G Contesso

The pathological features of 155 adult patients with soft-tissue sarcomas were studied retrospectively, in an attempt to set up a grading system for these tumors. As the first step, seven histological criteria (tumor differentiation, cellularity, importance of nuclear atypia, presence of malignant giant cells, mitosis count, pattern of tumor necrosis and presence of vascular emboli) were evaluated in a monofactorial analysis. Five of these (tumor differentiation, cellularity, mitosis count, tumor necrosis, and vascular emboli) were correlated with the advent of metastases and with survival. A multivariate analysis, using a Cox model, selected a minimal set of three factors (tumor differentiation, mitosis count, and tumor necrosis) the combination of which was necessary and sufficient to retain all the prognostic information. A grading system was elaborated, which turned out to be correlated with the advent of metastasis and with patients' survival. A second multivariate analysis introducing clinical prognostic features showed that the histological grade was the most important prognostic factor for soft-tissue sarcomas. Thus, this grading system appears to be highly interesting because of its prognostic value and the facility of its elaboration. However, its reproducibility should be tested.

PURPOSE: To define the prognostic factors in adult patients with locally controlled soft tissue sarcoma (STS) and to determine which patients should be considered for adjuvant treatment. PATIENTS AND METHODS: Five hundred forty-six patients with a nonmetastatic and locally controlled STS, collected in a cooperative data base by the French Federation of Cancer Centers (FNCLCC) Sarcoma Group from 1980 and 1989, were studied. Histologic slides of all patients were collegially reviewed. Initial treatment consisted of complete tumor resection with amputation in only 4% of the patients. Adjuvant radiotherapy was administered to 57.9% and adjuvant chemotherapy to 31%. Relationships between tumor characteristics were analyzed, and univariate and multivariate analyses were performed using Cox models for the hazards rate of tumor mortality, development of distant metastasis, and strictly local recurrence. RESULTS: Unfavorable characteristics with an independent prognostic value for tumor mortality were: grade 3 (P = 3 x 10(-10)), male sex (P = 1.5 x 10(-5)), no adjuvant chemotherapy (P = 5.4 x 10(-5)), tumor size > or = 5 cm (P = 3.8 x 10(-3)), and deep location (P = 4.6 x 10(-3)). Unfavorable characteristics for the development of distant metastasis were: grade 3 (P = 4 x 10(-12)), no adjuvant chemotherapy (P = 6.4 x 10(-4)), tumor size > or = 10 cm (P = 9.8 x 10(-4)), and deep location (P = 1.3 x 10(-3)). For the development of local recurrence, the unfavorable characteristics were: no adjuvant radiotherapy (P = 3.6 x 10(-6)), poor surgery (local excision) (P = 2 x 10(-4)), grade 3 (P = 7.6 x 10(-4)), and deep location (P = 10(-2)). Grade, depth, and tumor size were used to define groups of patients according to the metastatic risk. Adjuvant chemotherapy was beneficial in terms of overall survival and metastasis-free survival in grade 3 tumor patients only. Despite worse characteristics concerning tumor depth, tumor-node-metastasis (TNM) and American Joint Committee (AJC)/International Union Against Cancer (UICC) classifications and grade in patients with adjuvant radiotherapy, the latter experienced significantly fewer local recurrences than patients with no radiotherapy. CONCLUSION: Grade, tumor depth, and tumor size could be used to select patients with a high metastatic risk, for which adjuvant chemotherapy could be beneficial.

Tumor grade has been proposed as an essential factor in the staging of patients with soft tissue sarcomas. In a previous study, a histopathologic grading system using the evaluation of tumor differentiation, mitosis count, and tumor necrosis was described. The current study was conducted to test its reproducibility. The pathologic sections of 25 soft tissue sarcomas were submitted to a study group composed of 15 pathologists who had not been involved in the development of the grading system. The results were compared with those of a panel group. The crude proportion in agreement observed between the study group and the panel group was 81% for the evaluation of tumor necrosis, 74% for tumor differentiation, and 73% for the mitosis count. The crude proportion in agreement for the tumor grade was 75%, which was significantly better than the crude agreement rate of 61% for the diagnosis of histologic type (P = 0.001). A kappa statistical analysis, to check the possibility of chance-related concordance, showed a proportion in agreement of 68%. A two-way variance analysis showed that the homogeneity of the evaluation of tumor grade is impaired by tumor-related and observer-related factors. However, an improvement may be obtained by better training of pathologists. We conclude that the tumor grading system developed inside the French Federation of Cancer Centers, although perfectible, already provides reliable prognostic information and its use in prospective clinical studies may provide more information about its clinical usefulness.