OBJECTIVETo compare the clinical efficacy of postoperative intraperitoneal chemotherapy combined with systemic chemotherapy to systemic chemotherapy alone for serosa-involved colorectal cancer.

METHODSAccording to the criteria of serosa-involving in colorectal cancer, 332 cases were divided into 2 groups prospectively without randomization. Study group(n=166) was treated with intraperitoneal chemotherapy combined with systemic chemotherapy, and control group(n=166) with systemic chemotherapy alone. Incidence of local recurrence, peritoneal metastasis, hepatic metastasis, other distant metastasis and 3-year, 5-year overall survival(OS) rate of two groups were compared.

RESULTS3-year and 5-year OS rates of stage II(B in study group were similar to those in control group(chi(2)=0.612,P=0.434). The above rates of stage III( in study group were higher than those in control group(chi(2)=3.989,P=0.046). Either the study group or the control group, the 3-year and 5-year OS rates of patients undergone laparoscopic surgery or open surgery were similar(P=0.839, P=0.172). Incidences of local recurrence, peritoneal metastasis and hepatic metastasis in study group were 1.9%,3.8% and 3.8% respectively, lower than those in control group(8.2%,9.5% and 10.1%,P<0.05). Distant metastasis rate in study group was similar to that in control group. In study group, intraperitoneal chemotherapy regimen with Oxaliplatin had lower rates of peritoneal metastasis and hepatic metastasis as compared to that with Cisplatin(0.9% vs 8.8%,P=0.019), while the incidences of local recurrence and other distant metastasis were similar.

CONCLUSIONSPostoperative intraperitoneal chemotherapy combined with systemic chemotherapy improves 3-year and 5-year overall survival rates in patients with stage III( serosa-involved colorectal cancer, and decreases local recurrence, peritoneal metastasis and liver metastasis rate, especially when intraperitoneal chemotherapy regimen contains Oxaliplatin. Comparing with open surgery, laparoscopic surgery dose not improve 3-year and 5-year overall survival rates in patients receiving combined chemotherapy or systemic chemotherapy alone.