Comparative study of nasopharyngeal carcinoma staging system between the chinese 2008 and'92 Fuzhou / 中华放射肿瘤学杂志

ABSTRACT

Objective To carry out a comparative study between the Chinese 2008 and'92 staging system of nasopharyngeal carcinoma (NPC). Methods A total of 777 patients presented with untreated nondisseminated NPC who had received MRI scan of nasopharynx and neck were studied retrospectively. The clinical materials and information of imaging were collected. All patients were restaged according to the Chinese 2008 and 92 staging system of nasopharyngeal carcinoma. Distribution of T, N stage, survival and prognostic value were compared. 513 patients of the 777 cases were treated with conventional radiotherapy,264 cases with intensity modulated radiation therapy. Results The 3-year follow-up rate was 97.6%. The consistency of T stages was 95.0%. T, N and clinical stage distributions in two systems were similar ( Kappa = 0. 93, P = 0. 000; Kappa = 0. 58, P = 0. 000; Kappa = 0. 74, P = 0. 000). Local failure-free survival and disease specific survival were also similar. There was no difference of distant metastasis between N0 and N1(x2 = 1.94,P=0. 164), and a marginal difference between N1 and N2(x2 =3.83,P=0.051) in the Chinese'92 staging system. However, although there was also no difference of distant metastasis-free survival between No and N1a(x2 =0. 07,P =0. 797), ) the difference of overall survival among N1b, N2, and N3 were significant ( x2 = 4. 95, P = 0. 026; x2 = 6. 74, P = 0. 009) in the Chinese 2008 staging system. Conventional radiotherapy or intensity modulated radiation therapy was not a prognostic factor for survival ( x2 = 3.60,P =0. 058). It is reasonable for the Chinese 2008 staging system integrated lymph node characteristics such as laterality, level and extranodal neoplastic spread into the N staging criteria ( x2 = 6. 59, P = 0. 010; x2 =4.78,P=0. 029;x2=9.32,P=0. 002). Conclusions For the Chinese 2008 staging system, it was reasonable to simplify the previous T stage. The N stage showed a better predictive role of distant failure.The role of retropharyngeal lymph node in stage system needs further investigation.