Evaluation of lymph node metastasis in patients with gastric cancer: a comparison of the directionality of lymph node metastasis and the total number of metastatic lymph nodes

Preoperative N stage evaluation in advanced gastric cancer patients using multidetector CT: can the sum of the diameters of metastatic LNs be used for N stage evaluation?

AIM

To compare the diagnostic performance of total counts of metastatic lymph nodes (LN-sum) and conventional multidetector (MD) computed tomography (CT) staging in the nodal evaluation of advanced gastric cancer (AGC) patients.

MATERIALS AND METHODS

In total, 127 consecutive patients who underwent preoperative MDCT and gastrectomy for AGC were identified. Metastatic LNs on MDCT were defined as LNs with a short axis ≥8 mm, marked or heterogeneous enhancement, and morphological features (central necrosis, round shape, clustering). The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the N-stage using LN-sum and conventional MDCT staging were generated and compared. In addition, metastatic LN counts between the MDCT and the histopathological examinations and correlation between LN-sum and histopathological nodal status were analysed.

RESULTS

The total counts of metastatic LNs on MDCT was significantly smaller than those detected in histopathological assessments (p<0.0001). LN-sum showed significant correlation with the pathological N stage and the number of metastatic LNs (rho=0.69, 0.73, p<0.0001). The areas under the receiver operating characteristic curve were 0.896, and 0.835, for N stage ≥N2 and N3, with cut-off values of 12.5 and 23.5 mm, respectively. LN-sum provided better diagnostic performance than conventional MDCT staging for discriminating N0-2 versus N3; sensitivity, accuracy, PPV and NPV of LN-sum were significantly higher (80.4 versus 52.2%, 81.1 versus 68.5%, 71.2 versus 57.1%, and 88 versus 74.1%).

CONCLUSION

LN-sum may be sufficiently useful in assessing the N3 stage of AGC and may help to plan appropriate therapy for AGC patients.

The Significant Influence of the Neuroendocrine Component on the Survival of Patients with Gastric Carcinoma Characterized by Coexisting Exocrine and Neuroendocrine Components

Background

Gastric adenocarcinoma patients with a neuroendocrine (NE) component are frequently observed in routine practice. Several previous studies have investigated the influence of a NE component on the survival of these patients; however, the results were inconsistent.

Methods

We retrospectively investigated a consecutive series of 95 gastric adenocarcinoma patients with a NE component and 190 gastric adenocarcinoma patients without a NE component. We adopted 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90% as the cut-off proportions of the NE component, respectively, and analyzed the patients' overall survival according to the proportion of the NE component.

Results

The 1-, 3-, and 5-year actual survival rates of the patients with a NE component were 90.1%, 72.3%, and 67.2%, respectively, and for those without a NE component 94.2%, 79.3%, and 75.7%, respectively. The multivariate analysis showed that the patients with NE components >70% (HR: 2.156; 95% CI: 1.011, 4.597; p=0.047) and >90% (HR: 2.476; 95% CI: 1.088, 5.634; p=0.031) had significantly worse survival than those without a NE component. Only the diameter of tumors (>4.64 cm) (HR: 2.585; 95% CI: 1.112, 6.006; p=0.027) and pN3 (HR: 2.953; 95% CI: 1.051, 8.293; p=0.040) were independently associated with worse overall survival for gastric adenocarcinoma patients with a NE component (all p<0.05).

Conclusion

Gastric adenocarcinoma patients with a NE component >70% and >90% have significantly worse survival than those without a NE component. Only the diameter of tumors and the number of metastatic lymph nodes are independent prognostic factors for gastric adenocarcinoma patients with a NE component.

Prognostic significance of metastatic lymph node number, ratio and station in gastric neuroendocrine carcinoma

The objective of this study was to analyze the prognostic significance of metastatic lymph node status in gastric neuroendocrine carcinoma (GNEC) patients following radical gastrectomy. A consecutive series of 73 patients who underwent gastrectomy between 1999 and 2011 for GNEC was retrospectively reviewed. Indexes of lymph node involvement (the pN classification, metastatic lymph node number [MLNn], ratio [MLNr], and station [MLNs]) and other clinicopathological data were analyzed. Fifty-four patients met the inclusion criteria and were enrolled in the study. Among them, 44 patients (81 %) were found to have lymph node metastases. The median survival time of the entire cohort was 63.2 (range, 14-153) months with 3- and 5-year survival rates of 88.9 and 47.9 %, respectively. The median total number of lymph nodes, MLNn, and MLNr were 19 (range, 10-56), 5 (range, 1-21), and 25 % (6-100 %), respectively. Cox regression analysis revealed pN classification = 1, MLNn >2, MLNr >0.1, and MLNs = 2, and distant metastases influenced prognosis independently (P = 0.0266, 0.0091, 0.0031, 0.0119, and 0.0021, respectively). In addition to the pN classification, indexes of metastatic lymph node involvement, including MLNn, MLNr, and MLNs, were all significant predictors of survival in GNEC patients. Distant metastasis was also a significant prognostic factor. These indexes proved to be accurate and important supplements to survival factors, which may improve risk classification of GNEC patients.

Value of contrast-enhanced multiphasic spiral CT in detection of early gastric cancer and clinicopathologic features of early gastric cancer

AIM: To assess the value of contrast enhanced multiphasic spiral computed tomography (MDCT) in the detection of early gastric cancer and the clinicopathologic features of early gastric cancer.

METHODS: One hundred and four patients who underwent MDCT examination and were pathologically confirmed with early gastric cancer were included in the study. The thickness of the mucosa of the gastric wall, its changes in enhanced CT values in three enhancement phases, and clinicopathologic features of early gastric cancer were analyzed.

RESULTS: There were statistically significant differences in pN and pTNM stages between T1a and T1b patients (P = 0.0080; P = 0.0175), although no significant differences were found in sex, age, tumor location, tumor size, gastric operation type, number of retrieved lymph nodes, morphological classification, histological type, lymphatic invasion, venous invasion or nervous invasion (P > 0.05). All the patients showed thickening of the stomach wall to different degrees. The thickness of the gastric mucosa (4.37 mm ± 0.91 mm) in early gastric cancer patients was greater than that (2.62 mm ± 0.44 mm) in the control group (t = 14.65, P < 0.0001).The gastric mucosa in primary lesions in the arterial phase showed line like enhancement in the arterial phase (average △CT value = 26 Hu), and persistent enhancement in the venous phase (CT value was 27 Hu higher than that in arterial the phase). All cases showed a slightly lower degree of lesion enhancement in the equilibrium phase. There were statistically significant differences in the changes of CT values between early gastric cancer patients and normal controls in the arterial, portal venous and equilibrium phases (t = 3.44, P = 0.0008; t = 11.55, P < 0.0001; t = 7.67, P < 0.0001).

CONCLUSION: MDCT can provide useful in-formation to improve the diagnosis of early gastric cancer. There are significant differences in pN and pTNM stages between T1a and T1b patients.