561POncological outcome and safety of bevacizumab (BV) therapy in patients with occlusive colon cancer and self-expandable metal stents (SEMS)

• Published in: Annals of oncology Vol. 30; no. Supplement_5
• Main Authors: Pacheco-Barcia, V E, Mondejar, R, Martinez-Saez, O, Munoz, F Longo, Monteagudo, J A Moreno, Rogado, J, Donnay, O, Santander, C, Mena, A Carrato, Bosch, R Colomer
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01-10-2019
• ISSN: 0923-7534; 1569-8041
• DOI: 10.1093/annonc/mdz246.038

Abstract
Background
Malignant bowel obstruction can occur in 18% of cases. SEMS can be an alternative to surgery. BV has been associated with bowel perforation but data on the safety of SEMS for occlusive colon cancer during BV-containing regimens are lacking.
Methods
Retrospective analysis of 136 patients with malignant bowel obstruction who underwent placement of SEMS between 2012 and 2017 in two hospitals. Chemotherapy and BV-containing regimens, stent-related complications and outcomes were recorded.
Results
58 (42.6%) SEMS were placed as a bridge to surgery and 78 (57.4%) as a palliative intent for stage IV disease. 129 patients (94.9%) had a left-sided obstruction. Technical success was achieved in 133 of 136 (98%). Overall, major stent-related complications after two-weeks of insertion were observed in 36 patients (26.5%): Re-obstruction in 18 patients (50%), 11 perforations (30.5%), 5 bleeding (14%) and 2 migrations (5.5%). Complications in the metastatic group (n = 78) 14 (18%) had re-obstructions, 7 (9%) perforations, 4 (5%) minor bleeding and 2 (2.5%) migrations. Multivariate analysis identified stage IV and chemotherapy as significant risk factors for stent-related complications. Patients who received systemic therapy are more likely to develop complications (OR 1.84; CI95% 1.29-6.22, p = 0.0007). 16 patients received BV, 2 (12.5%) had a perforation. Univariate analysis did not show that BV was more likely to develop perforations, although the incidence was higher in this subset of patients. No differences were observed between chemotherapy alone and BV in overall complications. Kaplan-Meier analysis showed significant longer OS for patients treated with systemic therapy (27 vs. 11 months, p = <0.00001). There is a significant benefit of BV compared to chemotherapy alone (43 vs. 39 months, p = 0.02).
Conclusions
Placement of SEMS is effective and relatively safe but, with an overall complication rate of 26%. The major early risk is perforation that can increase up to 12% during BV treatment. In patients with obstructing advanced colorectal cancer that would benefit from SEMS, we should consider the risks associated with systemic therapies, taking into account the improvement in survival with BV.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.