Certain clinical prognostic factors (e.g., postoperative residue, age, immunohistological subtypes, invasion, tumor size, hormone levels, and postoperative radiotherapy) and biological prognostic factors (e.g., ki‐67, p53, cadherin, PTTG, MMP‐9, EGFR, fascin actin‐bundling protein 1, cyclooxygenase‐2) have been indicated to predict the risk of recurrence in PA patients.57 This evidence concerns the gene MKI67 and neoplasm.