Sentinel node biopsy in early gastric cancer: constant exertion for clinical application

A nomogram to predict risk of lymph node metastasis in early gastric cancer

Lymph node (LN) metastasis is known as one of the most important prognostic factors for early gastric cancer (EGC) patients. Patients without LNM normally have better prognosis. However, there is no evaluation criteria to accurately assess the possibility of LN metastasis. Therefore, this study aims to establish an effective nomogram for prognosis prediction. In this study, 285 EGC patients from January 2010 to December 2015 were enrolled. Pearson’s Chi-Square (χ²) test (including continuity correction when appropriate) and logistics regression analyses was used to identify the risk factors for LN metastasis. The independent risk factors identified were then incorporated in a nomogram model. The predictive accuracy and discriminative ability of the nomogram were evaluated by receiver operating characteristic curve (ROC) and calibration curve. LN metastasis occurred in 59 (20.7%) EGC patients. And most of these patients were submucosal cancers (48/59). Chi-square test indicated lymphovascular emboli, carbohydrate antigen 19-9 (CA19-9), ulcer, tumor size, tumor infiltration and histological grade were the risk factors, and multivariate logistics analyses confirmed all these six factors were independent risk factors of LN metastasis, which were selected to construct the nomogram. The nomogram proved well calibrated and had good discriminative ability (C-index value: 0.842). The proposed nomogram could result in more-accurate risk prediction for EGC patients.

Clinical features of second primary cancers arising in early gastric cancer patients after endoscopic resection

AIM: To investigate the incidence and distribution of second primary cancers (SPCs) in early gastric cancer (EGC) patients who underwent endoscopic resection (ER), compared to advanced gastric cancer (AGC) patients who underwent surgery.

METHODS: The medical records of 1021 gastric cancer (GC) patients were retrospectively reviewed from January 2006 to December 2010. The characteristics and incidence of SPCs were investigated in those with EGC that underwent curative ER (the EGC group) and those with AGC who underwent curative surgical resection (the AGC group).

RESULTS: We ultimately enrolled 184 patients in the EGC group and 229 patients in the AGC group. A total of 38 of the 413 (9.2%) GC patients had SPCs; the rate was identical in both groups. Of these 38 patients, 18 had synchronous and 20 had metachronous cancers. The most common SPC was lung cancer (18.4%), followed by colorectal cancer (13.2%) and esophageal cancer (13.2%). No significant risk factors were identified for the development of SPCs.

CONCLUSION: Endoscopists should provide close surveillance and establish follow-up programs to ensure SPC detection in GC patients undergoing curative resection regardless of their clinical characteristics.

Prediction of metachronous multiple primary cancers following the curative resection of gastric cancer

Background

Due to improved survival rate, gastric cancer (GC) patients have an increased risk of developing multiple primary cancer (MPC). The purpose of this study is to evaluate the clinicopathological features of MPC and to generate useful tools for the prediction of metachronous MPC following gastrectomy.

Methods

3066 patients who underwent curative resection of GC were reviewed retrospectively, based on the clinical information and the medical record.

Results

The 5-year incidence of MPC was 2.5%. Of these, 54.3% had a metachronous MPC, while 45.7% had a synchronous MPC. The most prevalent site of metachronous MPC was the colorectum (26.3%), followed by lung (23.7%) and liver (18.4%). Multivariate logistic regression analysis revealed that old age at the time of GC diagnosis (≥60 years), early stage of GC (stage I and II), and multiplicity of GC at the time of gastrectomy were independent predictive factors for metachronous MPC. GC patients with either metachronous or synchronous MPC showed poorer survival than patients without MPC. In addition, patients with a metachronous MPC showed late survival disadvantage, while patients with a synchronous MPC showed early survival disadvantage. Furthermore, we were able to develop and internally validate a nomogram to predict the metachronous MPC after curative gastrectomy (C-index = 0.72).

Conclusion

Patients at high risk of developing metachronous MPC after curative resection of GC were identified. Individual risk of developing metachronous MPC could be predicted by a novel nomogram. Further external validation with independent patient cohorts is required to improve the accuracy of prediction.

Laparoscopic gastrectomy for gastric cancer

Laparoscopic gastrectomy for gastric cancer is rapidly becoming popular because of the technical developments and the accumulated data of laparoscopic surgery in gastric cancer patients. The aim of this review is to present the current body of evidence and to highlight controversial issues of laparoscopic gastrectomy for gastric cancer. Laparoscopic distal gastrectomy (LDG) provides better or comparable outcomes compared to conventional open distal gastrectomy (ODG) in terms of short-term results. The long-term survival of LDG is expected to be comparable to that of ODG in early-stage gastric cancer, and an ongoing Korean multicenter randomized controlled trial (KLASS-01) will provide more clear evidence. Laparoscopic total gastrectomy is still selectively performed compared to LDG, and there is still debate on the safety of the laparoscopic esophagojejunostomy technique. Laparoscopic pylorus-preserving gastrectomy seems to be preferred for early gastric cancer in the middle third of the stomach in terms of functional advantages and comparable oncologic outcome. Evidence for LDG for advanced gastric cancer is still insufficient and the issue of lack of generalization still remains, even after ongoing multicenter randomized controlled trials have revealed clinical evidence. Laparoscopic sentinel node navigation surgery is still experimental and the surgical procedure has yet to be standardized. Robotic gastrectomy is feasible for early gastric cancer in terms of similar outcome, but is much more expensive in comparison to laparoscopic surgery. Its benefit over the conventional laparoscopic gastrectomy has not yet been proven.

Minimally invasive approaches for gastric cancer-Korean experience

Laparoscopic surgery in Korea increased rapidly because of the early detection of gastric cancer by the development of diagnostic tools and nationwide screening. The Korean Laparoscopic Gastrointestinal Surgery Study Group (KLASS group) played a leading role in various projects related with minimally invasive surgery. The justification of minimally invasive procedures including robotic surgery, sentinel-node biopsy, or single-port surgery/Natural Orifice Transluminal Endoscopic Surgery (NOTES) must be predetermined by the clinical trial before a wide application, and the medical industry as well as surgeons should have great responsibility.

Clinical trials in gastric cancer and the future

Following the first successful gastric resection for gastric cancer by Theodor Billroth in 1881 surgery has made tremendous progress leading to improved surgical mortality and morbidity. However, while treatment of early gastric cancer is frequently curative, 5-year survival rates for advanced gastric cancer remain dismal despite the application of perioperative multimodal treatment concepts. In this article we will outline key clinical trials that have lead to an improvement in treatment of gastric cancer patients with specific emphasis on the last 20 years. We will then outline recent concepts and key clinical trials that are currently being conducted in the field. Finally we will outline open questions that remain to be elucidated in the future.