FAMILIAL CLUSTERS OF NASOPHARYNGEAL CARCINOMA AND SALIVARY-GLAND CARCINOMAS IN GREENLAND NATIVES

Background. Nasopharyngeal carcinoma (NPC) and anaplastic salivary gla nd carcinoma (SGC), both associated with Epstein-Barr virus (EBV), are common among Inuit from Greenland, Canada, and Alaska. Because immigr ant studies have shown that factors acting early in life are important for the development of NPC, the authors interviewed new patients in G reenland with either NPC or SGC about their lifestyles during childhoo d and additional cases in their families. Methods. On admission, new p atients from Greenland with either NPC or SGC were interviewed about c hildhood life-style, family size, and other cases of NPC or SGC within the family. Additional cases were confirmed by review of the medical records concerning these patients. Results. During the 11 years from 1 980 through 1990, 17 of 63 (27%) cases in Greenland were found in fami lial clusters among first-degree relatives. There were no differences in the life-styles of multiple-case families and single-case families. Conclusions. The high rate of familial clusters among natives of Gree nland is of interest because EBV is believed to play a role in the ori gin of these two diseases similar to that of Marek disease in neurolym phomatosis of chickens. Therefore, the familial clustering of NPC and SGC may indicate that an enhanced oncogenic potential of an EBV strain may occur more frequently in Greenland than in other parts of the wor ld.