Objective: To investigate the impact of tumor size in the prognosis of T4a stage gastric cancer.
Methods: The best cut-off point depending on tumor size was selected by Kaplan-Meier. Compare cliniclópathological characteristics between small size gastric cancer (SSG) and large size gastric cancer (LSG). Univariate analysis was done by Log-rank test and multivariate analysis was performed using the Cox proportional hazard regression model. The independent prognostic factors of patients were performed subgroup analysis.
Results: Eight centimetre was the optimal cut-off of tumor size for T4a stage gastric cancer. There were significantly differences between SSG and LSG in tumor location (χ² = 15.695), histological grade (χ² = 4.393), macroscopic type (χ² = 5.629) and early recurrence (χ² = 4.292). Univariate analysis showed age (χ² = 4.463), tumor size (χ² = 9.057), macroscopic type (χ² = 6.679), histological grade (χ² = 5.122), location of tumor (χ² = 8.707) and N stage (χ² = 132.954) are related to survival (P < 0.05). Among them, tumor size (HR = 1.339), histological grade (HR = 1.169) and N stage (HR = 1.876) were independent risk factor for survival (P = 0.05). For SSG, N stage (HR = 2.014) and histological grade (HR = 1.192) were independent risk factor for survival (P = 0.05), and for LSG, N stage (HR = 1.876) was independent risk factor for survival (P = 0.000). Further stratified analysis indicated that the 5-year survival rate of LSG is significantly lower than that of SSG in T4a stage patients of gastric cancer without lymph nodes metastasis or poorly differentiated (HR = 0.182 and 0.653, P < 0.01).
Conclusions: Tumor size is an independent prognostic factor in patients of T4a stage gastric cancer. Tumor size cut-off point of 8 cm can exert significant impact on the prognosis of T4a stage gastric cancer without lymph nodes metastasis or poorly differentiated.