Morphometric analysis of regional lymph nodes with and without metastasis from early gastric carcinoma

Lymph nodes metastasis of gastric cancer: Measurement with multidetector CT oblique multiplanar reformation-correlation with histopathologic results

The aim of this study was to retrospectively evaluate the ability of multidetector computed tomography (MDCT) oblique multiplanar reformation (MPR) for differentiating metastatic lymph nodes (LNs) in patients with gastric cancer.Seventy-nine patients with gastric cancer underwent preoperative computed tomography (CT). One-to-one correlation of LN was made between CT oblique multiplanar reformation and histopathologic slides. Long diameters, short diameters, and short-to-long axis ratios of LNs were evaluated to differentiate metastasis.Short diameters of nodes performed better for diagnosing metastasis than long diameters and short-to-long ratios. Sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve of short diameter were 57.8%, 74.7%, 68.2%, and 0.713, respectively. With different thresholds of short diameters of nodes (No. 8 group >6 mm and other groups >4 mm), total sensitivity, specificity, and accuracy can reach 57.2%, 79.0%, and 70.3%, respectively.MDCT oblique MPR images have certain reference value to distinguish metastasis of LNs in gastric cancer. The diagnostic power for LN metastasis of gastric cancer can be improved by using different threshold for No. 8 group LNs and other groups.

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.

Predicting lymph node status in early gastric cancer

Accurate prediction of lymph node (LN) status is of crucial importance for appropriate treatment planning in patients with early gastric cancer (EGC). However, there is no definitive consensus yet on which patient and/or tumor characteristics are associated with LN metastasis. A systematic search for studies investigating the relationship between patient and/or tumor characteristics and LN metastasis in EGC was performed in PubMed/MEDLINE. Patient and/or tumor characteristics associated with LN metastasis were identified by meta-analyzing results of individual studies. Forty-five studies were included. Variables significantly associated with LN metastasis in gastric cancer limited to the mucosa were: age younger than 57 years, tumor location in the middle part of the stomach, larger tumor size, macroscopically depressed tumor type, tumor ulcerations, undifferentiated tumors, diffuse tumor type according to the Lauren classification, lymphatic tumor invasion, tumors with a proliferating cell nuclear antigen (PCNA) labeling index of more than 25%, and matrix metalloproteinase-9-positive tumors. Variables significantly associated with LN metastasis in gastric cancer limited to the submucosa were: female sex, tumor location in the lower part of the stomach, larger tumor size, undifferentiated tumors, increasing depth of submucosal invasion, lymphatic tumor invasion, vascular tumor invasion, increased submucosal vascularity, tumors with a PCNA labeling index of more than 25%, tumors with a gastric mucin phenotype, and vascular endothelial growth factor-C-positive tumors. We identified several variables associated with LN metastasis in EGC. These variables should be included in future research, in order to assess which of these variables remain as significant predictors of LN metastasis.

EUS staging of upper GI malignancies: results of a prospective randomized trial

BACKGROUND

Electronic 270 degrees transverse-array EUS (TA-EUS) provides high-quality cross-sectional images but cannot guide FNA. Linear EUS (L-EUS) provides longitudinal images of malignancies and the ability to guide FNA.

OBJECTIVE

We conducted a prospective randomized comparison of TA-EUS and L-EUS for the staging of upper-GI (UGI) malignancies.

DESIGN

Forty-three patients underwent L-EUS immediately followed by TA-EUS (N = 27, 63%) or TA-EUS immediately followed by L-EUS (N = 16, 37%).

PATIENTS

Forty-three subjects (mean age, 64 years; 37 men) with an UGI malignancy (4 stomach and 38 esophageal) were evaluated with both TA-EUS and L-EUS.

INTERVENTIONS

Abnormal lymph nodes were sampled by FNA for cytology.

RESULTS

There was agreement on the T stage by linear and radial techniques in 38 of 43 subjects (88%). Twenty-seven of 43 patients (63%) had abnormal lymph nodes by linear or transverse-array imaging. L-EUS demonstrated 66 abnormal lymph nodes in 27 subjects (average of 2.4 nodes/subject). TA-EUS demonstrated 90 abnormal lymph nodes in 27 subjects (average of 3.3 nodes/subject, P = .009, compared with L-EUS). In 16 of the 27 subjects, an FNA was performed, which was positive in 13 cases (81%) and negative in 3 cases (10%) for malignancy.

CONCLUSIONS

TA-EUS and L-EUS provide similar results of T staging of UGI malignancies. However, the number of abnormal lymph nodes detected by TA-EUS was more than by L-EUS. These findings suggest that radial or transverse-array EUS imaging should be the primary method for staging of UGI malignancies.

Modern treatment of early gastric cancer: review of the Japanese experience

BACKGROUND

Recently, detections of early gastric cancer (EGC) have been increasing, and the treatment strategies for gastric cancer have been changing. To demonstrate recent clinical experience of EGC in Japan and to assess modern strategies for the treatment of EGC, we investigated the English-language literature of the past 10 years through computer searches.

METHODS

This article intends to provide gastric surgeons with recent Japanese experience of the treatment for EGC. In a search for modern treatments of EGC, we selected 100 papers published in well-known medical journals, and focused on the following items of EGC: (1) prognostic factors, (2) endoscopic treatment, (3) surgical procedures, and (4) Japanese guidelines.

RESULTS

The most important factor influencing the survival of patients with EGC is the status of lymph node metastasis. The incidence of lymph node metastasis is 1-3% for mucosal cancers and 11-20% for submucosal cancers. Endoscopic mucosal resection (EMR) is a technique for the treatment of EGC, and the recent indication includes the tumors confined to the mucosa up to 3 cm in size or those invading the superficial submucosa. Surgical procedures include conventional Billroth I gastrectomy, limited resections, and laparoscopic surgery. Laparoscopic wedge resection using the lesion-lifting method and laparoscopy-assisted distal gastrectomy provide less pain, faster recovery and shorter hospital stay. Guidelines for the treatment of gastric cancer proposed by the Japanese Gastric Cancer Association show that patients with mucosal cancer can be managed by EMR or distal gastrectomy, whereas patients with submucosal cancer are candidates for distal gastrectomy with lymph node dissection.

CONCLUSION

Although the prognosis of patients with EGC depends on the presence or absence of lymph node metastasis, most are successfully treated by modern endoscopic or surgical techniques. Laparoscopic surgery and limited resections will contribute to the better quality of life of patients with EGC.

Clinicopathological analysis of early gastric cancer with solitary lymph node metastasis

BACKGROUND

The sentinel node concept has not yet been established in gastric cancer.

METHODS

Fifty-four patients with early gastric cancer who had only one lymph node metastasis were regarded retrospectively as patients with a possible sentinel node metastasis, and the morphological features of these nodes were assessed. The level I nodes in seven patients with a possible skip metastasis at routine haematoxylin and eosin staining were re-examined using cytokeratin (CK) immunostaining.

RESULTS

The shape of the gastric cancer lesion could be examined in 53 of the patients; more than one-third (20 of 53) were microfocal type. Concerning the intranodal cancer foci, the marginal sinus type was found in 32 affected nodes, medullary sinus type in 14 and mixed type in seven. Forty-three per cent of suspected sentinel nodes were the largest in size among all nodes from the station. CK immunostaining of seven non-metastatic nodes with haematoxylin and eosin revealed that three were CK positive.

CONCLUSION

These findings suggest that possible sentinel nodes detected by conventional means may not always be primary portions of any metastasis. Adoption of sentinel node biopsy in gastric cancer must await the development of improved procedures for diagnosis during surgery.

Is there a role for nontraditional resection of early gastric cancer?

Current trends in the treatment of gastric cancer indicate the emergence of a more sophisticated approach, with tailored therapy applied to individual cases. Treatment includes a broader spectrum of therapeutic options (Fig. 3), including EMR, laparoscopic or laparoscopy-assisted surgery, modified radical surgery, and typical radical surgery with lymph node dissections. Precise characterization of the lesions, especially the depth of invasion in the gastric wall, its size, histology and whether there is ulceration, is the key to successful treatment of N0 mucosal cancer. Micrometastasis and metastasis at the molecular level are issues that require further investigation. Laparoscopic surgery may be more widely accepted. The limitations of nodal dissection based on the concept of a sentinel node should be carefully evaluated in future studies. [figure: see text] Many treatment options, ranging from minimally invasive surgery to D2 node dissection, are available to the surgical oncologist who is treating EGC. As more information is gathered, surgeons will be better able to select patients who are good candidates for minimal surgical procedures.