Indications of a minimized scope of lymphadenectomy for submucosal gastric cancer

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Optimal extent of lymph node dissection in patients with gastric cancer who underwent non-curative endoscopic submucosal dissection with a positive vertical margin

BACKGROUND

The optimal extent of lymph node dissection in patients receiving non-curative endoscopic submucosal dissection (ESD) and diagnosed with a positive vertical margin is unclear. This study attempted to identify optimal candidates for D2 lymph node dissection among these patients.

METHODS

This study included patients who underwent gastrectomy for primary gastric cancer following non-curative ESD with a positive vertical margin between January 2002 and December 2018. We classified the patients according to the positive vertical margin pattern into an obvious exposure group and a non-obvious exposure group. We developed a score model for predicting lymph node metastasis (LNM) using factors selected by multivariate analyses and beta regression coefficients, and the incidence of LNM was evaluated.

RESULTS

This study included 110 patients. LNM was detected in 17 patients (15%). We developed a predictive scoring system as follows: tumor size >30 mm (0, No; 1, Yes) + undifferentiated type tumor in the invasive front (0, No; 2, Yes) + depth of submucosal invasion > 1500 μm (0, No; 1, Yes) + obvious tumor exposure at the vertical margin (0, No; 1, Yes). In patients with 5 points, the incidence rates of all and group 2 LNM were as high as 60% and 40%, respectively. Conversely, in patients with fewer than 5 points, the incidence rates of all and group 2 LNM were just 11% and 5%, respectively.

CONCLUSION

In patients with 5 points according to our score model for predicting LNM, gastrectomy with D2 lymph node dissection is recommended.

Multidisciplinary Approach in Improving Survival Outcome of Early-Stage Gastric Cancer

BACKGROUND

The necessity of extensive lymph node (LN) dissection/examination and adjuvant therapy for patients with early gastric cancer (EGC, Tis-T1, any N) remains controversial. We aim to refine treatment recommendations for patients with EGC through a reflective analysis for the survival gap between Eastern and Western countries.

METHODS

EGC patients diagnosed between 2004 and 2014 were identified from the National Cancer Database (NCDB) and a large medical center in China. Adequate LN yield was defined as ≥25 LNs examined.

RESULTS

In the US cohort, 14.4% of (1104/7641) patients with EGC had ≥25 LNs examined. The 5-y overall survival (OS) was significantly better than those with <25 LNs (78.9% versus 68.5%, P < 0.001). Examination of ≥25 LNs was an independent predictor of better OS after adjusting all known prognostic factors. Patients with ≥25 LNs examined had significantly higher chance of having LN-positive disease compared to patients with <25 LNs (14.9% versus 10.7%, P < 0.001). A similar stage migration phenomenon was observed in Chinese cohort (LN positive: 25.2% versus 18.4% in ≥25 LNs and <25 LNs examined group, respectively, P = 0.02). In the US cohort, adjuvant therapy was associated with a significant survival benefit for LN-positive patients (5-y OS: 71.0% versus 43.0% for with/without adjuvant therapy, respectively, P < 0.001) but not in LN-negative patients (5-y OS: 71.2% versus 71.5%, P = 0.90).

CONCLUSIONS

Adequate lymphadenectomy and LN examination are critical components of EGC management. Adjuvant therapy should be strongly encouraged for all EGC patients with LN-positive disease in the United States.

Laparoscopic gastrectomy for early gastric cancer and the risk factors of lymph node metastasis

Objective:

Lymph node metastasis (LNM) is one of the important prognostic factors of early gastric cancer (EGC). Moreover, LNM is also important when choosing therapeutic intervention for EGC patients. The purpose of this study is to explore the risk factors of LNM in EGC and to discuss the corresponding treatment.

Design:

We retrospectively reviewed the medical records of 253 patients with EGC who underwent surgical therapy in our department between 2012 and 2015. Univariate analysis and Multivariate Cox regression were used to evaluate the independent risk factors of LNM.

Results:

LNM was present in 38 cases among 253 patients (15%). Univariate analysis showed an obvious correlation between LNM and tumour location, tumour size, depth of invasion, morphological classification, gross type of the lesion and venous invasion. Multivariate analysis indicated that poorly differentiated carcinoma, submucosal cancer, tumour size ≥2 cm and venous invasion were the independent risk factors for LNM.

Conclusion:

Tumour size, depth of invasion, morphological classification and blood vessel invasion were predictive risk factors for LNM in EGC. We propose that EGC patients with those risk factors should be accepted gastrectomy with LN dissection.

Function-preserving gastrectomy for early gastric cancer

The number of early gastric cancer (EGC) cases has been increasing because of improved diagnostic procedures. Applications of function-preserving gastric cancer surgery may therefore also be increasing because of its low incidence of lymph node metastasis, excellent survival rates, and the possibility of less-invasive procedures such as laparoscopic gastrectomy being used in combination. Pylorus-preserving gastrectomy (PPG) with radical lymph node dissection is one such function-preserving procedure that has been applied for EGC, with the indications, limitations, and survival benefits of PPG already reported in several retrospective studies. Laparoscopy-assisted proximal gastrectomy has also been applied for EGC of the upper third of the stomach, although this procedure can be associated with the 2 major problems of reflux esophagitis and carcinoma arising in the gastric stump. In the patient with EGC in the upper third of the stomach, laparoscopy-assisted subtotal gastrectomy with a preserved very small stomach may provide a better quality of life for the patients and fewer postoperative complications. Finally, the laparoscopy endoscopy cooperative surgery procedure combines endoscopic submucosal dissection with laparoscopic gastric wall resection, which prevents excessive resection and deformation of the stomach after surgery and was recently applied for EGC cases without possibility of lymph node metastasis. Function-preserving laparoscopic gastrectomy is recommended for the treatment of EGC if the indication followed by accurate diagnosis is strictly confirmed. Preservation of remnant stomach sometimes causes severe postoperative dysfunctions such as delayed gastric retention in PPG, esophageal reflux in PG, and gastric stump carcinoma in the remnant stomach. Moreover, these techniques present technical difficulties to the surgeon. Although many retrospective studies showed the functional benefit or oncological safety of function-preserving gastrectomy, further prospective studies using large case series are necessary.

Successful type-oriented endoscopic resection for gastric carcinoid tumors: A case report

The standard treatment in Japan for gastric carcinoid has been gastrectomy with lymphadenectomy. This report describes the possibility of endoscopic treatment as an appropriate option for gastric carcinoid fulfilling certain conditions. A 46 year old woman underwent endoscopic mucosal resection for two 3 mm gastric carcinoids. The patient had hypergastrinemia with pernicious anemia and type A chronic atrophic gastritis, suggesting that the tumors were type I in Rindi's classification. Both tumors were located in the mucosal layer with no cellular polymorphism and were chromogranin A positive. Neither tumor recurrence in the stomach nor distant metastases have been documented during the 5 years of follow-up. Although many type I gastric carcinoids may be clinically indolent, reports on successful endoscopic treatment for this carcinoid have been scanty in the literature in Japan, presumably because of the hitherto surgical treatment stance for the disease. This report discusses how the size, number, depth and histological grading of the type I gastric carcinoid could allow the correct identification of a benign or malignant propensity of an individual tumor and how endoscopic resection could be a treatment of choice when these factors render it feasible. This stance could also obviate unnecessary surgical resection for more benign tumors.

Predicting the absence of lymph node metastasis of submucosal invasive gastric cancer: expansion of the criteria for curative endoscopic resection

OBJECTIVE

The conditions upon which endoscopic resection (ER) can be considered curative for submucosal invasive gastric cancer remain controversial; thus, unnecessary surgery is sometimes performed after ER. Our purpose is to evaluate the significance of several clinicopathological factors for predicting the absence of lymph node (LN) metastasis of submucosal invasive gastric cancer and thus determining cases in which ER can be considered curative.

PATIENTS AND METHODS

The study group comprised 220 patients with submucosal invasive gastric cancer that was resected surgically or endoscopically. Patients treated by ER underwent additional surgical resection. The presence of LN metastasis was evaluated in all patients, retrospectively.

RESULTS

LN metastasis was detected in 37 (16.8%) of the 220 patients. Independent risk factors for LN metastasis were width of submucosal invasion>6000 μm, lymphatic involvement, undifferentiated type at the deepest invasive portion, depth of submucosal invasion>1000 μm, and tumor diameter>30 mm. The group of 36 patients with submucosal invasion to a depth of ≤1000 μm, tumor diameter ≤30 mm, differentiated type as the dominant histologic type, and absence of vessel involvement was entirely free of LN metastasis (95% confidence interval, 0-8.0%).

CONCLUSIONS

Taken together, the five independent risk factors may allow expansion of the criteria for determining whether ER for submucosal invasive gastric cancer has been curative.

Survival benefit of pylorus-preserving gastrectomy in early gastric cancer

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is performed in some patients for the treatment of early gastric cancer. The aim of this study was to investigate longterm survival for patients having PPG with extensive lymph node dissection, except for the suprapyloric nodes, for early gastric cancer.

STUDY DESIGN

From January 1995 to December 2006, 305 patients underwent PPG if they met the following criteria: cT1 (mucosa or submucosa), cN0 gastric cancer in the middle body of the stomach. Overall 5-year survival, cancer-related mortality, and freedom from recurrence were assessed retrospectively.

RESULTS

The median followup period was 61 months (range 27 to 144 months). Seven patients died, and the overall 5-year survival probability was 98%. Gastric cancer-related mortality was 0% and none of the patients had evidence of tumor recurrence. The accuracy of the preoperative diagnosis of T1 gastric cancer using endoscopy or endoscopic ultrasonography was 95.7%.

CONCLUSIONS

PPG may provide a longterm survival benefit for patients with clinically diagnosed T1 (mucosa or submucosa), cN0 gastric cancer in the middle body of the stomach, only when the accuracy of preoperative diagnosis can be assured.

Predicting lymph node status in early gastric cancer

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

Lymph node metastasis in submucosal gastric cancer and reduction surgery

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

Risk factors for lymph node metastasis and evaluation of reasonable surgery for early gastric cancer

AIM

To give the evidence for rationalizing surgical therapy for early gastric cancer with different lymph node status.

METHODS

A series of 322 early gastric cancer patients who underwent gastrectomy with more than 15 lymph nodes retrieved were reviewed in this study. The rate of lymph node metastasis was calculated. Univariate and multivariate analyses were performed to evaluate the independent factors for predicting lymph node metastasis.

RESULTS

No metastasis was detected in No.5, 6 lymph nodes (LN) during proximal gastric cancer total gastrectomy, and in No.10, 11p, 11d during for combined resection of spleen and splenic artery and in No.15 LN during combined resection of transverse colon mesentery. No.11p, 12a, 14v LN were proved negative for metastasis. The global metastastic rate was 14.6% for LN, 5.9% for mucosa, and 22.4% for submucosa carcinoma, respectively. The metastasis in group II was almost limited in No.7, 8a LN. Multivariate analysis identified that the depth of invasion, histological type and lymphatic invasion were independent risk factors for LN metastasis. No metastasis from distal cancer (3.0 cm in diameter.

CONCLUSION

Segmental/subtotal gastrectomy plus D1/D1+No.7 should be performed for carcinoma (3.0 cm in diameter). Total gastrectomy should not be performed in proximal, so does combined resection or D2+/D3 lymphadenectomy.

Lymph node status in patients with submucosal gastric cancer

BACKGROUND

The aim of this study was to clarify the lymph node status in patients with submucosal gastric cancer.

METHODS

Between April 1994 and December 1999, 615 patients with histologically proven submucosal gastric cancer who underwent curative resection were included in this study. The results of the surgery and predictive factors for lymph node metastasis were evaluated by univariate and multivariate analyses. The accuracy of the predictive factors was assessed in a second population of a further 186 patients.

RESULTS

Lymph node metastasis was observed in 119 patients (19.3%). Multivariate analysis showed that pathologic tumor diameter (> or = 20 mm) and lymphatic invasion were independent predictive factors for lymph node metastasis. The incidence of lymph node metastasis without these 2 predictive factors was 1.8% (2 of 113), and it was 51.2% (85 of 166) with the 2 predictive factors, 9.5% (14 of 148) in tumors < 20 mm in diameter, and 5.3% (22 of 414) in tumors without lymphatic invasion. Among patients with a tumor < 20 mm in diameter, the incidence of lymph node metastasis was significantly reduced in those with a differentiated tumor: 4.2% (4 of 95). These results were almost identical to those observed in the second population.

CONCLUSIONS

Lymph node status can be accurately predicted on the basis of pathologic tumor diameter < 20 mm, lymphatic invasion (absence), and histological type (differentiated) in patients with submucosal gastric cancer. Less extensive surgery for these patients might be reconsidered after confirmation of the reproducibility of the results of this study by an appropriately designed prospective clinical trial.

Laparoscopy-assisted pylorus-preserving gastrectomy with quality controlled lymph node dissection in gastric cancer operation

BACKGROUND

Pylorus-preserving gastrectomy (PPG) with extensive lymph node dissection is useful for treatment of early gastric cancer with preservation of function. This technique could be improved by using laparoscopy-assisted gastrectomy.

STUDY DESIGN

Between September 2000 and September 2004, 109 patients with T1 gastric cancer underwent surgical treatment; 72 underwent laparoscopy-assisted PPG (LAPPG) and 37 underwent conventional PPG (CPPG). Total numbers of dissected lymph nodes, retrieval at each lymph node station, intraoperative blood loss, and operation times were used as measures of the quality of lymph node dissection to compare the procedures. Continuous data are summarized as mean +/- SE.

RESULTS

Operation times with the LAPPG procedure (279 +/- 6 minutes) were significantly, but only 20 minutes, longer than with CPPG (259 +/- 8 minutes) (p = 0.047), although estimated blood loss for LAPPG patients (153 +/- 13 mL) was not significantly different for those undergoing CPPG (184 +/- 13 mL, p = 0.13). Mean total number of dissected lymph nodes was 32.3 +/- 1.6 in the LAPPG group and 28.5 +/- 2.2 in the CPPG group (p = 0.16). There was no significant difference in the number of lymph nodes retrieved for any of the nodal stations between the LAPPG and CPPG procedures.

CONCLUSIONS

Clinical outcomes of surgical treatment were comparable for gastric cancer patients who underwent LAPPG and those treated with CPPG in terms of station-dependent lymph node dissection and estimated blood loss.

Concepts, rationale, and current outcomes of less invasive surgical strategies for early gastric cancer: data from a quarter-century of experience in a single institution

Previously proposed criteria of less invasive surgery for early gastric cancer (EGC) were based mainly on the pathological analyses of the resected specimens; however, preoperative and intraoperative information are also obviously essential for decision making on stage-dependent patient management. Furthermore, most indications and treatment options have not been systematically integrated or evaluated by treatment outcomes. We investigate in this report the rationality of less invasive surgery employed for EGC. Distribution analyses of positive nodes were investigated among 684 patients with primary solitary EGC (379 mucosal and 305 submucosal) who underwent curative resection between 1976 and 2000. Clinicopathological factors highlighted and analyzed included clinical (preoperative and intraoperative) and pathological (postoperative) cancer depth and nodal involvement, gross form, histological type, and maximum cancer diameter, as well as postoperative morbidity and mortality. The scope of lymphadenectomy can be reduced to a modified D1 for clinically mucosal, node-negative, nonpalpable gastric cancer, or for clinically submucosal, node-negative gastric cancer < or = 1.5 cm for intestinal type, or < or = 1.0 cm for diffuse type. Otherwise, a modified D2 lymphadenectomy is sufficient. Local resection can be recommended for clinically mucosal, node-negative gastric cancer without apparent ulceration < or = 4 cm if adjacent lymph nodes are proved cancer negative by a frozen section examination. If the gastric cancer has spread beyond the above criteria, a pylorus-preserving gastrectomy (PPG) can be recommended for tumors located in the middle or lower third of the stomach, provided the distal margin of the cancer is at least 4.5 cm from the pyloric ring. The PPG can be accompanied by a modified D1 or a modified D2 lymphadenectomy according to the respective dissection criteria. Results of these less invasive strategies showed reduced morbidity and mortality, as well as no recurrence or cancer-related deaths. These results suggest that each of our criteria for less invasive surgery for EGC is realistic, well stratified, and satisfactory.

Accuracy of linear-array EUS for preoperative staging of gastric cardia cancer

BACKGROUND

The feasibility of a less invasive operation for early stage cancer of the gastric cardia with a low frequency of lymph node involvement has been previously demonstrated by us. Precise discrimination among mucosal, submucosal, and advanced cancers, as well as accurate evaluation of the proximal tumor margin are prerequisites for such stage-specific treatment. EUS is considered the most reliable staging modality. However, there is no EUS study specifically of cardia cancer.

METHODS

Forty-five patients with gastric cardia cancer who underwent gastrectomy with at least first-tier lymphadenectomy were retrospectively analyzed. The results of preoperative linear-array echoendoscopy (7.5 MHz) with respect to cancer depth, lymph node involvement, and esophageal invasion were compared with postoperative histopathologic findings.

RESULTS

Overall diagnostic accuracy for depth of invasion was 71%. Sensitivity for T1, T2, and T3 lesions was 100%, 31% and 75%, respectively. Overstaging of T2 cancers was the main diagnostic error. Mucosal (pT1-m) and submucosal (pT1-sm) cancers were correctly discriminated in 81% of patients. Diagnostic accuracy for lymph node involvement was 80%. EUS had positive and negative predictive values of 90% and 80%, respectively, for esophageal invasion.

CONCLUSIONS

For gastric cardia cancer, the linear-array echoendoscope yielded satisfactory results with respect to depth of invasion, lymph node involvement, and esophageal invasion evaluation. The information obtained is useful to the performance of stage-specific treatment.

Gastric cancer

The past decade has seen many advances in knowledge about gastric cancer. Notably, tumour biology and lymphatic spread are now better understood, and treatment by surgical and medical oncologists has become more standardised. Since refrigerators have replaced other methods of food conservation, Helicobacter pylori has become a factor in the cause of gastric cancer. Cancers that arise at the oesophagogastric junction might be further examples of wealth-associated disease. To tailor treatment better, the western hemisphere needs to borrow from the East by establishing screening programmes for early diagnosis, through careful surgical resection, and through detailed analysis of tumour spread. In Europe and the USA, most patients reach treatment with cancers already at an advanced stage. For these patients, three important randomised trials are underway that evaluate combined therapy. Cytostatic drugs, especially angiogenesis inhibitors have proved disappointing; however, basic research efforts to detect familial gastric cancers and to assess minimally residual disease look more hopeful.

Treatment strategy of limited surgery in the treatment guidelines for gastric cancer in Japan

Surgical practice for gastric cancer in Japan is based on the Gastric Cancer Treatment Guidelines issued in 2001 by the Japanese Gastric Cancer Association. These recommendations list options for treatment of each stage of cancer, with clear distinctions between interventions recommended for routine use and those that should be confined to trial settings until further evidence for their curative potential becomes available. In this review, we discuss standard surgery, local resection, segmental resection, and pylorus-preserving gastrectomy (PPG) as examples of limited resection and describe in detail the indications for limited lymph-node dissection in cases of early-stage gastric cancer. At present, evidence does not support the conclusion that limited surgery is effective for local resection or for improving quality of life. Thus, use of limited surgery should be considered an experimental approach both in Japan and the West. We conclude that surgeons who are familiar with the criteria for selecting surgical procedures should decide on a case-by-case basis which technique is most appropriate. Choices should be made with consideration of the stage of the cancer, invasiveness of the surgical procedure, and the patient's history. For all procedures, the patient must give informed consent and the surgeons must accurately assess the success of the operation after surgery.