Novel prognostic markers associated with poor survival in stage III rectal cancers: Invasive growth pattern and Tumor necrosis

Abstract

Aim: Rectal carcinomas (RC) are one of the most common cancers in the western world. TNM system is the most significant predictive indicator in these tumors but patients characterized by the same stage often have prominent distinct survival. In this research, we analyzed the survival effect of Invasive growth pattern (IGP) and Tumor necrosis (TN) in stage III RC.Material and Methods: A hundred forty-five patients operated for stage III RC during 1999-2012 at Kırıkkale University were included in this research. These parameters were scored on hematoxylin and eosin stained sections. The relationship between the results and the clinicopathological characteristics was analyzed.Results: These parameters were significantly upregulated in RCs which classified as higher tumor size (IGP: p<0.001; TN: p=0.033), higher pT (IGP: p=0.016; TN: p=0.047), angiolymphatic invasion (IGP: p=0.025), high number metastatic lymph nodes (IGP: p<0.001; TN: p=0.001), advanced stage (IGP: p<0.001; TN: p=0.018), and advanced grade (IGP: p<0.001). In univariate analysis, patients with these two parameters had worse 5-year survival ([IGP= RFS: 50%, p=0.001; OS=55%, p=0.003], [TN= RFS: 53%, p=0.005; OS: 58%, p=0.017]). Multivariate analyzes confirmed that these two parameters are an independent worse survival parameter for RFS (IGP=Hazard ratio [HR]: 1.58 [1.05-2.66], p=0.005; TN=1.44 [1.07–2.34], p=0.013) and OS (IGP=HR: 1.55 [1.11–3.18], p=0.008; TN= 1.38 [1.09–2.28], p=0.024). In addition, IGP was found to be more successful than TN. Conclusion: Our data suggest that IGP and TN provide valuable prognostic information for RC, and adding these parameters to the current risk classification may contribute to better patient selection.