[Distinguishing second primary tumors from lung metastasis in patients with postoperative non-small cell lung cancer by microsatellite analysis].
OBJECTIVE
In patients with resected early stage non-small cell lung cancer (NSCLC), intrapulmonary solitary tumor represents either second primary tumor (SPT) or a metastasis. This study is to discern SPT from lung metastasis in patients with postoperative NSCLC followed a solitary intrapulmonary tumor by microsatellite analysis.


METHODS
Twenty-one patients with stage I - III(A) NSCLC resected by surgery during 1994.1 - 2002.8 were studied. Paired tumors from 21 patients with NSCLC and a solitary lung nodule were analyzed for their loss of heterozygosity (LOH) on chromosomal arms 3p, 9p and 17p. DNA from microdissected tumors and non-malignant lung tissues was subjected to polymerase chain reaction-based microsatellite analysis using 8 microsatellite markers. An effort was also made to distinguish SPT from lung metastasis on the basis of clinical and histopathologic features.


RESULTS
The paired tumors from 7 patients had concordant patterns of LOH at all microsatellite loci suggesting the same clonal origin, and supporting metastatic spread, where 4 paired tumors had discordant patterns of at all loci suggesting independent tumor origin. These observations were supported by the clinical and pathologic findings. Additional 6 paired tumors had concordant allelic loss on 3p and discordant loss on the other, clinical characteristics supporting metastatic disease. In contrast, 2 paired tumors had concordant allelic loss on 9p or 17p but discordant loss on the 3p, clinical data supporting SPT.


CONCLUSIONS
The paired tumors from 7 patients had concordant patterns of LOH at all microsatellite loci suggesting the same clonal origin, and supporting metastatic spread, where 4 paired tumors had discordant patterns of at all loci suggesting independent tumor origin. These observations were supported by the clinical and pathologic findings. Additional 6 paired tumors had concordant allelic loss on 3p and discordant loss on the other, clinical characteristics supporting metastatic disease. In contrast, 2 paired tumors had concordant allelic loss on 9p or 17p but discordant loss on the 3p, clinical data supporting SPT.
Wang
Jie
J
Department of Respiratory Medicine, Beijing University School of Oncology, Beijing Cancer Hospital, Beijing 100036, China.
Lu
Charles
C
Liu
Xu-yi
XY
Zhang
Hong-bing
HB
Zhao
Jun
J
Yang
Lu
L
Guo
Qing-zhi
QZ
An
Tong-tong
TT
Wu
Mei-na
MN
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D019656:Loss of Heterozygosity; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology / Q000556:secondary; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016609:Neoplasms, Second Primary / Q000175:diagnosis*; D011379:Prognosis