Should patients with peritoneal carcinomatosis of colorectal origin with synchronous liver metastases be treated with curative intent? A case-control study.

Abstract

e14158 Background: This aim of this case-control study was to assess the prognostic impact of the presence of liver metastases (LM) in patients operated on colorectal peritoneal carcinomatosis (PC) who underwent complete cytoreductive surgery (CRS) and LM resection followed by intraperitoneal chemotherapy. Methods: From a prospectively maintained database, all patients with colorectal PC and synchronous LM who underwent CRS followed by intraperitoneal chemotherapy, were manually matched to all identical patients with isolated PC, operated on over the same period, on the following matching criteria: age, peritoneal cancer index (PCI), site of the primary colorectal cancer (colon or rectum), lymph node involvement on the primary colorectal cancer specimen (pN), and postoperative chemotherapy. Results: From 1993 to 2009, 37 patients with PC and LM were matched to 61 patients with isolated PC. After a mean follow-up of 36 months, 3-year overall (OS) and disease free survival rates were significantly lower in patients with PC and LM, respectively 40% and 66% (p=0.04) and 6% and 27% (p=0.001). In Cox regression analysis, a PCI ≥ 12 (Odds-ratio (OR): 4.6), a pN+ status (OR: 3.3), no adjuvant chemotherapy (OR: 3.0) and presence of LM (OR: 2.0) were identified as independent factors of poor OS. Thus, 3 groups could be identified: 1) patients with a low PCI (<12) and no LM, with an associated a median OS of 76 months; 2) patients with a low PCI (<12) and 1 or 2 LM, with an associated OS of 40 months; and 3) patients with a high PCI (≥12) or patients with ≥ 3 LM, with an associated OS of 27 months. Conclusions: This first case-control study confirms that prolonged survival can be achieved in highly selected patients operated on limited carcinomatosis and liver metastases less than 3. When the peritoneal and the liver involvement are greater, the complete surgical treatment followed by intraperitoneal chemotherapy should be discussed according to criteria of aggressiveness of the tumor disease.