Surgeons and medical oncologists at Washington University and the Siteman Cancer Center have joined forces to design a treatment regimen that may offer better survival for patients with carcinomatosis of the abdomen that has spread from the colon or appendix. This type of cancer typically results when a mucin-producing tumor invades the wall of the colon or appendix and sheds cells, which are implanted in the abdominal cavity.
“As a group, these are very sick patients,” says James Fleshman Jr., MD, chief of the Section of Colon and Rectal Surgery at Washington University and Barnes-Jewish Hospital.
The standard of care, Fleshman says, is surgical debulking and stripping of the malignant tissue from the lining of the abdominal cavity, in combination with some form of chemotherapy. One method of delivering the chemotherapy is by heated intraperitoneal chemotherapy (HIPEC)—in which a heated, sterile chemotherapy solution is circulated throughout the abdominal cavity in an open surgical procedure only once. The method has proven to be effective but is very toxic.
Fleshman and medical oncologist Benjamin Tan, MD, developed an alternative method and have now tested it in a pilot study. Their method delivers nine to 14 doses of chemotherapy starting one month after the debulking operation using catheters inserted into both sides of the abdomen at the end of the debulking procedure. In the trial, Tan administered 5-fluorouracil via catheter and another agent, oxaliplatin, intravenously. Early results suggest that the delayed repeated intraperitoneal chemotherapy approach may be just as effective as heated chemotherapy given during the major operation but less toxic.
In the trial’s second phase, the physicians will change the drug delivery method again to avoid neurological side effects, delivering oxaliplatin into the abdomen and 5-fluorouracil by mouth. They will escalate the oxaliplatin dose gradually as more patients participate to determine the optimum level.
Tan says he is working more frequently with surgeons who treat gastrointestinal disease in developing and carrying out clinical trials. “At this institution, there are major collaborative efforts among surgeons, medical oncologists and radiation oncologists,” he says.