Endoscopic resection for undifferentiated early gastric cancer

The long-term outcome and risk factors of histologic discrepancy between forceps biopsies and endoscopic resections in early gastric cancer: An observational study

Although endoscopic forceps biopsy is the gold standard for early gastric cancer (EGC) diagnosis, the method can cause endoscopic resection of specimens and histological discrepancies. This study aims to examine the risk factors for histological discrepancies in EGC and long-term clinical outcomes. This retrospective study included patients diagnosed with differentiated-type EGC using forceps biopsy. Patients without histological discrepancies and with undifferentiated types in endoscopic resection histology were categorized into the concordant and discordant groups, respectively. Clinical characteristics and long-term outcomes related to histological discrepancies were analyzed. A total of 957 lesions from 936 patients were enrolled. An overall discrepancy rate of 8.7% was confirmed, with an undifferentiated-type discrepancy of 5.5%. The discordant group showed a higher tendency for lesions to be located in the upper third region, to have whitish discoloration, and to undergo a greater number of biopsies compared with the concordant group. Multivariate analysis confirmed that lesion location in the upper third region (odds ratio [OR]: 2.125; 95% confidence interval [CI]: 1.032-5.277; P = .041) and whitish surface discoloration (OR: 13.615; 95% CI: 6.028-28.728; P = .001) were significantly correlated with histologic discrepancy. Compared with the concordant group, the discordant group had a lower curative resection rate, but no differences were observed in complications, local recurrence, or survival rates. Upper third location and whitish discoloration were risk factors for the histologic discrepancy between differentiated and undifferentiated types in patients with EGC. For curative resections performed in patients with EGC and histologic discrepancies and without additional treatment, careful follow-up is possible.

Endoscopic Features of Undifferentiated-Type Early Gastric Cancer in Patients with Helicobacter pylori-Uninfected or -Eradicated Stomachs: A Comprehensive Review

Since the indications for endoscopic submucosal dissection have been expanded to include undifferentiated-type early gastric cancers, improvements in preoperative diagnostic ability have been an area of research. There are also concerns about the impact on the diagnosis of Helicobacter pylori infection. Based on our previous studies, in undifferentiated-type early gastric cancers, magnifying endoscopy with narrow-band imaging is useful for delineating the demarcation regardless of the tumor size. Additionally, inflammatory cell infiltration appears to be a cause of misdiagnosis, suggesting that the resolution of inflammation could contribute to the accurate diagnosis of demarcations. As such, the accuracy of demarcation in eradicated and uninfected cases is higher than that in non-eradicated cases. The common features of the endoscopic findings were discoloration under white-light imaging and a predominance of sites in the lower and middle regions. The uninfected group was characterized by smaller tumor size, flat type, more extended intervening parts in magnifying endoscopy with narrow-band imaging, and pure signet ring cell carcinoma. In contrast, the eradication and non-eradication groups were characterized by larger tumor size, depressed type, and wavy microvessels in magnifying endoscopy with narrow-band imaging. In this comprehensive review, as described above, we discuss the diagnosis of demarcation of undifferentiated-type early gastric cancers, undifferentiated-type early gastric cancers that developed following H. pylori eradication, and H. pylori-uninfected undifferentiated-type early gastric cancers, with a focus on studies with self-examination and endoscopic findings and describe the future direction.

A Rare Case of Primary Gastric Signet Ring Cell Carcinoma: a Review of Guidelines for the Management of Gastric Cancer

Gastric carcinoma is the fifth most common and the third leading cause of cancer deaths worldwide. The incidence of diffuse-type gastric cancer, of which signet ring cell carcinoma is a subtype, is rising in the world. Due to non-specific gastritis-like symptoms, difficulty in assessing true tumor characteristics owing to its horizontal spread, and non-distinguishable endoscopic appearance from other gastric pathologies, the diagnosis of this subtype is challenging. We present a case of a 67-year-old woman with progressively worsening abdominal pain who came for an endoscopic ultrasound evaluation of an incidentally noted pancreatic cyst on a previous MRI. During endoscopy, a 1-cm gastric ulcer was noted along the lesser curvature of the gastric body. Biopsy confirmed a diagnosis of gastric signet ring cell carcinoma (SRCC) with CDX-2 and keratin positivity. The patient underwent total gastrectomy with Roux-en-Y reconstruction. Gross specimen revealed a diffuse SRCC invading the muscularis propria, along with lymphovascular and perineural invasion. In the context of our case, we discuss the morphological features of SRCC and the effectiveness of treatment options based on existing literature. Early accurate diagnosis and staging play an important role in determining treatment options as well as the clinical course of gastric SRCC.

Update on diagnosis and treatment of early signet-ring cell gastric carcinoma: A literature review

Gastric signet-ring cell gastric carcinoma (GSRC) is an unfavorable subtype of gastric cancer (GC) that presents with greater invasiveness and poorer prognosis in advanced stage than other types of GC. However, GSRC in early stage is often considered an indicator of less lymph node metastasis and more satisfying clinical outcome compared to poorly differentiated GC. Therefore, the detection and diagnosis of GSRC at early stage undoubtedly play a crucial role in the management of GSRC patients. In recent years, technological advancement in endoscopy including narrow-band imaging and magnifying endoscopy has significantly improved the accuracy and sensitivity of the diagnosis under endoscopy for GSRC patients. Researches have confirmed that early stage GSRC that meets the expanded criteria of endoscopic resection showed comparable outcomes to surgery after receiving endoscopic submucosal dissection (ESD), indicating that ESD could be considered standard treatment for GSRC after thorough selection and evaluation. This article summarizes the current knowledge and updates pertaining to the endoscopic diagnosis and treatment of early stage signet-ring cell gastric carcinoma.

Endoscopic Resection of Undifferentiated Early Gastric Cancer

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

Endoscopic treatment for early gastric cancer

Background: In Korea, the number of screening endoscopies to detect early stage gastric neoplasms has increased exponentially following the active implementation of the National Cancer Screening Program.Current Concepts: Endoscopic treatment, including endoscopic mucosal resection and endoscopic submucosal dissection, is recognized as a minimally invasive treatment method with low morbidity and mortality for gastric dysplasia or early gastric cancer. Owing to improvement in the detection of early gastric cancer and advances in techniques, cases of endoscopic resection have increased and indications have been expanded. Endoscopic resection can preserve gastric function with excellent maintenance of the patient’s quality of life, and previous studies have shown better long-term follow-up outcomes compared to those with surgery. However, the fundamental limitation of endoscopic procedures is that gastric lymph-node dissection is not possible using endoscopic resection.Discussion and Conclusion: Although the usefulness of endoscopic resection is proven for tumors with a very low risk of lymph-node metastasis, follow-up examination using endoscopy and computed tomography should be performed for at least 5 years after curative resection of early gastric cancer.

Usefulness of Magnifying Endoscopy with Narrow-Band Imaging for Diagnosing Mixed Poorly Differentiated Gastric Cancers

INTRODUCTION

Curative rates of endoscopic treatment for undifferentiated-type early gastric cancer (EGC), particularly mixed poorly differentiated adenocarcinoma (MIXED-POR), are lower than those of endoscopic treatment for the differentiated type. Magnifying endoscopy with narrow-band imaging (ME-NBI) is useful for diagnoses of the histological type. This study aimed to investigate the detection rates of MIXED-POR among undifferentiated-type EGCs using biopsy and ME-NBI in order to improve curative rates through endoscopic treatment.

METHODS

We analyzed 267 lesions initially subjected to endoscopic submucosal resection (ESD) and histologically diagnosed as undifferentiated-type EGCs between July 2005 and December 2016 at our hospital. We obtained written informed consent from all participants. Biopsy and ME-NBI findings were compared to distinguish pure signet ring cell carcinoma (PURE-SIG) and MIXED-POR. ME-NBI findings were divided into 2 categories depending on the presence of irregular vessels. Results of biopsy and ME-NBI (combination method) were also analyzed, and detection rates of MIXED-POR and PURE-SIG were evaluated in terms of sensitivity, specificity, and accuracy.

RESULTS

Overall, 114 lesions were analyzed. Fifty-eight lesions (50.9%) were identified as MIXED-POR. With biopsy, the detection rate of MIXED-POR was significantly lower than that of PURE-SIG (p < 0.0001). ME-NBI detected significantly more MIXED-POR with irregular vessels than PURE-SIG (p < 0.0001). The combination method could detect significantly more MIXED-POR than PURE-SIG (p < 0.0001). The sensitivity and accuracy for MIXED-POR diagnosis were significantly higher with the combination method than with biopsy alone (p < 0.0001).

DISCUSSION/CONCLUSION

Combining biopsy and ME-NBI improved the accuracy of pretreatment diagnosis before ESD in undifferentiated-type cancer.

Subepithelial spread of early gastric cancer is common and extends more than expected

BACKGROUNDS

The clinical significance of subepithelial (SE) spread from early gastric cancer (EGC) is poorly understood. Thus, we evaluated the proportion and extent of SE spread from EGC, as well as related risk factors.

METHODS

We reviewed medical records and pathological specimens from patients with EGC who underwent surgery or endoscopic resection between January 2016 and December 2016 at Chungnam National University Hospital.

RESULTS

A total of 404 patients were reviewed and SE spread was identified for 142 patients (35.1%). The presence of SE spread was associated with gender, histological type, location, endoscopic appearance, color change, presence of lymphovascular invasion, and invasion depth. Multivariable analysis revealed that SE spread was only independently associated with histological type. The distance of SE spread was significantly different between histological types, and the maximum distance was 17 mm.

CONCLUSION

More than 30% of our patients with EGC had SE spread, which could reach up to 17 mm. Given the proportion of SE spread in these cases, a wider resection margin may be safe during endoscopic resection or surgery.

[Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer]

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Long-term outcomes of endoscopic resection followed by additional surgery after non-curative resection in undifferentiated-type early gastric cancer: a nationwide multi-center study

BACKGROUND

Undifferentiated-type early gastric cancer (UD EGC) shows lower curative resection rates after endoscopic submucosal dissection (ESD). Additional surgery is recommended after non-curative resection. We evaluated the long-term outcomes of ESD followed by additional surgery after non-curative resection in UD EGC compared to those for surgery as initial treatment.

METHODS

We reviewed 1139 UD EGC patients who underwent ESD at 18 hospitals and 1956 patients who underwent surgery at two hospitals between February 2005 and May 2015. We enrolled 636 patients with non-curative ESD and 1429 surgery subjects beyond the curative ESD criteria. Among them, 133 patients with additional surgery after ESD (ESD + OP group) and 252 patients without additional surgery (ESD-only group) were matched 1:1 using propensity scores to patients with surgery as initial treatment (surgery group). Overall survival (OS) and recurrence-free survival (RFS) were compared.

RESULTS

Signet ring cell carcinoma and poorly differentiated adenocarcinoma (PDA) were observed in 939 and 1126 cases, respectively. OS was significantly longer in the surgery group than in the ESD + OP group, especially for PDA. However, RFS was shorter in the ESD-only group than those in the ESD + OP and surgery groups. RFS did not differ significantly between the ESD + OP and surgery groups. Compared to the surgery group, the ESD-only and ESD + OP groups had an overall hazard ratio for RFS of 3.58 (95% confidence interval 1.44-8.88) and 0.46 (0.10-2.20), respectively.

CONCLUSIONS

ESD followed by additional surgery after non-curative resection showed comparable cancer-specific outcomes to initial surgery in UD EGC.

Different clinicopathologic features and prognostic significance of signet ring cell histology in early and locally advanced gastric cancer patients

BACKGROUND

Although many studies have evaluated the prognostic significance of signet ring cell (SRC) histology for gastric cancer (GC) patients, the results were conflicting. The objective of this study was to compare clinicopathologic characteristics between SRC type and other types, and evaluate its impact on survival outcome.

METHODS

We retrospectively reviewed clinicopathologic and survival data of 1891 patients who underwent curative resection for GC. All patients were divided into differentiated, undifferentiated and SRC type according to the histological classification. The prognostic differences between different types were compared and clinicopathologic factors were analyzed.

RESULTS

SRC histology type had a poorer disease-free survival (DFS) than differentiated type (5-year DFS, 37.7% vs 52.2%, P<0.001), but there was no prognostic difference between SRC type and undifferentiated type (37.7% vs 41.9%, P>0.05). For early GC patients, SRC type was more frequent in younger, female patients and T1a stage tumors; the 5-year DFS of SRC type was similar to that of any other histology type (P>0.05). SRC type showed more aggressive biological features, including extensive stomach involvement, large tumor size, advanced pTstage and pN stage, than other types for locally advanced GC patients; poorer DFS was observed in SRC type compared with differentiated type. Multivariate analysis indicated that SRC type (HR:1.71, 95%CI:1.10-1.68, P<0.01) and undifferentiated type (HR:1.21, 95%CI:1.04-1.40, P<0.05) were independently associated with poor DFS in locally advanced GC patients.

CONCLUSION

There was a significant difference between early and locally advanced GC patients with regard to clinicopathologic features and prognostic significance of SRC histology. SRC type was an independent prognostic factor for locally advanced GC patients, but not for early GC patients.

Endoscopic Resection of Undifferentiated-type Early Gastric Cancer

Early detection of gastric cancer is crucial because the survival rate can be improved through curative treatment. Although surgery and gastrectomy with lymph node dissection remain as the gold standard for curative treatment, early gastric cancer (EGC) with negligible risk of lymph node metastasis can be treated with endoscopic resection (ER), such as endoscopic submucosal dissection. Among gastric cancers, undifferentiated-type cancer is distinguished from differentiated-type cancer in various aspects in terms of clinical features and pathophysiology. The undifferentiated-type cancer is also known to be associated with an aggressive behavior and a poor prognosis. Therefore, the indication of ER for undifferentiated EGC is limited compared with differentiated-type. Recent studies have reported that ER for undifferentiated EGC is safe and shows favorable short- and long-term outcomes. However, it is necessary to understand the details of the research results and to selectively accept them. In this review, we aimed to evaluate the current practice guidelines and the short-term and long-term outcomes of ER for undifferentiated type EGC.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Different prognostic significance of signet ring cell histology for early and advanced gastric cancer patients: a systematic review and meta-analysis

OBJECTIVE

To review relevant studies and perform a meta-analysis to evaluate the prognostic significance of signet ring cell (SRC) histology for gastric cancer (GC) patients.

METHODS

Systematic literature search was performed using PubMed and Embase databases. The relevant data were extracted and the association between SRC histology and survival outcome were evaluated using a fixed-effect or random-effect model.

RESULTS

A total of 21 studies were included in this meta-analysis. The prevalence of SRC histology varied from 8.7% to 50%. SRC histology type was associated with poorer OS (HR: 1.12, 95%CI: 1.01-1.23, P = 0.034; I² = 85.1%) and DFS (HR: 1.17, 95%CI: 1.00-1.37, P = 0.040; I² = 63.6%). The subgroup analysis indicated that SRC type had a better OS than non-SRC type for early GC patients (HR: 0.60, 95%CI: 0.48-0.75, P < 0.001; I² = 33.7%). However, it was a poor prognostic factor for advanced GC when excluding stage IV patients (HR: 1.18, 95%CI: 1.07-1.29, P < 0.001; I² = 6.5%). SRC type had a higher risk of peritoneal recurrence than non-SRC type (OR: 1.36, 95%CI: 1.06-1.75, P = 0.017; I² = 1.3%).

CONCLUSION

SRC type had a distinctly different prognostic significance for early and advanced GC patients. SRC type was associated with better survival outcomes in early GC patients, but it was a predictive factor for poor survival in advanced GC patients.

Accuracy of endoscopic size measurements of early gastric signet ring cell carcinoma

BACKGROUND AND AIMS

Indications for endoscopic submucosal dissection (ESD) of early gastric cancer (EGC) are expanding, but signet ring cell carcinoma (SRC) is still unclear because of its unclear boundaries. The purpose of this study was to compare pathologic size and endoscopic size in SRC-type EGC and to find risk factors associated with tumor size underestimation.

METHODS

Medical records of 137 patients diagnosed with SRC-type EGC between January 2009 and December 2016 at our tertiary hospital were reviewed. According to pathologic and endoscopic tumor sizes, they were classified into correct estimation, underestimation, and overestimation groups, and risk factors related to underestimation were analyzed.

RESULTS

Among 137 patients with SRC-type EGC, 77 patients (56.2%) had undergone correct estimation, 43 patients (31.4%) had undergone underestimation, and 17 patients (12.4%) had undergone overestimation. Mean pathologic size (SD) was 20.1 (13.8) mm and mean endoscopic size (SD) was 17.9 (10.1) mm, the correlation coefficients were 0.919 (p < 0.001) , and there was no significant difference between the two groups. Multivariate analysis showed that tumor size more than 20 mm (OR 3.419; 95% CI 1.271-9.194; p = 0.015) and atrophy (OR 6.011; 95% CI 2.311-15.633; p = 0.001) were risk factors for tumor size underestimation.

CONCLUSION

There was no significant difference in pathologic and endoscopic size in SRC-type EGC. Therefore, ESD may be considered as a therapeutic option if the size of the tumor is less than 20 mm and atrophy is not present in the surrounding mucosa.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by <i>en bloc</i> fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Subepithelial Spread of Early Gastric Signet Ring Cell Carcinoma: How Far They Can Reach?

INTRODUCTION

Although signet ring cell carcinoma (SRC) is a poorly differentiated cancer subtype, recent studies suggest that endoscopic resection can be applied in small, mucosal early gastric SRC. However, other studies report frequent positive lines at the lateral resection margin after endoscopic treatment. Subepithelial spread beneath normal mucosa can exist in SRC, and such lesions may be the cause of positive margins after endoscopic resection. Thus, we conducted a retrospective study in order to evaluate the significance of subepithelial spread in early gastric SRC.

METHOD

Medical records of early gastric SRC patients who underwent surgery or endoscopic resection from January 2011 to December 2016 at a single tertiary hospital (Daejeon, South Korea) were reviewed to examine subepithelial spread and clinical datum. Two expert pathologists reviewed all pathologic specimens, and only patients showing a pure SRC component were included.

RESULTS

Eighty-six patients were initially enrolled, and subepithelial spread existed in 62 patients (72.1%). The mean distance of subepithelial spread was 1,132.1 µm, and the maximal distance was 6,000 μm. Only discoloration was significantly associated with the presence of a subepithelial spread (p < 0.05, χ2 test, and logistic regression test). Distance of subepithelial spread did not correlate with total lesion size.

CONCLUSION

Subepithelial spread of early gastric SRC occurs frequently and can reach up to 6 mm. Lesion discoloration may be associated with the presence of subepithelial spread. Our results suggest that careful decision of the margin is needed when performing endoscopic resection of early gastric SRC.

Effect of histologic differences between biopsy and final resection on treatment outcomes in early gastric cancer

BACKGROUND AND STUDY AIMS

Biopsy-based histologic diagnosis is important in determining the treatment strategy for early gastric cancer (EGC). However, there are few studies on how histologic discrepancy may affect patients' treatment outcomes. We aimed to investigate the impact of histopathologic differences between biopsy and final specimens from endoscopic resection (ER) or gastrectomy on treatment outcomes in patients with EGC. We also examined the predictive factors of histologic discrepancy.

PATIENTS AND METHODS

We analyzed the data of 1851 patients with EGC treated with ER or gastrectomy. We compared the histology between biopsies and final resected specimens from ER or gastrectomy. We also examined changes in treatment outcomes according to histologic differences.

RESULTS

Histologic discrepancy was observed in 11.9% of patients in the ER group and 10.7% of those in the gastrectomy group. In patients treated with ER who showed histologic discrepancy, 80.9% showed differentiated-type EGC (D-EGC) on biopsy but undifferentiated-type-EGC (UD-EGC) after ER, of which 78.9% were non-curative resection. In patients treated with gastrectomy who showed histologic discrepancy, 39% showed UD-EGC on biopsy but showed D-EGC after gastrectomy. A total of these patients had absolute and expanded indications for ER. Moderately differentiated and poorly differentiated adenocarcinoma on biopsy were predictive factors of histologic discrepancy in UD-EGC and D-EGC on final resection, respectively.

CONCLUSIONS

About 10% of patients showed histologic discrepancy between biopsy and final resection with ER or gastrectomy. Histologic discrepancy can affect treatment outcomes, such as non-curative resection in ER or missing the opportunity for ER in gastrectomy.

Pretreatment diagnosis factors associated with overtreatment with surgery in patients with differentiated-type early gastric cancer

This study aimed to clarify the pretreatment factors associated with overtreatment with surgery in patients with differentiated-type early gastric cancer. This single-centre, retrospective study included 781 patients with differentiated-type early gastric cancer treated by surgical resection between April 2005 and May 2017. Postoperative pathological results were used to divide patients into the accurate surgical indication group and overtreatment with surgery group; the groups were compared with respect to accurate diagnosis and misdiagnosis based on tumour diameter (≤30 mm or >30 mm), diagnosis of depth, diagnosis of ulcerative findings, and diagnosis of main histology. There were 224 patients in the overtreatment with surgery group. Multivariate analysis revealed significant differences in misdiagnosis of tumour diameter, misdiagnosis of depth, misdiagnosis of ulcerative findings, and misdiagnosis of main histology between the accurate surgical indication group and overtreatment with surgery group. Significant factors for pretreatment misdiagnosis leading to overtreatment in differentiated-type early gastric cancer were tumour diameter, depth, and main histology. It may be acceptable to perform endoscopic resection for patients with pretreatment tumour diameter ≤30 mm, mucosal invasion of pretreatment depth, and undifferentiated-type cancers containing differentiated-type components of pretreatment histology because this reduces overtreatment with surgery.

Comparison of Long-Term Outcomes of Endoscopic Submucosal Dissection and Surgery for Early Gastric Cancer: a Systematic Review and Meta-analysis

BACKGROUND

Endoscopic submucosal dissection (ESD) is an endoscopic alternative to surgical resection of early gastric cancer (EGC). Besides offering both diagnostic and therapeutic capability, it has the benefits of reducing post-operative complications and provides fast recovery and better quality of life compared to surgical resection of neoplastic lesions. However, due to limitations of the procedure, its long-term outcomes are rather controversial.

METHODS

This study has been carried out to investigate the long-term outcomes of ESD which includes the overall survival (OS), disease-free survival (DFS), and recurrence rate. The following databases were used to search for articles published until February 2018: Medline, Cochrane Library, PubMed, Web of Science, and EBSCO.

RESULTS

A total of 13 eligible studies covering 4986 patients were selected for a meta-analysis based on specified inclusion and exclusion criteria. The difference of OS and disease-specific survival (DSS) between ESD and surgical treatment was not statistically significant (RR = 0.90, 95% CI = 0.68-1.19, p = 0.46; RR = 0.40, 95% CI = 0.15-1.03, p = 0.06, respectively). However, DFS in the ESD group was much lower than that in the surgery group (RR = 3.40, 95% CI = 2.39-4.84, p < 0.001). In terms of the treatment after recurrence, the proportion of patients who could receive radical treatment was significantly higher in the ESD than that in the gastrectomy (OR = 5.27, 95% CI = 2.35-11.79, p < 0.001).

CONCLUSIONS

This meta-analysis showed that ESD might be an alternative treatment option to surgery for patients with EGC in Asian countries. But a close surveillance program after ESD is of necessity, considering the higher possibility of tumor recurrence after ESD.

Strategy for Curative Endoscopic Resection of Undifferentiated-Type Early Gastric Cancer

Endoscopic resection (ER) of undifferentiated-type early gastric cancer (UD-EGC) has a lower curative resection (CR) rate than differentiated-type EGC. However, if UD-EGC is curatively resected using ER, long-term outcomes can be favorable. Thus, the strategy for CR by ER is important in UD-EGC. To achieve CR in UD-EGC, biological behaviors including tumor growth patterns must be considered. This review aims to describe what is important for curative ER of UD-EGC.

Diagnostic accuracy of demarcation using magnifying endoscopy with narrow-band imaging for Helicobacter pylori-uninfected undifferentiated-type early gastric cancer

BACKGROUND

It is unknown how the accuracy rate of diagnostic demarcation of undifferentiated-type early gastric cancers (UD-type EGCs) differs between patients uninfected with Helicobacter pylori (H. pylori) and patients with and without H. pylori eradication. This study assessed and compared the diagnostic accuracy rate in the H. pylori-uninfected group and the non-H. pylori eradication and H. pylori eradication groups.

METHODS

Subjects were 81 patients with 81 lesions who underwent endoscopic submucosal dissection between January 2010 and January 2015. There were 21 lesions in the H. pylori-uninfected group, 27 in the H. pylori eradication group, and 33 in the non-H. pylori eradication group. The rate in the H. pylori-uninfected group was separately compared with the rates in the non-H. pylori eradication and H. pylori eradication groups, as was inflammatory cell infiltration.

RESULTS

The diagnostic accuracy rates were 60.6% in the non-H. pylori eradication group, 92.2% in the H. pylori eradication group, and 100% in the H. pylori-uninfected group; the rate was significantly higher in the H. pylori-uninfected group than in the non-H. pylori eradication group, but no significant difference was observed between the H. pylori-uninfected group and the H. pylori eradication group. In addition, the H. pylori-uninfected and H. pylori eradication groups showed no significant differences in neutrophil infiltration and intestinal metaplasia, whereas the state in the H. pylori-uninfected group was significantly milder.

CONCLUSIONS

Because neutrophil infiltration was classified as mild or none, the accuracy of diagnostic demarcation was high in the H. pylori-uninfected and H. pylori eradication groups.

Undifferentiated-type component mixed with differentiated-type early gastric cancer is a significant risk factor for endoscopic non-curative resection

BACKGROUND AND AIM

Previous studies of surgical specimens have found that the presence of mixed histological components in differentiated-type early gastric cancer (EGC) is a risk factor for lymph node metastasis and indicates greater malignancy. As there have been no reports on its endoscopic treatment, we examined endoscopic curative resection in relation to differentiated-type-predominant mixed-type (MT).

METHODS

This was a single-center, retrospective study. Subjects were 2585 differentiated-type EGC in 2551 patients treated with endoscopic submucosal dissection (ESD) in our hospital between March 2005 and January 2016. These lesions comprised 2231 cases of curative resection and 354 cases of non-curative resection. Histologically, 2339 lesions were pure differentiated-type (PDT) and 246 lesions were MT. Rates of curative resection were compared, according to tumor size, between different histological types.

RESULTS

When curative and non-curative cases were compared using multivariate analysis among lesions measuring ≤20 mm for factors other than those determining curative resection, significant differences were obtained for tumor diameter, ulcer, and MT. Among lesions measuring 21-30 mm, ulcer and MT were associated with significant differences. Among lesions measuring >30 mm, upper region and MT were associated with significant differences. Curative resection rates, in relation to histological type among lesions measuring ≤20 mm, were 93.4% for PDT and 63.4% for MT, whereas corresponding rates were 85.1% and 60.0%, respectively, among lesions measuring 21-30 mm, and 55.3% and 30.2%, respectively, among lesions measuring >30 mm.

CONCLUSION

We found that MT was a risk factor for non-curative resection irrespective of lesion size.

Mixed poorly differentiated adenocarcinoma in undifferentiated-type early gastric cancer predicts endoscopic noncurative resection

BACKGROUND

Comparisons between surgical cases of mixed poorly differentiated adenocarcinoma and pure signet ring cell carcinoma have revealed higher frequencies of lymph node metastasis and submucosal invasion in the former. However, this comparison has not been reported for endoscopically treated cases. Therefore, we compared cases of curative and noncurative resection in patients who underwent endoscopic submucosal dissection to determine what factors could influence the curative resection rate.

METHODS

We analyzed 268 undifferentiated-type early gastric cancers in 264 patients treated with endoscopic submucosal dissection in our hospital between March 2005 and March 2017, involving 229 and 39 cases of curative and noncurative resection, respectively. Treatment results were compared between 129 lesions of pure signet ring cell carcinoma and 139 lesions of mixed poorly differentiated adenocarcinoma.

RESULTS

The overall curative resection rate was 85.4% (229/268). On comparing noncurative and curative resection cases, after excluding factors that determine curative resection (e.g., tumor diameter), we found that the former was associated with older age and significantly more mixed poorly differentiated adenocarcinomas, with odds ratios of 1.052 [95% confidence interval (CI), 1.017-1.089] and 2.746 (95% CI, 1.162-6.485), respectively, on multivariate analysis. The curative resection rate was significantly higher in pure signet ring cell carcinoma than in mixed poorly differentiated adenocarcinoma (93.8% vs. 77.7%, respectively).

CONCLUSION

Advanced age and mixed poorly differentiated adenocarcinoma predicted endoscopic noncurative resection.

Long-term outcomes of endoscopic submucosal dissection in comparison to surgery in undifferentiated-type intramucosal gastric cancer using propensity score analysis

BACKGROUND

The treatment of intramucosal early gastric cancer with undifferentiated-type histologies (UD-EGCs) using endoscopic submucosal dissection (ESD) is controversial. This study aimed to compare the clinical and oncologic long-term outcomes of ESD and surgery for UD-EGCs.

METHODS

A prospectively collected database of patients who underwent ESD or surgery between January 2006 and December 2012 was established. Patients who diagnosed with UD-EGC and satisfied the expanded indications of ESD were included. Clinical data from 111 patients treated with ESD and 382 patients underwent surgery were analyzed, and 1-1 propensity score-matched 81 pairs of patients were also compared.

RESULTS

In both groups, two-thirds of the UD-EGCs had signet ring cell (SRC)-type histology and about 90% of UD-EGCs were flat or depressed types. The mean size of tumors was smaller in ESD group (9.7 vs. 13.2 mm; P < 0.001). After propensity score-matched, case-matching covariates were not significantly different between the groups. Disease-free survival (DFS) was significantly shorter in the ESD group, but overall survival (OS) was not different between the two groups both in overall comparison (DFS; P < 0.001 and OS; P = 0.078) and propensity score-matched analysis (DFS; P < 0.001 and OS; P = 0.850). According to histologic type, OS of SRC histology was not different between the group, both in overall comparison and propensity score-matched analysis (P = 0.286 and P = 0.210). On the other hands, OS of poorly differentiated adenocarcinoma was significantly shorter in ESD group in overall comparison (P = 0.007), but was not as so in propensity score-matched analysis (P = 0.088).

CONCLUSIONS

ESD might be a complementary option for the treatment of UD-EGCs, especially in those with SRC-type histology based on strict expanded indications. Nonetheless, close endoscopic surveillance is required because of a high incidence of intragastric recurrence.

Risk factors for lymph node metastasis of early gastric cancers in patients younger than 40

This research aims to explore the potential risk factors of lymph node metastasis (LNM) for early gastric cancers in young patients.We retrospectively collected data from 4287 patients who underwent gastrectomy from January 2005 to December 2015 at Linyi People's Hospital. Of these, we enrolled 397 eligible consecutive patients who had early gastric cancer, then divided them into 2 groups according to age (≤40 years and >40 years). The association between the clinicopathological factors and LNM was analyzed by univariate and multivariate analysis.Compared to older patients (>40 years), younger patients (≤40 years) with early gastric cancer had more diffuse and mixed types (51.1% and 37.8% vs 40% and 8.3%, respectively), less proximal gastric cancer (0% vs 33.8%, P < .01) and higher LNM (33.3% vs 13%, P < .01). Univariate analysis showed tumor invasion depth (P < .01), lymphovascular invasion (P < .01), and E-cadherin expression (P = .024) were associated with LNM in the younger cohort. Multivariate analysis revealed that lymphovascular invasion (OR = 17.740, 95% CI: 1.458-215.843) was an independent risk factor for LNM (P = .024). Further analysis showed 3 patients who were within expanded endoscopic resection indications were positive for LNM.Given the high risk of lymph node involvement in young patients with early gastric cancer, both endoscopic and surgical resection procedures should be performed with caution, and active postoperative surveillance is warranted.

Diagnostic accuracy of demarcation of undifferentiated-type early gastric cancer after Helicobacter pylori eradication

BACKGROUND

It is unknown whether Helicobacter pylori (H. pylori) eradication is beneficial when demarcating undifferentiated-type early gastric cancers (UD-type EGCs). This study aimed to determine whether H. pylori eradication is beneficial, and also when benefits become detectable.

METHODS

Sixty lesions that were detected as a ≤20-mm lesion without metastasis or ulceration on routine examination, diagnosed as UD-type EGC on biopsy, and treated with endoscopic submucosal dissection between January 2010 and January 2015 were studied. Magnifying endoscopy with narrow-band imaging (ME-NBI) was performed to demarcate the lesions. The most oral and most anal sites were marked. After endoscopic therapy, the markings were compared with the pathological examination results to calculate accurate diagnosis rates, which were compared between 27 patients with H. pylori eradication and 33 patients without. Mean intercrypt distance ratio and inflammatory cell infiltration were also compared, as were seven patients who underwent the procedure 1 month after H. pylori eradication and 20 patients who underwent the procedure more than 1 month after H. pylori eradication.

RESULTS

Accurate diagnosis rates were 92.2% with eradication and 60.6% without. Mean intercrypt distance ratios were 1.95 and 1.59, respectively. Neutrophil infiltration was mild in the eradication group. Significant differences were observed in each parameter (p < 0.05). No significant difference was observed between the 1-month eradication and >1-month eradication subgroups in terms of accurate diagnosis rate, mean intercrypt distance ratio, or histological grade of any item.

CONCLUSIONS

This study suggests that H. pylori eradication therapy aids the accurate delineation of UD-type EGC in ME-NBI.

Comparative study between endoscopic submucosal dissection and surgery in patients with early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) is accepted as a standard treatment in patients with early gastric cancer (EGC) who have a negligible risk of lymph node metastasis. The aim of this study was to compare the short-term and long-term outcomes between ESD and surgery in patients with EGC that fulfilled the expanded indication of ESD on their final pathologic report.

METHODS

We reviewed the clinical data of patients who underwent gastric ESD and surgery between January 2007 and December 2012. Patients with pathologically confirmed EGC that fulfilled the expanded indication of ESD on their final pathologic report were analyzed.

RESULTS

Among 2023 patients, 817 (40.4%) underwent ESD and 1206 (59.6%) underwent surgery. The proportion of cases meeting the absolute indication was significantly higher in the ESD group than in the surgery group (66.0 vs. 26.2%). Lesions on the middle third, >3 cm in size, flat or depressed, and of undifferentiated histology were significantly more common in the surgery group than in the ESD group. The ESD group showed lower acute complication rates [8.1% (66 of 817) vs. 18.1% (218 of 1206), P ≤ 0.001] and procedure-related mortality [0 vs. 0.3% (4 of 1206), P = 0.153] than the surgical group. The annual incidence of recurrent gastric cancer was 2.18% in the ESD group and 0.19% in the surgery group. The 5-year overall and disease-specific survival rates were not significantly different between the ESD group and the surgery group (overall survival: 96.4 vs. 97.2%, P = 0.423; disease-specific survival: 99.6 vs. 99.2%, P = 0.203).

CONCLUSIONS

Although EGC lesions had poorer features in the surgery group than in the ESD group, ESD was comparable to surgery for EGCs that fulfilled the expanded indication of ESD, with lower rates of acute complication and comparable overall survival.

A Risk-prediction Model Based on Lymph-node Metastasis for Incorporation Into a Treatment Algorithm for Signet Ring Cell-type Intramucosal Gastric Cancer

OBJECTIVE

The aim of the study was to develop a reliable and easy-to-use risk-scoring system (RSS) to predict lymph-node metastasis (LNM) and determine the feasibility of endoscopic submucosal dissection for mucosa-confined signet ring cell carcinomas (SRCs).

BACKGROUND

Fewer LNM and better survival rates have been reported for early gastric SRCs compared with other undifferentiated early gastric cancers (EGCs).

METHODS

Data from 1544 patients with mucosa-confined SRCs were reviewed. Stepwise logistic regression analysis determined the independent predictors of LNM. Risk scores were based on the final predictive factors for LNM, and performance was internally validated using a split-sample approach. External validation was also performed in an independent dataset (n = 208) to assess the discriminatory power of the RSS.

RESULTS

The overall LNM incidence was 3.8% (57/1544). Three risk factors (tumor size ≥1.7 cm, tumors of elevated type, and lymphatic-vascular involvement) were significantly associated with LNM. These factors were incorporated into the RSS, and were assigned scores ranging from 0 to 4. The area under the receiver-operating characteristic curve for predicting LNM after internal and external validation was 0.68 (95% confidence interval, 0.0793-0.2865) and 0.686 (95% confidence interval, 0.618-0.748), respectively. A score of 2 points was the optimal cut-off value for LNM prediction, and the overall diagnostic accuracy was 96%. LNM were found in 2.9% and 23.8% of the low and high-risk groups of the RSS, respectively.

CONCLUSIONS

A RSS may help to predict LNM and evaluate endoscopic submucosal dissection feasibility in patients with intramucosal SRC.

Prediction model for non-curative resection of endoscopic submucosal dissection in patients with early gastric cancer

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is a useful method for complete resection of early gastric cancer (EGC). However, there are still some patients who undergo additional gastrectomy after ESD because of non-curative resection. There is no model that can accurately predict non-curative resection of ESD. We aimed to create a model for predicting non-curative resection of ESD in patients with EGC.

PATIENTS AND METHODS

We reviewed the medical records, including all gross findings of EGC, of patients who underwent ESD for EGCs. We divided the patients into a non-curative resection group and a curative resection group. The clinicopathologic characteristics were compared between the groups to identify the risk factors for non-curative resection of ESD. We created a scoring system based on logistic regression modeling and bootstrap validation.

RESULTS

Of 1639 patients who had undergone ESD for EGCs, 272 were identified as being treated non-curatively with ESD. A large tumor size (≥20 mm), tumor location in the upper body of the stomach, the presence of ulcer, fusion of gastric folds, the absence of mucosal nodularity, spontaneous bleeding, and undifferentiated tumor histology were associated with non-curative resection of ESD. Points of risk scores were assigned for these variables based on the β coefficient as follows: tumor size (≥20 mm), 2 points; tumor location in the upper body of the stomach, 1 point; ulcer, 2 points; fusion of gastric folds, 2 points; absence of mucosal nodularity, 1 point; spontaneous bleeding, 1 point; and undifferentiated histology, 2 points. Our risk scoring model showed good discriminatory performance on internal validation (bootstrap-corrected area under the receiver operating characteristic curve, 0.7004; 95% confidence interval, 0.6655-0.7353).

CONCLUSIONS

We developed a validated prediction model that can be used to identify patients who will undergo non-curative resection of ESD. Our prediction model can provide useful information for making decisions about the treatment of EGC before performing ESD.

Predictive Factors for Lymph Node Metastasis in Undifferentiated Early Gastric Cancer: a Systematic Review and Meta-analysis

OBJECTIVES

Less invasive surgery is gaining popularity for the treatment of early gastric cancer (EGC), but there are no definitive guidelines for the use of less invasive surgery for the treatment of undifferentiated EGC. The aims of this meta-analysis were to identify potential predictive factors for lymph node metastasis (LNM) in undifferentiated EGC and to guide the personalized therapeutic modality for patients with undifferentiated EGC.

METHODS

An extensive search of the PubMed, Embase, and Cochrane Library databases was performed to identify relevant articles involving undifferentiated EGC and LNM. Eligible data were systematically reviewed through a meta-analysis using Review Manager 5.3.

RESULTS

In total, 23 studies were included in this analysis. The meta-analysis found that the variables sex (female), age (greater than 60 years), tumor size (greater than 20 mm), depth of invasion (submucosal invasion), presence of lymphovascular involvement, presence of ulcer findings, histology type (non-signet ring carcinoma), and tumor location (not in the middle part of the stomach) were significantly associated with LNM.

CONCLUSIONS

Eight variables were identified as predictive factors for LNM in undifferentiated EGC. The significance of these variables should be further confirmed during the process of LNM in undifferentiated EGC patients for future clinical application.

Therapeutic outcomes of endoscopic submucosal dissection for early gastric cancer: single-center study

OBJECTIVES

Endoscopic submucosal dissection (ESD) has been widely accepted for selected patients with early gastric cancer (EGC). The aim of this study was to assess the therapeutic outcomes after ESD according to the pathological extent.

PATIENTS AND METHODS

From January 2005 to December 2014, a total of 599 patients with 611 lesions were enrolled in this study. The tumors were categorized according to pathological results on the basis of absolute criteria (AC), expanded criteria (EC), EC with undifferentiated histology [(EC-U), mucosal cancer, ulcer (-), ≤20 mm], or beyond EC (BEC). The therapeutic outcomes among the four groups were analyzed retrospectively.

RESULTS

The number of patients in the AC, EC, EC-U, and BEC groups was 447, 91, 19, and 54. The complete resection rates of EGC were 97.8, 84.6, 94.4, and 45.5% (P=0.001) and en bloc resection rates in the AC, EC, EC-U, and BEC groups were 99.1, 98.9, 100, and 98.1% (P=0.833), respectively. The 5-year disease-free survival rate in the AC, EC, EC-U, and BEC groups was 90.6, 88.7, 75.0, and 83.3% (P=0.394). In multivariate analysis, undifferentiated histology (P=0.001) and tumor size (>30 mm, P=0.017) were risk factors related to local recurrence.

CONCLUSION

The efficacy of ESD for EGCs in EC is almost equal to that in AC when complete resection was achieved. However, the indication for ESD should be decided conservatively because the complete resection rate of EGC in the EC group was significantly lower than that in the AC group. Undifferentiated histology and tumor size over 30 mm were risk factors related to local recurrence.

Accuracy of diagnostic demarcation of undifferentiated-type early gastric cancer for magnifying endoscopy with narrow-band imaging: surgical cases

BACKGROUND AND AIM

The usefulness of magnifying endoscopy with narrow-band imaging (ME-NBI) in undifferentiated-type early gastric cancers (UD-type EGCs) is unclear. This study investigated the accuracy of ME-NBI in the diagnostic demarcation.

METHODS

Among UD-type EGCs that were initially surgically resected between June 2011 and August 2014 in this hospital, 74 lesions were studied that were preoperatively diagnosed with white-light imaging (WLI) or endoscopic ultrasonography as lesions for which endoscopic treatment was not indicated and found to be early gastric cancers by postoperative pathology. The demarcation line was marked on the most oral and anal sides with argon plasma coagulation using WLI and ME-NBI, and the diagnostic demarcation of cancer was defined as correct, if consistent with the results of postoperative pathology. The length of extension into the proliferative zone, distance between crypts and inflammatory cell infiltration (updated Sydney classification: USC) were compared between the correctly diagnosed and the misdiagnosed cases.

RESULTS

The diagnosis was correct in 62 cases (83.8 %). The average distance between crypts in correctly diagnosed and misdiagnosed cases was approximately 1.9 and 1.3 times, respectively, that in normal mucosa (p < 0.0001). The accuracy of diagnosis was higher when atrophy and neutrophil and monocyte infiltration were mild according to the USC (p < 0.05). The additional use of ME-NBI improved the accuracy of diagnosis by 36.5 % compared with the use of WLI alone.

CONCLUSION

The use of ME-NBI in the preoperative diagnosis of the demarcation of cancer is useful to prevent postoperative positive surgical margins.

Growth Patterns of Signet Ring Cell Carcinoma of the Stomach for Endoscopic Resection

Background/Aims

It is difficult to precisely detect the lateral margin during endoscopic submucosal dissection (ESD) for signet ring cell carcinoma (SRC) because SRC often expands to lateral direction through the lamina propria. Thus, the aim of this study was to classify the intramucosal spreading patterns of SRC and to analyze the patients’ clinicopathological findings according to the spreading patterns.

Methods

The intramucosal spreading patterns of SRC were classified as expansive or infiltrative types. A total of 100 surgical and 42 ESD specimens were reviewed.

Results

In the surgical specimens, the proportions of expansive and infiltrative types were 44% and 56%, respectively. The infiltrative type was more commonly associated with old age, atrophy, and intestinal metaplasia in surrounding mucosa and the absence of Helicobacter pylori compared with the expansive type. In ESD specimens, the proportions of expansive and infiltrative types were each 50%. When lateral margin-positive lesions were compared with -negative lesions, larger size, residual lesion, and the lack of a neutrophil infiltration were more significantly associated with lateral margin-positive lesions. All cases with residual tumors in lateral margin-positive lesions were classified as the infiltrative type.

Conclusions

SRC surrounded with atrophy and/or intestinal metaplasia often spreads subepithelially in the margin. This finding may suggest that a larger safety margin is necessary in this type during ESD.

Is the recent WHO histological classification for gastric cancer helpful for application to endoscopic resection?

BACKGROUND

Endoscopic resection is performed in undifferentiated-type early gastric cancer (UD-EGC), including poorly differentiated (PD) adenocarcinoma and signet ring cell (SRC) carcinoma. We previously found that different approaches are needed for PD adenocarcinoma and SRC carcinoma for curative resection. However, according to the 2010 WHO classification, diffuse-type PD adenocarcinoma and SRC carcinoma are categorized in the "poorly cohesive carcinomas." Thus, we assessed whether the WHO classification is helpful when endoscopic resection is performed for treatment of UD-EGC.

METHODS

We analyzed clinicopathological features of 1295 lesions with SRC carcinoma and PD adenocarcinoma treated by open surgery. We recategorized them into intestinal-type PD adenocarcinomas and poorly cohesive carcinomas (SRC carcinoma, diffuse-type PD adenocarcinoma). We also recategorized 176 lesions treated by endoscopic resection into intestinal-type PD adenocarcinomas and poorly cohesive carcinomas.

RESULTS

According to the open surgery data, the rates of lymph node metastasis (LNM) and lymphovascular invasion were significantly lower in SRC carcinoma than in diffuse-type and intestinal-type PD adenocarcinomas. The rates of LNM and lymphovascular invasion were significantly higher in diffuse-type PD adenocarcinoma than in SRC carcinoma. Endoscopic resection data showed no recurrence if the carcinoma was curatively resected. However, the commonest cause of noncurative resection was different in SRC carcinoma and PD adenocarcinoma. A positive lateral margin was the commonest cause in SRC carcinoma versus a positive vertical margin in both intestinal-type and diffuse-type PD adenocarcinoma.

CONCLUSIONS

The clinical behavior differs in diffuse-type PD adenocarcinoma and SRC carcinoma. On the basis of LNM and outcomes of endoscopic resection, the recent WHO classification may not be helpful when endoscopic resection is performed for treatment of UD-EGC.

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.

[A Case of Intra-abdominal Paragonimiasis Mimicking Metastasis of Lung Cancer Diagnosed by Endoscopic Ultrasound-guided Fine Needle Aspiration]

Paragonimiasis has been continuously decreasing in Korea. However, it still occurs by ingesting raw or incompletely cooked fresh water crab or crayfish. The diagnosis of paragonimiasis is challenging because of its rarity. It may be confused with other inflammatory disease or carcinomatosis. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has lower risk of complications such as bleeding, perforation than percutaneous fine needle aspiration. EUS-FNA is more accurate and popular method to find mucosal or submucosal tumors and the lesions of several organs. Benign and malignant tumors, infectious diseases have been diagnosed by EUS-FNA, but there was no report describing the use of EUS-FNA for diagnosing paragonimiasis. Herein, we present a 47-year-old male patient with paragonimiasis diagnosed by EUS-FNA. Imaging studies revealed mass lesions in the lung and peritoneal cavity, which was eventually confirmed as paragonimiasis using EUS-FNA.

Endoscopic Resection for Undifferentiated-Type Early Gastric Cancer: Immediate Endoscopic Outcomes and Long-Term Survivals

BACKGROUND

Endoscopic resection (ER) is considered carefully as a curative treatment option for selected cases of undifferentiated-type early gastric cancer (UEGC). This study investigated immediate endoscopic and long-term survival outcomes of patients with UEGC treated with ER.

METHODS

A review of a database of 2483 EGC consecutively enrolled patients who underwent ER between January 2004 and December 2010 identified 101 patients with UEGC who met the expanded indications. Outcomes were investigated in these patients.

RESULTS

The rates of R0 en bloc and curative resection were 86 and 70 %, respectively. Of 30 tumors non-curatively resected, 17 were larger than 20 mm in diameter, 12 had positive resection margins, and 13 had submucosal or lymphovascular invasion on resection pathology. ER-related complications occurred in 12 patients (12 %), with all complications treated endoscopically without surgery. The median ER procedure time was 26 min [interquartile range (IQR) 20-39 min]. Only tumor location in the lower part of the stomach was significantly associated with curative ER (P = 0.038). Tumor recurrence was observed in seven patients at a median 17 months (IQR 12-47 months) after ER. During a median follow-up of 60 months (IQR 48-80 months), the 5-year overall mortality rates were 5 % in the curative and 4 % in the non-curative resection groups (P = 0.927). There were no gastric cancer-related deaths.

CONCLUSIONS

ER shows acceptable immediate endoscopic and long-term survival outcomes in selected patients with UEGC.

Accuracy of diagnostic demarcation of undifferentiated-type early gastric cancers for magnifying endoscopy with narrow-band imaging: endoscopic submucosal dissection cases

BACKGROUND

The usefulness of magnifying endoscopy with narrow-band imaging (ME-NBI) for undifferentiated-type early gastric cancers (UD-type EGCs) is unclear. The present study examined the accuracy of the diagnostic demarcation of lesions using ME-NBI.

METHODS

The study population consisted of 76 patients with UD-type EGC lesions measuring ≤20 mm in diameter using white-light imaging (WLI) and endoscopic ultrasonography and diagnosed as intramucosa and UL(-); all the lesions were confirmed as early gastric cancer based on postoperative pathological examination. All the patients had undergone an initial endoscopic submucosal dissection (ESD) at this hospital between January 2010 and January 2014. After marking with demarcation lines at the utmost oral and anal sites of the lesion using argon plasma coagulation under ME-NBI for intervention, the cases with demarcations that were consistent with the postoperative pathological findings were defined as having been accurately diagnosed. The inflammatory cell infiltration (Updated Sydney System, USS) were also assessed.

RESULTS

The diagnostic demarcations of the lesion were consistent in 62 cases (81.6 %). The accurate diagnosis rate was higher for the USS cases with mild neutrophil and monocyte infiltration (P < 0.05). The addition of ME-NBI to WLI improved the accurate diagnosis rate by 27.6 %.

CONCLUSION

The use of ME-NBI in diagnostic demarcation of UD-type EGCs is recommended.

Are new criteria for mixed histology necessary for endoscopic resection in early gastric cancer?

PURPOSE

Early gastric cancer (EGC) of mixed histology is more aggressive than other histologies. In addition, signet ring cell (SRC) mixed histology shows more submucosal invasion and greater lymph node metastasis (LNM). However, there are no criteria for endoscopic resection (ER) in mixed histology. Therefore, this study investigated whether new criteria for mixed histology are necessary for ER in EGC.

METHODS

From January 2005 to December 2012, 3419 patients with EGC underwent surgery. Lesions were classified using three histological classifications: the Japanese classification; World Health Organization (WHO) classification including SRC mixed histology; and Lauren classification. The mixed type in the Lauren classification was also reclassified according to the proportion of differentiated and undifferentiated components. Clinicopathological characteristics were compared according to histological classifications, with special reference to the ER criteria.

RESULTS

With the Lauren classification, 179 (5.3%) lesions were classified as mixed type, including 54 (30.2%) lesions as the differentiated-predominant mixed type. There were 361 (10.6%) lesions classified as SRC mixed histology. Mixed-type lesions in the Lauren classification and SRC mixed lesions were significantly associated with larger size and a greater LNM. Among the lesions meeting the ER criteria, 20 (1.6%) and 55 (4.7%) were categorized as mixed type by the Lauren classification and SRC mixed histology, respectively. However, there was no LNM among the lesions recategorized into mixed histology.

CONCLUSIONS

Mixed histology showed no LNM among the lesions met the present ER criteria. Thus, separate criteria for mixed histology might be not necessary in the criteria for ER in EGC.

Important considerations when contemplating endoscopic resection of undifferentiated-type early gastric cancer

Endoscopic resection (ER) of undifferentiated-type early gastric cancer (UD-EGC) has a lower curative resection (CR) rate than does ER of differentiated-type EGC (D-EGC). However, a low CR rate does not mean that it is unreasonable to schedule ER of UD-EGC. If ER is in fact curative, the long-term outcomes including survival rate are excellent. Quality of life is good because maximal stomach preservation is possible. However, UD-EGC and D-EGC differ histologically. Thus, when ER is contemplated to treat UD-EGC, a careful approach employing strict criteria is essential because the biology of UD-EGC and D-EGC differ.

Lymph node metastasis in differentiated-type early gastric cancer: a single-center retrospective analysis of surgically resected cases

BACKGROUND

Lymph node metastasis (LNM) from early gastric cancer (EGC) is rare, especially for differentiated-type EGC. However, LNM has been reported in a few cases after endoscopic curative resection of differentiated-type EGC. This study aimed to evaluate LNM risk factors to identify those that should be considered during the preoperative evaluation of differentiated-type EGC.

PATIENTS AND METHODS

A total of 976 EGC patients who underwent radical gastrectomy were reviewed in this study. Univariate and multivariate analyses were used to analyze the predictive factors for LNM based on the histology of the differentiated-type EGC cases.

RESULTS

Differentiated-type EGC was observed in 59% of the cases. The rate of LNM was 6.6% (38/576 patients) in the differentiated-type EGC cases. Macroscopic shape, ulcers, tumor size, deeper invasion and lymphovascular invasion were shown to be related to LNM in differentiated-type EGC. Multivariate analysis revealed that size, depth, ulceration and lymphovascular invasion were independent predictors of LNM in differentiated-type EGC. When lymphovascular invasion was absent, the presence of one or more of the risk factors of ulcer lesions, tumor size >30 mm and submucosal invasion increased the rate of LNM. Thirteen patients who underwent radical gastrectomy were shown to have differentiated-type EGC with LNM that met the standard and expanded criteria of endoscopic submucosal dissection.

CONCLUSIONS

As endoscopic resection is widely used, it is important to clarify the clinical significance of LNM in differentiated-type EGC and to screen for LNM with this incidence in mind and to follow the clinical courses of such cases, especially in China.

Endoscopic submucosal dissection for early gastric cancer with undifferentiated-type histology: A meta-analysis

AIM: To evaluate the efficacy and safety of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) with undifferentiated-type histology.

METHODS: A systematic literature review was conducted using the core databases. Complete resection, curative resection, en bloc resection, recurrence and adverse event rate were extracted and analyzed. A random effect model was applied. The methodological quality of the enrolled studies was assessed using the Newcastle-Ottawa Scale. Publication bias was evaluated using a funnel plot, the trim and fill method, Egger’s test, and a rank correlation test.

RESULTS: Fourteen retrospective studies between 2009 and 2014 were identified (972 EGC lesions with undifferentiated-type histology). The total en bloc and complete resection rates were estimated as 92.1% (95%CI: 87.4%-95.2%) and 77.5% (95%CI: 69.3%-84%), respectively. The total curative resection rate was 61.4% (95%CI: 44.5%-75.9%). The overall recurrence rate was 7.6% (95%CI: 3.4%-16%). Limited to histologically diagnosed expanded-criteria lesions, the en bloc and complete resection rates were 91.2% and 85.6%, respectively. The curative resection rate was 79.8%.

CONCLUSION: In this analysis, ESD is a technically feasible treatment modality for EGC with undifferentiated-type histology. Long-term studies are needed to confirm these therapeutic outcomes.

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 predictors for undifferentiated histology in differentiated gastric neoplasms prior to endoscopic resection

BACKGROUND

There is often a discrepancy between results from endoscopic forceps biopsy and resected specimen. We aimed to identify endoscopic predictors for undifferentiated histology in differentiated gastric neoplasms prior to endoscopic resection.

METHODS

Medical records of the patients who underwent endoscopic submucosal dissection (ESD) for biopsy-proven differentiated gastric neoplasms at Seoul National University Hospital between July 2005 and July 2014 were retrospectively reviewed. The lesions were divided into two groups based on the final histologic result of ESD: differentiated adenocarcinoma (DA group) and undifferentiated histology (UDH group). The discordant rate, clinicopathologic characteristics, and endoscopic factors were analyzed.

RESULTS

A total of 1641 early gastric cancers from 1615 patients were included. Of these, 1556 (94.8%) were diagnosed as DA and 85 (5.2%) as UDH. The mean age was significantly lower, and number of women was higher in the UDH group than in the DA group. On multivariate analysis, age <65 years [odds ratio (OR) 1.75, 95 % confidence interval (CI) 1.10-2.80], female sex (OR 3.19, 95% CI 2.00-5.08), endoscopic size >10 mm (OR 1.81, 95% CI 1.12-2.92), depressed type (OR 2.85, 95% CI 1.56-5.21), nodularity (OR 2.83, 95% CI 1.59-5.05), and whitish discoloration (OR 19.64, 95% CI 6.98-55.25) were independent predictors.

CONCLUSIONS

Female sex, age <65 years, large endoscopic size, depressed morphology, surface nodularity, and whitish discoloration were predictors for UDH. Meticulous attention should be paid to the lesions with these endoscopic predictors for determining the risk of UDH prior to endoscopic resection.