PROGNOSIS FOLLOWING LOCALLY RECURRENT SOFT-TISSUE SARCOMA - A STAGINGSYSTEM BASED ON PRIMARY AND RECURRENT TUMOR CHARACTERISTICS

We have shown that the clinical growth rate of local recurrence from s oft-tissue sarcoma could be expressed as a growth-rate index (GRI) whi ch was predictive for metastasis, and which was able to identify 2 equ al populations of good (80% 2-year MFS) and poor survivors (33%). We n ow report the associations between characteristics of the primary and GRI, and combine primary and locally recurrent tumour characteristics in a staging system. We studied 460 adult patients with soft-tissue sa rcomas of the extremities and trunk wall who were diagnosed and treate d between 1964 and 1990, of whom 134 developed local recurrences and 1 51 metastases. The association of primary tumour size, histologic mali gnancy grade, depth, spontaneous necrosis, intratumoral vascular invas ion and S-phase fraction with local recurrence, GRI and metastasis wer e examined. High GRI was associated with primary tumours that were lar ger, deeper, more malignant, underwent spontaneous tumour necrosis, de monstrated intravascular invasion and had a higher S-phase fraction. T he same factors were also strongly associated with the incidence of me tastasis. A multivariate analysis found GRI and primary tumour necrosi s to be the strongest and most significant prognostic factors. GRI and tumour necrosis were combined in a staging system that identified gro ups with good survival (79 to 94% 2-year MFS), intermediate survival ( 6% 2-year MFS) and exceptionally poor survival (6% 2-year MFS). These findings validate our earlier assertion that high GRI reflects highly malignant tumours. A staging system composed of primary tumour necrosi s and GRI can identify patients who may be suitable candidates for tri als of adjuvant chemotherapy. (C) 1995 Wiley-Liss, Inc.