Background: Although the incidence of all cancers in Okinawa is the lowest
in Japan, that of lung cancer is high. This study was performed to clarify
the underlying mechanism of this tendency. Materials and Methods: Family hi
stories of the lung cancer patients in Okinawa, p53 nutation, microsatellit
e alterations and titers of serum anti-p53 antibodies were examined. Result
s: The number of patients who had relatives with some malignancies in relat
ives was low in Okinawa, but lung cancer was frequently observed in their r
elatives. Overexpression of p53 protein was frequently observed in squamous
cell carcinoma (SCC) than in adenocarcinoma (AD), and in smokers than in n
on-smokers. Anti-p53 antibodies were detected in 17.4%. The incidence of lo
ss of heterozygosity at D3S643 and at IFNA were higher in SCC than in AD. C
onclusions: Lung cancer was frequently observed in relatives of lung cancer
patients Pulmonary SCC had different genetic alterations compared with pul
monary AD in Okinawa.