A comparison of the prognoses for deep and subcutaneous sarcomas of the extremities

We evaluated 172 patients who had a soft-tissue sarcoma of the extremity in order to determine whether the prognosis for a subcutaneous sarcoma was better than that for a deep sarcoma. At a median of thirty-six months after the biopsy or definitive operation at our hospital, six of the fifty-two patients who had had a subcutaneous sarcoma had died and one had had a local recurrence; in contrast, forty of the 120 patients who had had a deep sarcoma had died and eight had had a local recurrence. Twenty-five (48 percent) of the subcutaneous sarcomas were malignant fibrous histiocytomas, and thirty-eight (73 percent) were small (five centimeters or less in the largest dimension). The three-year estimates of disease-free survival were 85 percent for the patients who had a subcutaneous sarcoma and 54 per cent for those who had a deep sarcoma (p = 0.002). Although the survival estimates remained significantly different when the groups were matched for histological diagnosis and for intracompartmental location (p = 0.0001 and 0.0006, respectively), they were not significantly different when the groups were matched for the size of the tumor (p = 0.42). A Cox proportional-hazards model confirmed that a tumor size of more than five centimeters and the histological grade are the most significant prognostic factors (p = 0.0007 and p = 0.004, respectively): a tumor size of more than five centimeters was associated with a relative risk of 3.5 (95 per cent confidence interval, 1.7 to 7.3), and a higher histological grade was associated with a relative risk of 4.0 (95 per cent confidence interval, 1.6 to 10.3). Subcutaneous location, when considered separately, was not a significant prognostic factor (p = 0.45). The data indicate that a tumor size of more than five centimeters is a more important prognostic indicator than histological diagnosis, depth, or intracompartmental location.