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.