Proposal of the surgical options for primary tumor control during sentinel node navigation surgery based on the discrepancy between preoperative and postoperative early gastric cancer diagnoses.

BACKGROUND: There is no consensus on the optimal method of primary tumor control, determined by preoperative clinical factors, during sentinel node (SN) navigation surgery for early gastric cancer (EGC). In this study, we investigated the accuracy of clinical diagnosis based on preoperative examination in patients with EGC and proposed surgical options for primary tumor control during SN navigation surgery.
METHODS: We analyzed 815 patients with clinical stage IA gastric cancer who underwent gastrectomy at the National Cancer Center in Korea between March 2001 and February 2011. The clinical stage was determined by endoscopy, endoscopic ultrasonography, and abdominal computed tomography.
RESULTS: The preoperative assessment of tumor depth and tumor size was accurate in 57.5 and 70.8 % of patients, respectively. Tumor depth and size were underestimated in 8 and 25.3 % of patients. The overall accuracy of histologic diagnosis by endoscopic biopsy was 87.2 %. Of those tumors diagnosed preoperatively as differentiated, 20.5 % revealed mixed histology of undifferentiated type.
CONCLUSIONS: The recommendation for SN biopsy may be limited to tumors sized 3 cm or smaller to avoid positive lateral margins and to minimize the risk of skip metastases. Endoscopic resection may safely be applied to small mucosal cancers, but other surgical options should be employed for undifferentiated large mucosal lesions, given their tendency for diffuse invasion. Full-thickness resection is preferable for submucosal cancers, to secure clear vertical margins.