Abstract
OBJECTIVE: To compare clinical characteristics between familial nasopharyngeal carcinomas (NPCs) and sporadic NPCs in Guangdong province, China, a high-risk area. METHODS: Between 1991 and 2001, 993 NPC patients treated at the Cancer Center of Sun Yat-Sen University in Guangdong were randomly selected as probands. Information about NPC among the probands' relatives and other information were obtained from a retrospective review of the patients' medical records. The patients were divided into sporadic NPC, low-frequency familial NPC (one NPC patient in addition to the proband in three generations), and high-frequency familial NPC (2 or more additional NPC patients in three generations) groups. Pathological and clinical characteristics were compared among these groups. RESULTS: Of the 993 patients, 131 (13.2%) had a familial history of NPC. The average age at diagnosis was the lowest in the high-frequency familial NPC group (39 years; P=0.048). Although the overall survival (OS), distant metastasis-free survival (DMFS), and disease-free survival (DFS) rates did not differ between familial and sporadic NPCs, the locoregional recurrence-free survival (LRFS) rate increased in the order sporadic NPCs, low-frequency familial NPCs, and high-frequency familial NPCs (P=0.009), with 5-year rates of 70%, 83%, and 87%, respectively. Multivariate analysis showed that family history of NPC was an independent favorable prognostic factor for LRFS, with adjusted hazard ratio (aHR) of 0.548, 95% CI (0.342-0.878). The high LRFS for familial NPCs was mainly noted among young, advanced-stage patients who received continuous radiation treatment. CONCLUSIONS: Genetic factors may play an important role in the etiology of high-frequency familial NPC and underlie the early age of onset and sensitivity to radiotherapy.