Han Hong Lee

Validation of the seventh edition of the American Joint Committee on Cancer TNM staging system for gastric cancer.

The seventh edition of the American Joint Committee on Cancer (AJCC) TNM classification for gastric cancer was published in 2010 and included major revisions. The aim of the current study was to evaluate the validity of the seventh edition TNM classification for gastric cancer based on an Asian population.

Negative impact of leakage on survival of patients undergoing curative resection for advanced gastric cancer.

Leakage has been shown to adversely affect survival in patients undergoing surgery for gastrointestinal malignancies. However, the effect of leakage following radical gastrectomy in patients with gastric cancer remains unclear.

Intragastric approach for submucosal tumors located near the Z-line: A hybrid laparoscopic and endoscopic technique

The present study was designed to evaluate the feasibility and impact of the “intragastric” approach to laparoscopic wedge resection as a surgical option for the treatment of suspected small sized gastric submucosal tumors (SMTs) located at the level of Z‐line.

Laparoscopic wedge resection for gastric submucosal tumors: a size-location matched case-control study.

BACKGROUND Laparoscopic local resection for gastric submucosal tumors (SMTs) has become accepted as a standard treatment because it offers less postoperative pain and faster recovery. However, until recently, the laparoscopic approach has been limited by tumor location and size. The aim of this study was to examine the efficacy and safety of laparoscopic wedge resection (LWR) in comparison to open wedge resection (OWR), based on tumor size and location. STUDY DESIGN In this case-control study, 50 patients who received LWR for gastric SMTs were carefully matched by size and location of the tumor; 50 patients underwent OWR during the same period. Patient demographics, clinicopathologic characteristics, and postoperative courses were compared. RESULTS After matching for tumor size and location, the LWR group showed more favorable results than the OWR group in terms of the starting time of soft meals (mean days, 3.4 vs 4.8, respectively; p < 0.001) and length of hospital stay (mean days, 5.7 vs 7.8, respectively; p < 0.001), but not in terms of operative time (mean minutes, 153 vs 127, respectively; p < 0.05). The rate of postoperative complications did not differ between the groups. CONCLUSIONS This case-control study suggests that laparoscopic surgery can be safely performed for gastric SMTs and results in a better postoperative recovery, regardless of tumor size or location.

Analysis of 151 consecutive gastric submucosal tumors according to tumor location

The aim of the present study was to evaluate the histopathological characteristics of gastric submucosal tumors (SMTs) according to their location.

Long-term outcomes and survival after laparoscopy-assisted distal gastrectomy for gastric cancer: three-year survival analysis of a single-center experience in Korea.

Laparoscopy‐assisted distal gastrectomy (LADG) has been established as an alternative treatment for early gastric cancer (EGC) because of excellent short‐term results. However, only a few reports have considered the long‐term outcomes of LADG. In this study, we investigated the 3‐year outcome and survival of patients who underwent LADG.

Low accuracy of endoscopic ultrasonography for detailed T staging in gastric cancer.

BackgroundThe accuracy of endoscopic ultrasonography (EUS) for preoperative staging of gastric cancer varies. The aim of this study was to investigate the accuracy of EUS tumor (T) and node (N) staging, and to identify the histopathological factors influencing accuracy based on the detailed tumor depth of gastric cancer.MethodsIn total, 309 patients with gastric cancer with confirmed pathological staging underwent EUS examination for preoperative staging at Seoul St. Mary’s Hospital, Korea, between January and December 2009. The T and N staging of EUS and the pathologic report were compared.ResultsThe overall accuracies of EUS for T stage and the detailed T stages were 70.2% and 43.0%, respectively. In detailed stage, tumors greater than 50 mm in diameter were significantly associated with T overstaging (odds ratio (OR) = 2.094). The overall accuracy of EUS for N staging was 71.2%. Tumor size (20 mm ≤ size < 50 mm, OR = 4.389; and 50 mm ≤ size, OR = 8.170), cross-sectional tumor location (circumferential, OR = 4.381) and tumor depth (submucosa, OR = 3.324; muscular propria, OR = 6.923; sub-serosa, OR = 4.517; and serosa-exposed, OR = 6.495) were significant factors affecting incorrect nodal detection.ConclusionsCareful attention is required during EUS examination of large-sized gastric cancers to increase accuracy, especially for T staging.

CD133 expression is correlated with chemoresistance and early recurrence of gastric cancer

CD133 has been suggested to be a cancer stem cell (CSC) marker in various types of cancers. The present study assessed the relationship between CD133 expression and clinicopathological features of gastric cancer. In addition, the prognostic value of CD133 for gastric cancer was evaluated.

The mutational burdens and evolutionary ages of early gastric cancers are comparable to those of advanced gastric cancers

Early gastric cancers (EGCs) precede advanced gastric cancers (AGCs), with a favourable prognosis compared to AGC. To understand the progression mechanism of EGC to AGC, it is required to disclose EGC and AGC genomes in mutational and evolutionary perspectives. We performed whole‐exome sequencing and copy number profiling of nine microsatellite (MS)‐unstable (MSI‐H) (five EGCs and four AGCs) and eight MS‐stable (MSS) gastric cancers (four EGCs and four AGCs). In the cancers, we observed well‐known driver mutations (TP53, APC, PIK3CA, ARID1A, and KRAS) that were enriched in cancer‐related pathways, including chromatin remodelling and tyrosine kinase activity. The MSI‐H genomes harboured ten times more mutations, but were largely depleted of copy number alterations (CNAs) compared to the MSS cancers. Interestingly, EGC genomes showed a comparable level of mutations to AGC in terms of the number, sequence composition, and functional consequences (potential driver mutations and affected pathways) of mutations. Furthermore, the CNAs between EGC and AGC genomes were not significantly different in either MSI‐H and MSS. Evolutionary analyses using somatic mutations and MSI as molecular clocks further identified that EGC genomes were as old as AGC genomes in both MSS and MSI‐H cancers. Our results suggest that the genetic makeup for gastric cancer may already be achieved in EGC genomes and that the time required for transition to AGC may be relatively short. Also, the data suggest a possibility that the mutational profiles obtained from early biopsies may be useful in the clinical settings for the molecular diagnosis and therapeutics of gastric cancer patients. Copyright

Undifferentiated-type gastric adenocarcinoma: prognostic impact of three histological types

BackgroundThe prognostic value of the three constituents of undifferentiated-type gastric adenocarcinoma remains unclear. The present study assessed the clinicopathological characteristics and prognosis of undifferentiated-type mucinous adenocarcinoma (uMAC) and signet ring cell carcinoma (SRC) compared with those of poorly differentiated adenocarcinoma (PDAC).MethodsIn total, 1,376 patients with undifferentiated-type gastric adenocarcinoma were included, consisting of 1,002 patients diagnosed with PDAC, 54 with uMAC and 320 with SRC. Clinicopathological factors and survival rates were compared among the three histological types.ResultsSignificant differences in the distribution of pathological stages were observed among the groups. Patients with SRC had a significantly better survival rate than those with PDAC or uMAC, in both the all patients including non-curative resected patients and curative-resected groups. In addition, there was significant difference in survival between the PDAC and uMAC groups. Multivariate analysis suggested that age, gender, tumor depth, lymph node metastasis and curability significantly affected survival. Histological type was not an independent prognostic factor. There was no significant difference in the pattern of recurrence among the three groups.ConclusionsThe uMAC and SRC had worse and favorable prognosis compared with PDCA, respectively. However, there were no differences in survival by pathological stage, thus histological type was not an independent predictor of prognosis.