Differential analysis of lymph node metastasis in histological mixed-type early gastric carcinoma in the mucosa and submucosa.
AIM
To investigate the relationship between histological mixed-type of early gastric cancer (EGC) in the mucosa and submucosa and lymph node metastasis (LNM).


METHODS
This study included 298 patients who underwent gastrectomy for EGC between 2005 and 2012. Enrolled lesions were divided into groups of pure differentiated (pure D), pure undifferentiated (pure U), and mixed-type according to the proportion of the differentiated and undifferentiated components observed under a microscope. We reviewed the clinicopathological features, including age, sex, location, size, gross type, lymphovascular invasion, ulceration, and LNM, among the three groups. Furthermore, we evaluated the predictors of LNM in the mucosa-confined EGC.


RESULTS
Of the 298 patients, 165 (55.4%) had mucosa-confined EGC and 133 (44.6%) had submucosa-invasive EGC. Only 13 (7.9%) cases of mucosa-confined EGC and 30 (22.6%) cases of submucosa-invasive EGC were observed to have LNM. The submucosal invasion (OR = 4.58, 95%CI: 1.23-16.97, P = 0.023), pure U type (OR = 4.97, 95%CI: 1.21-20.39, P = 0.026), and mixed-type (OR = 5.84, 95%CI: 1.05-32.61, P = 0.044) were independent risk factors for LNM in EGC. The rate of LNM in mucosa-confined EGC was higher in the mixed-type group (P = 0.012) and pure U group (P = 0.010) than in the pure D group, but no significant difference was found between the mixed-type group and pure U group (P = 0.739). Similarly, the rate of LNM in the submucosa-invasive EGC was higher in the mixed-type (P = 0.012) and pure U group (P = 0.009) than in the pure D group but was not significantly different between the mixed-type and pure U group (P = 0.375). Multivariate logistic analysis showed that only female sex (OR = 5.83, 95%CI: 1.64-20.70, P = 0.028) and presence of lymphovascular invasion (OR = 13.18, 95%CI: 1.39-125.30, P = 0.020) were independent risk factors for LNM in mucosa-confined EGC, while histological type was not an independent risk factor for LNM in mucosa-confined EGC (P = 0.106).


CONCLUSION
For mucosal EGC, histological mixed-type is not an independent risk factor for LNM and could be managed in the same way as the undifferentiated type.
['Zhong|Qian|Q|', 'Sun|Qi|Q|', 'Xu|Gui-Fang|GF|', 'Fan|Xiu-Qin|XQ|', 'Xu|Yuan-Yuan|YY|', 'Liu|Fei|F|', 'Song|Shi-Yi|SY|', 'Peng|Chun-Yan|CY|', 'Wang|Lei|L|']
D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D002277:Carcinoma D002454:Cell Differentiation D016009:Chi-Square Distribution D005260:Female D005743:Gastrectomy D005753:Gastric Mucosa D006801:Humans D016015:Logistic Models D008207:Lymphatic Metastasis D008297:Male D008875:Middle Aged D015999:Multivariate Analysis D009361:Neoplasm Invasiveness D009367:Neoplasm Staging D018193:Neoplasms, Complex and Mixed D016017:Odds Ratio D012189:Retrospective Studies D012307:Risk Factors D013274:Stomach Neoplasms D055815:Young Adult
Lymph node metastasis Mixed-type Early gastric carcinoma Mucosa Lymphovascular invasion