[p53 alterations in human lung cancer and their correlation with clinicopathological features and prognosis]

To investigate p53 protein accumulations and p53 mutations in squamous cell carcinoma and adenocarcinoma of the lung and their correlation with clinicopathological features and prognosis.

Immunohistochemistry (LSAB) and non-isotopic PCR-SSCP were used to detect p53 abnormalities in lung cancer.

The general positive rates for immunohistochemistry using anti-p53 monoclonal antibody Do-7 (DAKO) as first antibody was 50.5% in 95 cases of lung cancer, 56.5% (26/46) in squamous cell carcinoma and 44.9% (22/49) in adenocarcinoma. PCR-SSCP results showed that 39 cases (41.1%) showed abnormal bands. The mutation rate in squamous cell carcinoma was 47.8% (22/46) and 34.7% (17/49) in adenocarcinoma. In 15 (38.5%) cases, the mutations were located on exon 5, 3 (7.7%) were on exon 6, 13 (33.3%) on exon 7 and 8 (20.5%) on exon 8, respectively. The concordance rate of immunohistochemistry and PCR-SSCP was 77.9% (74/95). The mutation rates of p53 gene in N0, N1, N2 staged lung cancer were 22.6% (7/31), 44.2% (19/43) and 61.9% (13/21), respectively. The difference was statistically significant (P < 0.025). The 3 year survival rate in patients with p53 mutations was significantly lower than those without p53 mutations (P < 0.025).

The location of p53 mutations in squamous cell carcinoma and adenocarcinoma of the lung were more commonly seen on exon 5 and exon 7. p53 mutations were associated with increased lymph nodes metastasis and reduced survival rate in squamous cell carcinoma and adenocarcinoma of the lung.