Predictive factors for lymph node metastasis of differentiated submucosally invasive gastric cancer

A population-based predictive model to identify patients with signet ring cell carcinoma of the stomach who are most suitable for primary tumor resection

Background

Though the survival benefit of primary tumor operation for patients with signet ring cell carcinoma of the stomach is known, the specific characteristics of those patients who would profit from the operation are yet to be determined. To this end, a predictive model was developed to identify the conjecture that the survival profit from primary tumor operation would only be obtained by patients.

Method

The clinical data of the patients with signet ring cell carcinoma of the stomach were obtained from the Surveillance, Epidemiology, and End Results database, and then divided into operation and no-operation groups based on whether the patients underwent the primary tumor operation. To remove the confounding factors, propensity score matching was employed, and it was hypothesized that the patients who had been operated on and lived a longer life than the median cancer-specific survival time of those who hadn’t must have profited from the surgery. To discuss the independent factors of cancer-specific survival time in the beneficial group and the non-beneficial group, the Cox model was used, and based on the various vital predictive factors, a nomogram was drawn using logistic regression.

Result

The number of eligible patients was 12,484, with 43.9% (5483) of them having received surgery. After employing propensity score matching, the cancer-specific survival time of the operation group was found to be apparently longer (median: 21 vs. 5 months; p < 0.001) than the no-operation group. In the operation group, 4757 (86.7%) of the patients lived longer than five months (beneficial group). The six indexes (beneficial and non-beneficial group) included gender, age, Tumor Node Metastasis stage, histologic type, differentiation grade, and tumor position, and were used as predictors to draw the nomogram. The nomogram was used to divide the patients who had taken operations into two groups: the beneficial operation group and the non-beneficial operation group. The beneficial operation group, it was found, survived longer than the non-beneficial operation group (median cancer-specific survival time: 28 vs. 3 months, p < 0.001). Moreover, there was we could tell little difference in survival between the two groups (median cancer-specific survival time: 3 vs. 5 months).

Conclusions

The predictive model created to select suitable candidates for surgical treatment from patients with signet ring carcinoma of the stomach could be adopted to identify certain patients benefiting from the primary tumor operation.

Blood Free-Circulating DNA Testing of Methylated RUNX3 Is Useful for Diagnosing Early Gastric Cancer

The main modalities for gastric cancer screening are limited to upper gastrointestinal endoscopy and contrast radiography. The former is invasive, and the latter has high false-negative rates. Thus, alternative diagnostic strategies are required. One solution may be a liquid biopsy. Methylated RUNX3 is a well-known biomarker of gastric cancer but it is very difficult to detect with conventional bisulfite-based methylation assays when only a small amount of serum is available. We developed the combined restriction digital PCR (CORD) assay, a new methylation assay allowing for the counting of as little as one copy of a methylated gene in a small sample of DNA without necessitating DNA bisulfite treatment. We evaluated the sensitivity and specificity of the serum DNA testing of methylated RUNX3 by the CORD assay for the detection of early gastric cancer using 50 patients with early gastric cancer and 61 control individuals. The CORD assay had a sensitivity of 50.0% and a specificity of 80.3% for early gastric cancer. Methylated RUNX3 copies were significantly associated with tumor size, massive submucosal invasion, and lymph-vascular invasion. After the treatment, the median number of methylated RUNX3 copies was significantly decreased. The CORD assay may provide an alternative screening strategy to detect even early-stage gastric cancer.

Analysis of lymph node metastasis in early gastric cancer: a single institutional experience from China

BACKGROUND

Lymph node metastasis (LNM) has a strong influence on the prognosis of patients with early gastric cancer (EGC). The aim of this study was to reveal the incidence of LNM and evaluate risk factors for LNM to determine the appropriate treatment for EGC in a Chinese population.

METHODS

Patients who underwent radical gastrectomy with lymph node dissection for EGC between 2012 and 2017 were retrospectively analyzed. Univariate and multivariate analyses were conducted to identify clinicopathological features that were risk factors for LNM.

RESULTS

A total of 1033 patients with EGC were enrolled. Of these patients, 668 (64.7%) were men, and 365 (35.3%) were women, ranging in age from 19 to 82 years (mean 56.9 ± 10.9 years). LNM was detected in 173(16.7%) patients with EGC. Among 508 patients with mucosal cancer, 44 (8.7%) patients had LNM. In 525 patients with submucosal cancer, the incidence of LNM was 24.6% (129/525). The age, gender, tumor size, type of differentiation, Lauren classification, and lymphovascular and perineural invasion showed a significant correlation with the rate of LNM in EGC by univariate and multivariate analyses. Patients with submucosal gastric cancer had an older age, a higher proportion of proximal lesion, larger tumor size, more frequent lymphovascular invasion, perineural invasion, and more LNM than patients with mucosal gastric cancer.

CONCLUSIONS

Our study revealed a relatively high incidence of LNM in EGC, compared with Japanese and Korean cohorts. Female sex, large tumor size, undifferentiated-type, and lymphovascular invasion were independent risk factors for LNM in EGC. Radical gastrectomy with lymphadenectomy should be performed in EGC patients with a high risk of LNM.

Clinical outcomes of early gastric cancer with non-curative resection after pathological evaluation based on the expanded criteria

Additional surgical resection should be considered for the patients with pathological findings beyond the expanded criteria with the risk for LN metastasis. However, close observation without additional surgery may be applied because of various reasons. We aimed to determine the clinical outcomes of early gastric cancer beyond the expanded criteria after endoscopic resection according to the pathological extent. A total of 288 patients with 289 lesions beyond the expanded criteria of endoscopic submucosal dissection for early gastric cancer were analyzed between 2005 and 2016, and classified into two groups according to additional treatment: observation (n = 175 patients, 175 lesions) and surgery (n = 113 patients, 114 lesions). The depth of tumor invasion was greater and the tumor-positive vertical margin and lymphatic and venous invasion were more common in the surgery group than in the observation group (P<0.001). Residual, synchronous, and metachronous tumors were more common in the observation group; however, the occurrence of regional lymph node and distant metastasis did not differ between the groups. Overall survival and 5-year disease-specific survival did not differ between the groups (observation vs surgery, 88.6 vs 93.8%; P = 0.259, 98.2 vs 100%; P = 0.484, respectively), but the 5-year disease-free survival was lower in the observation group (73.5 vs 97.9%; P<0.001). On multivariate analysis, tumor-positive lateral margin was a risk factor for residual tumor and lymphatic and venous invasion were risk factors for regional lymph node metastasis. In conclusion, the clinical course of beyond the expanded criteria of endoscopic submucosal dissection for early gastric cancer showed good prognosis over 98% in 5-year disease specific survival. If additional surgery cannot be performed, a close follow-up with endoscopy and abdominal computed tomography can be considered as an alternative for carefully selected patients without lymphatic and vascular invasion.

Establishment of pathological quantitative method for determining undifferentiated component ratio in patients with differentiated/undifferentiated mixed-type early gastric cancer and clinical significance of this ratio

PURPOSES

The purpose of this study was to establish a pathological quantitative method for determining the undifferentiated components ratio (UCR) in patients with differentiated/undifferentiated mixed-type (Mixed-type) early gastric cancer (EGC) and to examine the clinical significance.

METHODS

The subjects were 410 patients who underwent surgical resection for EGC with the invasion limited to m or sm1. Analysis 1: In 12 randomly selected patients with Mixed-type cancer, we calculated the area ratio and the ratio of the length ratio using ImageJ and analyzed the correlation between them. Analysis 2: We generated ROC curves, and determined the cutoff UCR on the basis of the predictive risk factors for lymph node metastasis (LNM). Analysis 3: We analyzed the relationship between clinicopathological factors including UCR/length of undifferentiated component (LUC = maximum dimensions of tumor × UCR) and LNM.

RESULTS

Analysis 1: The length ratio can be used as a substitute parameter for the UCR (r = 0.996). Analysis 2: The cutoff UCR as a risk factor for LNM was 58% (sensitivity = 1, 1 - specificity = 0.404). Analysis 3: Lymphovascular invasion (p < 0.0001), UCR ≥58% (p = 0.023), and LUC ≥25 mm (p = 0.005) were identified as significant risk factors for LNM. No LNM was observed in patients with invasion limited to m or sm1 and negativity for lymphovascular invasion and UCR <58% (0/215).

CONCLUSIONS

In the patients with Mixed-type EGC, the length ratio of undifferentiated components can be a substitute parameter for the UCR. LNM rarely occurs in patients without lymphovascular invasion and with an UCR <58%. The analysis of the UCR has great significance in determining whether additional surgical resection is required after endoscopic resection.

Prediction of lymph node metastasis and sentinel node navigation surgery for patients with early-stage gastric cancer

Accurate prediction of lymph node (LN) status is crucially important for appropriate treatment planning in patients with early gastric cancer (EGC). However, consensus on patient and tumor characteristics associated with LN metastasis are yet to be reached. Through systematic search, we identified several independent variables associated with LN metastasis in EGC, which should be included in future research to assess which of these variables remain as significant predictors of LN metastasis. On the other hand, even if we use these promising parameters, we should realize the limitation and the difficulty of predicting LN metastasis accurately. The sentinel LN (SLN) is defined as first possible site to receive cancer cells along the route of lymphatic drainage from the primary tumor. The absence of metastasis in SLN is believed to correlate with the absence of metastasis in downstream LNs. In this review, we have attempted to focus on several independent parameters which have close relationship between tumor and LN metastasis in EGC. In addition, we evaluated the history of sentinel node navigation surgery and the usefulness for EGC.

Treatment Strategy after Incomplete Endoscopic Resection of Early Gastric Cancer

Endoscopic resection of early gastric cancer is defined as incomplete when tumor cells are found at the resection margin upon histopathological examination. However, a tumor-positive resection margin does not always indicate residual tumor; it can also be caused by tissue contraction during fixation, by the cautery effect during endoscopic resection, or by incorrect histopathological mapping. Cases of highly suspicious residual tumor require additional endoscopic or surgical resection. For inoperable patients, argon plasma coagulation can be used as an alternative endoscopic treatment. Immediately after the incomplete resection or residual tumor has been confirmed by the pathologist, clinicians should also decide upon any additional treatment to be carried out during the follow-up period.

A Risk Prediction Model Based on Lymph-Node Metastasis in Poorly Differentiated-Type Intramucosal Gastric Cancer

Background and Aim

Endoscopic submucosal dissection (ESD) for undifferentiated type early gastric cancer is regarded as an investigational treatment. Few studies have tried to identify the risk factors that predict lymph-node metastasis (LNM) in intramucosal poorly differentiated adenocarcinomas (PDC). This study was designed to develop a risk scoring system (RSS) for predicting LNM in intramucosal PDC.

Methods

From January 2002 to July 2015, patients diagnosed with mucosa-confined PDC, among those who underwent curative gastrectomy with lymph node dissection were reviewed. A risk model based on independent predicting factors of LNM was developed, and its performance was internally validated using a split sample approach.

Results

Overall, LNM was observed in 5.2% (61) of 1169 patients. Four risk factors [Female sex, tumor size ≥ 3.2 cm, muscularis mucosa (M3) invasion, and lymphatic-vascular involvement] were significantly associated with LNM, which were incorporated into the RSS. The area under the receiver operating characteristic curve for predicting LNM after internal validation was 0.69 [95% confidence interval (CI), 0.59–0.79]. A total score of 2 points corresponded to the optimal RSS threshold with a discrimination of 0.75 (95% CI 0.69–0.81). The LNM rates were 1.6% for low risk (<2 points) and 8.9% for high-risk (≥2 points) patients, with a negative predictive value of 98.6% (95% CI 0.98–1.00).

Conclusions

A RSS could be useful in clinical practice to determine which patients with intramucosal PDC have low risk of LNM.

Prognostic risk factors of early gastric cancer-a western experience

PURPOSE

Lymph node metastasis (LNM) is the leading cause of tumor recurrence in early gastric cancer (EGC). Since endoscopic resection (ER) can be performed in EGC with curative intention when no LNM are present, this study wants to determine the risk factors for LNM in EGC.

METHODS

One hundred twenty-four patients who have had an operative resection because of EGC were analyzed. Histopathological workup included tumor infiltration depth, lymphatic and vascular infiltration, lymph node infiltration, tumor differentiation, and the classification of Ming. A complete follow-up was achieved.

RESULTS

There was no LNM among tumors meeting the standard or extended criteria for an ER. Lymphatic infiltration (p < 0.001) and infiltration of the submucosal layers (p = 0.018) proved to be the strongest risk factors for LNM. Tumors with a deeper infiltration depth (p = 0.015) and a lower grade of differentiation (p = 0.029) presented with a higher grade of lymphatic infiltration. Tumors located in the body of the stomach (p = 0.003) and tumors with infiltrative growth according to Ming (p = 0.021) had a significantly higher risk for lymphatic infiltration. The 5-year overall survival was 84 % in nodal negative patients and 42 % in patients with LNM (p = 0.002).

CONCLUSIONS

ER within the extended criteria with a meticulous histological workup should be performed in EGC to determine whether risk factors for LNM are present. If lymphatic infiltration is observed, surgery with lymphadenectomy is recommended. Tumors exceeding the extended criteria should undergo primary surgery with adequate lymphadenectomy.

Endoscopic resection of early gastric cancer: current status and new approaches

Endoscopic resection (ER) of early gastric cancer (EGC) has been an optimal treatment for selected patients. As endoscopic submucosal dissection (ESD) has been widely used for treatment of EGC, concerns have been asked to achieve curative resection for EGC while guaranteeing precise prediction of lymph node metastasis (LNM). Moreover, a new microscopic imaging for precise endoscopic diagnosis of EGC is introduced. This review covers the current status and new approaches of ER of EGC.

Risk of lymph node metastases from early gastric cancer in relation to depth of invasion: experience in a single institution

BACKGROUND

An accurate assessment of potential lymph node metastasis is important for the appropriate treatment of early gastric cancers. Therefore, this study analyzed predictive factors associated with lymph node metastasis and identified differences between mucosal and submucosal gastric cancers.

MATERIALS AND METHODS

A total of 518 early gastric cancer patients who underwent radical gastrectomy were reviewed in this study. Clinicopathological features were analyzed to identify predictive factors for lymph node metastasis.

RESULTS

The rate of lymph node metastasis in early gastric cancer was 15.3% overall, 3.3% for mucosal cancer, and 23.5% for submucosal cancer. Using univariate analysis, risk factors for lymph node metastasis were identified as tumor location, tumor size, depth of tumor invasion, histological type and lymphovascular invasion. Multivariate analysis revealed that tumor size >2 cm, submucosal invasion, undifferentiated tumors and lymphovascular invasion were independent risk factors for lymph node metastasis. When the carcinomas were confined to the mucosal layer, tumor size showed a significant correlation with lymph node metastasis. On the other hand, histological type and lymphovascular invasion were associated with lymph node metastasis in submucosal carcinomas.

CONCLUSIONS

Tumor size >2 cm, submucosal tumor, undifferentiated tumor and lymphovascular invasion are predictive factors for lymph node metastasis in early gastric cancer. Risk factors are quite different depending on depth of tumor invasion. Endoscopic treatment might be possible in highly selective cases.

Can we resect EGC with Signet ring cells in Europe?

PURPOSE

The proposed guideline for performing endoscopic resection of early gastric carcinoma (EGC) in Paris classification is a well-differentiated carcinoma with maximum involvement Sm1. Signet ring cell carcinomas (SRC) are excluded from this recommendation. Authors from Eastern countries have proposed extending this resection to include selected undifferentiated EGC. Via an analysis of a series of cases of signet ring carcinoma, we will discuss whether it is possible to resect EGC with signet ring cells in Europe.

METHODS

We retrospectively included patients with histological classification pT1 of EGC showing SRC. Data was extracted from the hospital gastrectomy register. Lymphadenomectomy D1.5 was performed on all patients. Histology results were retrospectively obtained from the electronic patient file.

RESULTS

Twelve patients (mean age = 55.4, four women, eight men) underwent surgery, without previous chemotherapy, between 2000 and 2012, for EGC with SRC. Mean size of the lesions was 20.2 mm (5-35 mm). Seven lesions were located in the antrum, five in the fundus. In the case of nine patients, histology showed no lymphovascular involvement. None of these nine patients presented lymph node metastases (LNM). Five patients had intramucosal carcinoma, four were classified as Sm1, one patient was Sm2, and one patient was Sm3. On surgery, the three patients with lymphovascular invasion showed LNM.

CONCLUSION

Endoscopic resection of EGC with SRC does not systematically imply complementary treatment by surgery, although criteria for endoscopic resection are difficult to determine because of the lack of data in Europe.

Prediction of risk factors for lymph node metastasis in early gastric cancer

AIM: To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.

METHODS: A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.

RESULTS: The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ² = 122.901, P = 0.001; χ² = 7.14, P = 0.008; χ² = 79.523, P = 0.001; χ² = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ² = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN₁ (P = 0.008).

CONCLUSION: The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.

Suitability of endoscopic submucosal dissection for treatment of submucosal gastric cancers

BACKGROUND

Endoscopic submucosal dissection (ESD) is not considered appropriate for all submucosal cancers owing to the risk of lymph node metastasis and difficulty estimating the deep margin status. This study aimed to determine predictive factors for lymph node metastases in submucosal cancer and to explore in which patients ESD might be feasible.

METHODS

Details of patients who had curative gastrectomy for submucosal gastric cancer at Asan Medical Centre from 2007 to 2011 were reviewed retrospectively to determine the relationship between lymph node metastasis and clinicopathological characteristics, including age, sex, tumour location, size, gross appearance, depth of invasion, histological type/differentiation, presence of lymphovascular/perineural invasion, and immunohistochemical staining results for p53, human epidermal growth factor receptor (HER) 1 and HER2.

RESULTS

A total of 1773 patients were analysed. The presence of lymphovascular invasion was related most strongly to lymph node metastasis. Multivariable analysis revealed that depth of invasion, tumour size, differentiation, gross appearance and perineural invasion were also related. Metastatic lymph nodes were found in four of 105 patients who met the classical criteria for ESD; all showed a moderately differentiated histological appearance. No lymph node metastases were observed in well differentiated SM1 tumours of any size (infiltration into upper third of submucosa), or in well differentiated SM2 (infiltration into middle third of submucosa) tumours of 2 cm or less without lymphovascular invasion.

CONCLUSION

Patients with well differentiated SM1 cancer of any size and those with well differentiated SM2 cancer of 2 cm or less without lymphovascular invasion may be suitable candidates for ESD.

Predictive factors for lymph node metastasis in patients with poorly differentiated early gastric cancer

BACKGROUND

Endoscopic submucosal dissection is gaining popularity in the treatment of early gastric cancer. This study aimed to identify clinicopathological factors predictive of lymph node metastasis in patients with the poorly differentiated early gastric cancer to assess the feasibility of using endoscopic submucosal dissection for these cancers.

METHODS

The records of patients with poorly differentiated early gastric cancer who had undergone gastric cancer surgery between January 2002 and December 2009 were reviewed. Associations between clinicopathological factors and the presence of lymph node metastasis were analysed by univariable and multivariable logistic regression analysis.

RESULTS

Some 1005 patients were included in the analysis. Univariable analysis indicated that lymph node metastasis was associated with sex, ulceration, tumour size, depth of invasion, macroscopic type, lymphatic invasion and venous invasion. Logistic regression revealed that lymph node metastasis was significantly associated with sex, tumour size, depth of tumour invasion and lymphatic involvement. In the group with none of these risk factors (men with mucosal tumour no larger than 2 cm in size, with no lymphatic involvement), lymph node metastasis was present in four (3·2 per cent) of 124 patients.

CONCLUSION

In the present study 3·2 per cent of patients who were negative for all identified risk factors had lymph node metastasis. The use of endoscopic submucosal dissection should be considered carefully in the treatment of poorly differentiated early gastric cancer.

Additional gastrectomy after endoscopic submucosal dissection for early gastric cancer patients with comorbidities

Purpose. We investigated the clinicopathologic features of early gastric cancer (EGC) patients who have undergone additional gastrectomy after endoscopic submucosal dissection (ESD) because of their comorbidities. Methods. Eighteen (7.1%) of 252 GC patients were gastrectomized after prior ESD. Reasons for further surgery, preoperative and postoperative problems, and the clinical outcome were determined. Results. The 18 patients had submucosal EGC and several co-morbidities. Other primary cancers were observed in 8 (44.4%). Histories of major abdominal operations were observed in 6 (33.3%). Fourteen patients (77.8%) hoped for endoscopic treatment. Due to additional gastrectomy, residual cancer was suspected in 10, and node metastasis was suspected in 11. A cancer remnant was histologically observed in one. Node metastasis was detected in 3 (16.7%). Small EGC was newly detected in 4. Consequently, additional gastrectomy was necessary for the one third. No patient showed GC recurrence. However, 9 (50%) had new diseases, and 4 (22.2%) died of other diseases. The overall survival after surgery in these patients with additional gastrectomy was poorer than those with routine gastrectomy for submucosal EGC (P = 0.0087). Conclusions. Additional gastrectomy was safely performed in EGC patients with co-morbidities. However, some issues, including presence of node metastasis and other death after surgery, remain.

Endoscopic treatment for early gastric cancer

Endoscopic resection has been accepted as a curative modality for early gastric cancer (EGC). Since conventional endoscopic mucosal resection (EMR) has been introduced, many improvements in endoscopic accessories and techniques have been achieved. Recently, endoscopic submucosal dissection (ESD) using various electrosurgical knives has been performed for complete resection of EGC and enables complete resection of EGC, which is difficult to completely resect in the era of conventional EMR. Currently, ESD is accepted as the standard method for endoscopic resection of EGC in indicated cases. In this review, the history of endoscopic treatment for EGC, overall ESD procedures, and indications and clinical results of endoscopic treatment will be presented.

Gastric adenocarcinoma of fundic gland type (chief cell predominant type) treated with endoscopic aspiration mucosectomy

Upper endoscopy screening in an asymptomatic 56-year-old man showed a small, yellowish elevated lesion with a central depression on the posterior wall in the gastric cardia. Biopsy specimens from this lesion were suspicious of carcinoid tumor. We suspected this lesion to be a sporadic gastric carcinoid tumor with a diameter of 5 mm, limited to the mucosal layer. We then performed an endoscopic aspiration mucosectomy with a cap-fitted endoscope. Microscopically, the lesion obtained from the resected specimen was minimally invasive to the submucosa and showed highly differentiated columnar cells in irregularly anastomosing glands. Immunohistology was positive for pepsinogen-I, and MUC6, partially positive for H(+)/K(+)-ATPase, and negative for MUC5AC. In addition, it was positive for synaptophysin and CD56, and negative for chromogranin A. We finally diagnosed the patient as having gastric adenocarcinoma of fundic gland type (chief cell predominant type) with minimal invasion (100 µm) to the submucosa. Surveillance endoscopy with biopsy specimens and abdominal computed tomography at 1 year revealed no evidence of tumor recurrence. We herein report this rare case of gastric adenocarcinoma of fundic gland type (chief cell predominant type).

Predictive factors for lymph node metastasis in early gastric cancer

AIM: To analyze the predictive factors for lymph node metastasis (LNM) in early gastric cancer (EGC).

METHODS: Data from patients surgically treated for gastric cancers between January 1994 and December 2007 were retrospectively collected. Clinicopathological factors were analyzed to identify predictive factors for LNM.

RESULTS: Of the 2936 patients who underwent gastrectomy and lymph node dissection, 556 were diagnosed with EGC and included in this study. Among these, 4.1% of patients had mucosal tumors (T1a) with LNM while 24.3% of patients had submucosal tumors with LNM. Univariate analysis found that female gender, tumors ≥ 2 cm, tumor invasion to the submucosa, vascular and lymphatic involvement were significantly associated with a higher rate of LNM. On multivariate analysis, tumor size, lymphatic involvement, and tumor with submucosal invasion were associated with LNM.

CONCLUSION: Tumor with submucosal invasion, size ≥ 2 cm, and presence of lymphatic involvement are predictive factors for LNM in EGC.

Endoscopic versus surgical therapy for early cancer in Barrett's esophagus: a decision analysis

BACKGROUND

Esophagectomy for early esophageal adenocarcinoma is associated with increased operative mortality and morbidity, but possibly a decreased recurrence rate compared with endoscopic therapy when using EMR and radiofrequency ablation.

OBJECTIVE

To compare the cost-effectiveness of esophagectomy and endoscopic therapy in the treatment of early esophageal adenocarcinoma.

DESIGN

Decision analysis model.

MAIN OUTCOME MEASUREMENTS

Incremental cost-effectiveness ratio.

RESULTS

During the 5-year study period, endoscopic therapy cost $17,000.00 and yielded 4.88 quality-adjusted life years, compared with $28,000.00 and 4.59, respectively, for esophagectomy. Varying the recurrence rates of cancer or Barrett's esophagus metaplasia after endoscopic therapy did not change the overall outcome. The sensitivity analysis demonstrated, however, that the outcome depended on the rate of lymph node involvement and operative mortality. Under the best of circumstances in favor of esophagectomy, such as 2% operative mortality, no reduced quality of life after esophagectomy, and a low 5-year survival rate after recurrence of endoscopic ablation, the risk of positive lymph nodes still needed to exceed 25% before esophagectomy became the preferred treatment option. This threshold is twice as high as the values reported for early submucosal cancer invasion.

LIMITATIONS

Limited data are available about the long-term outcome of EMR and radiofrequency ablation.

CONCLUSIONS

Endoscopic therapy for early Barrett's esophagus adenocarcinoma is more effective and less expensive than esophagectomy. Even in early esophageal adenocarcinoma with submucosal invasion, endoscopic therapy is a cost-effective alternative to esophagectomy, especially in patients with a high operative risk.

Usefulness of endoscopic ultrasonography in determining the depth of invasion and indication for endoscopic treatment of early gastric cancer

INTRODUCTION

Endoscopic ultrasonography (EUS) is a useful method for visualizing features of gastric cancer. However, a previously reported classification system tended to result in overstaging. We investigated the usefulness of EUS for evaluation of the depth of gastric cancer invasion and indications for endoscopic treatment.

METHODS

Accuracy of EUS for determining the depth of invasion and incidences of a positive basal margin were assessed in 235 patients who underwent endoscopic treatment or surgery for gastric cancer. The EUS-determined depth of invasion was classified as follows: EUS-M (lesion confined to sonographic layers 1 and 2); EUS-M/SM border (lesion with changes in sonographic layer 3 but no deeper than 1 mm); EUS-SM (lesion with changes in sonographic layer 3 deeper than 1 mm); or EUS-AD (lesion with changes in sonographic layer 4 or 5).

RESULTS

Accuracy of EUS for determining the depth of invasion was as follows: EUS-M, 99% were M and SM1 lesions; EUS-M/SM border, 87% were M and SM1 lesions; EUS-SM, 91% were SM2 lesions; EUS-AD, 100% were muscularis propria or deeper lesions. There was no EUS-M or EUS-M/SM border lesion for which endoscopic treatment resulted in a positive basal margin.

CONCLUSIONS

EUS is useful for accurately determining the depth of invasion of gastric cancer. When there are no endoscopically determined ulcerous changes, endoscopic treatment should be considered for EUS-M and EUS-M/SM border lesions, and EUS-SM lesions should be treated surgically.

Long-term results of endoscopic resection in early gastric cancer: the Western experience

OBJECTIVES

In the West, neither acute nor long-term results of endoscopic resection (ER) for early gastric cancer (EGC) have been reported in large studies. The aim of this study was to prospectively evaluate the efficacy and safety of ER in patients with EGC in a long-term follow-up (FU).

METHODS

From May 1995 to October 2004, 179 patients were referred to our department for endoscopic therapy (ET) of gastric cancer (GC). Of these, 43 patients had intramucosal GC with a diameter of up to 30 mm and underwent ER with curative intent. All patients underwent a strict FU protocol at regular intervals.

RESULTS

Of the 43 patients, 42 fulfilled our low-risk criteria for ET of EGC: gross tumor type I/II, intramucosal GC, diameter up to 30 mm, tumor differentiation G1/G2, and no infiltration into lymph vessels/veins. Two patients were not available for FU (remission status not evaluated). In another patient, gastric mucosa-associated lymphoid tissue lymphoma was detected simultaneously, and he was referred for surgery. 38 (97%) of the remaining 39 patients who underwent definitive ET (23 males (59%); mean age 69+/-10 years) achieved complete remission (CR) after a mean of 1.3+/-0.6 ER sessions. Minor complications (not Hb-relevant bleeding) occurred in 7 of the 39 patients (18%) and major complications (5 Hb-relevant bleeds, 1 covered perforation; all managed conservatively) in 6 patients (15%). During FUs (mean 57 months; range 5-137), recurrent or metachronous lesions were observed in 11 patients (29%). All lesions were successfully treated by repeated ET. No tumor-related deaths occurred during FU.

CONCLUSIONS

Although ER for EGC in Western countries is effective, it is associated with a relevant risk of complications. In view of the possibility of recurrent or metachronous neoplasia, a strict FU protocol is mandatory.

Heterogeneous prognoses of patients with tumors invaded within muscularis propria according to tumor depth in the layers of the muscularis propria

BACKGROUND

The muscularis propria of the stomach is histologically divided into three layers; namely, the innermost oblique, the inner circular, and the outer longitudinal layers. In patients with gastric cancer the depth of tumor invasion has been reported to correlate with lymph node metastasis and prognosis. However, it is unclear whether the depth of tumor invasion in the muscularis propria has an effect on lymph node metastasis and prognosis.

METHODS

Fifty-nine gastric cancer patients with muscularis propria invasion were analyzed retrospectively. These patients were divided into two groups, the inner group, with invasion up to the inner circular layer; and the outer group, with invasion beyond the inner circular layer. The relationships between tumor invasion and clinicopathological factors and survival were evaluated.

RESULTS

Of the 59 patients, 34 were classified as the inner group, and 25 were classified as the outer group. The inner group had a significantly lower probability of lymph node metastasis (P = 0.0053) and a significantly better overall cancer-specific survival (P = 0.017) than the outer group.

CONCLUSION

Gastric cancers with muscularis propria invasion had heterogeneous prognoses according to the tumor depth in the muscularis propria layers.

Stretching Causes Extensive Changes of Gastric Submucosa: Is It Acceptable to Define 500 microm as the Safe Margin?

BACKGROUND/AIMS

Endoscopic mucosal resection can cure early gastric cancer. The risk of lymphatic metastasis is related to the depth of submucosal invasion by the mucosal malignancy, with a resection depth of 500 microm generally accepted as a safe cut-off. However, excessive thinning induced by stretching of the resected tissue sometimes preventing a precise diagnosis. We studied the effects of stretching on different layers and sites of gastric tissue.

METHODS

Porcine stomachs were cut into 2.0x2.0 cm pieces, and pieces from body were stretched to 2.5, 3.0, and 3.5 cm. Pieces from the cardia, body, and antrum were also stretched to 3.0 cm. The thickness of each layer was measured and analyzed statistically.

RESULTS

Whole gastric wall and submucosal layers showed gradual thinning, with stretching to 3.5 cm tearing the tissues and resulting in imperfect extension. The submucosa was thinner in body tissue than in cardia and antrum tissues. Stretching to 3.0 cm induced a consistent decrease in submucosal thickness (30-70%). The change in thickness varied widely between individual samples.

CONCLUSIONS

A resection margin of 500 microm might be insufficient for the complete removal of malignancy. Moreover, the thickness of the submucosal layer differs with the gastric site and between individuals. Future studies are needed to confirm the findings in human tissue.

Clinicopathological study of lymph-node metastasis in 1,389 patients with early gastric cancer: assessment of indications for endoscopic resection

BACKGROUND

The endoscopic resection of early gastric cancers (EGC) is a standard technique in Japan and is increasingly used throughout the world. Further experience in the treatment of EGC and a clearer delineation of the factors related to lymph-node metastasis would permit a more accurate assessment of endoscopic resection.

METHODS

The study group comprised 1,389 patients with EGC who underwent gastrectomy with lymph-node dissection. We evaluated the relations of lymph-node metastasis to clinicopathological factors.

RESULTS

Of the 718 patients with intramucosal carcinomas, 14 (1.9%) had lymph-node metastasis. All cases of lymph-node metastasis were associated with ulceration. No lymph-node metastasis was found in patients with intramucosal carcinomas without ulceration, irrespective of tumor size and histological type. Lymph-node metastasis was present in 14 (4.7%) of the 296 patients who had cancer with a submucosal invasion depth of less than 500 microm (sm1). Significantly increased rates of lymph-node metastasis were associated with undifferentiated types, ulcerated lesions and lymphatic invasion. No lymph-node metastasis was found in patients with differentiated sm1 carcinomas 30 mm or less in diameter without ulceration. Lymph-node metastasis occurred in 29% of the patients who had cancer with a submucosal invasion depth of 500 microm or more (sm2).

CONCLUSION

This large series of patients with EGC provides further evidence supporting the expansion of indications for endoscopic treatment, as well as warns against potential risks.

Endoscopic resection of early oesophageal and gastric neoplasia

In the last decades, endoscopic treatment of early neoplastic lesions in the oesophagus and stomach has evolved as a valid and less invasive alternative to surgical resection. Endoscopic resection (ER) is the cornerstone of endoscopic therapy. Apart from the curative potential of ER, by removing neoplastic lesions, ER may also serve as a diagnostic tool. The relatively large tissue specimens obtained with ER enable accurate histological staging of a lesion, allowing for optimal decision making for further patient management. ER was pioneered in Japan, mainly for the resection of gastric lesions and squamous oesophageal neoplasia, and also Western countries have been increasingly implementing ER in the treatment of early gastro-oesophageal neoplasia, mostly associated with Barrett oesophagus. In this review we will give an overview of the different techniques that have been developed and modified for ER of early gastro-oesophageal neoplasia, and we will discuss the indications for ER in the oesophagus and stomach.

Laparoscopic local resection based on sentinel node evaluation for early gastric cancer: a preliminary report

We previously reported that lymphatic mapping using isosulfan blue can be used to identify sentinel nodes (SNs). This study was undertaken to evaluate the feasibility of using the SN technique in treating early gastric cancer and to explore its usefulness for minimal invasive surgery. Twenty-three patients with early gastric cancer who underwent SN biopsy were retrospectively evaluated. Based on SN evaluation, individualized surgery was performed in five patients with T1N0M0 gastric cancer. When pathological examination of frozen sections revealed metastasis in SNs, we performed a standard D2 gastrectomy. Laparoscopic local resection was applied when the SN biopsy was negative. Our results showed that the success rate with SN biopsy in early gastric cancer was 100%, as were the accuracy, sensitivity, and specificity. All five patients with early gastric cancer had SNs negative for metastases both by frozen section and by postoperative pathology. Thus, all these patients underwent laparoscopic local resection without extended lymphadenectomy. We conclude that SN biopsy is a useful tool to individualize the operative procedure, and laparoscopic local resection can be safely performed using SN guidance in selected patients with early gastric cancer.

Lymph node metastasis in submucosal gastric cancer and reduction surgery

Although the concept of early gastric cancer (EGC) has been accepted, lymph node metastasis is the most important prognostic factor for EGC. Submucosal gastric cancer is greatly concerned because of its high lymph node metastasis incidence accounting for about 20% of all lymph node metastases. Many researchers suggest that reduction surgery should be performed for submucosal gastric cancer patients at a lower risk of developing lymph node metastasis. Submucosal gastric cancer can be divided into 3 levels (Sm1, Sm2, Sm3) based on its depth of invasion, which has been proven useful for predicting lymph node metastasis, directing treatment and evaluating prognosis. Recently, with the advances in clinical pathology and molecular biology, the risk factor for lymph node metastasis of submucosal gastric cancer can be accurately evaluated and its treatment has become rather rational. This paper reviews the relative factors for lymph node metastasis of submucosal gastric cancer and advances in its rational surgical treatment.

Predictive factors for lymph node metastasis and endoscopic treatment strategies for undifferentiated early gastric cancer

BACKGROUND AND AIM

Although more than 80% of undifferentiated early gastric cancers (EGC) are not associated with lymph node metastasis, endoscopic mucosal resection is not generally accepted as a means of curative treatment because of an abundance of conflicting data concerning clinicopathological characteristics and prognoses. The aim of this study was to define a subgroup of undifferentiated EGC that could be cured by endoscopic treatment without the risk of lymph node metastasis.

METHOD

A total of 591 patients surgically resected for undifferentiated EGC between January 1999 and March 2005 were reviewed. Associations between various clinicopathological factors and the presence of lymph node metastasis were analyzed to identify the risk factors of lymph node metastasis.

RESULTS

Lymph node metastasis was found in 79 patients (13.4%). By multivariate logistic regression analysis, a tumor diameter 2.5 cm or larger, invasion into the middle third of the submucosal layer or deeper, and lymphatic involvement were identified as independent risk factors of lymph node metastasis (P < 0.001, respectively). Lymph node metastasis was not found in any patient with undifferentiated EGC smaller than 2.5 cm confined to the mucosa or upper third of the submucosal layer without lymphatic involvement.

CONCLUSIONS

Undifferentiated intramucosal EGC smaller than 2.5 cm without lymphatic involvement was not associated with lymph node metastasis. Thus, we propose in this circumstance that endoscopic mucosal resection could be considered a definitive treatment without compromising the possibility of cure.

Predictive factors for lymph node metastasis in early gastric cancer with submucosal invasion: analysis of a single institutional experience

OBJECTIVE

An accurate assessment of a potential lymph node metastasis is an important issue for the appropriate treatment of early gastric cancer. Minimizing the amount of invasive procedures used in cancer treatment is critical for improving the patient's quality of life. Therefore, this study analyzed the predictive risk factors for a lymph node metastasis in early gastric cancer with a submucosal invasion.

METHODS

The data from 1043 patients surgically treated for early gastric cancer with submucosal invasion between 2002 and 2005 were reviewed retrospectively. The patients were divided into 3 layers according to their depth: SM1, SM2, and SM3. The clinicopathological variables predicting a lymph node metastasis were evaluated.

RESULTS

A lymph node metastasis was observed in 19.4% of patients. The tumor size, histologic type, Lauren classification, tumor depth, and perineural invasion showed a positive correlation with the rate of lymph node metastasis and N category by univariate analysis. Multivariate analyses revealed the tumor size (>or=2 cm) and lymphatic involvement to be significantly and independently related to lymph node metastasis. The presence of lymphatic involvement was the strongest predictive factor for a lymph node metastasis, being observed in 43.8% of cases in which a lymph node metastasis had been revealed. No lymph node metastasis was observed in the 12 cases with no lymphatic involvement, SM1 invasion, and tumor size <1 cm.

CONCLUSIONS

Lymphatic involvement and tumor size are independent risk factors for a lymph node metastasis in early gastric cancer with submucosal invasion. Minimal invasive treatment, such as endoscopic mucosal resection, may be possible in highly selective submucosal cancers with no lymphatic involvement, SM1 invasion, and tumor size <1 cm.

Stage IV early gastric cancer: two cases with microsatellite instability

BACKGROUND

We experienced two rare cases of stage IV early gastric carcinoma with extensive lymph node metastasis (pT1N3) and microsatellite instability caused by methylation of the MLH1 gene.

MATERIALS AND METHODS

The clinicopathological features of patients with stage IV EGC were examined. Microsatellite instability (MSI) was analyzed using five microsatellite markers and MLH1 gene promoter methylation patterns were determined by methylation specific polymerase chain reaction (PCR) from paraffin-embedded tissue samples. Loss of hMLH1 was identified by immunohistochemical study.

RESULTS

In both cases, the carcinomas were located in the antrum of the stomach, confined within the submucosa (SM3) and accompanied by endolymphatic tumor emboli. Immunohistochemical analysis for hMLH1 showed negative nuclear staining in the carcinoma cells. The tumor demonstrated methylation of the MLH1 gene and MSI-H because they manifested instability in three and two of the five markers tested. One patient is alive without any clinical, radiological, or pathological evidence of recurrence or metastasis at 37 months, while the other patient died after a cerebrovascular accident 5 months after surgery.

CONCLUSION

Our rare cases support that MSI caused by MLH1 promoter methylation and the loss of hMLH1 protein play an important role in stage IV EGC development.

Indications for EMR/ESD in cases of early gastric cancer: relationship between histological type, depth of wall invasion, and lymph node metastasis

BACKGROUND

Limited surgery by endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) for gastric cancer is frequently performed in many institutions. These techniques do preserve gastric function and maintain a high quality of life but may compromise survival. The treatment strategy for early tumors should therefore be based on a complete cure, and limited surgery must thus have clear indications.

METHODS

D2 gastric resection was performed in 278 early gastric adenocarcinomas, and a retrospective histological review of the specimens was made. The extended indications for EMR or ESD, according to the Japanese Gastric Cancer Association Treatment guidelines for gastric cancer in Japan, were also assessed.

RESULTS

Of the 278 early gastric cancers, 115 were mucosal (M) cancers without ulcer. No lymph node metastases were seen in these specimens. Six of the 41 specimens of M cancer with ulcers had lymph node metastases at the N1 level only. One of these had lymph node metastases from a tumor measuring less than 3 cm in size. Twenty-eight of 122 submucosal cancers had lymph node metastases (23%). Twenty of these were SM1 tumors and 5 had lymph node metastases; 4 of these 5 had lymph node metastases despite the absence of vascular invasion.

CONCLUSION

Three cases had lymph node metastases that met the extended criteria for EMR/ESD. EMR and/or ESD should be limited to M cancers without ulcer or differentiated-type M cancer with ulcers smaller than 2 cm. When the depth of tumor invasion is deeper than M, then a gastric resection with lymph node dissection is necessary.

Interventional endoscopy

PURPOSE OF REVIEW

This review is an update of key issues in gastric interventional endoscopy. It focuses on the areas of patient preparation, endoscopic mucosal resection, gastroduodenal stenting, and endoscopic placement of enteric feeding tubes.

RECENT FINDINGS

Clopidogel (Plavix), a newer antiplatelet agent, can increase the risk of bleeding. Therefore, in selected cases, it should be held for 7-10 days prior to interventional procedures. In experienced hands, endoscopic mucosal resection (success rate, 76-100%; complication rate, 4-28%) and gastroduodenal stenting (success rate, 81-92%; complication rate, 1-17%) seem to be safe and effective techniques.

SUMMARY

The field of interventional endoscopy continues to advance and to conquer new frontiers. These advances create new problems that need to be addressed and studied by researchers, however. It is only through these types of reviews that our state of knowledge can be updated to help provide the latest information for clinicians in the field and to challenge researchers with future problems that need to be studied.

Minimally invasive and local treatment for mucosal early gastric cancer

BACKGROUND

Early gastric cancer (EGC) can present an indication for local resection procedures under pertain circumstances. Especially endoscopic mucosal resections (EMRs) and laparoscopic resections or those combined with endoscopy have been made possible in recent years.

METHODS

From 1996 to 2004, of a total of 425 patients with gastric cancer, 58 patients with EGC (13.6%) were prospectively analyzed and observed. Of these, 35 patients had preoperatively diagnosed submucosal infiltration and subsequently underwent gastrectomy and standard lymphnodectomy. Of the 23 patients with intramucosal EGC, 22 underwent local resection. One patient displayed lymph node and liver metastasis at the time of diagnosis and received chemotherapy following staging laparoscopy.

RESULTS

Among the 23 patients with intramucosal EGC, 13 were female and 10 male. The average age of the patients was 77.4 years (range: 69-86). The rate of lymph node metastasis was 12.5% (n = 35) for submucosal EGC and 4.3% (n = 23) for intramucosal EGC. Twenty-two patients with intramucosal EGC underwent local resection (four EMR, six laparoscopic intragastric resection, 12 laparoscopic wedge resection). The average tumor size was 1.2 cm (range 0.3-2.3). The definitive histological findings yielded in all patients tumor-free resection margins without venous or lymphangic infiltration. In 10 of 18 patients undergoing laparoscopic resection a simultaneous sentinel lymph node sampling (4 +/- 3 LN) was performed. There were no metastases detected. Method-specific complications did not occur. The morbidity of this patient group was 13.6% (three of 22). Mortality was zero. The average postoperative hospital stay was 6.5 days (range 2-12). In the median follow-up of 30.3 months (range 1-86) no recurrences have yet been diagnosed. Four patients died within the observation period of non-cancer-related causes.

CONCLUSIONS

Minimally invasive local resection of intramucosal EGC represents a favorable option when strict determination of indication has taken place.