer. This study defined the role of curative surgery in the prognosis of type IV gastric cancer. We analyzed 168 patients with Borrmann type IV undergoing surgery at Seoul St. Mary's Hospital from 1989 to 2010. We categorized the patients into curative (R0) and non-curative (R1, R2, and non-resection) groups. The curative and non-curative groups comprised 88 and 80 patients, respectively. The preoperative predictive value of Borrmann type IV was 50.5, and 8.9 % of the patients had microscopic resection margin involvement. The 3- to 5-year overall survival (OS) of patients in the curative group was significantly higher than that of in the non-curative group (p < 0.001). However, in a multivariate analysis, curability was not a significant predictor of survival (p = 0.187). In the curative group, the most frequent recurrence site was the peritoneum (85.7 %). Most recurrences occurred within 2 years. The role of surgery for Borrmann type IV is quite limited. Such cases have a poor prognosis even after curative surgery. In addition, microscopic resection margin involvement is frequent in type IV cancer because it is difficult to diagnose preoperatively. Therefore, multimodal diagnostic tools and treatment strategies should be developed for Borrmann type IV 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.

At which stage of gastric cancer progression do levels of carcinoembryonic antigen and carbohydrate antigen 19-9 increase? Application in advanced gastric cancer treatment

Purpose

Since there are no proven tumor markers that reflect the course of gastric cancer, carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are commonly used alternatives. However, the degree of progression that corresponds to an increase in these markers, and the values of these markers at different cancer stages, remains unclear.

Materials and Methods

This study enrolled 1,733 gastric cancer patients who underwent surgery and whose pre-operative CEA and CA19-9 levels were known. Survival curves and mean values of the two markers were compared according to the degree of cancer progression: serosa-unexposed (SU), serosa-exposed (SE), direct invasion (DI), localized seeding (P1), and extensive seeding (P2).

Results

The 5-year overall survival rates at each stage differed significantly, except between DI and P1 patients (17.1% vs. 10.5%, P=0.344). The mean CEA values in SU, SE, DI, P1, and P2 patients were 5.80, 5.48, 13.36, 8.06, and 22.82, respectively. The CA19-9 values for these patients were 49.40, 38.97, 101.67, 73.77, and 98.57, respectively. The increase in CEA in P2 patients was statistically significant (P=0.002), and the increases in CA19-9 in DI and P2 patients were significant (P=0.025, 0.007, respectively). There was a fair correlation between the two markers in P2 patients (r=0.494, P<0.001).

Conclusions

CA19-9 can be used to assess DI of gastric cancer into adjacent organs. Both markers are useful for predicting the presence of extensive peritoneal seeding.

State-of-the-art preoperative staging of gastric cancer by MDCT and magnetic resonance imaging

Gastric cancer is one of the most common and fatal cancers. The importance of accurate staging for gastric cancer has become more critical due to the recent introduction of less invasive treatment options, such as endoscopic mucosal resection or laparoscopic surgery. The tumor-node-metastasis staging system is the generally accepted staging system for predicting the prognosis of patients with gastric cancer. Multidetector row computed tomography (MDCT) is a widely accepted imaging modality for the preoperative staging of gastric cancer that can simultaneously assess locoregional staging, including the gastric mass, regional lymph nodes, and distant metastasis. The diagnostic performance of MDCT for T- and N-staging has been improved by the technical development of isotropic imaging and 3D reformation. Although magnetic resonance imaging (MRI) was not previously used to evaluate gastric cancer due to the modality’s limitations, the development of high-speed sequences has made MRI a feasible tool for the staging of gastric cancer.

Rt-PCR increases detection of submicroscopic peritoneal metastases in gastric cancer and has prognostic significance

BACKGROUND

Positive peritoneal cytology confers the same prognosis as clinical stage IV disease in gastric cancer. Conventional cytology examination, however, has low sensitivity. We hypothesize that real-time polymerase chain reaction (RT-PCR) may have increased sensitivity and provide more accurate staging information.

METHODS

From February 2007 to April 2009, peritoneal lavage samples were collected prospectively from 156 patients with biopsy-proven gastric cancer undergoing staging laparoscopy. These washings were analyzed by both Papanicolaou staining and RT-PCR for the tumor marker carcinoembryonic antigen (CEA).

RESULTS

Visible peritoneal disease was seen at laparoscopy in 38 patients (LAP+, 24%). Cytology was positive (CYT+) in 23 patients, while RT-PCR was positive (PCR+) in 30. The sensitivity of CYT for the detection of visible disease was 61% compared to 79% for PCR (P = 0.02). No visible peritoneal disease was seen at laparoscopy (LAP-) in 118 (76%) patients. Eight (7%) were CYT+, while 28 (24%) were PCR+. Predictors of PCR positivity included advanced-stage disease (T3-4 vs. T1-2 tumors) and poor pathologic features such as vascular or perineural invasion. Long-term follow-up demonstrated a worse survival of LAP-CYT-PCR+ (P = 0.0003) and LAP-CYT+PCR+ (P = 0.0004) compared to LAP-CYT-PCR- patients. There was no significant difference in survival between CYT-PCR+ and CYT+PCR+ patients. PCR positivity also predicted a higher likelihood of disease recurrence after resection. An R0 resection was performed in 85 LAP- patients (54%): only 1 (1%) was CYT+, while 13 (15%) were PCR+. Of this group, PCR+ demonstrated a worse survival than PCR- patients (P = 0.02). Further analysis showed that, in R0 resection, stage III/IV, CYT- subgroup, PCR+ was associated with a trend towards worse survival (P = 0.09) compared to PCR- patients.

CONCLUSION

RT-PCR for CEA increases the detection of subclinical peritoneal disease and is more sensitive than cytology. Predictors of positive PCR included advanced-stage disease, vascular invasion, and perineural invasion. PCR positivity was associated with increased disease recurrence and decreased survival. Further follow-up is required to determine if PCR positivity alone is an independent predictor of poor survival in gastric cancer.

The role of laparoscopic surgery in gastric cancer

The laparoscopic surgery in gastric cancer is applied with increasing frequency nowadays; noticeable reports come mainly from Korea and Japan with satisfactory results. This review presents briefly the issue by evaluating its role. A PubMed search of relevant articles published up to 2010 was performed to identify current information. Most data come from Far East, where gastric cancer occurs more often, and the proportion of early gastric cancer is high. Laparoscopic approach includes both the diagnostic laparoscopy and laparoscopic resection. Laparoscopic gastrectomy has currently limited application for gastric cancer in the West; it is not widely accepted and raises important considerations necessitating the planning of multicentre randomised control trials based mainly on the long-term results.

Recent advances in preoperative staging of gastric cancer

A more differentiated therapy regimen for gastric carcinoma requires more precise preoperative staging. In patients with early gastric cancer (EGC), especially in cases with carcinoma confined to mucosa, endoscopic resection (ER) is usually performed to avoid unnecessary surgical procedures. To achieve R0 resection for locally advanced gastric cancer (AGC), neoadjuvant treatments have been investigated. Clinical staging of gastric cancer has been greatly improved by advances in imaging techniques, such as endoscopic ultrasonography (EUS), transabdominal ultrasonography (TAUS), multi-slice spiral CT (MSCT), magnetic resonance imaging (MRI), positron emission tomography (PET), combined PET-CT scans, and laparoscopic staging. This paper aims to summarize the recent advances in preoperative staging of gastric cancer.