More Liver Metastases Detected Intraoperatively Indicates Worse Prognosis for Colorectal Liver Metastases Patients after Resection Combined with Microwave Ablation

Abstract

Background. Whether more tumor numbers detected in surgery compared to preoperative image affecting survival of colorectal liver metastases (CRLM) patients after hepatectomy combined with microwave ablation (MWA) remains unclear. Methods. From 2013 to 2018, 85 CRLM patients who underwent hepatectomy combined with MWA were retrospectively assessed. Compared to the tumor numbers in preoperative image, patients with equal intraoperative tumor numbers were defined as the equal number group ( $n=45$ ); patients detected more tumor numbers in surgery were defined as the more number group ( $n=40$ ). Clinicopathological factors and prognosis were compared between two groups. Results. Compared to the equal number group, the more number group was characterized by more lymphatic metastasis, synchronous metastasis of liver lesion, and tumor numbers over 5 (all $P<0.05$ ). Median survival time was 46.7 months and 26.8 months in the equal and more number group. Significantly worse overall survival (OS) was found in more number group to the equal number group ( $P=0.027$ ). In Cox analysis, more tumor number than image and high level of carbohydrate antigen 19-9 (CA19-9) were poor prognostic factors for OS. Conclusion. In patients receiving hepatectomy combined with MWA, detecting more liver metastases in surgery than preoperative image indicates poor long-term survival. These patients were characterized by more lymphatic metastasis, synchronous metastasis of liver lesion, and tumor numbers over 5. Intensive follow-up to detect early recurrence and potent postoperative therapy to improve survival may be justified in patients detected more tumor numbers in surgery with a high CA19-9 level.