Familial Nasopharyngeal Carcinoma 6

Familial Nasopharyngeal Carcinoma 69Table 6.3. Salient characteristics of familial NPCRate of familial NPC inhigh-risk populationsRisk of first-degree relativeof NPC patients being diagnosedwith NPCLikely 8%, ranging from 6to 15%2–15 times of general populationGenetic associations Chromosomes 3, 4, 5reported. Possible chromosome6Environmental factors associatedwith familial NPCGender differenceAge at diagnosisTNM stageSpecific radiological featuresSpecific EBV antibody levelsOutcomes of familial NPCafter definitive treatmentNone reportedNo gender differenceFamilial NPC patients maybe diagnosed younger thansporadic patientsNo difference from sporadicNPCNone reportedNone reportedNo evidence outcomes differentfrom sporadic NPCscreened once an NPC patient is diagnosed. Such asuggestion is relatively practical as the life expectancyof most siblings of the newly diagnosed patientscould be well over 5 years.6.5Clinical Significance of Familial NPCThe relatively high incidence indicated that screeningfor early diagnosis in the first-degree relative ofNPC patients might be beneficial. Available datareported by Ng et al. and Friborg et al. supportedscreening first-degree relatives, especially in highriskpopulations, mostly due to the higher incidenceof the condition when compared with other commonlydiagnosed malignancies (Ng et al. 2005;Friborg et al. 2005). Both authors suggested thatscreening should be performed in the siblings andchildren of NPC patients. And when a case of NPC isdiagnosed, screening should be offered to the siblingsas soon as possible. The children of NPCpatients can be screened from 25 to 30 years old.However, whether screening among first-degreefamily members of NPC patients would result inearly diagnosis of the disease and the long-termeffect of such screening programs remain to beconfirmed. Furthermore, specifics such as the testutilized and the frequency of an optimal screeningprotocol are open to debate. A detailed discussion ofsuch protocols is out of the scope of this chapter;however, no evidence supports one protocol overanother currently.The outcomes after definitive treatment of familialNPC have not been reported; however, as the biologicalbehavior of NPC in familial NPC is similar tothe sporadic form, significant differences in treatmentoutcome are not likely to be identified. Presently,standard management strategy using radiotherapyor chemoradiation is suggested for patients withfamilial NPC as in the sporadic cases.6.6SummaryApproximately 2%–15% of all nasopharyngeal cancercases are familial with two or more first-degree membersof the same family diagnosed with the malignancy.Clinical evidence suggests that first-degreerelatives especially siblings are at a higher risk ofdeveloping NPC than the general population.Although genetic factors are very likely to be responsiblefor the majority of the familial NPC cases, noclear-cut chromosomal changes have been confirmed.Clinically, familial NPC does not represent a distinctentity regarding its presentation and treatment strategy.Cancer syndromes associated with familial NPChave yet to be reported. It is suggested that firstdegreerelatives of newly diagnosed NPC patients inthe endemic population be targeted for screening.ReferencesAlbeck H, Bentzen J, Ockelmann HH, et al (1993) Familial clustersof nasopharyngeal carcinoma and salivary gland carcinomasin Greenland natives. Cancer 72:196–200Brown TM, Heath Jr CW, Lang RM, et al (1976) Nasopharyngealcancer in Bermuda. Cancer 37:1464–1468Chen CJ, Liang KY, Chang YS, et al (1990) Multiple risk factorsof nasopharyngeal carcinoma: Epstein–Barr virus, malarialinfection, cigarette smoking and familial tendency.Anticancer Res 10:547–554Chen DL, Huang TB (1997) A case-control study of risk factorsof nasopharyngeal carcinoma. Cancer Lett 117:17–22Coffin CM, Rich SS, Dehner LP (1991) Familial aggregation ofnasopharyngeal carcinoma and other malignancies: a clinicopathologicdescription. Cancer 68:1323–1328