|Budget Amount *help
¥3,100,000 (Direct Cost : ¥3,100,000)
Fiscal Year 1998 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1997 : ¥1,900,000 (Direct Cost : ¥1,900,000)
60 cases of oral squamous cell carcinoma from 1993 to 1996 in Okinawa, southern Japan were compared with -12 cases of tumors over the same period in Sapporo, northern Japan. 35(58.3%) cases of Okinawan tumor were well differentjatd type, but in Sapporp, only 18(12.8%) cases. Furthermoe, in Okinawa, tumours of the mouth floor(17%) and pharynx(20%) were frequently ohserved, whereas in Sapporo, only 5 case(12%) of each was found.
HPV(human papillomavirus) DNA was demonstrated in 78.3% of Okinawan cases and 26.2% of Sapporo cases by either PCR or NISII(non-isotopic in situ hybridisation). On the other hand, in the case of EBV(Epstein-Barr virus), 76.6% of OkLnawan and 38.1% of Sapporo cases were positive by PCI? . But by NISH, in only 9 Okinawan cases(l5%) and .1 Sapporo cases(9.5%), positive signals were demonstrated on the cancer cells themselves.
The number of infiltrating lymphocytes in Okinawan cases was higer than those in Sapporo, and T-lymphocytes were predominant over B-lymphocytes The presence of such lymphocytes in the materials in which EBV was positively demonstrated by NISH was analyzed by PCR.
EBV was not demonstrated on the normal squamous cells by NISH, but was demonstrated on a small number of cancer cells and dysplastic cells. In two Okinawan cases, CD 21 was demonstrated in only a few cancer cells immunohistochemically. EBV infection is considered to depended upon a different mechanism than one mediated by the CD 21 receptor. Preceding dysplasia or cancer seemed to be necessary for EBV infection.