Familial Nasopharyngeal Carcinoma 6

116 J-C. LinTable 9.8. Summary of prognostic impact of age in nasopharyngeal carcinomaSeries No. of cases cutoff Univariate analysis Multivariate analysis5-y OS 5-y DSS OS DSSTeo et al. (1996) 903 50 p < 0.0001 p < 0.0001 p = 0.000 p < 0.001Yi et al. (2006) 905 £vs.>48 p = 0.00 p = 0.00 p = 0.062 p = 0.003Liu et al. (2008) 749 £vs.>50 – – p < 0.001 –Mao et al. (2009) 924 £vs.>50 – – – n.s.5-y 5-year; OS overall survival; DSS disease-specific survival; n.s. not statistically significant differencethat the treatment benefit of concomitant chemotherapyand altered fractionated radiation decreases withincreasing age (Pignon et al. 2007). The proportion ofdeaths not due to head-and-neck cancer increased withage, from 18% at age 50 years to 41% at age ³ 71 years inthe meta-analyses of chemotherapy in head-and-neckcancer, and from 15% to 39% in the meta-analysis ofradiation therapy in carcinoma of head and neck.et al. 2001a, 2007; Au et al. 2003; Yeh et al. 2005; Liuet al. 2008). Some studies show that gender may affectother endpoints of prognostic analyses significantly,such as local failure-free survival (Mao et al. 2009),regional failure-free survival (Au et al. 2003), metastasisfailure-free survival (Ma et al. 2001a; Au et al. 2003;Lee et al. 2005b; Yeh et al. 2005; Liu et al. 2008), anddisease failure (Tang et al. 2008).9.5.1.2GenderThe incidence rates in male populations are commonlytwo to threefold that of female population in NPC.There are no studies focusing specifically on the prognosticimpact of gender in NPC. In addition, manyreports with studying the main purpose of other prognosticfactors have shown controversial results withregard to the prognostic impact of gender. Largerseries from the SEER database or EUROCARE databaserevealed that there was no (Jiong et al. 1998; Ouet al. 2007) or a borderline (Burt et al. 1992; Sun et al.2007) statistically significant difference between genderin overall survival by multivariate analysis. Studiescontaining several hundred Chinese NPC patientsreported no significant difference of overall survivalbetween gender (Lee et al. 2005b; Leung et al. 2005; Yiet al. 2006). Female gender was reported as a favorablefactor on overall survival in some Chinese series (Ma9.5.1.3Ethnic BackgroundNPC is a rare disease in the Western world; however,it is particularly common in Southern China,especially in Guangtong, Guangxi, Fujian, HongKong, and Taiwan. Results from survival studies ofNPC are inconsistent, as some studies have and othershave not found differences by race. Different raceshave different genetic susceptibility, and may alsohave different prognosis. Most of the populationbasedstudies in NPC are from endemic countrieswhere the ethnic makeup of the population was fairlyhomogeneous and the undifferentiated/nonkeratinizingcarcinoma is the predominant histology. Thus,it remains unknown whether ethnicity is truly anindependent prognostic factor for survival in NPC.In the United States, every WHO histological typeis diagnosed in each of the major racial groups. Thus,epidemiological data from the SEER of the United