Missed lesions in synchronous multiple gastric cancer

Background: The aims of this study were to define differences between synchronous multiple gastric cancer (MGC) and solitary gastric cancer (SGC) and to evaluate the characteristics of missed lesions in MGC so as to improve the detection rate of missed lesions during perioperative procedure. Methods: The authors retrospectively analysed data on 9157 gastric cancer patients who underwent gastrectomy for gastric cancer in a single hospital. The characteristics of 8893 SGC and 264 MGC patients were evaluated. The characteristics of missed lesions in MGC were compared with those of diagnosed lesions found in preoperative endoscopy. Results: Of the 9157 gastric patients, 264 patients with MGC showed a total of 565 cancer lesions, 70 of which were missed at endoscopy. The patients with MGC demonstrated different characteristics compared with those with SGC in terms of sex, age, type of operation, depth of tumour, lymph node metastasis, tumour size, tumour location and curability (P < 0.05). The characteristics of the missed lesions (n = 70) were a small size (P < 0.05), a middle one-third location (P < 0.001) and a flat type by macroscopic examination (P < 0.05) as compared with detected lesions (n = 495). No survival difference was detected between patients with and without missed lesions over a mean follow-up of 36.0 +/- 22.7 month. Conclusions: Preoperative gastroscopy should be performed meticulously in the entire stomach, especially in older men, in order to identify the presence and locations of cancer lesions that might otherwise be missed.