Risk factors for lymph node metastasis in patients with early gastric cancer and signet ring cell histology

Background: Early gastric cancer with signet ring cell histology has been reported as a favourable histological type. The aim of this study was to identify risk factors associated with lymph node metastasis in patients with this type of early gastric cancer. Methods: A cross-sectional study of patients with early gastric cancer with differentiated and signet ring cell histology undergoing surgery was conducted. Risk factors were evaluated using multiple logistic regression analysis with odds ratios and 95 per cent confidence intervals. Results: In 1362 patients undergoing gastrectomy for early gastric cancer, the rate of lymph node metastasis was similar for tumours with signet ring cell and differentiated histological findings (10.7 versus 9.0 per cent respectively; P = 0.307). Logistic regression analysis showed that depth of tumour invasion was predictive of lymph node metastasis in patients with signet ring cell histology (P < 0.001). Tumour size was not associated with lymph node metastasis in either univariable or multivanable analysis. Lesions smaller than 2 cm were not uncommon in patients with signet ring cell gastric tumours and lymph node metastases (six of 48; 13 per cent). Conclusion: Patients with early gastric cancer with signet ring cell-type histology are probably hest treated by gastrectomy with lymph node dissection.