Construction Of A Modified Prognosis Prediction Model For Colorectal Peritoneal Metastasis—A Single Center Retrospective Study

Background:Peritoneal metastasis(PM)is the second leading cause of death in patients with colorectal cancer(CRC)except for liver metastasis.It is currently considered that cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy(CRS/HIPEC)is an effective treatment mode for patients with PM.However,not all patients with peritoneal metastases from colorectal cancer benefit from the CRS/HIPEC treatment model.How to screen out patients suitable for this treatment mode before surgery and to find out the factors affecting the prognosis of patients is the current research focus.This study retrospectively analyzed the prognostic factors of CRS/HIPEC in the treatment of peritoneal metastasis from colorectal cancer,and established a more objective and simple prognostic prediction model.Material and Methods:A retrospective analysis of 62 patients with peritoneal metastasis from colorectal cancer who underwent CRS/HIPEC treatment has been done in our center during 2014-2016.The Kaplan-Meier method was used to calculate the survival rate.The COX proportional hazards model was used to explore the risk factors affecting the prognosis.The mCOREP(modified colorectal peritoneal score)was validated and a new prognostic prediction model mPM-Score(modified Peritoneal Metastasis Score)was established.The predictive accuracy was compared of the two models for patient prognosis.Finally,perioperative complication rate and mortality was analyzed to assess the safety of CRS/HIPEC treatment model.Results:All patients with an average age of 55.39 years,a median survival time of 31.6 months,1-year survival rate of 82%,and 3-year survival rate of 40.9%.The median survival time for patients with a degree of tumor reduction of CCRO-1 was 33 months,compared with a median survival time of 6.8 months for patients with CCR2-3(p<0.001).The median survival time for patients with mCOREP<11 was 33.0 months,while the median survival time for patients with>11 was 13.2 months(p=0.004).Incompleteness of tumor cell depletion,mCOREP>11,small mesenteric invasion,ascites,preoperative CA125>40kU/L and preoperative albumin<34g/L are independent poor prognostic factors.The median survival time of the new prognostic prediction model with mPM-Score total score<6 was 42.5 months,while for patients with>6 was 25.1 months(p<0.001).The prognostic accuracy of mPM-Score was better than mCOREP score.The short-term complication rate and mortality rate after CRS/HIPEC were 22.5%and 6.4%,respectively.Conclusion:Preoperative high-level CA125,preoperative low-level albumin,incompleteness of cytoreduction,mCOREP with high score,invasion of small mesentery and ascites are independent risk factors for peritoneal metastasis of colorectal cancer.New predictive model mPM-Score has a higher prognostic value than the mCOREP score.Therefore,CRS/HIPEC is a safe and effective treatment for specific subgroup of patients with peritoneal metastasis from colorectal cancer.