Tumor histopathological response to neoadjuvant chemotherapy in bone sarcomas: A single-institutional experience.

BACKGROUND : The histological response to chemotherapy is regarded as an independent prognostic variable in bone tumours. The surgical pathologist, thus has an important role in the management of primary malignant bone tumors like osteosarcomas and Ewing′s sarcoma subsequent to neoadjuvant chemotherapy. AIMS AND OBJECTIVES: We report a short series of fifteen cases of osteosarcoma and three cases of Ewing′s sarcoma in which the histological response of the tumor after giving neoadjuvant chemotherapy to the patient of bone tumours was assessed and graded. MATERIAL AND METHODS: Bone tumours was assessed and graded by Huvos grading. The correlation of this histopathologic tumor response with clinical outcome is a well-established routine investigation in patients with bone sarcomas and the grading of the tumor response is based on definable histopathologic criteria. RESULT: Fifteen out of eighteen cases in this study showed a response to neoadjuvant chemotherapy, which was categorized as Huvos Grade 1 (%50%) and Huvos Grade 2 (50% to 90%). One case of osteosarcoma showed a Grade 4 response with a total absence of tumor cells in all the sections. One case of osteosarcoma and Ewing′s sarcoma each were categorized as Grade 3, showing tumor foci. CONCLUSION: It was concluded that necrosis of tumor area when greater than 90%, is regarded as a powerful positive prognostic indicator for survival in patients of high grade bone sarcomas. [ABSTRACT FROM AUTHOR]