[Clinical study on radiotherapy-related typing of nasopharyngeal carcinoma]

To advance a new system of clinico-radiotherapeutic typing of nasopharyngeal carcinoma (NPC) and compare it with the typing system of Xie Zhiguang.

842 patients with NPC, 559 males and 283 females, aged 48 (15-76), that had undergone CT and were treated with radical radiotherapy alone as the first therapeutic measure at least 5 years ago, were followed up for 5 years. Their cancers were divided into 4 types according to whether recurrence occurred in the primary focus and/or regional lymph nodes and whether distant metastasis occurred. The cancers without recurrence in the primary foci and regional lymph nodes and without distant metastasis was defined as radiosensitive and not liable to metastasize type (type I), those with recurrence in the primary foci and/or regional lymph noses but without distant metastasis were defined as radio-resistant and not liable to metastasize type (type II), those without recurrence in the primary foci and/or regional lymph nodes but with distant metastasis were defined as radiosensitive and liable to metastasize type (type III), and those with recurrence in the primary foci and/or regional lymph nodes and distant metastasis as well were defined as radio-resistant and liable to metastasize type (type IV). The distribution of these four clinico-radiotherapeutic types and the relation between them and the Xie Zhi-guang types: ascending type (type A), descending type (type D), and ascending and descending type (type AD).

(1) The percentages of the Types I, II, III, and IV were 50.6% (426 cases), 23.2% (195 cases), 20.7% (174 cases), and 5.6% (47 cases) respectively. (2) 264 of the 842 patients could be typed according to Xie Zhi-guang typing criteria: 65 were defined as type A (24.6%), 61 (23.1%) as type D and 138 (52.3%) as type AD. Among the 65 patients of type A 58.5% were of type I, 29.2% were of type II, 10.8% were of type III, and 1.5% were of type IV; among the type D patients 47.5% were of type I, II 9.8% were of type, 36.1% were of type III, and 6.6% were of type IV; and among the type AD patients 34.8% were of type I, 26.8% were of type II, 33.3% were of type III, and 5.1% were of type IV. (3) 307 patients were at the early stage of Fuzhou clinical classification 1992 (stages I and II) among which 191 were of type I (62.2%), and 65 were of type II (21.2%), 38 were of the type III (12.4%), and 13 were of the type IV (4.2%). Among the 535 patients at the late stage (stages III and IV), 235 were of the type I (43.9%), 130 of the type II (24.3%), 136 were of the type III (25.4%), and 34 were of the type IV (6.4%).

There are four radiotherapy-related types in NPC with the constituent ratio as: radiosensitive and not liable to metastasize type (type I) > radio-resistant and not liable to metastasize type (type II) > radiosensitive and liable to metastasize type (type III) > radio-resistant and liable to metastasize type (type IV). Among the NPC patients of the type D and type AD according to the Xie Zhiguang classification and the NPC patients at the advanced stage (stages III and IV) of the Fuzhou staging system 1992, the proportion of radiosensitive and liable to metastasize type (type III) exceeds that of the radio-resistant and not liable to metastasize type (type II). The radiotherapy-related typing system is a supplement to the clinical typing and staging of NPC.