Abstract
PURPOSE: The purpose of this study was to determine whether macroscopic growth patterns had an impact on the prognosis of colorectal cancer (CRC) patients with different tumor-node-metastasis (TNM) stages and responses to chemotherapy in stage III patients. PATIENTS AND METHODS: We retrospectively recruited 4,080 stage I-III CRC patients who underwent curative resection at Shandong Provincial Hospital affiliated to Shandong University. All patients were grouped by macroscopic growth patterns (expansive, infiltrative and ulcerative subtypes), and stage III patients were further divided into chemotherapy and nonchemotherapy groups. Kaplan-Meier methods, univariate and multivariate analyses and subset analyses were performed to assess the overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS). RESULTS: Kaplan-Meier survival curves and univariate analyses revealed better OS (HR=0.731; 95% CI=0.584-0.916), CSS (HR=0.714; 95% CI=0.548-0.932) and DFS (HR=0.722; 95% CI=0.602-0.864) in the expansive subtype and worse OS (HR=2.121; 95% CI=1.457-3.088), CSS (HR=2.499; 95% CI=1.664-3.753) and DFS (HR=2.360; 95% CI=1.756-3.170) in the infiltrative subtype. Subset analyses based on the tumor-node-metastasis stage showed that the infiltrative subtype was associated with inferior DFS in stage II (HR=2.357; 95% CI=1.210-4.595) and stage III patients (HR=1.941; 95% CI=1.394-2.702) and inferior OS and CSS in stage III patients (HR=1.805; 95% CI=1.210-2.693 and HR=1.981, 95% CI=1.280-3.065, respectively). In addition, multivariate Cox proportional hazard regression models revealed similar results. Furthermore, in stage III patients, the OS, CSS and DFS in both the expansive and ulcerative subtypes were significantly extended after the administration of chemotherapy (all, P<0.001). However, the OS, CSS and DFS in the infiltrative subtype did not change significantly after the administration of chemotherapy (P=0.486, 0.290 and 0.731, respectively). CONCLUSION: The macroscopic growth pattern was an independent prognostic factor among stage I-III CRC patients. The infiltrative subtype had the worst prognosis in stage III patients and did not display survival benefits from chemotherapy.