Analysis of early (pT1) gastric cancer with submucosal invasion: surgical management and possibility to schedule less invasive surgery

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.

Endoscopic holmium:YAG laser ablation of early gastrointestinal intramucosal cancer

Various endoscopic techniques are being increasingly used in early gastrointestinal (GI) cancer. The holmium: yttrium-aluminum-garnet (Ho:YAG) laser has precise tissue cutting ability and good hemostatic properties and has been widely applicated to soft tissue, but the use of endoscopic Ho:YAG laser ablation for early gastrointestinal cancer has not been reported. Twenty patients with biopsy-proven early GI cancer who had a high surgical risk or refused surgery were treated by endoscopic Ho:YAG laser ablation. The tumors of all patients were confined to the mucosal layer without ulceration and without lymph node metastasis. The tumor diameter was not more than 2.5 cm. Endoscopy, endoscopic ultrasound, and computed tomography scan were performed 1-3 months after the treatment, and a biopsy was performed to evaluate the effects of the therapy. Long-term endoscopic follow-up was maintained. Complete eradication was achieved in all the 20 patients, including four patients with high-grade dysplasia associated with focal canceration, seven patients with well-differentiated squamous cell cancer, and nine patients with well-differentiated adenocarcinoma, resulting in a complete response rate of 100% at 1-3 months after treatment. No recurrence was found during 36-73 months of follow-up in all 20 patients. No operative or delayed complications were observed in any of the 20 patients. Preliminary study shows that endoscopic Ho:YAG laser ablation may be an effective, safe, and minimally invasive method for selected patients with early GI intramucosal cancer. Further research is required to confirm the safety and efficacy of this technique compared to its alternative techniques in a multicenter randomized controlled trial.

Recurrence in early gastric cancer with lymph node metastasis

BACKGROUND

Early gastric cancer (EGC) has an excellent prognosis, but some patients with lymph node-positive disease will develop recurrence. In this study we investigated the risk factors for recurrence in this selected group of patients.

METHODS

The clinical and pathological records of 2368 patients who underwent gastrectomy for solitary EGC between 1980 and 1999 at the National Cancer Center Hospital, Tokyo, were examined. Two hundred and thirty-eight patients (10%) were lymph node-positive (positive for lymph node metastasis) and form the population of this study.

RESULTS

Nineteen (8%) of the 238 patients with lymph node-positive disease developed recurrence. The most common site of recurrence was lymph node (37%), followed by liver (21%). The interval between surgery and the detection of recurrence ranged from 3 to 98 months, with a median of 26 months. Multivariate analysis demonstrated that the number of metastatic nodes was an independent risk factor for recurrence. Patients with seven or more metastatic nodes had the highest rate of recurrence, at 38%.

CONCLUSION

The number of nodes positive for metastasis was the only independent risk factor for recurrence after curative surgery in patients with lymph node-positive early gastric cancer. These high-risk patients may obtain additional survival benefit if targeted with adjuvant chemotherapy.

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.

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.

Expression of vascular endothelial growth factor (VEGF)-C in preoperative biopsy specimens and metastatic foci of regional lymph nodes in submucosal gastric carcinoma

BACKGROUND: Vascular endothelial growth factor (VEGF)-C is implicated in lymphangiogenesis, however the exact role of VEGF-C in promoting lymphatic spread of cancer cells remains largely unknown. METHODS: The expression of VEGF-C was immunohistochemically determined in 97 endoscopic biopsy specimens from 46 patients with submucosal gastric carcinoma (SGC). Nodal metastases including micrometastasis and isolated tumor cells (ITC) were evaluated by immunohistochemical staining for cytokeratin in 1650 lymph nodes, and tumor cells in these metastatic nodes were also examined for VEGF-C expression. RESULTS: In biopsy samples, VEGF-C was positively detected in 21 (47%) patients. Metastases were identified in 46 (2.8%) nodes from 15 (33%) patients. Metastases were detected in 39 nodes by hematoxylin-eosin (H&E) staining and in additional 7 nodes as ITC by immunohistochemical staining. The rate of lymph node metastases was significantly correlated with VEGF-C expression in biopsy samples (p < 0.05). The positive and negative predictive values of VEGF-C in biopsy specimens for nodal metastasis were 44 %(10/21) and 80% (20/25), respectively. Among the 46 metastatic nodes, tumor cells in 29 (63%) nodes positive patients expressed VEGF-C, whereas those in 17 (37%) nodes did not. VEGF-C expression was high in macronodular foci in medullary areas, whereas more than half of ITC or micrometastasis located in peripheral sinus lacked the expression of VEGF-C. CONCLUSIONS: Despite the significant correlation, immunodetcetion of VEGF-C in endoscopic biopsy specimens could not accurately predict the nodal status, and thus cannot be applied for the decision of the treatment for SGC. VEGF-C may not be essential for lymphatic transport, but rather important to develop the macronodular lesion in metastatic nodes.

[Prolapsed malignant polyp of the stomach causing acute pancreatitis]

Polyps of the stomach are rare lesions with an incidence between 1.7% and 3.9%. Until now, most cases were asymptomatic and found during endoscopic examination. Only three cases of prolapsing gastric polyps causing acute pancreatitis have been reported. Prolapsed polyps of the stomach should be included in the differential diagnosis of secondary pancreatitis. If endoscopic polypectomy is impossible, surgical treatment is necessary. In case early gastric cancer of the mucosa is detected in a polyp, limited surgery is possible. Otherwise, gastrectomy with lymphadenectomy of the D2 compartment is required

Preoperative simulation of vascular anatomy by three-dimensional computed tomography imaging in laparoscopic gastric cancer surgery

BACKGROUND

Treatment of early gastric cancer may be an ideal application for laparoscopic surgery. But laparoscopic surgery has various limitations derived from the lack of tactile feedback and a two-dimensional display of the operative field. So, laparoscopic surgery is technically challenging and requires a more detailed understanding of local anatomy than conventional open surgery does. The purpose of this study was to evaluate the value of three-dimensional computed tomography imaging in the preoperative simulation of laparoscopic gastric cancer surgery.

STUDY DESIGN

Multidetector-row helical CT was performed preoperatively in 49 patients who underwent laparoscopic gastric cancer surgery. Scanning was initiated approximately 20 seconds after an intravenous injection of 100 mL of contrast material at 5 mL/second. Three-dimensional CT images were reconstructed using the volume-rendering technique.

RESULTS

3D-CT imaging depicted the stomach, arterial, and venous anatomy and was able to identify important vascular variants. Preoperative information concerning the right gastric artery led us to the site of its branching and facilitated dissection of suprapyloric lymph nodes. The left gastric artery furnishing the aberrant left hepatic artery was successfully revealed and this information enabled us to avoid accidental hemorrhage and ischemic liver damage. Preoperative confirmation of the drainage routes of the left gastric vein was also useful in accomplishing secure lymphadenectomy.

CONCLUSIONS

3D-CT imaging provides a vascular "road map," which is critical for surgical guidance, and prevents the risks involved in surgery. Preoperative 3D-CT imaging may be an informative device to overcome the disadvantages of laparoscopic gastric cancer surgery.

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.