Cohort analysis of patients with localized, high-risk, extremity soft tissue sarcoma treated at two cancer centers: chemotherapy-associated outcomes

Abstract

Purpose: Patients with American Joint Committee on Cancer stage III soft tissue sarcoma (STS) have high risks of distant recurrence and death. The role of chemotherapy for these patients remains controversial despite several randomized trials and a meta-analysis.

Methods: We reviewed the treatments and outcomes of 674 consecutive adult patients presenting with primary stage III extremity STS between 1984 and 1999. Pre- or postoperative doxorubicin-based chemotherapy was used in a nonrandomized fashion in approximately half of this high-risk population. The objective of this review was to evaluate the impact of chemotherapy while accounting for known prognostic variables.

Results: Among 674 patients, 338 (50%) were treated with local therapy only, and 336 (50%) were treated with local therapy plus chemotherapy. The median follow-up for survivors was 6.1 years. Five-year local and distant recurrence-free interval probabilities were 83% and 56%, respectively, for the two groups combined. The 5-year disease-specific survival (DSS) rate was 61%. Cox regression analyses showed a time-varying effect associated with chemotherapy. During the first year, the hazard ratio associated with DSS for patients treated with chemotherapy versus no chemotherapy was 0.37 (95% CI, 0.20 to 0.69; P = .002). Thereafter, this hazard ratio was 1.36 (95% CI, 1.02 to 1.81; P = .04).

Conclusion: It seems that the clinical benefits associated with doxorubicin-based chemotherapy in patients with high-risk extremity STS are not sustained beyond 1 year. These results suggest that caution should be used in the interpretation of randomized clinical trials of adjuvant chemotherapy that seem to demonstrate clinical benefits with relatively short-term follow-up.