Recurrence rate of intramucosal gastric cancer with positive vertical margin due to lesion damage during endoscopic submucosal dissection

Background and study aim: In principle, additional surgery is performed after endoscopic submucosal dissection for early gastric cancer if the vertical margin is positive, regardless of lesion damage. The recurrence rate of vertical margin-positive lesions due to lesion damage after endoscopic submucosal dissection is unknown, and unnecessary surgeries may be performed. In this study, we investigated whether there was a difference in the recurrence rate between vertical margin-positive lesions due to lesion damage and vertical margin-negative lesions. Patients and methods: We included 1,294 intramucosal gastric cancer lesions that were resected by endoscopic submucosal dissection between January 2008 and December 2016, without additional surgery. The lesions were divided into the Damage and No damage groups based on vertical margin status. The Damage group had only one non-curative indication: a positive vertical margin due to lesion damage. The No damage group had no non curative indications. We compared the recurrence rate between the Damage and No damage groups. Results: The recurrence rates of the Damage and No damage groups were 0% (0/23; 95% confidence interval: 0-14.8%) and 0% (0/1,271; 95% confidence interval: 0-0.003%), respectively, with no statistically significant difference. Conclusions: In intramucosal gastric cancer, the recurrence rate of vertical margin-positive lesions due to lesion damage was 0%, which did not differ from that of vertical margin-negative lesions with curative resection. Follow-up, instead of additional surgery, may be an option for patients with non-curative resection when the only non-curative indication is a positive vertical margin due to lesion damage.

The prognostic significance of a histological response to preoperative chemotherapy in patients with synchronous colorectal liver metastases

Background Preoperative chemotherapy (PC) for colorectal liver metastasis (CRLM) is widely used to improve prognosis, but its clinical benefit has not been fully established. This study aimed to assess the effectiveness of PC for synchronous CRLMs, and to analyze the correlation between histological response to PC and survival. Methods We retrospectively analyzed the clinicopathological factors and outcomes of 69 patients who underwent initial hepatectomy for synchronous CRLM between 2004 and 2018 after receiving PC (PC group: n = 43) or who underwent upfront hepatectomy without PC (Non-PC group: n = 26). In the PC group, the patients were divided into two groups, Grade 1 (n = 27) and Grade 2/3 (n = 16) groups according to their histological responses to PC. Results The median survival and 5-year overall survival (OS) rates were 80.9 months and 61.5%, respectively, in the PC group and 71.7 months and 61.5%, respectively, in the Non-PC group (P = 0.867). Regarding recurrence-free survival (RFS) and remnant liver-RFS, there were no significant differences between the two groups (P = 0.087 and 0.291). However, in a subgroup analysis according to the histological response to PC, the median 5-year OS, RFS, and remnant liver-RFS in the Grade 2/3 group were significantly longer than in the Grade 1 group (OS: 66 vs. 53 months; P = 0.008, RFS: 15 vs. 6.7 months; P = 0.002, remnant liver-RFS: 62 vs. 8.3 months; P < 0.001). Surgical margin positive status (< 1 mm) was associated with a high remnant liver recurrence rate (hazard ratio 2.597, P = 0.008). Conclusion PC should not be routinely administered to all patients with synchronous CRLMs. However, some patients benefit from PC, and the histological response to PC had prognostic significance for patients with synchronous CRLM.