Frequent incidence of extrapulmonary sites of initial metastasis in patients with liposarcoma.

BACKGROUND: The vast majority of soft tissue sarcomas spread initially to the lungs and then to other sites. The lung has been the most carefully monitored organ system during routine surveillance for a metastasis. Liposarcoma is one of the most common soft tissue sarcomas and has been noted to have extrapulmonary sites of initial metastasis. This study was undertaken to investigate both the frequency and distinguishing features of initial extrapulmonary metastasis in patients with liposarcoma.

METHODS: A review of 60 patients with liposarcoma treated at the Massachusetts General Hospital (MGH) from 1971 to 1990 was performed. Survival and regression analyses were used to analyze disease free intervals and prognostic factors.

RESULTS: Metastatic disease occurred in 37% of patients and local failure in 17%. Among the subset of patients who underwent primary definitive surgery at the MGH, the incidence of local failure was 3%. An unusually high incidence of extrapulmonary site of first metastasis was found. Isolated extrapulmonary disease was the site of initial metastasis in 59% of patients. In contrast to patients with an initial pulmonary metastasis, patients with an initial extrapulmonary metastasis had a statistically significant (P = 0.001) longer disease free interval from diagnosis to first metastasis.

CONCLUSIONS: Liposarcoma, in comparison with other soft tissue sarcomas, has a different pattern of metastatic spread, with a tendency toward extrapulmonary sites. In addition, patients with extrapulmonary metastases have a longer disease free interval compared with patients with pulmonary metastasis.