To explore the application value of carbon nanoparticle labeled lymph node staining in radical resection of adenocarcinoma of esophagogastric junction with preoperative chemoradiotherapy.

The retrospective cohort study was conducted. The clinicopathological data of 56 patients with adenocarcinoma of esophagogastric junction who underwent preoperative chemoradiotherapy in the Peking University Cancer Hospital from January 2014 to November 2017 were collected. There were 52 males and 4 females, aged from 22 to 76 years, with an average age of 62 years. Among 56 patients undergoing total gastrectomy and D₂ lymphadenectomy, 17 using carbon nanoparticle lymph node staining and 39 using traditional lymph node sorting were respectively allocated into observation group and control group. Observation indicators: (1) treatment situations; (2) detection of lymph nodes; (3) perioperative complications; (4) follow-up. Follow-up using outpatient examination and telephone interview was performed to detect tumor recurrence or metastasis up to May 2019. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was evaluated by the independent sample t test. Measurement data with skewed distribution were represented as M (range), and comparison between groups was evaluated by the Mann-Whitney U test. Count data were described as absolute numbers, and comparison between groups was analyzed using the chi-square test or Fisher exact propability. Comparison of ordinal data was analyzed using the nonparametric rank sum test.

(1) Treatment situations: patients in both groups were successfully treated with concurrent chemoradiotherapy based on intensity modulated radiotherapy before operation. Radical gastrectomy with D₂ lymphadenectomy was successfully performed after chemoradiotherapy, and Roux-en-Y esophagojejunostomy was used to reconstruct the digestive tract during operation. The operation time and volume of intraoperative blood loss were respectively (217±58)minutes and (112±60)mL in the observation group, and (235±65)minutes and (119±77)mL in the control group, with no statistically significant difference between the two groups (t=1.017, 0.341, P>0.05). (2) Detection of lymph nodes: the average number of harvested lymph nodes, average number of radiation target lymph nodes, and average number of peritarget lymph nodes were respectively 32±10 , 21±8, and 7±4 in the observation group, and 22±7, 16±5, 5±3 in the control group, with statistically significant differences between the two groups (t=4.138, 2.881, 2.401, P<0.05). The median number of positive lymph nodes harvested, median number of positive radiation target lymph nodes, and median number of positive peritarget lymph nodes were respectively 0 (range, 0-2), 0 (range, 0-2), and 0 (range, 0-0) in the observation group, and 0 (range, 0-7), 0 (range, 0-3), and 0 (range, 0-1) in the control group, showing no statistically significant difference between the two groups (Z=1.305, 1.101, 0.660, P>0.05). (3) Perioperative complications: 6 and 18 patients in the observation group and the control group had complications, respectively, with no statistically significant difference between the two groups (χ²=0.570, P>0.05). Patients with complications were improved after drug treatment and local treatment without second operation. No local or systemic adverse reactions caused by carbon nanoparticles was observed during and after operation in the observation group. (4) Follow-up: 56 patients were followed up for 5-65 months, with a median follow-up time of 32 months. There were 14 and 6 patients in the observation group and the control group with tumor recurrence or metastasis, respectively, showing no significant difference between the two groups (χ²=0.002, P>0.05).

Carbon nanoparticle labeled lymph node staining in radical resection of adenocarcinoma of esophagogastric junction with preoperative chemoradiotherapy can increase the number of harvested lymph nodes.

Neoplasms of esophagogastric junction; Adenocarcinoma of esophagogastric junction; Preoperative chemoradiotherapy; Carbon nanoparticles; Lymph nodes sorting; Radical gastrectomy with D₂ lymphadenectomy