Teo P M, Chan A T, Leung S F, Chau R M, Yu P K, King W W, Johnson P J
Department of Clinical Oncology, Prince of Wales Hospital, Shatin, Hong Kong, China.
Eur J Cancer. 1999 Feb;35(2):219-25. doi: 10.1016/s0959-8049(98)00386-4.
The aim of this study was to define the risk of tongue and other aerodigestive tract cancers developing after primary radiation therapy for nasopharyngeal carcinoma (NPC). A cohort of 903 patients with non-disseminated NPC given radical radiotherapy between 1984 and 1989 was studied for the incidence of tongue cancer and other malignancies during follow-up. A contemporary cohort of 87 patients with tongue cancer, without a history of NPC, was studied for demographic data, cigarette smoking and alcohol consumption habits. These were then compared with all the NPC patients and with the NPC patients who later developed tongue cancers. There was a significantly increased number of tongue cancers following radiotherapy for NPC. The risk of developing tongue cancer after radiotherapy for NPC was 0.13% per patient per year. There was no increase in the number of other malignancies. The association between NPC and tongue cancer was that of a non-random temporal sequence with tongue cancers following NPC but not in the reverse order. The demographic data and smoking and alcohol consumption history of the 7 NPC patients who subsequently developed tongue cancer were significantly different from the de novo tongue cancer patient population. The absence of common aetiological factors between NPC and tongue cancer and the non-random sequence of tongue cancers occurring after NPC suggests that these seven tongue cancers could be radiation induced. The estimated radiation dose received by the part of the tongue developing cancer was substantial and significantly higher than the dose to the cancer-free tongue. An increase of tongue cancers after radiotherapy for NPC is reported and arguments are made in support of the hypothesis that these were radiation-induced malignancies. We suggest a decrease in the volume of tongue included within the planning target volume of NPC in the absence of oropharyngeal and/or parapharyngeal infiltration. Awareness of the association should make early diagnosis of this likely radiation-induced cancer possible.
本研究的目的是确定鼻咽癌（NPC）接受初次放射治疗后发生舌癌及其他上呼吸消化道癌症的风险。对1984年至1989年间接受根治性放疗的903例非播散性NPC患者队列进行随访，研究舌癌及其他恶性肿瘤的发病率。对87例无NPC病史的当代舌癌患者队列进行人口统计学数据、吸烟和饮酒习惯研究。然后将这些数据与所有NPC患者以及后来发生舌癌的NPC患者进行比较。NPC放疗后舌癌数量显著增加。NPC放疗后发生舌癌的风险为每位患者每年0.13%。其他恶性肿瘤数量没有增加。NPC与舌癌之间的关联是一种非随机的时间顺序，舌癌发生在NPC之后，而非相反顺序。7例随后发生舌癌的NPC患者的人口统计学数据以及吸烟和饮酒史与原发性舌癌患者群体显著不同。NPC和舌癌之间不存在共同的病因学因素，且舌癌在NPC之后发生的非随机顺序表明这7例舌癌可能是辐射诱发的。发生癌症的舌部所接受的估计辐射剂量很大，且显著高于未发生癌症的舌部所接受的剂量。报告了NPC放疗后舌癌数量增加的情况，并提出论据支持这些是辐射诱发恶性肿瘤的假说。我们建议在不存在口咽和/或咽旁浸润的情况下，减少NPC计划靶体积中包含的舌部体积。认识到这种关联应有助于对这种可能由辐射诱发的癌症进行早期诊断。
