Synchronous PM is a well-known predictor of poor prognosis in CRC patients. Other poor independent factors influencing recurrence and prognosis for CRC with PM are presence of lymph node metastases, five or fewer dissected lymph nodes, positive resection margins (pathologist and residual tumor classification),high preoperative serum CA 19-9 levels, hematogenousmetastases, focal number and range of PM, and absenceof postoperative adjuvant chemotherapy