The importance of staging systems for the determination of prognosis of well-differentiated thyroid cancer
Varlık Erol1, Özer Makay1, Gökhan İçöz1, Timur Köse2, Yeşim Ertan3, Ülkem Yararbaş4, Mahir Akyıldız1, Mustafa Yılmaz1
1Department of General Surgery, Ege University Faculty of Medicine, İzmir, Turkey
2Department of Biostatistics, Ege University Faculty of Medicine, İzmir, Turkey
3Department of Pathology, Ege University Faculty of Medicine, İzmir, Turkey
4Department of Nuclear Medicine, Ege University Faculty of Medicine, İzmir, Turkey
Objective: In this study we aimed to determine the significance of the staging systems (EORTC, De Groot, MACIS, and TNM) on the prognosis of well differentiated thyroid cancer patients who underwent surgery in our clinic.
Material and Methods: This retrospective study included 181 patients who were operated between December 1995-December 2007, with diagnosis of thyroid cancer. In order to obtain data related to cancer staging, a computer program for PDA was developed to enter determined parameters easily. Survival analyses were performed. The findings were compared with the prescribed rates by the staging systems.
Results: According to the De Groot staging system, stage 1 and stage 2 patients' results were compatible, stage 3 and 4 patients' results were determined to be different (stage 3; 87% versus 66.6%, stage 4; 35% versus 100%, p=0.04). In the MACIS staging system, 20-year survival rates are determined and there is insufficient follow-up period in this study for compaison. Compared to the EORTC staging system, stage 3 and stage 4 patients' results were determined different (stage 3; 51% versus 100%, stage 4; 33% versus 50%, p=0.02). The most consistent results in terms of prognosis was determined in comparison with the TNM staging system (stage 1; 100% versus 97.8%, stage 4; 45.3% versus 50%).
Conclusion: Until recently, in order to be able to predict the behavior of the tumor, many classification systems were made up for well differentiated thyroid cancer. In this study, we concluded that in the determination of the prognosis of well-differentiated thyroid cancer, the TNM staging system can determine the prognosis in a manner consistent with the clinical findings.
Keywords: Thyroid cancer, staging systems, prognosis
Study concept and design - V.E., Ö.M., M.A.; Acquisition of data - V.E., Ö.M., M.A., G.İ., M.Y., Y.E., T.K., Ü.Y.; Analysis and interpretation of data - V.E., Ö.M., M.A., G.İ., M.Y., T.K.; Preparation of the manuscript - V.E., Ö.M.; Statistical analysis - T.K.
No conflict of interest was declared by the authors.
The authors declared that this study has received no financial support.