Tumor progression and loss of heterozygosity at 5q and 18q in non-small cell lung cancer.

We investigated the frequency and clinical significance of loss of heterozygosity (LOH) at the APC, MCC, and DCC tumor suppressor gene loci in 108 cases of resected non-small cell lung cancer (NSCLC). LOH at the APC/MCC gene cluster at chromosome 5q21 occurred frequently; it affected 29% of informative NSCLC cases and correlated with a significantly worse survival (P < 0.01). Furthermore, in the subtype most frequently affected (SCC), LOH at 5q not only correlated with a worse survival but also tumor involvement of the mediastinal and/or hilar nodes. In contrast, LOH at the DCC locus at chromosome 18q was far less frequent, occurring in 14% of NSCLC cases, and it was not associated with advanced stage or prognosis. These data suggest that LOH at 5q has a role in determining tumor progression and survival in NSCLC, and may prove to be a clinically useful prognostic indicator.