USEFULNESS OF ARGYROPHILIC NUCLEOLAR ORGANIZER STAINING FOR PREDICTING PROGNOSIS OF PATIENTS WITH RECURRENT SOFT-TISSUE SARCOMA

Local recurrence of tumor is a common phenomenon in soft tissue sarcom a (STS) and may be accompanied by an increase in malignant potential. In the present study, an increase of proliferative activity in recurre nt tumors compared to primary tumors was observed using a silver stain for nucleolar organizer regions (AgNOR), and its implication for pred icting prognosis is assessed. 44 patients with STS showing local tumor recurrence were selected. Local recurrence was defined as new tumor g rowth more than 2 months after the initial surgery in the same region where the primary tumor occurred. All patients received surgery, follo wed in 11 patients by adjuvant radiotherapy and/or chemotherapy. The h istologic subtype was malignant fibrous histiocytoma in 22 cases, syno vial sarcoma in 5, leiomyosarcoma in 4, liposarcoma in 3, malignant sc hwannoma in 3, and others in 7. The interval between initial surgery a nd local recurrence ranged from 2 to 72 months. No patients changed fr om one histological subtype to another. Histological changes included an increase in mitosis, cellularity, and sclerosis in 43.2, 31.8, and 27.3%, respectively. The AgNOR count (mean +/- SD) in recurrent tumors (7.22 +/- 2.59) was significantly higher than that in primary tumors (5.58 +/- 2.28; p < 0.0057), clearly showing a tendency for an increas e in proliferative activity during recurrence. The 5-year survival rat e of patients with a marked increase (> 4) in AgNOR count (16.7%) was worse than with minor to moderate increases (60.0%; p < 0.02). Marked AgNOR increase was more frequently observed in the tumors located in t he head and neck and retroperitoneum (40%) than in other sites (9%). I rrespective of the primary site of tumors, a marked AgNOR increase res ulted in an unfavorable prognosis. Multivariate analysis of change in histologic factors including AgNOR, cellularity, mitotic counts, pleom orphism, myxoid change, necrosis, sclerosis, and tumor size showed tha t increase of AgNOR counts was significant (p < 0.05). The present fin dings suggest that AgNOR counts can be used as a prognostic factor in recurrent STS.