Operative outcome and prognosis

The operative results and prognosis were compared between the two groups. Tumor size, measured by MRI at the initial diagnostic procedure and immediately prior to surgery, was used to evaluate tumor response to NAC, and the response was classified according to the Response Evaluation Criteria in Solid Tumors, version 1.1 (4). Complete response (CR) was defined as disappearance of the tumor; partial response (PR) as a ≥30% decrease of the longest diameter (LD) of the tumor; progressive disease (PD) as a ≥20% increase of the LD; and stable disease (SD) as a change of less than the PR or PD limits.