KAI1/CD82 expression in nonsmall cell lung carcinoma is a novel, favorable prognostic factor: an immunohistochemical analysis.
BACKGROUND
The KAI1/CD82 gene, the product of which is a member of the transmembrane-4 superfamily, is a suppressor of metastasis; as a result, it is inversely associated with tumor progression and is a favorable prognostic factor in some tumors. This study was performed to determine the prognostic value of KAI1/CD82 protein levels in nonsmall cell lung carcinoma (NSCLC). In addition, levels of KAIl/CD82 expression in metastatic lesions were determined and compared with those in primary NSCLC lesions.


METHODS
KAI1/CD82 expression in 200 NSCLC patients who underwent potentially curative surgery was immunohistochemically detected with C33, an anti-KAI1/CD82 monoclonal antibody. According to the degree of KAI1/CD82 positive cancer cells within the tumor tissue, each sample was classified as KAI1/CD82 positive, KAI1/CD82 reduced, or KAI1/CD82 negative.


RESULTS
Sixty-five samples (32.5%) were KAI1/CD82 positive, 31 (15.5%) were reduced, and 104 (52%) were negative. There was no significant association between KAI1/CD82 expression and clinicopathologic factors, but patients who were positive for KAI1/CD82 expression had significantly favorable prognoses for overall survival (P = 0.0026) and disease free survival (DFS; P = 0.0007) compared with the other groups. In particular, among patients with adenocarcinoma, similar results were even more significant. In multivariate analysis, immunohistochemical KAI1/CD82 expression in patients with NSCLC was an independent prognostic factor for overall survival and DFS; in those with adenocarcinoma, it was an even more valuable factor. In some patients with NSCLC, especially those with adenocarcinoma, KAI1/CD82 expression levels in metastatic lesions were diminished compared with levels of expression in the primary lung lesions.


CONCLUSIONS
The immunohistochemically determined level of KAI1/CD82 expression in NSCLC cells within tumor tissue appears to be a favorable prognostic factor for overall survival as well as DFS. The results of this study suggest that decreased KAI1/CD82 expression may be associated with tumor progression and enhanced metastatic potential in some patients with this disease.
Higashiyama
M
M
Department of Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
Kodama
K
K
Yokouchi
H
H
Takami
K
K
Adachi
M
M
Taki
T
T
Ishiguro
S
S
Nakamori
S
S
Yoshie
O
O
Miyake
M
M
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000032:analysis*; D002289:Carcinoma, Non-Small-Cell Lung / Q000737:chemistry* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D051861:Kangai-1 Protein; D008175:Lung Neoplasms / Q000737:chemistry* / Q000401:mortality / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016133:Polymerase Chain Reaction; D011379:Prognosis; D011518:Proto-Oncogene Proteins; D015996:Survival Rate
D015703:Antigens, CD; C497688:CD82 protein, human; D051861:Kangai-1 Protein; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins