Clinicopathological characteristics and prognostic factors of T1 (≤5 cm) soft tissue sarcoma -- a comparative study with T2 (>5 cm) soft tissue sarcoma.

BACKGROUND

T1 (≤5 cm) soft tissue sarcoma (STS) may represent a distinct subgroup with different biological characteristics resulting in favorable outcomes, when compared with T2 (>5 cm) STS. However, only few studies focusing on T1 STS have been reported.

METHODS

A retrospective review was conducted on 373 patients (163 with T1 STS [T1 group] and 210 with T2 STS [T2 group]) who underwent surgical removal of STS. Clinicopathologic characteristics and prognostic factors for local recurrence and disease-specific survival (DSS) of T1 STS was investigated and compared with those of T2 STS.

RESULTS

T1 group was younger (p = 0.004), had fewer metastases at initial presentation (p < 0.001), more previous unplanned excisions (p < 0.001), more synovial sarcomas (p = 0.024), fewer liposarcomas (p < 0.001), lower histological grade (p = 0.013), and fewer deep-seated tumors (p < 0.001) than T2 group. For local recurrence, older age (p = 0.008), previous unplanned excision (p = 0.012), and malignant peripheral nerve sheath tumor subtype (p = 0.014) independently predicted poor prognosis in the T2 group whereas only anatomical site of lower extremity (p = 0.046) was a favorable prognostic factor in the T1 group. For DSS, higher histologic grade (p = 0.037) and larger tumor size (p = 0.020) predicted poor prognosis in T2 group whereas only older age (p = 0.005) was prognostic in the T1 group.

CONCLUSIONS

Clinicopathological characteristics and prognostic factors of T1 STS differed from those of T2 STS. Established prognostic factors for STS were of limited value for T1 STS. These findings suggest the necessity of a different assessment strategy for T1 STS.