Results of cytoreduction followed by HIPEC in carcinomatosis of colorectal origin

Abstract

Stage IV colorectal cancer is defined as colon or rectal cancer with metastasis, disregarding the site of the metastasis. It traditionally includes liver metastasis, lung metastasis, bone metastasis as well as metastasis on the peritoneum. Historically, patients suffering from stage IV colorectal cancer have a 5-year survival of 10% and a median survival just beyond one year [1]. Recent studies in this field show a more promising survival with a median survival of up to 20 months reported [2]. Peritoneal carcinomatosis (PC) is a special form of stage IV colorectal cancer. The existence of PC limits the survival in stage IV colorectal carcinoma patient even further to only half a year [3]. There are many studies concerning the chemotherapeutic treatment of metastatic colorectal cancer. These studies include patients with metastases of colorectal cancer of any location. However, to enable proper response evaluation most studies include only those patients who have measurable disease. For practical reason measurements are most often made on liver metastasis or lymph nodes. Thus, the data of stage IV colorectal cancer trials are dominated by the results found in the treatment of liver and lung metastases. For patients with metastases elsewhere (including PC), the data are limited limited in these studies. Peritoneal carcinomatosis forms an all-covering thin layer of metastasis on the peritoneum. Imaging this layer is difficult. It lacks a volume density, which means that there is only a limited amount of tumour per cubical unit. It is like a paper sheet, if one looks at it, it can be seen quite easily. But if the paper is in a box it does not fill any significant part of the volume of the box. The consequence of this is that CT scan, MRI scan and even PET scan, which detect volume-density differences, leave PC undetected until the total amount of tumour is important [4]. In fact, most cases of PC stay undetected until there is secondary evidence of its presence, e.g. bowel or urinary tract obstruction. Peritoneal carcinomatosis is often associated with bowel dysfunction resulting from tumour deposits that grow on the visceral peritoneum causing a so-called "hosepipe" phenomenon, indicating that peristaltic movements are blocked the encasing tumour shelf. As a consequence, many PC patients suffer from malnutrition. This malnutrition is one of the elements explaining the poor tolerance of systemic chemotherapy in PC patients, as opposed to patients with metastatic disease confined to the liver or lungs. As detailed in chapter 7, data from retrospective studies have highlighted that the natural history of PC is characterized by a median survival of approximately half a year [5-7]. Treatment in these studies was not standardized and varied from no treatment at all to the most modern chemotherapy at that time. The only prospective study in this field stems from an update of a randomised trial [8]. In this study 5-fluorouracil (5FU) with leucovorin was given according to the Laufmann scheme, representing the most effective therapy in stage IV colorectal cancer at the time the study was done [9]. This study resulted in a median survival of 12 months.