Effect of World Health Organization (WHO) Histological Classification on Predicting Lymph Node Metastasis and Recurrence in Early Gastric Cancer.

BACKGROUND The World Health Organization (WHO) histological classification for gastric cancer is widely accepted and used. However, its impact on predicting lymph node metastasis and recurrence in early gastric cancer (EGC) is not well studied. MATERIAL AND METHODS From 1987 to 2005, 2873 EGC patients with known WHO histological type who had undergone curative resection were enrolled in this study. In all, 637 well-differentiated adenocarcinomas (WD), 802 moderately-differentiated adenocarcinomas (MD), 689 poorly-differentiated adenocarcinomas (PD), and 745 signet-ring cell adenocarcinomas (SRC) were identified. RESULTS The distribution of demographic and clinical features in early gastric cancer among WD, MD, PD, and SRC were significantly different. Lymph node metastasis was observed in 317 patients (11.0%), with the lymph node metastasis rate being 5.3%, 14.8%, 17.0%, and 6.3% in WD, MD, PD, and SRC, respectively. Univariate and multivariate analyses indicated that gender, tumor size, gross appearance, depth of invasion, and WHO classification were significantly associated with lymph node metastasis. Recurrence was observed in 83 patients (2.9%), with the recurrence rate being 2.2%, 4.5%, 3.0%, and 1.6% in WD, MD, PD, and SRC, respectively. Multivariate analysis confirmed that MD, elevated gross type, and lymph node metastasis were independent risk factors for recurrence in EGC. MD patients showed worse disease-free survival than non-MD patients (P=0.001). CONCLUSIONS WHO classification is useful and necessary to evaluate during the perioperative management of EGC. Treatment strategies for EGC should be made prudently according to WHO classification, especially for MD patients.

Prediction of recurrence of early gastric cancer after curative resection.

BACKGROUND: Recurrence of early gastric cancer (EGC) after curative resection is rare, and the types of EGC that may recur have not been well studied. We attempted to create a system for predicting recurrence of EGC after R0 resection. METHODS: From January 1987 to April 2005, 2,923 patients with EGC who underwent curative resection were retrospectively studied. Of them, 79 patients (2.7%) experienced recurrence. Logistic regression was performed to identify independent risk factors for overall recurrence and early recurrence (recurred within 24 months after resection) of EGC. A nomogram was developed on the basis of a Cox regression. RESULTS: Median time to recurrence was 20.5 months, and early recurrence accounted for 60.7% of instances. Presence of lymph node metastasis and elevated gross type were independent risk factors for overall recurrence; patients with both identified risk factors had a higher recurrence rate than average level (17.5% vs. 2.7%, P < 0.001). Meanwhile, male gender, elevated gross type, and presence of lymph node metastasis were significantly associated with early recurrence, and in patients with all of the aforementioned identified risk factors, the early recurrence rate was higher (12.2% vs. 1.6%, P < 0.001). A nomogram for predicting the disease-free survival after operation was constructed. Its c-index was 0.79 and it appeared to be accurate. CONCLUSIONS: Recurrence of EGC after curative resection can be predicted by using common clinical characteristics. Patients at high risk of overall and early recurrence could be identified; individual disease-free survival was predictable by the internally validated nomogram.

Clinicopathologic characteristics and prognosis for young gastric adenocarcinoma patients after curative resection.

BACKGROUND: Conflicting results from previous studies on gastric adenocarcinoma (GC) in young patients have led to controversy surrounding the prognosis for young GC patients. METHODS: The authors studied 6954 patients with GC who received curative resections. They were classified into three groups: those aged 40 years or less ("young," 12.7%); those aged 41-65 years ("middle-aged," 66.7%); and those aged more than 65 years ("elderly," 20.6%). Clinicopathologic characteristics and overall survival rates were analyzed. RESULTS: Young patients were predominately female and had tumors that were histologically undifferentiated. However, in regard to T4 invasion, N3 lymph node metastasis, and TNM stage IV, the characteristics of the tumors of young patients were similar to those of middle-aged and elderly patients. Overall survival rate was significantly better in young patients than middle-aged patients (P = .018) and elderly patients (P < .001). Stratified by TNM stage, young patients showed better overall survival at stage I than middle-aged patients, and at stages I, II, and IIIa than elderly patients. Multivariate analysis indicated that age was an independent prognostic factor (as well as gender, operation type, depth of invasion, and lymph node status). CONCLUSIONS: The predominance of female cases and tumors that were histologically undifferentiated were distinctive characteristics in young patients. Young patients could gain a survival benefit after curative resection with stage I disease.

Risk factors for lymph node metastasis in undifferentiated early gastric cancer.

BACKGROUND: Endoscopic surgery has not been accepted as a curative treatment for intramucosal undifferentiated early gastric cancer (EGC). The purpose of this study was to evaluate the predictive factors of lymph node metastasis and explore the possibility of using endoscopic surgery for undifferentiated EGC. METHODS: We retrospectively analyzed 646 patients with undifferentiated EGC who had undergone gastrectomy with D2 lymphadenectomy from January 2000 to March 2005. We used univariate and multivariate analysis to identify clinicopathological features that were predictive factors for lymph node metastasis. RESULTS: The incidence of lymph node metastasis was 4.2% in intramucosal and 15.9% in submucosal undifferentiated EGC. Multivariate analysis revealed that submucosal invasion, larger tumor size (greater than 2 cm), and presence of lymphovascular invasion (LVI), were significantly associated with lymph node metastasis in patients with undifferentiated EGC. Tumor size and LVI were independent risk factors for lymph node metastasis in cases of intramucosal EGC. Lymph node metastasis was found in only one patient (0.5%) who had neither of the two risk factors for intramucosal EGC. CONCLUSION: Complete endoscopic resection may be acceptable as a curative treatment for intramucosal undifferentiated EGC when the tumor size is less than or equal to 2 cm, and when LVI is absent in the postoperative histological examination. Radical gastrectomy should be recommended if LVI or unexpected submucosal invasion is present.

Solitary lymph node metastasis in gastric cancer.

The feasibility and diagnostic reliability of sentinel node (SN) biopsy for gastric cancer are still controversial. We studied the clinicopathological features and localization of solitary lymph node metastasis (SLM) in gastric cancer to provide useful information for use of the SN concept in gastric cancer. From 2000 to 2004, 3,267 patients with gastric cancer underwent D2 radical gastrectomy. The clinicopathological features of 195 patients with histologically proven SLM and the distribution of metastasized nodes were assessed. The incidence of SLM was 6.0% in all cases. Compared with the node-negative patients, significant differences were observed in age, tumor size, depth of invasion, and surgical type. The cumulative 5-year survival rate of patients with SLM was 80.5%, which was significantly lower than 90.2% for node-negative patients (P<0.001). Of patients with SLM, 82.6% had it in the perigastric node area (N1), and the other 17.4% patients had skip metastasis in the N2-N3 nodes. Perigastric nodes were the most common first sites of drainage from the tumor, making them the main targets of the operative SN mapping procedure. Due to the higher than expected incidence of skip metastasis in gastric cancer, D2 lymphadenectomy should be performed until the reliability of SN navigation surgery is validated in multicenter prospective clinical trials.

Advanced gastric carcinoma with signet ring cell histology.

BACKGROUND: Gastric signet ring cell carcinoma (SRC) is a histological type based on microscopic characteristics and not on biological behavior. This study compared the clinicopathological features and prognosis of advanced SRC with non-signet ring cell adenocarcinoma (NSRC) of the stomach. METHODS: We reviewed the records of 4,759 consecutive patients diagnosed with advanced gastric adenocarcinoma who were resected surgically from 1987 to 2003. Of these, 662 patients (13.9%) had SRC and were compared with 4,097 patients with NSRC. RESULTS: Significant differences were noted in tumor size, Borrmann type, depth of invasion, lymph node metastasis, peritoneal dissemination and TNM stage. The cumulative 5-year survival rate for advanced SRC was 42.4%, compared with 50.1% in NSRC (p = 0.009). Multivariate analysis showed that tumor size > or =5 cm, Borrmann III and IV, T3-4 invasion and SRC histology were independent risk factors for lymph node metastasis. Depth of invasion, lymph node metastasis, hepatic and peritoneal metastasis and surgical curability were significant factors affecting survival. SRC histology alone was not an independent prognostic factor. CONCLUSIONS: Advanced gastric SRC tends toward deeper tumor invasion and more lymph node and peritoneal metastasis than NSRC. Advanced gastric SRC had a worse prognosis than NSRC. Therefore, curative surgical operation with extended lymph node dissection is recommended.