Endoscopic management of early gastric cancer

Unsaturated free fatty acids: a potential biomarker panel for early detection of gastric cancer

Changes in the levels of free fatty acids (FFAs) are closely associated with physiological status. Serum levels of C16:1, C18:3, C18:2, C18:1, C20:4, and C22:6 in 164 gastric cancer (GC) patients and 111 benign gastric disease (BGD) patients were significantly decreased compared with 252 healthy controls. Receiver operating characteristic analysis showed that the biomarker panel including C16:1, C18:3, C18:2, C20:4, and C22:6 presents a high diagnostic ability to differentiate early-stage GC patients from healthy controls plus BGD patients, with a sensitivity of 80.6% and a specificity of 72.7%.

[Comparison on the long term outcome between endoscopic submucosal dissection and surgical treatment for undifferentiated early gastric cancer]

BACKGROUND/AIMS

There are controversies on the efficacy and safety of endoscopic submucosal dissection (ESD) for un-differentiated early gastric cancer (EGC) despite the expansion of ESD indications. The aim of this study was to evaluate the long term outcome of ESD compared to that of surgical treatment in patients with undifferentiated EGC.

METHODS

A total of 76 patients who underwent ESD for undifferentiated EGC and 149 patients who met the ESD indication and received surgical treatment from January 2005 to December 2010 at Chonnam National University Hwasun Hospital were included.

RESULTS

In the ESD group, en bloc resection and complete resection were achieved in 84.2% (64/76) and 76.3% (58/76) of patients, respectively. Among these patients, 58 (76.3%) met the ESD indication (indication group), and the remaining 18 (23.7%) did not meet the ESD indication (above indication group). Complete resection rates for indication group and above indication group were 86.2% (50/58) and 44.4% (8/18), respectively (p<0.05). The mean follow-up period was 42.2 ± 19.2 months. Total recurrence rates in the ESD group and operation group were 14.1% (9/76) and 0.7% (1/149), respectively (p<0.05). The main complication of ESD was bleeding (5.2%, 4/76). In the operation group, 2 (1.3%) patients died from postoperative bleeding and leakage of anastomosis site.

CONCLUSIONS

ESD may be a feasible and safe treatment modality compared to that of surgical treatment for undifferentiated EGC when managed according to the expanded criteria. However, close endoscopic surveillance is required in this group because of higher incidence of intragastric recurrence.

Follow-up outcomes of endoscopic resection for early gastric cancer with undifferentiated histology

BACKGROUND

The application of endoscopic resection (ER) for undifferentiated-type early gastric cancer (UD-EGC) remains controversial. The aim was to examine long-term outcomes of ER for UD-EGC. Furthermore, we investigated whether long-term outcomes of ER differed between poorly differentiated adenocarcinoma (PD) and signet ring cell carcinoma (SRC).

METHODS

From 2001 to 2011, 209 lesions in 209 patients with UD-EGC (82 PD; 127 SRC) were treated by ER. We retrospectively assessed the clinical outcomes of ER in 209 patients. The survival rate and disease-free survival rates after ER were evaluated as long-term outcomes.

RESULTS

The en bloc resection and curative resection (CR) rates were 91.4 and 55.0 %, respectively. The en bloc and CR rates in PD were 90.2 and 45.1 %, whereas those in SRC were 92.1 and 61.4 %. For patients with PD who underwent non-curative resections, 51.1 % were vertical-cut end-positive and for those with SRC, 63.3 % were lateral-cut end-positive, a statistically significant difference. In those patients where CR was achieved, no case of local recurrence or distant metastasis was observed during the follow-up period (32.7 ± 22.2 months). The 3- and 5-year survival rates were 99.0 and 98.6 %, with no significant difference between CR patients with SRC and PD.

CONCLUSIONS

ER may yield good long-term outcomes for UD-EGC if CR is achieved, with no difference between PD and SRC. However, to increase the current CR rate of ER, stricter criteria for performing ER in UD-EGC may be required.

Cadherin-17 induces tumorigenesis and lymphatic metastasis in gastric cancer through activation of NFκB signaling pathway

Cadherin-17 (CDH17), as a structurally unique member of the cadherin superfamily, has been identified to predict a poor prognosis for gastric cancer (GC). Our previous study demonstrated the positive correlation between CDH17 and lymph node micrometastasis in GC. We sought to further identify the role of CDH17 in the tumorigenesis and lymphatic metastasis of GC. Hence, we inhibited the CDH17 expression in MKN-45 gastric cancer cells by using RNA interference. Consequently, the malignant potency of cancer cells was evaluated, and the change in NFκB signaling pathway was also probed. Tumor growth and lymphatic metastasis model were conducted in nude mice to confirm the hypothesis. Downregulation of CDH17 not only suppressed the proliferation, adherence and invasion potency of MKN-45 cells, but also induced cell cycle arrest. Meanwhile, the NFκB signaling pathway was inactivated as well, with the reductions of downstream proteins including VEGF-C and MMP-9. Moreover, silencing CDH17 inhibited tumor growth in vivo significantly, and there was no lymph node metastasis detected in the mice without CDH17 expression, as opposed to the positive nodes found in controls. CDH17 is a novel oncogene in gastric cancer cells, which is associated with lymphatic metastasis and proliferation strongly. The inactivation of NFκB signaling pathway might be involved in targeting CDH17 in GC. On the whole, CDH17 is proposed to serve as a biomarker and attractive therapeutic target in GC.

Outcome after endoscopic submucosal dissection for early gastric cancer in Korea

Endoscopic treatment, such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), has been established as one of the treatment options for selected cases with early gastric cancer (EGC). Most studies on this topic have been carried out by researchers in Japan. Recently, the experience in EMR/ESD for EGC outside Japan is increasingly reported. In Korea, gastric cancer is the most common malignant disease, and the second leading cause of cancer death. Currently, EMR for EGC is widely performed in many centers in Korea. Early results with a short-term follow-up period are very promising in Korea. The complete resection rate of EMR was 37.8%-94.3%, and that of ESD was 77.4%-93.1%. In this review, we will provide an overview of the outcomes of endoscopic treatments in Korea.

Endoscopic submucosal dissection for gastric cancer

Endoscopic submucosal dissection (ESD) is a novel endoscopic treatment that enables a clinician to resect an early-stage gastric cancer in en bloc fashion. ESD is indicated for those cancers in which there is a high probability of en bloc resection and low probability of lymph node metastasis. The latter may be the limiting factor at institutions skilled at ESD. Several ESD techniques are available with similar outcomes. Thus, selection depends on operator preference and expertise. Gastrectomy with lymphadenectomy should be applied initially to those early gastric cancers with high probability of positive lymph nodes or as an additional treatment after ESD. Endoscopic mucosal resection (EMR) should be reserved for small, nonulcerated, intramucosal, differentiated cancers. Disadvantages of ESD in comparison with EMR are longer operation times and higher incidences of intraoperative bleeding and perforation, but the indication for ESD includes larger and ulcerative lesions not amenable to EMR.

Treatment strategy for early gastric cancer

Gastric cancer ranks the second leading cause of cancer-specific mortality worldwide. With a poor prognosis, 5-year survival rate of gastric cancer is less than 20%-25% in the USA, Europe, and China [1]. However, early gastric cancer(EGC) offers an excellent (over 90%) chance of cure based on surgical resection [2]. As the increasing detection of EGC, more treatment options have been developed both curatively and minimally invasively to maintain a good quality of life(QOL). One of the advanced therapeutic techniques is endoscopic dissection. Improvements in surgical treatment include minimizing lymph node dissection, reconstruction methods, laparoscopy-assisted surgery, and sentinel node navigation surgery(SNNS) [3]. With technological advances, even Natural Orifice Transluminal Endoscopy Surgery (NOTES) and robotic surgery are expected to represent the next revolution [4]. However, there still remains much dispute among these treatments, which arouses further clinical trials to verify. Update of the treatments, controversial indications, prognosis and current strategies for EGC are discussed in this review.

The usefulness of magnifying endoscopy with narrow-band imaging to distinguish carcinoma in flat elevated lesions in the stomach diagnosed as adenoma by using biopsy samples

BACKGROUND

Therapeutic strategies for flat elevated (0-IIa) lesions in the stomach diagnosed as adenoma by biopsy are currently not established, because some difficulties have previously been reported in the evaluation of vascular patterns alone for the differential diagnosis between adenoma and carcinoma.

OBJECTIVE

We attempted to evaluate the 0-IIa lesions diagnosed as adenoma by using magnifying endoscopy with narrow-band imaging (MENBI) to distinguish them as either adenoma or carcinoma.

SETTING

Department of Gastroenterology, Fujita Health University.

PATIENTS

Fourteen adenomatous lesions (6 adenomas and 8 carcinomas confirmed postoperatively) diagnosed with preoperative biopsies from patients who had undergone endoscopic submucosal dissection were evaluated.

INTERVENTIONS

We selected 5 sites per lesion for MENBI. Selected sites were divided into superficial structures (SSs) and irregular microvascular patterns (IMVPs).

MAIN OUTCOME MEASUREMENTS

The rate of SSs and IMVPs in adenoma and carcinoma.

RESULTS

Significant SSs were tubular in the adenoma and unclear in the carcinoma. Regarding IMVP subcategories, (1) slight intrastructual irregular microvascular patterns (ISIMVPs) accounted for 97%, (2) severe ISIMVPs accounted for 0%, (3) fine networks accounted for 3%, and (4) corkscrews accounted for 0% of cases in the adenomas. The corresponding proportions in the carcinomas were (1) 40%, (2) 15%, (3) 45%, and (4) 0%. Severe ISIMVPs and fine networks were significant findings for carcinomas.

LIMITATIONS

The number of cases was limited.

CONCLUSIONS

Our combined evaluation method using MENBI offers the ability to establish proper therapeutic strategies for lesions that are difficult to identify as adenoma or carcinoma.

Clinicopathological features associated with lymph node metastasis in early gastric cancer: analysis of a single-institution experience in China

BACKGROUND

An accurate assessment of potential lymph node metastasis is an important issue for the appropriate treatment of early gastric cancer. Minimizing the number of invasive procedures used in cancer therapy is critical for improving the patient's quality of life.

OBJECTIVE

To evaluate the clinicopathological features associated with lymph node metastasis of early gastric cancer in patients from a single institution in China.

METHODS

A retrospective review of data from 410 patients surgically treated for early gastric cancer at the First Affiliated Hospital (Nanjing, China) between 1998 and 2007, was conducted. The clinicopathological variables associated with lymph node metastasis were evaluated.

RESULTS

Lymph node metastasis was observed in 12.20% of patients. The macroscopic type, tumour size, location in the stomach, depth of gastric carcinoma infiltration, and presence of vascular or lymphatic invasion showed a positive correlation with the incidence of lymph node metastasis by univariate analysis. Multivariate analyses revealed histological classification, macroscopic type, tumour size, depth of gastric carcinoma infiltration, and the presence of vascular or lymphatic invasion to be significantly and independently related to lymph node metastasis. The depth of gastric carcinoma infiltration was the strongest predictive factor for lymph node metastasis. For intramucosal cancer, tumour size was the unique risk factor for lymph node metastasis. For submucosal cancer, histological classification and tumour size were independent risk factors for lymph node metastasis.

CONCLUSIONS

Histological classification, macroscopic type, tumour size, depth of gastric carcinoma infiltration, and the presence of vascular or lymphatic invasion are independent risk factors for lymph node metastasis in patients with early gastric cancer in China. Minimal invasive treatment, such as endoscopic mucosal resection, may be possible for highly selected cancers.

Endoscopic resection for undifferentiated early gastric cancer

BACKGROUND AND OBJECTIVE

Endoscopic resection (ER) has become an important curative option for early gastric cancer (EGC). However, the application of ER for undifferentiated EGC remains controversial. The aim of this study was to evaluate the clinicopathologic outcomes of ER performed in undifferentiated EGC with special reference to histopathologic subtypes to examine the feasibility of ER in undifferentiated EGC.

DESIGN AND SETTING

Retrospective, single-center study.

PATIENTS

From January 2001 to April 2007, 58 lesions in 58 patients with undifferentiated EGC (17 poorly differentiated adenocarcinoma; 41 signet-ring cell carcinoma) were treated by ER at Severance Hospital, Seoul, Korea.

MAIN OUTCOME MEASUREMENTS

The therapeutic efficacy of ER was assessed according to en bloc resection, histologic complete resection (CR), lateral or vertical cut end-positive (including submucosal invasion), and recurrence rates in 3- to 65-month follow-up periods.

RESULTS

The en bloc resection and CR rates were 84.5% and 67.2%, respectively. The en bloc and CR rates in poorly differentiated were 82.4% and 58.8%, whereas those in signet-ring cell were 85.4% and 70.7%, respectively. There were no significant differences between poorly differentiated and signet-ring cell. However, all (100%) of the histologic incomplete resections in poorly differentiated were vertical cut end-positive, whereas 83.3% of these resections in signet-ring cell were lateral cut end-positive. The recurrence rate was 5.1% in CR during the follow-up period.

LIMITATIONS

Retrospective, short-term follow-up period.

CONCLUSIONS

ER may be a feasible local treatment for undifferentiated EGC if CR can be achieved. However, a different approach is necessary between poorly differentiated and signet-ring cell before ER to prevent incomplete resection.

Endoscopic mucosal resection of early gastric cancer: Experiences in Korea

Endoscopic mucosal resection (EMR) has been established as one of the treatment options for early gastric cancer (EGC). However, there are many uncertain areas such as indications of EMR, best treatment methods, management of complications and follow-up methods after the procedure. Most studies on this topic have been carried out by researchers in Japan. In Korea, gastric cancer is the most common malignant disease, and the second leading cause of cancer death. In these days, EMR for EGC is widely performed in many centers in Korea. In this review, we will provide an overview of the techniques and outcomes of EMR in Korea.

Infrared fluorescence endoscopy for the diagnosis of superficial gastric tumors

BACKGROUND

Indocyanine green (ICG) is a fluorescent marker that is excited by rays at a wavelength of 768 nm to emit fluorescence at a wavelength of 807 nm in the infrared (IR) range. We developed an IR fluorescence endoscope (IRFE) to observe superficial gastric tumors and assessed its clinical usefulness.

OBJECTIVE

To evaluate the clinical usefulness of an IRFE for the assessment of superficial gastric tumors.

DESIGN

An observational study.

SETTING

University hospital.

INTERVENTIONS

Newly developed IRFE.

PATIENTS

Thirty patients with gastric tumors were enrolled in this study, and their lesions were subjected to endoscopic submucosal dissection (ESD), or laparoscopic gastrectomy after observation with the IRFE.

METHODS

Gastric lesions were subjected to conventional observation, followed by IR fluorescence observation before and after intravenous ICG (0.01 mg/kg) injection.

MAIN OUTCOME MEASUREMENTS

The relationship between the positive fluorescence and invasivity of each tumor.

RESULTS

Fluorescence was positive in 8 of 10 gastric cancers with submucosal invasion (80%) and 1 of 20 adenomas or intramucosal gastric cancers (5%); the difference was statistically significant (P<.01).

CONCLUSION

IRFE is a useful diagnostic tool for estimating the invasivity of gastric tumors.