Advancement in Aptamer-based Biosensors for Gastric Cancer and Therapeutic Strategies / 中国生物化学与分子生物学报

The timely diagnosis of early gastric cancer is important for guiding the choice of treatment and prolonging the survival of patients. However, current screening of early gastric cancer still relies on endoscopic examination due to the lack of sensitive, accurate, and convenient screening tools. The cost of large-scale screening through gastrointestinal endoscopy is high and many countries and regions cannot afford it. At present, many types of biomarkers have been proved to own the ability to predict and diagnose tumors. Aptamer, as single-stranded oligonucleotides DNA or RNA, can be used to construct sensitive and reliable biosensors based on fluorometry, colorimetric, electrochemistry, etc. through label modification, coupling with various novel materials, etc. Additionally, it is also widely used in the field of precision medicine due to its small molecular weight, high specificity, and natural biological properties. We summarized and concluded aptamer-based gastric cancer diagnostic and therapeutic studies to help researchers quickly get access to tumor-related aptamers screening process, biosensor construction and optimization methods, and therapeutic strategies. This study aimed to provide a reference for the subsequent development of gastric cancer-related aptamers that meet clinical needs and assist in the endoscopic examination, diagnosis, and follow-up.

Function-Preserving Surgery in Gastric Cancer

The rising incidence of early gastric cancer has enabled the development of function-preserving gastrectomy with the focus on post gastrectomy quality of life and adherence to sound oncologic principles. It is concurrent with the growing popularity of minimally invasive surgery; and both are commonly used together. The different kinds of function-preserving gastrectomy included in this review are: pylorus-preserving and proximal gastrectomy, vagus nerve preservation, sentinel node navigation, and various endoscopic & minimally-invasive techniques. In this article the indications, techniques, oncologic safety, functional benefit, and outcomes of each kind of function-preserving gastrectomy are discussed.

Endoscopic submucosal dissection and gastrectomy for early gastric cancer: a Meta-Analysis / 中国内镜杂志

Objective To compare the difference of the effects and safety of endoscopic submucosal dissection (ESD) and surgery for early gastric cancer. Methods We searched the Pubmed, CBM, Embase, Cochrane Library, CNKI, CQVIP and WanFang data from January 1990 to June 2016 studies comparing endoscopic resection with gastrectomy for treatment of early gastric cancer. We selected the eligible studies according the including and excluding criteria. The quality of the included studies was assess using the Newcastle-Ottawa Scale (NOS), then using Revman 5.3 to make the Meta analysis. Result The meta-analysis enrolled 12 studies with 4331 patients, all of the studies were retrospectively analyzed. The result of the meta-analysis showed that there were no significant difference regarding the recurrence rate [(22/2586, 0.85%) vs (6/1134, 0.53%), P = 0.370] and five-year survival rate [(852/909, 93.72%) vs (707/746, 94.77%), P = 0.340] between endoscopic resection and gastrectomy. Gastrectomy was associated with higher en bloc resection rate, which were 100.00% and 92.23% respectively. However, gastrectomy was also related to longer operative time (SMD = -3.04, 95%CI: -3.64 ~ -2.45, P = 0.000) and hospital stay (SMD = -2.53, 95%CI: -3.73 ~ -1.32, P = 0.000). The postoperative complication was also higher than endoscopic, which were (45/816, 5.50%) vs (101/686, 14.72%) respectively. Conclusion There were no significant difference regarding recurrence rate and five-year survival rate between endoscopic and gastrectomy. While the en bloc resection rate was lower than gastrectomy, endoscopic offers a shorter hospital stay, shorter operative time with minimal invasive and fewer operating and postoperative complications than gastrectomy. Endoscopic should be recommended as a standard treatment for early gastric cancer with indications.

Surgical Treatment for Patients Who Underwent Endoscopic Mucosal Resection (EMR)/Endoscopic Submucosal Dissection (ESD) of Early Gastric Cancer (EGC)

PURPOSE: To evaluate the necessity for additional surgical treatment after Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD), we analyzed the pathologic results of patients who underwent surgical treatment. METHODS: 140 consecutive patients underwent additional surgical treatment after EMR/ESD with en bloc resection between April 2005 and November 2009 at ASAN Medical Center. Additional surgical treatments were undergone for following conditions such as incomplete dissection (involvement of margin), undifferentiated-type histology (> or =2 cm) and submucosal cancer. RESULTS: One patient with deep margin involvement displayed advanced gastric cancer after gastrectomy. Three of 74 patients with clear resection margin were confirmed to have residual cancer at ESD site and 2 of 3 patients displayed advanced gastric cancer after surgery. In univariate analysis for metastasis of lymph node, deep submucosal invasion (over sm2 or 500microm) and the presence of lymphovascular invasion showed significant differences for lymph node metastasis. Especially, lymphovascular invasion was an important predictive factor for lymph node metastasis in multivariate analysis. In analysis for residual cancer, lateral margin involvement and large tumor (>3 cm) were risk factors. And, only lateral margin involvement showed significant risk in multivariate analysis. CONCLUSION: Although EMR/ESD were fully accomplished for resection margin, gastrectomy and lymph node dissection were positively necessary for patients with deepsubmucosal invasion (over sm2 or 500microm) and the presence of lymphovascular invasion to eliminate the possibility of residual cancer or more advanced gastric cancer or metastatic lymph nodes.

The Early Experience with a Laparoscopy-assisted Pylorus-preserving Gastrectomy: A Comparison with a Laparoscopy-assisted Distal Gastrectomy with Billroth-I Reconstruction

PURPOSE: Pylorus-preserving gastrectomy (PPG), which retains pyloric ring and gastric function, has been accepted as a function-preserving procedure for early gastric cancer for the prevention of postgastrectomy syndrome. This study was compared laparoscopy-assisted pylorus-preerving gastrectomy (LAPPG) with laparoscopy-assisted distal gastrectomy with Billroth-I reconstruction (LADGB I). MATERIALS AND METHODS: Between November 2006 and September 2007, 39 patients with early gastric cancer underwent laparoscopy-assisted gastrectomy in the Department of Surgery at Korea Cancer Center Hospital. 9 of these patients underwent LAPPG and 18 underwent LADGBI. When LAPPG was underwent, we preserved the pyloric branch, hepatic branch, and celiac branch of the vagus nerve, the infrapyloric artery, and the right gastric artery and performed D1+beta lymphadenectomy to the exclusion of suprapyloric lymph node dissection. The distal stomach was resected while retaining a 2.5~3.0 cm pyloric cuff and maintaining a 3.0~4.0 cm distal margin for the resection. RESULTS: The mean age for patients who underwent LAPPG and LADGBI were 59.9+/-9.4 year-old and 64.1+/-10.0 year-old, respectively. The sex ratio was 1.3:1.0 (male 5, female 4) in the LAPPG group and 2.6:1.0 (male 13, female 5) in the LADGBI group. Mean total number of dissected lymph nodes (28.3+/-11.9 versus 28.1+/-8.9), operation time (269.0+/-34.4 versus 236.3+/-39.6 minutes), estimated blood loss (191.1+/-85.7 versus 218.3+/-150.6 ml), time to first flatus (3.6+/-0.9 versus 3.5+/-0.8 days), time to start of diet (5.1+/-0.9 versus 5.1+/-1.7 days), and postoperative hospital stay (10.1+/-4.0 versus 9.2+/-3.0 days) were not found significant differences (P>0.05). The postoperative complications were 1 patient with gastric stasis and 1 patient with wound seroma in LAPPG group and 1 patient with left lateral segment infarct of liver in the LADGB I group. CONCLUSION: Patients treated by LAPPG showed a comparable quality of surgical operation compared with those treated by LADGBI. LAPPG has an important role in the surgical management of early gastric cancer in terms of quality of postoperative life. Randomized controlled studies should be undertaken to analyze the optimal survival and long-term outcomes of this operative procedure.

Follow-up result of endoscopic mucosal resection for gastric adenoma and early gastric cancer / 대한내과학회지

BACKGROUND: Endoscopic mucosal resection (EMR) is now widely accepted as a useful treatment method for gastric adenoma and early gastric cancer (EGC) because of its minimal invasiveness and satisfactory post-procedure results. The purpose of this study is to define the follow-up results and usefulness of EMR. METHODS: We analyzed 54 cases from June 2000 through September 2004. Endoscopy with histological examination was carried out every 3 months for 1 year after EMR. RESULTS: The patients consisted of 42 men and 12 women, and the mean age was 60 years old. The histological results were 42 gastric adenoma and 12 EGC cases. There were 9 cases that had the histological diagnosis changes after EMR. Complete resections was performed for 48 cases and the en block resections were 33 of 34 cases (97%) and piecemeal resections were done in 15 of 20 cases (75%). Recurrence was seen in 4 cases (7.1%), and the mean recurrence period was 7 months. There were 3 gastric adenomas of 42 cases (7.1%), one case of EGC of 12 cases (8.3%), one en block resection of 34 cases (2.9%) and three piecemeal resections of 20 cases (15%). CONCLUSIONS: EMR is a safe and useful treatment method for gastric adenoma and EGC. However, EMR has some limitations that EGC may have lymph node metastases or multiple tumors. So, periodic follow-up is very important. As we acquire more clinical experience, EMR may be accepted as the standard treatment method for gastric adenoma and EGC.

Prognosis of Early Gastric Cancer: Impact of Lymph Node Metastasis

PURPOSE: Early gastric cancer (EGC) is defined as gastric cancer confined to the mucosa or submucosa, regardless of lymph node (LN) metastasis. The prognosis of EGC is more favorable than that of advanced gastric cancer. Due to the variety of prognosis of EGC, in relation to LN metastasis, this study was undertaken to determine the impact of LN metastasis on the survival of patients with EGC, and to aid in planning therapeutic approaches for such patients. METHODS: A retrospective study of 517 patients with EGC, who had undergoing a gastrectomy with lymphadenectomy, between 1990 and 1999 was performed. Stages were classified using the UICC TNM classification (1997). RESULTS: LN metastasis was observed in 67 cases (13.0%). 6.7% (17/288) of the EGC within the mucosa, and 19.0% (50/281) within the submucosa, had LN metastasis. The overall Five-year survival rates (5YSR) of 517 EGC patients was 95.5%, and for the EGC patients in N0, N1, N2 and N3 groups were 98.3, 82.2, 27.8 and 0%, respectively (P<0.001). The 5YSRs for patients with mucosal and submucosal cancers were 98.9 and 92.4%, respectively (P= 0.023), and was poorer in those EGC patients with tumor sizes above 5 cm than in those below 5 cm (5YSR 96.3 and 86.7%, respectively. P=0.020). However, the survival rates for EGC patients did not differ significantly based on the gross and histological types. The 5YSR for EGC patients with stage IA, IB, II and IV were 98.3, 82.1, 40.0 and 33.3%, respectively (P<0.001). LN metastasis and depth of invasion were found to be significant risk factor from the multivariate analysis. CONCLUSION: Based on the results of this study, the significant prognostic factors of EGC were LN metastasis and depth of invasion. Although the prognosis of EGC is favorable, it depends upon the prognostic factors.

Clinicopathologic Findings of Early Gastic Cancer / 대한암학회지

PURPOSE: The prognosis forearly gastric cancer (EGC) is generally excellent after curative gastrectomy alone. However, the EGC of young patients was generally more invasive and metastasizing, and the prognosis of them was poorer than those of the elderly. We performed a retrospective study to evaluate clinica1 and pathological factors influencing the prognosis of EGC. MATERIALS AND METHODS: The authors investigated 66 cases of EGC resected at Inha Hospital in Song-Nam, from January 1987 to December 1996. We analyzed 9 clinicopathologic factors: age, sex, macroscopic type, tumor size, depth of invasion, location, lymph node metastasis, Williss classification and Laurens classification. RESULTS: Out of 66 cases (42 males, 24 females) of EGC, the sex ratio (M: F) was 1.75: 1, and the mean age was 55.5 years in male and 54.3 in female. The age incidence revealed a greater prevalence on 6th decade (33.3%). The most common macroscopic type of EGC was IIb and its combined type (43 cases, 65.2%). In tumor size, 16 cases (24.2%) were between 2.0 and 2.9 cm, and 13 cases (19.6%) between 1.0 and 1.9 cm, 10 cases (15%) between 3.0 and 3.9 cm. The tumors smaller than 2.0 cm were 33.2% but greater than 5.0 cm were 18.8%. In male, mucosal lesions were more common (66.6%) than submucosal lesions (33.4%); but in female, the incidence of both types of lesions were the same. The submucosal lesion in female was the most frequent at 4th decade. The major location of EGC was antrum (51.5%). Lymph node metastases were found in 3 females and 1 male. By Williss classification, poorly differentiated adenocarcinoma and signet ring cell carcinoma were more common in female (29.2%, 25%) than in male (11.9%, 14.3%). By Laurens classification, the diffuse type was more common in female (50%) than in male (33.3%). This type was the most frequent in 4th decade female patients. However, none of the above data reached statistical significance. CONCLUSION: We found the generalized tendency, though not statistically confinned, that the young female patients of EGC frequently had larger and poorly differentiated, diffuse adenocarcinomas with more frequent lymph node metastasis than male. The authors emphasizes that a further study would be needed in young female patients of EGC on hormonal factors influencing its clinicopathologic findings.

A Comparative Retrospective Study of Mucosal and Submucosal Cancer in Early Gastric Cancer

BACKGROUND: The 5-year survival rate for early gastric cancer (EGC) now exceeds 90% and EGC is now recognized as a curable malignancy. The less extensive treatment has attracted interest. It is of vital importance to select a surgical method appropriate to each individual case. A retrospective study was undertaken to compare clinicopathologic features between mucosal (M) and submucosal (SM) cancers and to evaluate treatment modality for EGC. METHODS: We analyzed clinicopathologic data on 345 surgically treated patients with early gastric cancer between September 1983 and December 1996 at the Department of Surgery, Korea University College of Medicine: 183 patients with mucosal cancer and 162 patients with submucosal cancer. RESULTS: The rate of detection of EGC has been increasing as high as 25% since 1990. There were significant differences between M and SM cancers with regard to the location of the tumor, lymph node metastasis and histologic type. The SM cancer had lower 1/3 in location, more lymph node metastasis and more differentiated than M cancer. Nodal involvement was evident in 49 patients (14.2%): 6.6% (12/183) with M cancer and 22.8% (37/162) with SM lesions. The 5-year survival rate of all patients was 94.7%: 95.3% in M cancer and 94.0% in submucosal SM cancer. The 5-year survival rates for SM cancer were 96.1% in node-negative cases and 86.3% in node-positive cases with significance and M cancer had no survival difference. CONCLUSIONS: As early gastric cancer can be cured by surgery, the submucosal carcinomas in this series had no indications for less extensive treatment, such as endoscopic or laparoscopic limited surgery. These carcinomas should be subject to standard surgery with gastrectomy and combined dissection of lymph nodes.