The Prognostic Impact of Unplanned Excisions in a Cohort of 728 Soft Tissue Sarcoma Patients: A Multicentre Study

Unplanned excisions (UE) of soft tissue sarcomas (STS) carry a high risk for local recurrence (LR) due to marginal/intralesional resections. However, there are reports about improved prognosis for UE patients who have re-resection compared with patients who undergo planned surgery. The present multicentre study was designed to define characteristics of UE patients and to investigate the impact of UE on subsequent therapy and patient outcomes. A total of 728 STS patients (376 males, 352 females; mean age: 58 years) who underwent definite surgery at one of three tumour centres were retrospectively included. Time-to-event analyses were calculated with log-rank and Gray's tests, excluding patients with primary metastasis (n = 59). A propensity-score (PS) of being in the UE group was estimated, based on differences at baseline between the UE group and non-UE group. An inverse-probability-of-UE weight (IPUEW) was generated and time-to-event analyses calculated after IPUEW weighting. Before referral, 38.6% of patients (n = 281) had undergone UE. Unplanned excision patients were younger (p = 0.036), rather male (p = 0.05), and had smaller (p < 0.005), superficially located tumours (p < 0.005). Plastic reconstructions (p < 0.005) and adjuvant radiotherapy (p = 0.041) more often were needed at re-resection. In univariable analysis, re-resected patients had improved overall survival (OS; p = 0.027) and lower risk of distant metastasis (DM; p = 0.002) than primarily resected patients, whereas risk of LR was similar (p = 0.359). After weighting for the IPUEW, however, differences in terms of OS (p = 0.459) and risk of DM (p = 0.405) disappeared. The present study does not support prior findings of improved outcome for UE patients. Unplanned excisions have a major impact on subsequent therapy, yet they do not seem to affect negatively the long-term oncology outcome.