Single skip metastasis in sentinel lymph node: In an early gastric cancer

Biomimetic nanoplatform with selectively positioned indocyanine green for accurate sentinel lymph node imaging

The status of draining lymph nodes (LNs) is critical for determining the treatment and prognosis of cancer that spreads through the lymphatic system. Indocyanine green (ICG) fluorescence imaging has been widely used in sentinel LN (SLN) biopsy technology and has shown favorable effects. However, this too has its own limitations, such as fluorescence instability and diffusion imaging. In this study, we developed macrophage cell membrane-camouflaged ICG-loaded biomimetic nanoparticles (M@F127-ICG) for accurate SLN imaging. ICG selectively positioned at the hydrophobic-hydrophilic interfaces of pluronic F127 micelles protected itself from quenching in aqueous solution, thereby maintaining fluorescence stability and improving fluorescence intensity. In addition, to further improve the aggregation in SLN, the micellar surface was coated with a layer of biomimetic macrophage cell membrane to target LN-resident macrophages. In vivo fluorescence imaging demonstrated that M@F127-ICG significantly enhanced the fluorescence signal and improved the imaging efficiency of SLN. Thus, selectively positioning ICG in the biomimetic nanoplatform enhanced the fluorescence intensity and stability, providing a novel tracer for timely and accurate SLN imaging.

Sentinel lymph node detection for gastric cancer: Promise or pitfall?

At present, optimal surgery for gastric cancer is still under debate, especially the extent of lymph node dissection. Gastrectomy with D1/D2 lymphadenectomy is standard treatment for resectable advanced gastric cancer. However, in early gastric cancer without lymph node metastasis, gastrectomy with D1/D2 lymphadenectomy may not be unnecessary, which could increases morbidity and mortality and reduces the quality of life (QOL). Therefore, the concept of sentinel lymph node could be applied in gastric cancer. But due to the complexity of gastric lymphatic drainage, there are still many issues under debate, such as suitable tracers, the method of mapping and collecting and the oncologic safety of sentinel node navigation surgery (SNNS). In addition, skip metastasis and unreliability of intraoperative pathological diagnosis are two main reasons for false negative cases. In this review, we summarize the current status and controversy of sentinel lymph node detection in gastric cancer, attempting to help with practical application. Further, we hold opinion that we should be cautious about performing sentinel lymph node detection in gastric cancer before an accurate and effective method occurs.

Sentinel node biospy using intravital blue dye: An useful technique for identification of skip metastases in gastric cancer

As the lymph node status remains the main prognostic factor of gastric cancer (GC), several lymph node-based staging systems have been recently proposed for an appropriate postoperative therapy. The identification of sentinel lymph nodes (SLNs) might improve the postoperative protocols. The aim of this study was to present our experience in detecting SLNs in GC using methylene blue dye.We have performed an observational study and retrospectively analyzed all of the consecutive cases of GC operated by the same surgical team and managed by the same pathologists during 2013 to 2015. In all of the cases SLN status was determined using the methylene blue that was intraoperatively administered in the peritumoral subserosal tissue. All blue colored nodes were histopathologically examined. In the node negative cases immunohistochemical stains using AE1/AE3 keratin were performed.The blue SLNs were identified in 48 out of the 50 cases included in the study, with a 96% sensitivity and 87.50% specificity. From the 48 cases, 34 (70.83%) presented positive SLNs; in the other 14 cases the SLNs were negative (29.17%). False negativity was observed in 6 of the 14 cases. In 2 of the cases the false negativity of the group 20 was induced by the anthracotic pigment. In other 2 false negative cases, although no regional metastases were founded, sentinel skip metastases in the group 8 and 15, respectively, were identified.Mapping of the SLNs is a simple and cheap method that might improve the accuracy of LN-based staging of patients with GC and favor identification of skip metastases.

Immunohistochemical features and staging of early gastric cancer

INTRODUCTION

The aim of this study was to analyze the particularities of early gastric cancer (EGC) and their importance for staging, prognosis, and therapy.

MATERIAL AND METHODS

A total of 338 GCs diagnosed and surgically removed in three medical institutes from Eastern Europe were retrospectively examined, and the EGCs were further examined. Besides the demographic factors and tumor characteristics, immunostains were performed with E-cadherin, HER-2, p53, Ki67, MLH-1, MSH-2, COX-2, VEGF-A, CD31, and CD105.

RESULTS

From the 338 GCs, 29 were EGCs, the average being similar in Poland and Hungary (12.37% and 13.33% respectively) but lower in Romania (5.61%). The rate of lymph node metastases was 20.69% (n = 6). Two of the cases presented liver metastases, both of them having a multifocal aspect. In 1 of these cases, limited to the mucosa, intramural carcinomatosis of the lymph vessels was seen in submucosa, muscularis propria, and subserosa. COX-2 positivity was observed in 14 (48.72%) cases. COX-2 was directly correlated with microvessel density determined with CD31 (p < 0.001) and CD105 (p = 0.03). Same correlation with CD31 and CD105 was seen for HER-2 (p = 0.03 and p = 0.0007). The only negative independent prognostic factors for overall survival were tumor localization at the proximal stomach and male gender, regardless of age.

CONCLUSIONS

In EGCs, intramural carcinomatosis of the lymph vessels and multifocality should be separately described in every surgical pathology report, as indicators of aggressiveness. Microsatellite status, E-cadherin, HER-2, p53, and Ki67 do not have prognostic value in EGC, but the highly angiogenic pattern is a possible therapeutic target.

Value and impact factors of multidetector computed tomography in diagnosis of preoperative lymph node metastasis in gastric cancer: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Multidetector computed tomography (MDCT) exhibited wide ranges of sensitivities and specificities for lymph node assessment of gastric cancer (GC) in several individual studies. This present meta-analysis was carried out to evaluate the value of MDCT in diagnosis of preoperative lymph node metastasis (LNM) and to explore the impact factors that might explain the heterogeneity of its diagnostic accuracy in GC.

METHODS

A comprehensive search was conducted to collect all the relevant studies about the value of MDCT in assessing LNM of GC within the PubMed, Cochrane library and Embase databases up to Feb 2, 2016. Two investigators independently screened the studies, extracted data, and evaluated the quality of included studies. The sensitivity, specificity, and area under ROC curve (AUC) were pooled to estimate the overall accuracy of MDCT. Meta-regression and subgroup analysis were carried out to identify the possible factors influencing the heterogeneity of the accuracy.

RESULTS

A total of 27 studies with 6519 subjects were finally included. Overall, the pooled sensitivity, specificity, and AUC were 0.67 (95% CI: 0.56-0.77), 0.86 (95% CI: 0.81-0.90), and 0.86 (95% CI: 0.83-0.89), respectively. Meta-regression revealed that MDCT section thickness, proportion of serosal invasion, and publication year were the main significant impact factors in sensitivity, and MDCT section thickness, multiplanar reformation (MPR), and reference standard were the main significant impact factors in specificity. After the included studies were divided into 2 groups (Group A: studies with proportion of serosa-invasive GC subjects ≥50%; Group B: studies with proportion of serosa-invasive GC subjects <50%), the pooled sensitivity in Group A was significantly higher than in Group B (0.84 [95% CI: 0.75-0.90] vs 0.55 [95% CI: 0.41-0.68], P < .01). For early gastric cancer (EGC), the pooled sensitivity, specificity, and AUC were 0.34 (95% CI: 0.15-0.61), 0.91 (95% CI: 0.84-0.95), and 0.83 (95% CI: 0.80-0.86), respectively.

CONCLUSION

To summarize, MDCT tends to be adequate to assess preoperative LNM in serosa-invasive GC, but insufficient for non-serosa-invasive GC (particularly for EGC) owing to its low sensitivity. Proportion of serosa-invasive GC subjects, MDCT section thickness, MPR, and reference standard are the main factors influencing its diagnostic accuracy.

Sentinel Lymph Node Mapping In Gastric Cancer Surgery: Current Status

Lymphonodular metastases remain an important predictive and prognostic factor in gastric cancer development. The precise determination of the lymphonodular invasion stage can be made only by extended intraoperative lymphadenectomy and histopathological examination. But the main controversy is the usefulness of extended lymph dissection in early gastric cancer. This increases the duration of the surgery and the complications rate, and it is unnecessary without lymphonodular invasion. The identification of the sentinel lymph nodes has been successfully applied for some time in the precise detection of lymph nodes status in breast cancer, malignant melanoma and the use for gastric cancer patients has been a controversial issue. The good prognosis in early gastric cancer had been a surgery challenge, which led to the establishment of minimally invasive individualized treatment and acceptance of sentinel lymph node mapping. The dual-tracer method, submucosally administered endoscopically is also recommended in sentinel lymph node biopsy by laparoscopic approach. There are new sophisticated technologies for detecting sentinel lymph node such as: infrared ray endoscopy, florescence imaging and near-infrared technology, carbon nanoparticles, which will open new perspectives in sentinel lymph nodes mapping.

Impact on long-term survival of the number of lymph nodes resected in patients with pT1N0 gastric cancer after R0 resection: A multicenter study in China

Although studies on the association between the number of lymph nodes resected and prognosis in patients with pT2-4N0 stages of gastric cancer have reported consistent results, there is no consensus on the optimal number of lymph nodes to be examined for pT1N0 stage gastric cancer. The aim of this study was to evaluate the long-term effect of the number of lymph nodes removed on the outcomes of patients with pT1N0 stage gastric cancer after R0 resection.From December 2009 to December 2011, 227 patients undergoing R0 resection of pT1N0 stage gastric cancer at 4 Chinese centers were enrolled in this study. Patients were assigned to 2 groups according to the number of lymph nodes dissected (≤15 or > 15). Standard survival methods and restricted multivariable Cox regression models were applied.More women (P = 0.031) were in the ≤15 group than in the >15 group. The mean number of lymph nodes removed from women was greater than that from men (P = 0.007). The 5-year survival rate was significantly higher in the >15 lymph nodes resected group than the ≤15 group. The number of lymph nodes resected was identified as an independent prognostic factor and was significantly correlated with overall survival (OS).A lymphadenectomy with dissection of more than 15 lymph nodes improved the long-term survival of patients with pT1N0 gastric cancer after R0 resection. Therefore, it is necessary to consider removing more than 15 lymph nodes among such patients.

Aberrant metastatic behavior and particular features of early gastric cancer

In this paper, we have focused on the metastatic behavior of EGC and its particularities. The main factors that are currently considered as predictors of the metastatic behavior and that are used in the therapeutic decision (endoscopic resection vs surgical removal) are the tumor size (upper or bellow 2 cm), depth of infiltration, angiolymphatic invasion, the presence or absence of ulceration, and histologic type (undifferentiated vs differentiated carcinomas). However, most of the metastatic cases were published as case reports or case series. This is the reason why a proper estimation of metastatic risk in EGC is not well known. To date, 79 cases presenting bone metastases, three reports of brain metastases, and one EGC that was associated with skin metastasis were published. However, occult metastasis, lymph node micrometastasis, and skip metastasis can also occur and should be identified. Making a synthesis of the literature data that is correlated with our experience, we finally proposed the inclusion of the six Japanese subgrouping system, tumor size, angiolymphatic invasion, and micrometastasis as components of the pTNM staging system, which should be particularly adapted for EGC.