[The impact of modified T3 sub-staging on the prognosis of gallbladder cancer patients].

ABSTRACT

Objective: To explore the value of a new modified T3 sub-staging for the prognosis evaluation in gallbladder cancer patients. Methods: This is a retrospective case-series study. The clinical data of patients with pathologically confirmed stage T3 gallbladder cancer who were admitted to the Department of Hepatobiliary Surgery,the First Affiliated Hospital of Xi'an Jiaotong University from January 2011 to December 2021 were retrospectively analyzed. A total of 190 patients were enrolled in this study, 67 males and 123 females, with an age (M(IQR)) of 63(14) years (range17 to 88 years). The stage T3 was divided into four sub-stages according to the site of tumor invasion (1) T3atumor perforates the serosa,but not invading the liver and one other adjacent structure; (2) T3btumor perforates the serosa and invades one other adjacent structure,but not the liver; (3) T3ctumor perforates the serosa and invades the liver,but not one other adjacent structure; (4) T3dtumor perforates the serosa,invades the liver and one other adjacent structure. To evaluate the application value of this modified sub-staging,the Kaplan-Meier method was used to draw the survival curve,univariate analysis and multivariate analysis were done using the Log-rank test and Cox proportional hazard model respectively. Results: According to the modified T3 sub-staging method,34 patients (17.9%) were in stage T3a,24 cases(12.6%) were in stage T3b, 97 cases (51.1%) were in stage T3c, and 35 cases (18.4%) were in stage T3d. The median survival time of patients in stages T3a,T3b,T3c and T3d after radical resection was 72.0 months, 32.0 months, 12.0 months and 10.0 months, respectively. The 1-, 3-, and 5-year survival rates of patients in stage T3a, T3b, T3c and T3d were 79.4%, 53.3%, and 53.3%; 79.2%, 44.6%, and 26.0%;49.5%,27.5%,and 18.1%;42.9%,15.9%, and 15.9% (χ2=18.349,P<0.01),respectively. Univariate analysis showed that gallbladder stones,pathological differentiation,perineural invasion, N stage,postoperative adjuvant therapy and modified T3 substage were factors affecting patient prognosis(all P<0.05). Cox multivariate analysis showed that modified sub-stages with T3c (HR=2.043, 95%CI1.176 to 3.549) and T3d(HR=2.419, 95%CI1.284 to 4.555), accompanied by gallbladder stones (HR=1.661,95%CI1.150 to 2.398),pathological differentiation with poorly differentiated(HR=1.709,95%CI1.198 to 2.438), and the N stage with N1 and N2(HR=1.602, 95%CI1.090 to 2.355, 2.714, 95%CI 1.621 to 4.544) were independent prognostic risk factors for patients in stage T3,while postoperative adjuvant chemotherapy(HR=0.351) was a protective factor for prognosis. There was no statistically significant difference in survival between patients with stage T3a and T3b who underwent hepatic wedge resection and liver segment or major resection (P=0.402). For patients with stage T3c and T3d with liver invasion,the survival difference after hepatic wedge resection and segmental or major resection was statistically significant (P=0.008). Conclusion: The modified T3 sub-staging system based on the depth and direction of tumor invasion maybe helpful to further stratify the prognosis of patients with gallbladder cancer.