Clinicopathological Features And Survival Analysis In Colorectal Cancer Patients With Peritoneal Metastases

Objective: To investigate the clinic pathological features and the outcome of colorectal cancer patients with peritoneal metastases.Methods: Data from patients with colorectal cancer treated in the First Hospital of China Medical University from February 2002 to October 2016 were retrospectively collected.The clinical pathological features,diagnostic and treatment strategy were analyzed.The short term outcome to the standard treatment as well as long term survival were also investigated.Results: Among the 1067 new cases of colorectal cancer diagnosed between February2002 to October 2016,107(10.0%)cases were diagnosed with peritoneal metastases.19 of them(17.8%)had peritoneal metastases only,and 88(82.2%)also combined with other metastases: 30(28.1%)with liver metastases,7(6.5%)with lung metastases,14(13.1%)with liver and lung metastases,12(11.2%)with ovarian metastases,and 25(23.3%)with other metastases.56.1% of peritoneal metastases were discovered during surgery by intraoperative palpation and were confirmed by postoperative pathology 32.7% were diagnosed by imaging(CT or PET-CT scan)and11.2% by others.Clinic pathological features analysis of stage IV colorectal cancer showed that peritoneal metastasis was associated with type of histology and tumor site.Mucinous adenocarcinoma and right-sided colorectal cancer are more prone to transfer to peritoneum.Survival analysis showed that the 1-year and 3-year survival rates of advanced colorectal cancer with peritoneal metastasis were 68.2% and 29.6%,respectively,and the median overall survival for the patients with peritoneal metastases was significantly shorter than the patients without peritoneal metastases(22.8 months(95%CI 17.3-28.3)vs.27.5 months(95%CI 25.1-29.8),P=0.035).According to different chemotherapy regimens,survival analysis showed that the median OS in based on oxaliplatin group was 22.4 months(95% confidence interval20.3-24.5),and the median OS in based on irinotecan group was 32.7 months(P=0.511)in 89 patients with synchronous peritoneal metastasis.The median PFS in oxaliplatin group was 9.0 months(95% confidence interval 6.6-11.3),and the median PFS in irinotecan group was 9.0 months(95% CI 0.0-21.8,P=0.219).The univariateand multivariate analyses of the clinicopathological features and OS of patients with stage IV colorectal cancer with peritoneal metastases revealed that radical surgery for peritoneal metastases can improve the overall survival of patients with peritoneal metastases.Conclusion: Peritoneal metastasis in Chinese colorectal cancer patients was just common,and its occurrence is related to some clinicopathological characteristics(mucinous adenocarcinoma ? right side colorectal is more prone to peritoneal metastasis)? The prognosis of patients with advanced colorectal cancer with peritoneum metastasis is significantly worse than that without peritoneum metastasis.The treatment regimen containing irinotecan is not different form the oxaliplatin regimen.