Abstract
We examined the validity of our diagnostic criteria of synchronous multiple lung cancer and intrapulmonary metastasis in 115 patients with intrapulmonary multiple lesions who underwent pulmonary resection. Our criteria for synchronous multiple lung cancer were cancers physically distinct and separate, and which meet the following requirement a, b or c.
(a) different histology
or similar histology but in different segments, lobes, or lungs, if:
(b) cancers with in situ components, e.g. a roentgenographically occult squamous cell carcinoma
(c) nO or n1 cancers with two intrapulmonary lesions and no extrapulmonary metastasis
The 5-year-survival rate of 58 patients with synchronous multiple lung cancer was 45%, which was significantly better than that (4%) of 57 patients with intrapulmonary metastasis. In the patients with synchronous multiple lung cancer, the 5-year-survival rate of (c) was 54%, which was significantly better than the 2-year-survival rate (0%) of (a), and which was also better than the 5-year-survival rate (43%) of (b). Prognosis of patients with n0 or n1 lung cancers with 2 intrapulmonary lesions and no extrapulmonary metastasis was good, and surgical treatment is justified. They should be treated as synchronous multiple lung cancers, not as intrapulmonary metastasis, from a therapeutic point of view.
