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

Risk Factors for Lymph Node Metastasis in a Western Series of Patients with Distal Early Gastric Cancer

Background: Assessment of potential lymph node metastasis is mandatory in the appropriate treatment of early gastric cancers. This study analysed factors associated with lymph node metastasis to identify differences between node-negative and node-positive patients and between T1a and T1b cancers. Methods: The clinicopathological features of 129 early gastric cancer patients who had undergone radical gastrectomy were analysed to identify predictive factors for lymph node metastasis. Results: Lymph node metastasis was detected in 76 (59.0%) patients. Node-positive patients were younger (58.1 ± 11.3 years) than those without metastasis (61.9 ± 9.6 years, p = 0.02). Greater tumour sizes were observed in patients with lymph node metastasis (3.6 ± 1.0 cm) compared to node-negative patients (1.9 ± 0.5 cm, p = 0.00001). Depressed form, ulceration, diffuse histological type, and undifferentiated lesions were more frequent in node-positive patients than in the node-negative group. Tumour size > 3.0 cm showed a correlation with lymph node metastasis in both T1a (p = 0.0001) and T1b (p = 0.006) cancer. The male sex (p = 0.006) had a significant correlation with lymph node metastasis in T1a cancer. Depressed appearance (p = 0.02), ulceration (p = 0.03), differentiation (p = 0.0001), diffuse type (p = 0.0002), and lower third location (p = 0.005) were associated with lymph node metastasis in T1b cancer. Conclusions: Tumour size > 3 cm, undifferentiated lesions, ulceration, diffuse type, lower third location, and submucosal invasion are risk factors for lymph node metastasis in early gastric cancer.

Pathology and Prognosis of Colonic Adenocarcinomas With Intermediate Primary Tumor Stage Between pT2 and pT3

CONTEXT.—

Primary tumor stage (pT) is an important prognostic indicator in colonic adenocarcinomas; however, cases that have no muscle fibers beyond the advancing tumor edge but also show no extension beyond the apparent outer border of muscularis propria (termed pT2int), have not been previously studied.

OBJECTIVE.—

To address the clinicopathologic characteristics and prognosis of pT2int tumors.

DESIGN.—

We recharacterized 168 colon carcinomas and compared pT2int cases to bona fide pT2 and pT3 tumors.

RESULTS.—

In side-by-side analysis, 21 pT2int cases diverged from 29 pT2 tumors only in terms of larger size (P = .03), but they were less likely to show high-grade (P = .03), lymphovascular (P < .001), and extramural venous invasion (P = .04); discontinuous tumor deposits (P = .02); lymph node involvement (P = .001); and advanced stage (P = .001), compared with 118 pT3 tumors. Combining pT2int with pT2 cases (versus pT3) was a better independent predictor of negative lymph nodes in multivariate analysis (P = .04; odds ratio [OR], 3.96; CI, 1.09-14.42) and absent distant metastasis in univariate analysis (P = .04), compared with sorting pT2int with pT3 cases (versus pT2). Proportional hazards regression showed that pT2 and pT2int cases together were associated with better disease-free survival compared with pT3 tumors (P = .04; OR, 3.65; CI, 1.05-12.70). Kaplan-Meier analysis demonstrated that when pT2int were grouped with pT2 tumors, they were significantly less likely to show disease progression compared with pT3 (P = .002; log-rank test) and showed a trend toward better disease-specific survival (P = .06), during a mean patient follow-up of 44.9 months.

CONCLUSIONS.—

These data support the conclusion that pT2int carcinomas have clinicopathologic characteristics and are associated with patient outcomes more closely aligned with pT2 rather than pT3 tumors.

Feasibility of endoscopic treatment and predictors of lymph node metastasis in early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) has been routinely performed in applicable early gastric cancer (EGC) patients as an alternative to conventional surgical operations that involve lymph node dissection. The indications for ESD have been recently expanded to include larger, ulcerated, and undifferentiated mucosal lesions, and differentiated lesions with slight submucosal invasion. The risk of lymph node metastasis (LNM) is the most important consideration when deciding on a treatment strategy for EGC. Despite the advantages over surgical procedures, lymph nodes cannot be removed by ESD. In addition, whether patients who meet the expanded indications for ESD can be managed safely remains controversial.

AIM

To determine whether the ESD indications are applicable to Chinese patients and to investigate the predictors of LNM in EGC.

METHODS

We retrospectively analyzed 12552 patients who underwent surgery for gastric cancer between June 2007 and December 2018 at the Affiliated Hospital of Qingdao University. A total of 1262 (10.1%) EGC patients were eligible for inclusion in this study. Data on the patients’ clinical, endoscopic, and histopathological characteristics were collected. The absolute and expanded indications for ESD were validated by regrouping the enrolled patients and determining the positive LNM results in each subgroup. Predictors of LNM in patients were evaluated by univariate and multivariate analyses.

RESULTS

LNM was observed in 182 (14.4%) patients. No LNM was detected in the patients who met the absolute indications (0/90). LNM occurred in 4/311 (1.3%) patients who met the expanded indications. According to univariate analysis, LNM was significantly associated with positive tumor marker status, medium (20-30 mm) and large (>30 mm) lesion sizes, excavated macroscopic-type tumors, ulcer presence, submucosal invasion (SM1 and SM2), poor differentiation, lymphovascular invasion (LVI), perineural invasion, and diffuse and mixed Lauren’s types. Multivariate analysis demonstrated SM1 invasion (odds ration [OR] = 2.285, P = 0.03), SM2 invasion (OR = 3.230, P < 0.001), LVI (OR = 15.702, P < 0.001), mucinous adenocarcinoma (OR = 2.823, P = 0.015), and large lesion size (OR = 1.900, P = 0.006) to be independent risk factors.

CONCLUSION

The absolute indications for ESD are reasonable, and the feasibility of expanding the indications for ESD requires further investigation. The predictors of LNM include invasion depth, LVI, mucinous adenocarcinoma, and lesion size.

Endoscopic management of patients with early gastric cancer before and after endoscopic resection: A review

With the wide application of endoscopic resection for early gastric cancer (EGC) by not only Asian endoscopists but also those from Western countries, reviews on standardized treatment processes before and after endoscopic resection are nevertheless lacking. In this article we provide a narrative review of studies on the selection of appropriate EGC for endoscopic resection and the follow-up strategies for those with histologically confirmed EGC after endoscopic resection. EGC should be comprehensively assessed before endoscopic resection, including its exact margin, invasive depth and risk of lymph node metastasis (LNM). While the curative resection status of EGC may be evaluated after endoscopic resection based on the newly developed eCura system, although this needs to be further verified. Surveillance with endoscopy and computed tomography scan is necessary for patients with an EGC level A or B. An additional endoscopic resection is recommended for patients with a level-C1 EGC. For patients with a level-C2 EGC, close follow-up is suggested for low-risk tumors of level C2 and additional surgery for those at high risks. Further postoperative strategy is suggested based on comprehensive assessment of the risk of LNM, patient's quality of life and wishes.

Risk of lymph node metastasis in undifferentiated-type mucosal gastric carcinoma

BACKGROUND

Endoscopic resection (ER) has come to be recognized as a standard treatment for early gastric cancer (EGC). While its adoption is expanding, ER remains restricted to cases of EGC without lymph node metastasis for the treatment of local resection. On the other hand, histopathological analyses of surgically resected specimens of EGC have revealed the presence of lymph node (LN) metastasis in some cases of mucosal gastric cancer (MGC) and undifferentiated MGC (UD-MGC) is considered to have higher risk of nodal metastases than differentiated MGC (D-MGC). To evaluate the risk factors for LN metastasis in MGC, we investigated the characteristics of UD-MGC associated with LN metastasis.

METHODS

Among all UD-MGC patients who underwent surgery as initial treatment, between January 2000 and March 2016, we reviewed the clinicopathological data, including the preoperative endoscopic findings and histopathological findings in the resected specimens, of the 11 UD-MGC patients who were identified as having lymph node metastasis. Furthermore, in comparison with cases without lymph node metastasis, we examined the possibility of expansion of the indication for local treatment.

RESULTS

In most of the cases of UD-MGC with LN metastasis, the lesions were relatively large (> 20 mm in diameter) and of the clearly depressed type with faded color and apparent border, and histopathology revealed a high percentage of cases with lymphatic invasion and a predominance of signet ring cell carcinomas. No cases with LN metastasis without depressed macroscopic type nor signet ring cell carcinoma component existed. A degree of invasion of lamina propria (LP) or muscularis mucosae (MM) had same relation to the risk of LN metastasis.

CONCLUSIONS

In this study, none of the cases of undifferentiated-type mucosal cancer (UD-MGC) with LN metastasis satisfied the current adoption criteria for ER. We suggested significant risk factors for LN metastasis in UD-MGC cases as depressed tumor type, presence of a signet ring cell carcinoma component, presence of lymphatic tumor invasion, and a large tumor size. More detailed analyses of the endoscopic and histopathological findings may allow further risk classification for LN metastasis in cases of UD-MGC.

Pilot Research for the Correlation between the Expression Pattern of E-cadherin-β-Catenin Complex and Lymph Node Metastasis in Early Gastric Cancer

Aims and background

Early gastric cancer without lymph node metastasis can be treated with minimally invasive endoscopic surgery. Hence, a better modality for predicting lymph node metastasis should be beneficial to early gastric cancer patients who may only require minimally invasive treatment. In vitro, phosphorylation of β-catenin induces the loss of membranous β-catenin and E-cadherin, subsequently increasing the potential for metastasis. We investigated the behavior of these molecules comparing lymph node metastasis-positive and lymph node metastasis-negative groups, using the specimens from the patients with early gastric cancer. This was a pilot research evaluating the usefulness of combined analysis of these molecules in predicting lymph node metastasis in early gastric cancer.

Methods

The clinicopathological features and immunohistochemical expression patterns of E-cadherin and β-catenin in the primary lesion were studied retrospectively in 28 patients (lymph node metastasis-positive versus lymph node metastasis-negative: 14 vs 14) selected from 272 patients. These patients underwent radical surgery for the early gastric cancer treatment from April 2000 to March 2004 at our hospital. All patients gave written informed consent to use their tissues for the clinical study. Statistical analyses were performed by the chi-square test and Mann-Whitney test.

Results

More loss of membranous E-cadherin was observed in the lymph node metastasis-positive group than in the lymph node metastasis-negative group. Although the finding was slightly more marked in the intestinal than in the diffuse type early gastric cancer, there was no statistical significance. Loss of membranous β-catenin showed a similar trend and no statistical significance. When we evaluated the expression patterns of both molecules, dual loss of membranous E-cadherin and β-catenin significantly correlated with lymph node metastasis [dual loss in lymph node metastasis-positive versus lymph node metastasis-negative patients: 12 (86%) vs 6 (43%), P = 0.046]. Additionally, corresponding proportions in intestinal type early gastric cancer were 5 of 6 (83%) vs 0 of 6 (0%), P = 0.015.

Conclusions

Based on our results, the combined analysis of E-cadherin and β-catenin localizations may be helpful to accurately predict lymph node metastasis in intestinal type early gastric cancer.

Lymph Node Metastasis in Mucosal Gastric Cancer: Reappraisal of Expanded Indication of Endoscopic Submucosal Dissection

OBJECTIVE

To evaluate risk factors for lymph node (LN) metastasis in mucosal gastric cancer, particularly the effect of cellular differentiation, and implications for the indication of endoscopic submucosal dissection (ESD).

SUMMARY BACKGROUND DATA

The indication of ESD has been expanded to undifferentiated-type (UD-type) gastric cancer despite risk of LN metastasis.

METHODS

Patients who underwent radical gastrectomy for pT1a stage primary gastric adenocarcinoma between 2008 and 2012 were retrospectively analyzed. We evaluated risk factors of LN metastasis using univariate and multivariate analyses. Pathologic slides of primary tumor and metastatic LNs from LN positive patients were reviewed.

RESULTS

A total of 1003 mucosal gastric cancer patients were enrolled, and mean number of retrieved LNs was 35.5. Eighteen (1.8%) among them had LN metastasis: 2 of the 502 differentiated-type (D-type) patients and 16 of the 501 UD-type patients (0.4% vs 3.2%, P < 0.001). Type of cellular differentiation was a significant risk factor for LN metastasis in univariate and multivariate analyses. Of 216 UD-type patients satisfying the expanded indication of ESD, 5 patients (2.3%) showed LN metastasis. Despite more aggressive clinical features such as larger size of tumor and more LN metastasis, the UD-type cancer showed a less invasion into the muscularis mucosae layer than the D-type cancer.

CONCLUSIONS

Because UD-type cancer is a risk factor for LN metastasis in mucosal gastric cancer, ESD cannot be concluded to be a better option than surgery in all UD-type cancer patients. Redefinition of the expanded indication of ESD is required.

Expanded endoscopic therapy criteria should be cautiously used in intramucosal gastric cancer

OBJECTIVE

Accurate estimation of lymph node metastasis (LNM) in intramucosal gastric cancer is essential to select less invasive treatment options and even avoid surgery. The aim of this study was to evaluate combined clinicopathological features to predict the presence of LNM.

METHODS

A retrospective review of data from 386 intramucosal gastric cancer patients who underwent gastrectomy with extended lymphadenectomy from 2003 to 2010 was conducted. The mutual relation between clinicopathological characteristics and LNM was analyzed.

RESULTS

LNM was detected in 40 (10.4%) of the 386 patients. Histological type and vascular or lymphatic invasion presence showed a positive correlation with LNM occurrence by univariate analysis. Multivariate analysis revealed that histological type was the only factor associated with LNM. Combined clinicopathologic characteristics would be more predictable for LNM. We found no LNM when we used combined clinicopathological characteristics conforming to Japanese absolute indications for endoscopic therapy. The LNM rate was as high as 8.7% when Japanese expanded criteria were used. Univariate analysis in cancer conformity to expand endoscopic submucosal dissection (ESD) indication also revealed that the undifferential type was the only significant factor for LNM.

CONCLUSIONS

It was possible to predict intramucosal gastric cancer cases without LNM using combined clinicopathological characteristic analysis. Extended indication for ESD should be cautiously used for intramucosal gastric cancer patients.

The risk of lymph node metastases in 3951 surgically resected mucosal gastric cancers: implications for endoscopic resection

BACKGROUND AND AIMS

Endoscopic resection for mucosal gastric cancer (MGC) is highly recommended in the absence of lymph node metastasis (LNM). We aimed to clarify the risk factors for LNM in MGC and to investigate the association of LNM with the indication criteria for endoscopic submucosal dissection (ESD).

METHODS

A retrospective cohort study was performed on 3951 patients with MGC who underwent radical gastrectomy at the Samsung Medical Center in Seoul, Republic of Korea, between September 1994 and September 2010.

RESULTS

Of the patients with MGC, 101 (2.60%) were positive for LNM. Multivariate analysis, followed by univariate analysis, revealed the following risk factors for LNM in MGC: large tumor size, undifferentiated tumor type, lymphatic invasion, perineural invasion, and associated ulceration in the tumor (hazard ratio 1.25, 7.49, 20.65, 23.45, and 4.07, respectively). Patients without LNM had significantly increased survival and/or recurrence-free survival rates than patients with LNM (188.4/209.8 months vs 169.5/188.0 months; P = .029/.004, respectively). Only 3 of 1065 patients (0.3%) who met the absolute indication criteria for ESD had LNM. Of those who met the expanded indication criteria for ESD, 11 of 2678 patients (0.4%) had LNM. LNM also was found in 2 patients who had a differentiated tumor <0.5 cm without ulceration.

CONCLUSION

The risk for LNM was very low when patients with MGC met the absolute and/or expanded criteria for endoscopic resection, which meant the indication criteria for ESD was safe and acceptable. However, although the risk for LNM is very low, it should not be considered negligible in endoscopic resection.

Detection and Management of Early Gastric Cancer

OPINION STATEMENT

Early gastric cancer (EGC), defined as being confined to the submucosa, is a curable condition. In recent years, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been widely applied to subgroups of mucosal cancers, thereby avoiding the burden of operation while preserving gastric function. However, it can be difficult to identify mucosal cancers, which often evade detection due to their flat shapes without ulceration. Proper preparation to clean the mucosal surface, detailed systematic observation of the entire stomach, and the use of high-resolution systems for both endoscopies equipped with image-enhanced modality and monitors would facilitate the detection of such lesions. It is also critical to evaluate the resected specimen to confirm completeness of resection (tumor-free lateral and vertical margins as well as the absence of lymphatic and vascular invasion). If the resection is incomplete, further treatment is usually recommended-further endoscopic resection for patients with positive lateral margins or surgery for patients with positive vertical margins or with lymphatic or vascular involvement. The five-year survival for endoscopically resected EGC is excellent-and comparable to that of surgical therapy. Since most gastric cancers are caused by Helicobacter pylori, this infection should be tested for routinely. If a patient is H. pylori-positive, eradication is recommended, as heterotopic, metachronous recurrence of EGC is subsequently reduced. Importantly, basic principles for early diagnosis and endoscopic treatment of EGC can be applied to neoplasms arising in other parts of the gut, such as the esophagus and colon, and would be beneficial for patients through preserving organ function and minimizing operative intervention.

Upgrading the definition of early gastric cancer: better staging means more appropriate treatment

Since Murakami defined early gastric cancer (EGC) as a "carcinoma limited to the gastric mucosa and/or submucosa regardless of the lymph node status", several authors have focused on the most influential histopathological parameters for predicting the development of lymph node metastases by considering the lymph node status as an important prognostic factor. A few authors have also considered the depth of invasion as one of the keys to explaining the existence of subgroups of patients affected by EGC with poor prognoses. In any case, EGC is still considered an initial phase of tumor progression with good prognosis. The introduction of modern endoscopic devices has allowed a precise diagnosis of early lesions, which can lead to improved definitions of tumors that can be radically treated with endoscopic mucosal resection or endoscopic submucosal dissection (ESD). Given the widespread use of these techniques, the Japanese Gastric Cancer Association (JGCA) identified in 2011 the standard criteria that should exclude the presence of lymph node metastases. At that time, EGCs with nodal involvement should have been asserted as no longer fitting the definition of an early tumor. Some authors have also demonstrated that the morphological growth pattern of a tumor, according to Kodama's classification, is one of the most important prognostic factors, thereby suggesting the need to report it in histopathological drafts. Notwithstanding the acquired knowledge regarding the clinical behavior of EGC, Murakami's definition is still being used. This definition needs to be upgraded according to the modern staging of the disease so that the appropriate treatment would be selected.

Incidence of lymphatic involvement in differentiated-type intramucosal gastric cancers as examined by endoscopic resection

BACKGROUND

Lymphatic involvement may sometimes be detected in differentiated-type intramucosal cancer resected endoscopically during routine examination, but its incidence and clinical significance remain unknown.

METHODS

We examined 300 endoscopically resected lesions obtained from 238 patients diagnosed with differentiated-type intramucosal gastric cancer. All sections were subjected to D2-40 monoclonal-based immunohistochemistry.

RESULTS

The incidence of lymphatic involvement in differentiated-type intramucosal cancer was 2.0% (6/300). An incidence of 1.8% (5/279) was determined in lesions that were ≤ 3 cm in size and 2.2% (6/276) in those without an ulcer or ulcer scar. Of the six lesions presenting lymphatic involvement, three were determined to be histologically mixed with a predominance of differentiated type, while the other three lesions were pure differentiated type.

CONCLUSIONS

We determined that the incidence of lymphatic involvement in differentiated-type intramucosal cancer was 2.0%. To clarify the clinical significance of such lymphatic involvement, it is necessary to detect it with this incidence in mind and to gather and follow up the clinical courses of such cases.

Feasible endoscopic therapy for early gastric cancer

AIM

To analyze the relationship between lymph node metastasis and clinical pathology of early gastric cancer (EGC) in order to provide criteria for a feasible endoscopic therapy.

METHODS

Clinical data of the 525 EGC patients who underwent surgical operations between January 2009 and March 2014 in the West China Hospital of Sichuan University were analyzed retrospectively. Clinical pathological features were compared between different EGC patients with or without lymph node metastasis, and investigated by univariate and multivariate analyses for possible relationships with lymph node metastasis.

RESULTS

Of the 2913 patients who underwent gastrectomy with lymph node dissection, 529 cases were pathologically proven to be EGC and 525 cases were enrolled in this study, excluding 4 cases of gastric stump carcinoma. Among 233 patients with mucosal carcinoma, 43 (18.5%) had lymph node metastasis. Among 292 patients with submucosal carcinoma, 118 (40.4%) had lymph nodemetastasis. Univariate analysis showed that gender, tumor size, invasion depth, differentiation type and lymphatic involvement correlated with a high risk of lymph node metastasis. Multivariate analysis revealed that gender (OR = 1.649, 95%CI: 1.091-2.492, P = 0.018), tumor size (OR = 1.803, 95%CI: 1.201-2.706, P = 0.004), invasion depth (OR = 2.566, 95%CI: 1.671-3.941, P = 0.000), histological differentiation (OR = 2.621, 95%CI: 1.624-4.230, P = 0.000) and lymphatic involvement (OR = 3.505, 95%CI: 1.590-7.725, P = 0.002) were independent risk factors for lymph node metastasis. Comprehensive analysis showed that lymph node metastasis was absent in patients with tumor that was limited to the mucosa, size ≤ 2 cm, differentiated and without lymphatic involvement.

CONCLUSION

We propose an endoscopic therapy for EGC that is limited to the mucosa, size ≤ 2 cm, differentiated and without lymphatic involvement.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Redefining early gastric cancer

BACKGROUND

The problem is that current definitions of early gastric cancer allow the inclusion of regional lymph node metastases. The increasing use of endoscopic submucosal dissection to treat early gastric cancer is a concern because regional lymph nodes are not addressed. The aim of the study was thus to critically evaluate current evidence with regard to tumour-specific factors associated with lymph node metastases in "early gastric cancer" to develop a more precise definition and improve clinical management.

METHODS

A systematic and comprehensive search of major reference databases (MEDLINE, EMBASE, PubMed and the Cochrane Library) was undertaken using a combination of text words "early gastric cancer", "lymph node metastasis", "factors", "endoscopy", "surgery", "lymphadenectomy" "mucosa", "submucosa", "lymphovascular invasion", "differentiated", "undifferentiated" and "ulcer". All available publications that described tumour-related factors associated with lymph node metastases in early gastric cancer were included.

RESULTS

The initial search yielded 1494 studies, of which 42 studies were included in the final analysis. Over time, the definition of early gastric cancer has broadened and the indications for endoscopic treatment have widened. The mean frequency of lymph node metastases increased on the basis of depth of infiltration (mucosa 6% vs. submucosa 28%), presence of lymphovascular invasion (absence 9% vs. presence 53%), tumour differentiation (differentiated 13% vs. undifferentiated 34%) and macroscopic type (elevated 13% vs. flat 26%) and tumour diameter (≤2 cm 8% vs. >2 cm 25%).

CONCLUSION

There is a need to re-examine the diagnosis and staging of early gastric cancer to ensure that patients with one or more identifiable risk factor for lymph node metastases are not denied appropriate chemotherapy and surgical resection.

Risk of lymph node metastasis in differentiated type mucosal early gastric cancer mixed with minor undifferentiated type histology

BACKGROUND

The possibility of lymph node metastasis is critical to the assessment of the indication for endoscopic submucosal dissection. The differentiation of tumors is an important predicting factor for lymph node metastasis. Even though gastric cancers frequently show intratumoral heterogeneity, most studies have not considered the effects of the minor histologic components. The purpose of this study was to investigate the relationship between the presence of undifferentiated type histology (UD-min) within differentiated type tumors and lymph node metastases in early gastric cancer confined to the mucosal layer.

METHODS

A retrospective study of 847 patients who underwent surgery for differentiated early gastric cancer, confined to mucosa, was conducted. We analyzed the proportion of the undifferentiated type components of the tumor and their relationship with lymph node metastasis.

RESULTS

The overall rate of lymph node metastasis was 1.7 % (14/847 patients) and 215 differentiated tumors (25.4 %) have UD-min. UD-min was associated with female sex, younger age, larger tumor size, and the presence of ulcer. Lymph node metastasis rate with or without UD-min was 5.1 % (11/215) versus 0.5 % (3/632), respectively (p < 0.001). UD-min was found to be associated with lymph node metastasis in the multivariate analyses (odds ratio [OR] = 4.39, CI 1.08-17.89). When three risk factors (tumor size >2 cm, ulcer, and UD-min) were present concurrently, the rate of lymph node metastasis was high (10 %).

CONCLUSIONS

The presence of an UD-min component should be considered when assessing curative resection status of endoscopic submucosal dissection for differentiated type mucosal cancer.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients’ desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Endoscopic submucosal dissection and surgical treatment for gastrointestinal cancer

Endoscopic submucosal dissection (ESD) is widely used in Japan as a minimally invasive treatment for early gastric cancer. The application of ESD has expanded to the esophagus and colorectum. The indication criteria for endoscopic resection (ER) are established for each organ in Japan. Additional treatment, including surgery with lymph node dissection, is recommended when pathological examinations of resected specimens do not meet the criteria. Repeat ER for locally recurrent gastrointestinal tumors may be difficult because of submucosal fibrosis, and surgical resection is required in these cases. However, ESD enables complete resection in 82%-100% of locally recurrent tumors. Transanal endoscopic microsurgery (TEM) is a well-developed surgical procedure for the local excision of rectal tumors. ESD may be superior to TEM alone for superficial rectal tumors. Perforation is a major complication of ESD, and it is traditionally treated using salvage laparotomy. However, immediate endoscopic closure followed by adequate intensive treatment may avoid the need for surgical treatment for perforations that occur during ESD. A second primary tumor in the remnant stomach after gastrectomy or a tumor in the reconstructed organ after esophageal resection has traditionally required surgical treatment because of the technical difficulty of ER. However, ESD enables complete resection in 74%-92% of these lesions. Trials of a combination of ESD and laparoscopic surgery for the resection of gastric submucosal tumors or the performance of sentinel lymph node biopsy after ESD have been reported, but the latter procedure requires a careful evaluation of its clinical feasibility.

Genomic profiling of submucosal-invasive gastric cancer by array-based comparative genomic hybridization

Genomic copy number aberrations (CNAs) in gastric cancer have already been extensively characterized by array comparative genomic hybridization (array CGH) analysis. However, involvement of genomic CNAs in the process of submucosal invasion and lymph node metastasis in early gastric cancer is still poorly understood. In this study, to address this issue, we collected a total of 59 tumor samples from 27 patients with submucosal-invasive gastric cancers (SMGC), analyzed their genomic profiles by array CGH, and compared them between paired samples of mucosal (MU) and submucosal (SM) invasion (23 pairs), and SM invasion and lymph node (LN) metastasis (9 pairs). Initially, we hypothesized that acquisition of specific CNA(s) is important for these processes. However, we observed no significant difference in the number of genomic CNAs between paired MU and SM, and between paired SM and LN. Furthermore, we were unable to find any CNAs specifically associated with SM invasion or LN metastasis. Among the 23 cases analyzed, 15 had some similar pattern of genomic profiling between SM and MU. Interestingly, 13 of the 15 cases also showed some differences in genomic profiles. These results suggest that the majority of SMGCs are composed of heterogeneous subpopulations derived from the same clonal origin. Comparison of genomic CNAs between SMGCs with and without LN metastasis revealed that gain of 11q13, 11q14, 11q22, 14q32 and amplification of 17q21 were more frequent in metastatic SMGCs, suggesting that these CNAs are related to LN metastasis of early gastric cancer. In conclusion, our data suggest that generation of genetically distinct subclones, rather than acquisition of specific CNA at MU, is integral to the process of submucosal invasion, and that subclones that acquire gain of 11q13, 11q14, 11q22, 14q32 or amplification of 17q21 are likely to become metastatic.

Improving the AJCC/TNM classification for use in early gastric cancer

PURPOSE

The current TNM classification is still unsatisfactory for collecting all the prognostic information from the clinical presentation of early gastric cancer: "T" is limited to two levels, the classes of "N" are still wide and "M" is generally absent.

PATIENTS AND METHODS

This study involved 99 patients who underwent radical gastric resection for early gastric cancer. Clinical and histological parameters were prognostically analyzed for both observed and relative survival. Univariate and multivariate analyses were applied to the proportional hazards model.

RESULTS

Number of metastatic lymph nodes and measure of the largest diameter of the tumor were the only independent prognosticators of observed and relative survival. Their similar relative hazards allowed an additive use of them in the N class. Two cut-off values of this composite clinical parameter are proposed for a good discrimination of the relative survival.

DISCUSSION

The number of metastatic lymph nodes is the cornerstone of the current TNM system and was confirmed as adequate. The possibility of adding tumor size to the number of the involved lymph nodes improves and amplifies the prognostic ability, which is presently limited by the rarity of lymph node involvement and the small number of the lymph nodes usually involved.

Frequency and predictive factors of lymph node metastasis in mucosal cancer

Purpose

The incidence of lymph node metastasis has been reported to range from 2.6 to 4.8% in early stage gastric cancer with mucosal invasion (T1a cancer). Lymph node metastasis in early stage gastric cancer is known as an important predictive factor. We analyzed the prediction factors of lymph node metastasis in T1a cancer.

Materials and Methods

A total of 9,912 patients underwent radical gastrectomy due to gastric cancer from October 1994 to July 2006 in the Department Of Surgery at Samsung Medical Center. We did a retrospective analysis of 2,524 patients of these patients, ones for whom the cancer was confined within the mucosa.

Results

Among the 2,524 patients, 57 (2.2%) were diagnosed with lymph node metastasis, and of these, cancer staging was as follows: 41 were N1, 8 were N2, and 8 were N3a. Univariate analysis of clinicopathological factors showed that the following factors were significant predictors of metastasis: tumor size larger than 4 cm, the presence of middle and lower stomach cancer, poorly differentiated adenocarcinoma and signet-ring cell carcinoma, diffuse type cancer (by the Lauren classification), and lymphatic invasion. Multivariate analysis showed that lymphatic invasion and tumor larger than 4 cm were significant factors with P<0.001 and P=0.024, respectively.

Conclusions

The frequency of lymph node metastasis is extremely low in early gastric cancer with mucosal invasion. However, when lymphatic invasion is present or the tumor is larger than 4 cm, there is a greater likelihood of lymph node metastasis. In such cases, surgical treatments should be done to prevent disease recurrence.

Independent histological risk factors for lymph node metastasis of superficial esophageal squamous cell carcinoma; implication of claudin-5 immunohistochemistry for expanding the indications of endoscopic resection

Endoscopic resection is curative for superficial esophageal squamous cell carcinoma (ESCC) limited to the lamina propria. Endoscopic resection is not recommended for superficial ESCC invading muscularis mucosa or submucosa, however, because of the high frequency of lymph node metastasis (LNM) in such patients. Methods to more accurately predict LNM by analysis of endoscopically resected specimens are needed. Patients with superficial ESCC who underwent surgery without prior chemoradiotherapy (n= 110) were retrospectively examined to determine whether LNM correlated with immunohistochemical parameters and conventional histological parameters, including depth of invasion and vascular permeation. Cancer cell expression of claudins-1, 5, and 7, E-cadherin, beta-catenin, and matrix metalloproteinase 7 was evaluated. Univariate analysis revealed that LNM correlated with claudin-5 expression, but not any other immunohistochemical parameter examined. Multivariate analysis revealed three independent risk factors for LNM: aberrant claudin-5 expression in cancer cells (odds ratio; OR [95% confidence interval]= 4.61[1.44-14.77]), depth of submucosal invasion greater than 200 microm (3.55 [1.02-13.17]), and positive lymphatic permeation (3.34 [1.22-9.15]). LNM was found in one of 29 (3.4%) patients with none of these three risk factors, and in 32 of 81 (39.5%) patients with one or more of these risk factors. In superficial ESCC, routine analysis of claudin-5 expression in cancer cells together with depth of invasion and lymphatic permeation may be useful for predicting LNM and thereby reducing the number of patients undergoing additional surgery after successful endoscopic resection.

The demographic characteristics of histological types of gastric cancer with gender, age, and tumor location

OBJECTIVE

The objective of this paper is to study demographic characteristics of different histological types with patient's gender, age, and tumor location in gastric cancer.

METHODS

Three hundred and fifty-one patients who had gastric cancer and undergone a D2 or greater gastrectomy were analyzed retrospectively. The association between gender and age, tumor location and histological types, including tubular adenocarcinoma (TUB), poorly differentiated adenocarcinoma (POR), signet-ring cell carcinoma (SIG), mucinous adenocarcinoma, and undifferentiated carcinoma (UND), were analyzed by chi-square test or Fisher exact test.

RESULTS

The proportion of TUB in males was higher than that in females (52.4% vs 30.1%, p value of 0.000), and the proportion of SIG in females was higher than that in males (26.2% vs 12.9%, p = 0.002). The prevalence of TUB in patients aged >60 years (54.9%) was significantly higher than that in patients aged 40-60 years (42.2%) and <40 years (24.1%). The prevalence of SIG in the group aged <40 years was significantly higher than that in the other two age groups (44.8% vs 15.6%, 12.7%, p = 0.000). Among the three age groups, the proportion of UND was highest in patients aged 40-60 years (7.8% vs 0%, 1.4%, p = 0.012). The proportion of TUB was highest in the upper part of the stomach as compared to the middle and lower parts of the stomach (56.1% vs 30.8%, 48.2%, p = 0.016). POR was commonly found in the middle part of the stomach as compared to the upper and lower parts (44.6% vs 26.1%, 14.6%, p = 0.002).

CONCLUSION

TUB was commonly found in the upper part of the stomach in old, male patients, and SIG was the most common histological type in young, female patients. UND was common in middle-aged patients, and POR was mainly found in the middle part of the stomach.