Diane Goéré

3558 Background: Patients with synchronous peritoneal carcinomatosis (PC) and liver metastasis (LM) of colorectal cancer (CRC) are generally considered for exclusive systemic palliative chemotherapy. Aggressive surgical approaches combining hepatectomy and peritoneal resection with curative intent remain controversial in such a setting and based on no solid data. The aim of this prospective cohort was to assess morbidity, mortality, disease-free survival (DFS) and overall survival (OS) of patients with PC and LM of aCRC origin treated with an aggressive therapeutic approach combining surgical treatment of liver and peritoneal lesions followed by hyperthermic intraperitoneal chemotherapy (HIPEC). Methods: All patients with PC and synchronous LM who undergone cytoreductive surgery and LM resection in the same time followed by HIPEC were registered in the prospective database of the French Association of Surgery and analysed. The primary endpoint was survival from the time of surgery. Results: From 1993 to 2015, 146 patients were analyzed. After a mean follow-up of 36 months, the median OS and DFS, were respectively 27,2 and 9.5 months. The median number of LM was 4 (range, 1–8).Postoperative morbidity Grade III - IV (Dindo Classification) rate was 14.8% with no postoperative death reported. Patients with complete cytoreductive surgery (n = 132) had higher OS than those with incomplete cytoreduction (n = 14) with a median of 29, versus 4 months respectively (p = 0.0001). Rectal primary tumor, PCI of 13 or more, positive nodal status of the primitive tumor, and more than 3 LM were not identified as independent factors for poor OS. Conclusions: This multicenter study is the largest series currently reported confirming that prolonged survival can be achieved in selected patients suitable for PC and LM surgery. Multimodality treatment, including surgical treatment of PC and LM with curative intent, and heated intraperitoneal chemotherapy had acceptable in terms of morbidity and allows prolonged survival.

Considering the suspected link between mucinous neoplasm (MN) and pseudomyxoma peritonei (PMP), one option could be to propose prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) to selected patients in order to prevent the occurrence of PMP. The aim of this study was to identify risk factors for developing PMP after curative surgery for a MN of the appendix. All consecutive patients referred to our single tertiary care cancer center between September 1992 and March 2014 for MN of the appendix, initially without PMP, were retrospectively studied. Patients who had received prophylactic intraperitoneal treatment were excluded from the analysis. Twenty-five patients with a median age of 51 (range=25-74) years were identified. At the initial appendectomy, 19 (76%) patients had a perforated MN. Nine of these patients (40%) exhibited disseminated-free acellular intraperitoneal mucin without PMP. Six (24%) patients had an unperforated MN without free intraperitoneal mucin. After a median follow-up of 50 months, 12 (52%) patients had developed PMP after a median time of 61 (range=13-121) months. Complete cytoreductive surgery plus HIPEC was possible in only seven (64%) out of these 12 patients. No factor reached statistical significance in predicting the occurrence of PMP but a trend was found in the case of perforated MN (p=0.068), associated with a 65% recurrence rate, compared to 17% without perforation. An appendicular MN cannot be considered a benign occurrence because PMP is common after resection and can occur up to 10 years after the initial appendectomy. Patients should be systematically followed up to detect PMP as early as possible. Patients with a perforated MN could be at higher risk of developing PMP.

The peritoneum is one of the most frequent sites of recurrent gastric carcinoma after curative treatment, despite the administration of pre- and/or postoperative systemic chemotherapy. Indeed, the prognosis of peritoneal carcinomatosis from gastric carcinoma continues to be poor, with a median survival of less than one year with systemic chemotherapy. Whereas the prognosis of peritoneal carcinomatosis from colorectal cancer has changed with the development of locally administered hyperthermic intraperitoneal chemotherapy (HIPEC), survival results following carcinomatosis from gastric cancer remain disappointing, yielding a 5-year survival rate of less than 20%. Innovative surgical therapies such as intraperitoneal immunotherapy therefore need to be developed for the immediate postoperative period after complete cytoreductive surgery. In a recent randomised study, a clinical effect was obtained after intraperitoneal infusion of catumaxomab in patients with malignant ascites, notably from gastric carcinoma. Catumaxomab, a nonhumanized chimeric antibody, is characterized by its unique ability to bind to three different types of cells: tumour cells expressing the epithelial cell adhesion molecule (EpCAM), T lymphocytes (CD3) and also accessory cells (Fcγ receptor). Because the peritoneum is an immunocompetent organ and up to 90% of gastric carcinomas express EpCAM, intraperitoneal infusion of catumaxomab after complete resection of all macroscopic disease (as defined in the treatment of carcinomatosis from colorectal cancer) could therefore efficiently treat microscopic residual disease. The aim of this randomized phase II study is to assess 2-year overall survival after complete resection of limited carcinomatosis synchronous with gastric carcinoma, followed by an intraperitoneal infusion of catumaxomab with different total doses administered in each of the 2 arms. Close monitoring of peri-opertive mortality, morbidity and early surgical re-intervention will be done with stopping rules. Besides this analysis, translational research will be conducted to determine immunological markers of catumaxomab efficacy and to correlate these markers with clinical efficacy.

Rectal surgery via a single-port access is complex with unknown benefits. This study aimed to compare the short-term outcome between single-port and multiport procedures. We undertook a retrospective analysis of prospectively collected data in a large, tertiary care cancer center in France. From November 2008 to June 2012, 45 patients underwent a sphincter-saving rectal resection through a single-port (n = 13) or a multiport (n = 32) approach. The single-port approach used an abdominal single port (n = 6) alone or a combined abdominal and transanal single port (n = 7). This study analyzed the morbidity, mortality, pain, and quality of the oncologic resection. The groups had a similar median operative time (290 vs 280 minutes, p = 0.54) and conversion rates (8% vs 6%, p = 0.90). No mortality occurred, and there was no difference in major morbidity (23% vs 16%, p = 0.50), anastomotic leakage (8% vs 9%, p = 1), or the length of the hospital stay (12 vs 14 days, p = 0.23). The median pain score was lower on postoperative day 2 in the single-port group (1.5 vs 4, p = 0.01). The 2 groups had similar quality criteria for oncologic resection, namely the median number of harvested lymph nodes (14 vs 15, p = 0.63), a good mesorectal dissection rate (85% vs 75%, p = 0.56), and positive resection margins (0% vs 6%, p = 0.10). This study's limitations include the retrospective nature of the data and the small number of patients. Rectal cancer surgery through a single-port access is feasible with similar outcomes and less postoperative pain than with multiport laparoscopy.

Objective: This study aimed to assess the prognostic impact of liver metastases (LM) in patients with colorectal peritoneal carcinomatosis (PC) who underwent complete cytoreductive surgery and resection of LM, followed by intraperitoneal chemotherapy. Background: Synchronous surgical treatment of PC and LM with curative intent remains controversial. Methods: From a prospective database, all patients with PC and synchronous LM who had undergone cytoreductive surgery and LM resection followed by intraperitoneal chemotherapy were matched with patients with PC alone according to the following criteria: age, peritoneal cancer index (PCI), site and lymph node involvement (pN) of primary cancer, and postoperative chemotherapy. Results: From 1993 to 2009, 37 patients with PC and LM were matched with 61 patients with PC alone. After a mean follow-up of 36 months, 3-year overall survival (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). A PCI of 12 or more [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 for poor OS. Three groups were singled out: (1) patients with a low PCI (<12) and no LM (median OS: 76 months); (2) patients with a low PCI (<12) and 1 or 2 LM (median OS: 40 months); and (3) patients with a high PCI (≥12) or patients with 3 LMs or more (median OS: 27 months). Conclusions: This case-control study seems to confirm that prolonged survival can be achieved in highly selected patients operated on for limited PC and fewer than 3 LM.

Although a randomized trial demonstrated a survival benefit of cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) over systemic chemotherapy alone, the treatment of peritoneal carcinomatosis from colorectal cancer (CRPC) is still a matter of debate. The aims of this study were to evaluate long-term outcome after CRS and IPC and to identify the prognostic factors associated with a cure. Patients were considered cured if the disease-free survival interval lasted at least 5 years after the treatment of CRPC or its last recurrence. Patients who had died postoperatively, or from non-cancer-related deaths, or patients with a follow-up of less than 5 years since the last curative treatment were excluded from the analysis. From 1995 to 2006, 107 patients (median age, 48 years; range, 19-67 years) underwent complete CRS, followed by IPC. Postoperative complications occurred in 50 patients (53%), including 4 postoperative deaths. After a median follow-up of 77 months (range, 60-144 months), 5-year and 10-year overall survival rates were 35% and 15%, respectively. Seventeen patients (16%) were considered cured after a disease-free interval of at least 5 years, of whom 14 never developed a recurrence. Cured patients had a significantly lower median peritoneal cancer index than noncured patients, respectively 4 (3-16) and 12 (2-36) (P = 0.0002). In multivariate analysis, a peritoneal cancer index of 10 or less was the only independent factor predicting cure. The cure rate (16%) after complete CRS of colorectal peritoneal carcinomatosis, followed by IPC, in selected patients is close to that obtained after resection of colorectal liver metastases.