Can peritoneal spread be prevented in high risk colon cancer patients?

This study compared two treatment approaches on the long-term outcomes of colon cancer patients at risk of peritoneal metastases (spread of the cancer to the lining of the abdomen).

The spread of colon cancer to the peritoneum is a life-threatening condition. One treatment is cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CS/HIPEC). CS/HIPEC involves surgically removing affected parts of the peritoneum and then bathing the abdominal cavity in heated chemotherapy.

CS/HIPEC has improved patient outcomes, but newer treatments which stop peritoneal spread are needed. Treating patients who are at risk for peritoneal metastases before any signs of peritoneal spread occur may improve patient outcome. 

This study selected 25 colon cancer patients who were at high risk of peritoneal metastases. Risk factors included the depth of cancer invasion through the bowel wall and how the cancer looked under the microscope (mucinous cancer; cancer of the cells involved in making mucus is a risk factor). All 25 patients had aggressive surgery to remove part of the colon, the ovaries, some of the abdominal lining, the appendix and the round ligament of the liver. After the surgery the abdominal cavity was bathed in heated chemotherapy (proactive group). This involved oxaliplatin (Elotaxin) chemotherapy being heated to 43°C (109.4°F) and delivered over 30 minutes. The outcomes of these patients were compared to the outcomes of 50 similar patients who underwent standard colon surgery (standard group).

After 4 years the cancer relapsed in fewer patients from the proactive group (28%) than frem the standard group (42%). Of the 7 patients that relapsed in the proactive group the cancer returned in the liver (4 patients), liver and lungs (2 patients), or in the abdominal wall (1 patient). Of the 21 patients that relapsed in the standard treatment group 14 had cancer in the peritoneum. Other sites of relapse in the standard group included the liver, lung, ovary, or multiple sites.

The rate of cancer returning near to the original cancer site was less in the proactive group (4%, in the abdominal wall) than the standard group (28%, in the peritoneum). On average patients in the proactive group survived longer than patients in the standard group, 59.5 compared to 52 months.

The authors concluded that this proactive approach is promising for patients at risk of peritoneal spread. They highlight that future investigation is needed in a larger study.