The relation of tumour necrosis and survival in patients with osteosarcoma

We investigated whether tumour necrosis was associated with disease-free survival (DFS) and overall survival (OS) of osteosarcoma patients treated in our institution.We retrospectively studied the predictive value of percentage of necrosis in 40 cases of IIB osteosarcoma treated from 1999 to 2008 in our institution. Patient and treatment factors such as age, gender, tumour site, surgery type, pathological type, tumour size, margin status, percentage of tumour necrosis, chemotherapy regimens and cycles were recorded. The average follow-up was 85.9 months (range, 25-135 months).Two patients had local recurrence (LR) alone, five patients had both LR and metastasis, 14 patients had metastasis alone. Twenty-four patients were alive and 16 had died. The five-year DFS and OS were 47.8% and 65.9%, respectively. Tumour necrosis grouped by 90% was not associated with DFS and OS. Patients with greater than 70% necrosis rate had a significantly higher DFS than those with less than 70%.We found no survival advantage at 90% tumour necrosis in our study. Further study with more patients should be performed to evaluate the predictive value of necrosis rate at the cutoff of 70%.