Metastases from the colon and rectum
Median survival is usually 6 months if the carcinomatosis is left untreated. Using modern chemotherapy, the limit may be moved to approximately 2 years for the median patient.
A French study compated CRS-HIPEC with systemic chemotherapy and palliative surgery with oxaliplatin and found a median survival of 23.9 months in the standard group and 62.7 months in the CRS-HIPEC group after complete cytoreductive surgery (CC-0). The equivalent 5-year survival is 13% and 51%. In the study, CRS-HIPEC achieved better results compared to modern chemotherapy (17).
Different centers set different limits for disease extent to accept patients for CRS-HIPEC (which was low in the French study). CRS-HIPEC has been found to be especially effective in patients with low tumor volume measured by PCI, with high or moderately differentiated tumors, and if a complete surgical cytoreduction was possible.
For peritoneal metastases from colorectal cancer (minus appendix) the national treatment results for CRS- HIPEC in Norway show a 5-year survival of 34% with long-term follow-up.(8).
The prognosis of pseudomyxoma is good. For carcinomatosis originating from colorectal cancer, CRS-HIPEC has shown promising results in a group with very short long -term survival. In those with limited or moderate carcinomatosis, extensive treatment has increased the survival rate up to 35-50% of 5-year survival. (8,14, 21)
Significant factors for survival:
- tumor differentiation, PCI, and grade of cytoreduction (15)
- number of organ resections has not been found to implicate survival (16)
- pseudomyxoma peritonei originating from the appendix
Disseminated peritoneal adenomucinous (DPAM)
About 85% 10-year survival after peritonectomy and intraperitoneal chemotherapy. The specific effect of HIPEC compared to other intraperitoneal chemotherapy is not clear. Also, early postoperative intraabdominal chemotherapy may be associated with good results.
Peritoneal mucinous carcinomatosis (PMCA) and peritoneal mucinous carcinomatosis, intermediary type (PMCA-I/D)
About 40% 10-year survival after peritonectomy and intraperitoneal chemotherapy. It is assumed that recurrence in the peritoneum after tumor that is benign in appearance can have malignant transformation over time.
In a study from Oslo University Hospital on cytoreductive surgery 1994-2009, the Norwegian treatment which was implemented in 1994, was assessed and the results were equivalent to those from international cooperative centers.
If a mucus-filled and distended appendiceal mucoceles is diagnosed, the appendix should be removed without tearing it up to avoid mucus/cells leaking in the pelvis. If this extirpation is successful, and there are no signs of mucus or cells in the abdominal cavity, the patient shall be followed up conservatively and not referred further to CRS-HIPEC. By follow-up at local hospitals, CEA should be controlled and CT abdomen/pelvis should be performed after 1, 2, 4 and 6 years. If signs of clinical pseudomyxoma peritonei occurs, the patient should be referred to the national treatment service.
The prognosis is poor for the entire group, but there are subgroups which can be treated producing very good results. CRS-HIPEC has become the new treatment strategy. In a study from 8 institutions with together 405 patients given HIPEC (18), the median survival was 53 months with 47% calculated 5-year survival. Four prognostic factors for survival were found:
- epithelial subtype
- absence of nodal metastases
- achievement of CC-0/1
- performing HIPEC