颈部淋巴结的最大径不是早期鼻咽癌单纯放疗的预后因素

Maximal diameter of lymph node is not a prognostic factor for early stage nasopharyngeal carcinoma treated by radiotherapy alone

背景与目的:2008年国内鼻咽癌分期中,颈部淋巴结的大小成为分期的依据之一,即单侧淋巴结直径>3 cm为N2,而AJCC分期对直径<6 cm的淋巴结,其大小没有考虑在分期内。本文旨在分析颈部淋巴结最大直径在早期鼻咽癌中的预后作用。方法:回顾性分析本院2000年1月—2003年12月357例经病理证实伴有颈部淋巴结转移的初治早期鼻咽癌患者临床资料。年龄10～87岁,中位年龄49岁,男性267例,女性90例。根据2002年UICC分期:T1、T2期分别为117、240例,淋巴结最大直径(Dmax)≤3 cm和3 cm<Dmax≤6 cm分别为271例、86例。鼻咽原发病灶主要采用60Co-γ线、6 MV X线常规分割照射,每次1.8～2.0 Gy,总剂量64～74 Gy。常规放疗结束后,如鼻咽镜或CT提示有肿瘤残存者,则通过耳后野、颅底野、后装及适形加量6～20 Gy。颈部放射源用60Co-γ线、180 kV X线和9 MeV电子束,预防剂量50～56 Gy,根治剂量60～68 Gy。结果:全部病例随诊时间3～90个月,中位随访54个月。共计有14例患者颈部复发,33例患者原发灶复发;47例发生远处转移,其中骨转移20例,肺转移10例,肝脏转移7例,另有10例合并2个或以上器官转移。共计有68例患者死亡,其中32例死于远处转移,23例死于局部区域失败,5例死于局部复发和远处转移,2例死于第二原发肿瘤,6例死于其他原因。总的5年生存率(overall survival,OS)为78.6%;5年无复发生存率(recurrent-free survival,RFS)、无远处转移生存率(distant metastasis free survival,DMFS)和无病生存率(disease free survival,DFS)分别为86.7%、85.6%和74.7%。颈部淋巴结的Dmax为1～6 cm,中位3 cm,均值为2.7 cm。淋巴结Dmax≤3 cm和3 cm<Dmax≤6 cm的5年OS(80.6%vs 78.3%,P=0.731)、DFS(75.8%vs 72.2%,P=0.614)、RFS(88.6%vs 85.8%,P=0.337)和DMFS(86.6%vs 82.4%,P=0.227)差异均无统计学意义。T1和T2的5年OS、DMFS、DFS分别为85.6%vs75.4%、93.4%vs 81.9%和83.5%vs 70.8%,差异有统计学意义(P<0.05);多因素分析显示,颈部淋巴结的Dmax和预后无关(P=0.972)。结论:颈部淋巴结的Dmax不是早期鼻咽癌单纯放疗的预后因素。

Background and purpose： Unilateral lymph nodes greater than 3 cm is N2 according to 2008 domestic nasopharyngeal cancer staging system. When lymph node is less than 6 cm in diameter, its size is not considered in AJCC staging. So we conducted a retrospective study to investigate whether the maximal diameter of lymph nodes was a prognostic factor for early-stage nasopharyngeal carcinoma （NPC） treated by radiation alone. Methods： From Jan. 2000 to Dec. 2003, 357 patients with early-stage NPC existing lymph node metastasis were retrospectively analyzed. The T classification showed that there were 117 cases at T~ （32.8%）, and 240 cases at T2 （67.2%）. The total irradiation dose was 64-74 Gy, 1.8-2.0 Gy per fraction over 6.5-7.5 weeks to the primary tumor, and 64-70 Gy to lymph node, 50-56 Gy to lower risk neck areas. The maximal diameter （Din,x） of lymph node was evaluated by CT image and clinical examination. Results： The median follow-up time was 54 months （range 3-90 months）. Fourteen cases experienced neck recurrence, 33 patients with local recurrence in the primary area. In addition, 47 patients developed distant metastasis. A total of 68 cases died. Thirty-two patients died from distant metastasis, and 23 died from progression of local or regional disease after recurrence. Five cases died from local-regional and distant failure. Two patients died from second primary tumor and the causes of death of additional 6 cases were unknown. The 5-year overall survival rate （OS） was 78,6%. 5-year relapse-free survival rate （RFS）, distant metastasis-free survival rate （DMFS） and disease-free survival rate （DFS） were 86.7%, 85.6% and 74.7% respectively. T classification was the significant prognostic factor for predicting OS. While Dm~ of lymph node was not a prognostic factor for early-stage NPC treated by radiotherapy alone. Five-year OS, DFS, RFS and DMFS were 80.6% and 78.3% （P=0.731）, 75.8% and 72.2% （P=0.614）, 88.6% and 85.8% （P=0.337）, 86.6% and 82.4% （P=0.227） for Dmax≤3 cm and 3 cm〈Dmax〈6 cm respectively. Conclusion： Dmax of lymph node is not a prognostic factor for early-stage NPC after definitive radiotherapy alone.