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.

Peritoneal carcinomatosis is diagnosed when cancer spreads into the abdominal cavity and tumors develop on the surface of abdominal organs.  In the past peritoneal carcinomatosis has been a difficult condition to treat with very poor results from chemotherapy.  However, surgery to remove all signs of tumor followed by washing the open abdomen after surgery with heated chemotherapy is achieving some remarkable results.

Five years after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy (HIPEC) in a French cancer center, 51 percent of patients were alive.  Research surgeons compared these results to a comparable group of patients treated with modern systemic chemotherapy where cytoreductive techniques were not available.

After systemic chemotherapy with modern drugs, 13 percent of patients were alive five years later.  Median survival time was 24 months, compared to 63 months for patients treated with cytoreductive surgery and HIPEC.  All patients in the study had tumors that were isolated in their abdomens, and their cancer had not spread beyond the abdomen.

About 11 percent of people with colorectal cancer will develop peritoneal carcinomatosis.  Traditionally, it has been extremely difficult to treat.  Older chemotherapies, that did not include oxaliplatin or irinotecan, resulted in median survival times from 5 to 12 months.  In this study, using more modern chemotherapy that included irinotecan and oxaliplatin, median survival for standard therapy group reached 24 months.

However, results after surgery and HIPEC were much better with a median survival of more than 5 years (63 months.)

It is important to understand that patients in the study were carefully selected to have cytoreductive surgery and the patients in the standard group were similar in having cancer that would have been treated with the cytoreductive technique had it been available.  All had tumors that surgeons believed could be completely removed, and none had cancer that had spread beyond their abdominal cavity.

Dominique Elias from the Gustave Roussy Institute in Villejuif, France where the cytoreductive surgery and HIPEC was performed concluded,

Patients with isolated, resectable peritoneal carcinomatosis achieve a median survival of 24 months with modern chemotherapies, but only surgical cytoreduction plus HIPEC is able to prolong median survival to roughly 63 months, with a 5-year survival rate of 51%.

SOURCE: Elias et al., Journal of Clinical Oncology, published ahead of print, December 22, 2008.