[Assessment of prognosis and p 53 mutations in patients with multiple tumors of the lung; intrapulmonary metastasis or double primary cancers?].

To assess whether a satellite lesion in the primary-tumor lobe is intrapulmonary metastasis from primary cancer (pm 1) or they are double primary lung cancers, we examined the postoperative prognosis of patients with pm 1 and the p 53 genetic differentiation between a satellite lesion and a primary lesion. Of 772 consecutive patients with N0-2M0 non-small cell lung cancer who underwent surgical resections between 1979 and 2000, 31 patients had a satellite lesion in the primary-tumor lobe. The 5-year survival rate was 26.3% in the pm 1 (+) T 4 group (n = 37), 14.7% in the pm 1 (-) T 4 group (n = 43), and 32.5% in the T 3 group (n = 132), suggesting that pm 1 cases should be classified as T 3. We examined 16 of 37 patients with pm 1 for mutations of the p 53 gene occurring exons 5 through 8 by the fluorescence-based polymerase chain reaction single-strand conformation polymorphism. Seven of the 16 patients analyzed had at least one p 53 mutations in their tumors. The mutational status of the p 53 gene was discordant in 5 patients, suggesting they were double primary lung cancers. The mutational status including DNA sequencing of the p 53 gene was concordant in 2 patients, suggesting they were intrapulmonary metastases. It remains arguable in the TNM staging system whether a satellite lesion in the primary-tumor lobe is intrapulmonary metastasis from primary cancer or they are double primary lung cancers.