Discordance of oncologic surgical classifications in COG studies.

Abstract

10528 Background: “Wide resection” (a cuff of normal tissue) versus “radical resection” (the entire compartment) indicate very distinct oncologic surgical procedures and hence potential margin status. Distinguishing between these two oncologic classifications is important for understanding oncologic outcomes. Methods: We examined the available data for COG AOST0331: A Randomized Trial of the European and American Osteosarcoma Study Group to Optimize Treatment Strategies for Resectable Osteosarcoma Based on Histological Response to Pre-Operative Chemotherapy. We reviewed the surgical and pathology reports of patients considered to have received a wide or radical resection according to the investigator at the patient’s institution. Results: In 956 patients, the overall discordance rate was 43%. Of those patients reported to have had a wide excision by the reporting institution, only 5% of patients were reclassified to radical resection. However, of those patients reported to have undergone radical resection, 75% were reclassified to wide. In the absence of this re-review of the data, 56% of the patients would have been reported to have had a radical resection when in fact only 17% met the criteria for true radical resection. The greater number of patient reclassified to wide from radical is likely indicative of the influence and limits of the CPT coding system currently used for billing by surgeons; only CPT codes for radical resection currently exist. Conclusions: These discrepancies complicate subsequent data analysis, particularly assessing predictors of local recurrence. While this reporting problem is not unique to COG studies, we aim to use this example to raise awareness among our colleagues about the importance of accurate data reporting. Providing better training to those individuals responsible for submitting data may decrease the incidence of erroneous data entry and is essential to the successful completion of study objectives.