Objective: We hypothesized that the cause of one-lobe intrapulmonary metastasis of primary lung cancer is mainly lymphatic, and investigated by means of the long-term outcome.
Methods: From 1988 to 2000, 860 patients underwent complete resection of primary lung cancer patients in our hospital without neoadjuvant therapy. Patients were classified into 4 groups: group A (n 0 pm 0, n = 573), group B (n 0 pm 1, n = 37), group C (n 1 pm 0-1, n = 122), and group D (n 2 pm 0-1, n = 128).
Results: No significant difference was seen between groups in median age, sex ratio, histological cell type, or pathological tumor-size and p-factor. The rates of bi-lobectomy and pneumonectomy were higher in groups C and D than in groups A and B. The 5-year survival rate was 73% for group A, 57% for group B, 43% for group C, and 28% for group D. The 10-year survival rate was 57% for group A, 45% for group B, 20% for group C, and 16% for group D. There was a significant difference (p < 0.0001) between 4 groups in the 5- and 10-year survival rate.
Conclusion: The hypothesis that the cause of one-lobe intrapulmonary metastasis may be lymphatic was not incompatible with the long-term results.