Comprehensive Treatment Using Cytoreductive Surgery Combined with Perioperative Chemotherapy Improved Outcome of Colorectal Cancer Patients with Metachronous Peritoneal Metastasis.

To analyze the role of cytoreductive surgery(CRS)plus perioperative chemotherapy on the survival of colorectal cancer(CRC)patients with metachronous peritoneal metastasis(PM). A comprehensive treatment consisting of neoadjuvant chemotherapy plus CRS was performed in 291 CRC patients. Among the 291, 142 and 149 patients had synchronous and metachronous PM, respectively. The results showed no survival difference between the 2 groups. Median survival time(MST)of patients with metachronous PM with complete cytoreduction(CCR-0), small bowel(SB)-PCIC2, PCIC14 and differentiated histologic type ranged from 3.1 to 4.1 years. Five-year survival rates of metachronous group of the CCR-0, SB-PCIC2, PCI C14 and differentiated histologic type ranged from 25.8 to 38.9%. However, the 5-year survival rates of the incomplete cytoreduction(CCR-1), SB-PCIB3, PCIB15 and poorly differentiated type were significantly lower than those of the CCR-0, SB-PCIC2, PCIC14 and differentiated histologic type. Postoperative Grade 3, and Grade 4 morbidity were experienced in 11(5.8%)and 16(10.7%)in metachronous group. Mortalities of metachronous group were 1.3%(2/149). The comprehensive treatment can be performed safely and improves the survival of CRC patients with metachronous PM. After NAC, patients with SB-PCIC2, PCIC14 and differentiated type of histology are candidates for CRS, and CCR-0 resection combined with HIPEC is recommended.