Intraperitoneal chemotherapy for peritoneal carcinomatosis from colonic or appendiceal cystadenocarcinoma: rationale and results of treatment.

The natural history of cystadenocarcinoma of colonic or appendiceal origin was reviewed. This tumor represents a minimally invasive mucus producing tumor similar to what is commonly recognized within the bowel lumen as villous adenoma. This tumor is usually at an advanced stage at the time of presentation, and tends to recur at the site of tumor resection and on peritoneal surfaces. The fact that this tumor does not metastasize hematogenously or lymphatically nor does it invade locally was contrasted to its marked tendency to implant on all abdominal surfaces. The large variations in the efficiency of different types of tumor dissemination (metastases, invasion, and spread by implantation) need to be noted for this malignant process. The unique clinical features of cystadenocarcinoma were reviewed and the particular suitability of intraperitoneal chemotherapy for its treatment was discussed. Our treatment plan utilizing cytoreductive surgery and early plus delayed postoperative intraperitoneal chemotherapy was presented. The surprisingly good results of treatment was discussed. The effects of chemotherapy on tumor histology were presented in detain in six patients. Changes induced by intraperitoneal chemotherapy included a reduction in the number of foci of atypical adenomatous epithelium and marked cytologic atrophy. This plan of treatment is recommended for patients to prevent or to treat the spread of mucinous gastrointestinal cancer on peritoneal surfaces and within the resection site of the primary tumor.