Extragastric recurrence in patients who underwent surgical resection of stage I gastric cancer: Incidence, risk factors, and value of abdominal computed tomography as a postoperative surveillance method

Extragastric recurrence after radical resection of stage I gastric cancer is very rare. We investigated the incidence of extragastric recurrence and risk factors in patients who underwent surgical resection of stage I gastric cancer and evaluated the value of abdominal CT as a surveillance tool. This retrospective study enrolled 914 patients with stage I gastric cancer who underwent surgical resection at a single tertiary hospital. We investigated extragastric recurrence during the follow-up period, and disease-free survival (DFS) was assessed. Over a median follow-up period of 39 months, the overall incidence of extragastric recurrence was 2.2% (20/914). Risk factors for extragastric recurrence included deep submucosal invasion (SM2-3), muscularis propria invasion, and lymph node metastasis (hazard ratio [HR]=10.37, 28.101, and 6.843; P = .028, .002, and .001, respectively). Based on the number of risk factors, patients were stratified into 3 subgroups: low-risk (pT1aN0, pT1b(SM1)N0, 496/914), moderate-risk (pT1aN1, pT1b(SM1)N1, pT1b(SM2-3)N0, pT2N0, 369/914), and high-risk (pT1b(SM2-3)N1, 49/914). DFS was significantly longer in the low-risk group, followed by the moderate-risk and high-risk groups. We propose that postoperative CT surveillance should be omitted for stage 1A cases involving the mucosa and SM1 because of the extreme rarity of extragastric recurrence.