Tumor volume increase during preoperative chemotherapy as a novel predictor of local recurrence in extremity osteosarcoma.

BACKGROUND: Known risk factors (surgical margin, tumor necrosis) of local recurrence (LR) in osteosarcoma are determined by results available after surgery. However, relations between preoperative characteristics and LR have not been clearly defined.
METHODS: We compared the clinicopathologic characteristics of 36 osteosarcoma patients with LR and 394 patients without LR after surgery. In addition, prognostic variables were evaluated to establish factors could influence LR.
RESULTS: Compared to the non-LR group, the LR group showed an increase in tumor volume ratio (TVR) during preoperative chemotherapy (P < 0.01), inadequate surgical margin (P < 0.01), and poor histologic response (P < 0.01). Univariate analysis of data from 430 patients revealed that an increased TVR (P < 0.01), inadequate surgical margin (P < 0.01), poor histologic response (P < 0.01), and nonosteoblastic pathologic subtype (P = 0.04) were negatively related to LR-free survival. In multivariate analysis, an elevated TVR (P < 0.01, relative risk = 10.26) and inadequate surgical margin (P < 0.01, relative risk = 5.91) emerged as the key prognostic factors for LR.
CONCLUSIONS: A TVR increase during preoperative chemotherapy could be used to predict patients at high risk of LR. This finding might be useful when considering surgical options to decrease the risk of LR.