Hye Seong Ahn

Evaluation of the Seventh American Joint Committee on Cancer/International Union Against Cancer Classification of gastric adenocarcinoma in comparison with the sixth classification

The seventh TNM staging system for gastric cancer of the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) had a more detailed classification than the sixth TNM staging system for both the tumor (T) and lymph nodes (N). The authors compared survival rates assessed by the seventh staging system with those by the sixth system.

Stage Migration Effect on Survival in Gastric Cancer Surgery With Extended Lymphadenectomy: The Reappraisal of Positive Lymph Node Ratio as a Proper N-Staging

Objective:The purpose of this study is to analyze the relationship between the number of examined lymph nodes (NexLN) and survival in gastric cancer and to determine whether the metastatic/examined lymph node ratio (LN ratio) system can compensate for the shortcomings of the UICC/AJCC staging. Methods:Prospective data of 8949 primary T1-T4a gastric cancer patients who underwent curative surgery were reviewed. The patients were stratified by T-stage and grouped according to NexLN; 1 to 14 exLN denoted the first group and every subsequent 10 LNs thereafter. Numbers of LN and 5-year survival rates were analyzed according to NexLN. “The NR-staging system” was generated using 0.2 and 0.5 as the cut-off values of LN ratio and then compared with UICC/AJCC stages. Results:The proportion of advanced N-stage increased with NexLN. Survival and the LN ratio were constant regardless of NexLN when combining all N0-N3b patients, however, T2/3 and T4a patients showed an increasing tendency toward survival in N1/2 and N3a as NexLN increased, mainly due to a stage migration effect. The LN ratio system showed better patterns of distribution of the LN stage and survival graph. The power of the differential staging of the LN ratio system was fortified with higher NexLN. Conclusion:The relationship between NexLN and survival is probably affected by stage migration in a high-volume gastric cancer center. The LN ratio system could be a better option to compensate for this effect, and the value of the prognosis prediction in this system increases with a higher NexLN.

Diagnostic accuracy of T and N stages with endoscopy, stomach protocol CT, and endoscopic ultrasonography in early gastric cancer

Preoperative accurate diagnosis of the T and N stages in early gastric cancer (EGC) is important in determining the application of various limited treatments. The aim of this study is to analyze the accuracy of T and N staging of EGC with esophagogastroduodenoscopy (EGD), Stomach protocol CT (S‐CT), and endoscopic ultrasonography (EUS), and the factors influencing the accuracy.

General perioperative management of gastric cancer patients at high-volume centers

BackgroundGastric cancer is very common in Korea and Japan, where many hospitals annually perform high numbers of gastrectomies for gastric cancer. The aim of this study was to compare the general management of gastric cancer in high-volume centers in Korea and Japan.MethodsWe undertook a survey of the general management of gastric cancer at high-volume centers (over 200 cases/year) and analyzed the answers.ResultsIn six of 14 hospitals surveyed, antimicrobial prophylaxis for elective gastrectomy was administered until postoperative day 3. A Levin tube and an abdominal drain were routinely inserted in seven and ten hospitals, respectively. Laboratory tests, such as complete blood cell count, liver function test, electrolytes, and blood urea nitrogen/creatinine were performed frequently on postoperative days 1, 2, 3, and 5. Sips of water after open distal gastrectomy were restarted up to postoperative day 3 in twelve hospitals. The surgical pathology was reported up to postoperative day 10 in thirteen hospitals. Twelve hospitals provided a regular patient education program and only one hospital provided an integrated education program which included the participation of a surgeon, an oncologist, a nurse, and a nutritionist.ConclusionsThe general management of gastric cancer in 14 high-volume centers was not so different among the centers. The general management protocols noted here are expected to provide useful information for perioperative care.

Overexpression of Plasminogen Activator Inhibitor-1 in Advanced Gastric Cancer with Aggressive Lymph Node Metastasis

Purpose The purpose of this study is to investigate differentially expressed genes using DNA microarray between advanced gastric cancer (AGC) with aggressive lymph node (LN) metastasis and that with a more advanced tumor stage but without LN metastasis. Materials and Methods Five sample pairs of gastric cancer tissue and normal gastric mucosa were taken from three patients with T3N3 stage (highN) and two with T4N0 stage (lowN). Data from triplicate DNA microarray experiments were analyzed, and candidate genes were identified using a volcano plot that showed ≥ 2-fold differential expression and were significant by Welchs t test (p < 0.05) between highN and lowN. Those selected genes were validated independently by reverse-transcriptase–polymerase chain reaction (RT-PCR) using five AGC patients, and tissue-microarray (TMA) comprising 47 AGC patients. Results CFTR, LAMC2, SERPINE2, F2R, MMP7, FN1, TIMP1, plasminogen activator inhibitor-1 (PAI-1), ITGB8, SDS, and TMPRSS4 were commonly up-regulated over 2-fold in highN. REG3A, CD24, ITLN1, and WBP5 were commonly down-regulated over 2-fold in lowN. Among these genes, overexpression of PAI-1 was validated by RT-PCR, and TMA showed 16.7% (7/42) PAI-1 expression in T3N3, but none (0/5) in T4N0 (p=0.393). Conclusion DNA microarray analysis and validation by RT-PCR and TMA showed that overexpression of PAI-1 is related to aggressive LN metastasis in AGC.

Primary Retroperitoneal Malignant Gastrointestinal Stromal Tumor Mimicking Adrenal Mass.

Gastrointestinal stromal tumor (GIST) is the most common non-epithelial tumor in the gastrointestinal tract. Although GIST occurs mainly in the gastrointestinal tract, it also occurs, rarely, in non-gastrointestinal tract and in this case, it is often named as extra-gastrointestinal stromal tumor (EGIST). We experienced a 68-year-old male patient who had been diagnosed preoperatively with accidentaloma of the left adrenal gland by computed tomography, and finally diagnosed as primary retroperitoneal malignant GIST, postoperatively. The operation was performed via anterior abdominal approach, and complete surgical resection was done for a 7 cm sized retroperitoneal tumor near the left adrenal gland. Primary retroperitoneal malignant GIST was the final pathologic diagnosis and the size of the tumor was 6.5 cm and the mitotic count was 7 per high-power field. Diffuse strong positive staining for c-kit protein, CD34 and negative staining for desmin were observed in a immunohistochemistry test. We report here the unusual case of primary retroperitoneal malignant GIST mimicking adrenal mass.

Prognostic factors for reoperation of recurrent retroperitoneal sarcoma: The role of clinicopathological factors other than histologic grade

Reoperation is recommended for resectable retroperitoneal sarcoma (RS) recurrence; however, the long‐term overall survival (OS) benefit varies. Although histologic grade is an important OS predictor after primary tumor resection, its prognostic value tends to diminish with subsequent reoperations. The objective of this study was to identify prognostic factors of OS after reoperation for recurrent RS.

Gastric cancer staging with radiologic imaging modalities and UICC staging system.

There are two major stage classification systems for gastric cancer: the tumor-node-metastasis (TNM) stages by the International Union against Cancer (UICC) and the Japanese Classification of Gastric Carcinoma by the Japanese Gastric Cancer Association (JGCA). Preoperative stage classification using either of these systems is essential for deciding on the treatment strategy in the era of various multimodal therapeutic options. Evolution of multidetector computerized tomography with isotropic volumetric imaging and various 3D images has increased the accuracy of T and N staging in patients with gastric cancer, although detection of peritoneal deposits and nodal metastasis in the absence of lymphadenopathy remain problematic with the imaging tools currently available. The TNM and JGCA classifications have undergone revisions independent of each other, and the discrepancies were not helpful when international comparisons and cooperation were needed. More recently, the JGCA and TNM classifications were merged to have identical T and N categories, in addition to the more straightforward M categories that indicate the presence of distant metastasis. The result of these efforts is that researchers in Japan and the rest of the world are now looking at a similar disease when they discuss cancer that belongs to the same stage. A nomogram that incorporates other established prognostic determinants in addition to the TNM component may be a future direction for a more sophisticated means of predicting outcome. The increasing incidence of junctional (esophagogastric junction) cancer in the Far East has spurred researchers from this region to adequately stage the disease and to consider suitable treatment modalities for this disease entity, whereas Western researchers are more inclined to treat this disease as esophageal cancer. This could be an area for future international debate. For the next more accurate staging, we suggest the collaboration between Eastern and Western high-volume centers in gastric cancer because the inconsistency of surgical approaches, especially with respect to nodal resection, remains a barrier to mutual understanding.

Clinical Outcome of Modified Laparoscopy-Assisted Proximal Gastrectomy Compared to Conventional Proximal Gastrectomy or Total Gastrectomy for Upper-Third Early Gastric Cancer with Special References to Postoperative Reflux Esophagitis

Purpose This study evaluated the functional and oncological outcomes of proximal gastrectomy (PG) in comparison with total gastrectomy (TG) for upper-third early gastric cancer (EGC). Materials and Methods The medical records of upper-third EGC patients who had undergone PG (n=192) or TG (n=157) were reviewed. The PG group was further subdivided into patients who had undergone conventional open PG (cPG; n=157) or modified laparoscopy-assisted PG (mLAPG; n=35). Patients who had undergone mLAPG had a longer portion of their intra-abdominal esophagus preserved than patients who had undergone cPG. Surgical morbidity, recurrence, long-term nutritional status, and the incidence of reflux esophagitis were compared between the groups. Results The rate of postoperative complications was significantly lower for PG than TG (16.7% vs. 31.2%), but the five-year overall survival rate was comparable between the two groups (99.3% vs. 96.3%). Postoperative levels of hemoglobin and albumin were significantly higher for patients who had undergone PG. However, the incidence of reflux esophagitis was higher for PG than for TG (37.4% vs. 3.7%; P<0.001). mLAPG was related to a lower incidence of reflux esophagitis after PG (P<0.001). Conclusions Compared to TG, PG showed an advantage in terms of postoperative morbidity and nutrition, and there was a comparable prognosis between the two procedures. Preserving the intra-abdominal esophagus may lower the incidence of reflux esophagitis associated with PG.

Clinicopathological Features of Upper Third Gastric Cancer during a 21-Year Period (Single Center Analysis)

Purpose The aim of this study was to determine proportions of upper third gastric cancer (UTG) among all gastric cancers and analyze clinicopathological features of the disease. Materials and Methods The medical records of 12,300 patients who underwent gastric surgery between 1986 and 2006 at Seoul National University Hospital (SNUH) were retrospectively reviewed. Clinicopathological features of 1,260 patients with UTG and 9,929 patients with middle or lower third gastric cancer (MLG) were compared, and annual proportions of UTG were evaluated. Results The proportion of patients with UTG rapidly increased from 2.6% in 1986 to 12.5% in 1992. However, linear regression analysis showed that the rate of increase was reduced (0.21%/year) after 1992 (12.5% to 14.2% from 1992 to 2006). Compared with the MLG group, the UTG group had a lower proportion of (22.3% vs. 39.7%, P<0.001) and a greater proportion of stage III/IV disease (39.4% vs. 31.7%, P<0.001). The UTG group also had larger tumors than the MLG group in stages I/II and III (3.5 cm/5.3 cm/6.5 cm vs. 3.2 cm/5.0 cm/5.8 cm, P=0.020/0.028 /<0.001), a higher proportion of undifferentiated cancer (63.1% vs. 53.7%, P<0.001), and less intestinal Laurens type (38.8% vs. 47.4%, P<0.001). The 5-year survival rate of the UTG group was significantly lower than that of the MLG group in stages I/II and III (85.6%/63.1%/34.2% vs. 91.6%/ 69.2%/44.7%, P<0.001/0.028/0.006). Conclusions The proportion of UTGs has increased over the last two decades at SNUH, but the rate of increase has been greatly reduced since 1992. The UTG group showed a poorer prognosis compared with the MLG group in stages I/II and III.