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.
Department of Thoracic Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Japan.
M
M
Higashiyama
K
K
Kodama
H
H
Yokouchi
K
K
Takami
M
M
Adachi
T
T
Taki
S
S
Ishiguro
S
S
Nakamori
O
O
Yoshie
M
M
Miyake
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