Multifocality in early gastric cancer does not increase the risk of lymph node metastasis in a single-center study.

Background: The multifocality rate of EGC ranges from 4 to 20%, but there are few data regarding both lymph node metastasis and feasibility of the endoscopic treatment. We investigated the risk of lymph node metastasis with the purpose to evaluate the potential for endoscopic treatment in patients with multifocal EGC.
Methods: We retrospectively reviewed the medical records of patients who underwent radical gastrectomy to treat EGC between January 2001 and December 2007 at Severance Hospital, Seoul, Korea. Synchronous multifocal EGC was defined as EGC having two or more malignant foci, whereas solitary EGC was defined as EGC having single focus.
Results: Of 1,693 patients, 55 (3.2%) were diagnosed with synchronous multifocal EGC. The rates of lymph node metastasis were 12.7% in synchronous multifocal EGC and 10% in solitary EGC. In the multivariate analysis, synchronous multifocal EGC was not associated with lymph node metastasis (odds ratio, 1.1; 95% confidence interval, 0.4-2.7) compared with solitary EGC. In a subgroup analysis of 55 patients with synchronous multifocal EGC, older age (≥65 years) and lymphovascular invasion were associated with lymph node metastasis. In synchronous multifocal EGC, none of the cases had lymph node metastasis in major and minor lesions representing mucosal cancer without lymphovascular invasion.
Conclusions: Synchronous multifocality of EGC does not increase the risk of lymph node metastasis compared with solitary EGC. Therefore, endoscopic treatment can be planned when major and minor lesions are predicted to represent mucosal cancer without lymphovascular invasion.