Prognostic significance of bcl-2, c-myc, survivin and tumor grade in synovial sarcoma.

OBJECTIVE

We aimed to determine the prognostic value of bcl-2, c-myc and survivin in synovial sarcoma cases and to evaluate the relationship between the conventional morphological findings with prognosis.

MATERIAL AND METHOD

In this study, we evaluated 81 synovial sarcoma cases referred to our tertiary tumor center during a period of 20 years. We applied bcl-2, c-myc and survivin immunohistochemically and investigated the relationship with prognosis for those 65 cases with follow-up. The relationship between the conventional morphological findings (mitosis, necrosis, grade) with prognosis was also investigated.

RESULTS

Five-year disease free survival rate was 44% and ten-year progression free survival rate was 38%, reflecting the aggressive behavior of synovial sarcoma. Tumor grade (according to FNCLCC) was the most significant prognostic input in this study. We obtained a significant difference between grade II (40 cases) and grade III (24 cases) group regarding progression-free survival and overall survival (p < 0.001 and p < 0.001 respectively). Grade II was divided into two groups according to mitotic index and necrosis (grade IIa and IIb) and there was a significant difference between them regarding prognosis (p=0.013 for progression free survival, p=0.003 for overall survival). There was a significant relationship between bcl-2 negative plus focally weak positive cases (9 cases) and focally strong cases (21 cases) and diffuse strong cases (35 cases) (p=0.042 and p=0.016 respectively). There was a significant relation between c-myc negative cases (25 cases) and nuclear positive cases (17 cases) regarding overall survival (p=0.043) and between c-myc negative cases and cytoplasmic positive cases (23 cases) regarding progression free survival (p=0.05). The relation between survivin and prognosis was not significant.

CONCLUSION

Tumor grade was the most significant prognostic parameter in this study. The grade IIa group (with less than 10 mitoses in 10 HPF, without necrosis) had a better prognosis than both the grade IIb and III groups. The grade IIb group was closer to grade III regarding the prognosis. Bcl-2 and c-myc (nuclear and/or cytoplasmic) immunohistochemical positivity had prognostic value but this finding has to be confirmed by large series.