[Management of soft tissue sarcomas in first isolated local recurrence: a retrospective study of 83 cases]

To analyse the management and clinical outcome of patients treated for a first isolated local recurrence of soft tissue sarcoma (trunk or extremities) and to identify prognosis factors.

This is a retrospective study of 83 adult patients treated between 1980 and 1999. Mean tumor size was 6 cm. Most sarcomas were located in extremities (N =74), were deep (N =60), and proximal (N =53). Thirty involved nerves or vessels. Histologic subtypes were mainly grade 2 (42%) or 3 (36%) histocytofibrosarcomas (49%) and liposarcomas (20%). Surgical treatment of recurrences consisted in wide excision (32 cases), marginal resection (46 cases), five patients requiring amputation. Final results were R0 (N =33), R1 (N =47) or R2 (N =3) resection. Beside surgery, six patients received neoadjuvant and seven others adjuvant chemotherapy. Twenty-three patients received postoperative external beam radiotherapy (EBRT) (mean dose 55 Gy) and 26 interstitial (192)Ir low dose rate brachytherapy (BCT) (mean dose 45 Gy for BCT alone, 22 Gy when associated with EBRT), 19 patients being re-irradiated.

Mean follow up was 59 months. Thirty-seven (45%) tumors relapsed, 62% locally as first event. Nineteen patients developed secondary distant metastases. Multivariate analysis showed only tumour depth (P =0.05) and re-resection for primary R1 resection for the recurrence (P =0.018) being independent prognosis factors for tumour control, radiotherapy (EBRT and/or BCT) being significant in univariate analysis (P =0.05). Overall survival rate was 73, 54, and 47% at respectively 3, 5 and 10 years, and was 65, 35 and 32% after a further local recurrence. Multivariate analysis showed trunk (P =0.0001) or inferior extremity locations (P =0.023), symptomatic (P =0.001), high grade (P =0.01), deep (P = 0.01) tumours, and the occurrence of a further local failure (P =0.004) as unfavourable characteristics for overall survival.

Because of the high relapse rate in this series, a first isolated local recurrence of STS increases mainly the risk of a subsequent local relapse. Quality of local treatment for the first local relapse is decisive. When a conservative treatment is feasible, it should combine surgical resection and radiotherapy, brachytherapy being the best suited in previously irradiated patients. Efforts have to be pursued to increase quality of the treatment of primary tumours, at best performed in centers that have expertise in this field.