When we see patients in our offices with metastatic colon cancer which is confined to the peritoneal cavity and the histology of the cancer shows mucinous carcinoma, we consider not only chemotherapy but also think about specialized surgery to remove the cancer in the abdomen and combine this with hyperthermia and chemotherapy given directly into the cavity during surgery.
Why is that?
This subtype of colorectal carcinoma accounts for 10 – 20 % of all colorectal neoplasms. Compared to the more common nonmucinous variety, mucinous tumors metastasize to lymph nodes with increased frequency and are more prone to spread to the peritoneal cavity. These mucinous colorectal adenocarcinomas (MCA) are a recognized subgroup of colon cancer and usually spread to peritoneal surface without spreading to the liver and lungs.
It is important to know that mucinous tumors are also more often associated with a genetic predisposition syndrome particular when they are located on the right side of the colon.
Since these are very complicated surgeries, these combined treatment procedures should be done only with a highly experienced surgeon.
Nevertheless, an increasing number of international treatment centers have published their results using cytoreductive surgery, and intraperitoneal chemotherapy and hyperthermia in the management of peritoneal surface malignancies of colorectal origin.
Because these patients need to be considered for this special therapy, I want to share with you some of the larger trials using this approach. In the retrospective multicenter study by Glehen et al. of cytoreductive surgery combined with perioperative intraperitoneal chemotherapy for the management of PC of colorectal cancer, 506 patients were analyzed. Patients in whom cytoreductive surgery was complete had a significant longer survival than patients with incomplete surgery.
Recently, Elias et al performed a retrospective-cohort, multicenter French-study of peritoneal colorectal carcinomatosis treated with surgery and perioperative intraperitoneal chemotherapy including 523 patients which confirmed the results obtained by Glehen.
The risk of surgery is high and should be only be performed in high volume centers familiar with this surgery. When patients with MCA with peritoneal carcinomatosis were treated either with standard therapies and standard surgery or with this novel approach called HIPEC, patients did much better with HIPEC, in fact the study was stopped early because HIPEC was doing so much better.
If you have mucinous colon cancer which is limited to the abdominal cavity please discuss this with your treatment oncologist.
The main criticism against the combined treatment is the lack of nonstandardized treatment techniques. Most of the centers are currently using HIPEC whereas only a few are using EPIC. Both procedures are not standardized and many variations exist in exposure techniques, drugs, drug doses, duration, temperature and flow rates, which may contribute to the differences in the results. Finally, a proper patient selection is essential to benefit from combined cytoreductive surgery and intraperitoneal chemotherapy.