Peritoneal surface oncology: review of a personal experience with colorectal and appendiceal malignancy

Peritoneal surface malignancy usually results from implantation of gastrointestinal cancer. In the past, this clinical situation was treated with palliative intent. A definitive approach to peritoneal surface malignancy involves peritonectomy procedures, visceral resections, perioperative intraperitoneal chemotherapy and knowledgeable patient selection. The quantitative prognostic indicators necessary for valid clinical judgements include the cancer histopathology (invasive vs. expansive progression), the preoperative abdominal and pelvic CT, the peritoneal cancer index and the completeness of cytoreduction score. Proper patient selection is mandatory for optimizing the results of treatment. In a series of phase II studies, appendiceal tumors with peritoneal seeding became the paradigm for success with an 85% long-term survival in selected patients. Carcinomatosis from colon cancer had an overall 5-year survival of 45% with selected patients. In all malignancies, early aggressive treatment of minimal peritoneal surface dissemination showed the greatest benefit. The definitive prognostic indicator was the complete cytoreduction. Oncologists must seek new knowledge regarding the management of peritoneal surface dissemination of cancer because a curative approach has been demonstrated in large phase II studies; in contrast all historical controls show 0% long-term survival. Additional adjuvant phase III studies with perioperative intraperitoneal chemotherapy in diseases where peritoneal surface spread occurs are indicated.