P53 labeling index as a prognostic factor in adult soft tissue sarcomas an analysis of 97 patients

ABSTRACT

Soft tissue sarcomas are rare neoplasms with a dismal prognosis, accounting for 1 percent of all malignancies. Their management presents several challenges, particularly when the tumor is over 5 cm in diameter, when histological grade is high, when the tumor is localized in the trunk and when it has metastasized. Immunohistochemical findings have suggested a possible prognostic role for the immunodetection of p53 protein in soft tissue sarcomas. The present study investigated the possible association between p53 protein immunodetection and prognosis in a group of patients with soft tissue sarcomas receiving care at Hospital Araújo Jorge in Brazil. Ninety-seven adult patients were included in the study. Formaldehyde-fixed and paraffin-embedded tissue sections were used in the immunohistochemical analysis, which was carried out using DO-7 monoclonal antibody and the avidin-biotin-peroxidase complex (ABC) technique. Forty-one cases (42.2 percent) were positive for p53 protein immunodetection. No statistically significant association was found between p53 immunodetection and clinical or pathological features. The p53 protein immunodetection in tumor cells revealed a labeling index > 50 percent in 32 cases (78 percent) and < 50 percent in 9 cases (32 percent). The 5-year survival rate was higher for patients in whom p53 immunodetection was negative (52.8 percent) compared to those with positive immunodetection (38.9 percent); however, the difference between the two groups was not statistically significant (p=0.159). A p53 labeling index > 50 percent was significantly associated with a lower 5-year survival rate (85.7 percent versus 27.6 percent) (p= 0.017). These results suggest that the p53 labeling index is a negative prognostic factor for soft tissue sarcoma.