Influence of K-ras status and anti-tumour treatments on complications due to colorectal self-expandable metallic stents: A retrospective multicentre study

Background This study aimed to explore the relationship between K-ras status, anti-tumour treatments, and the complications of colorectal self-expandable metallic stenting in colorectal cancer. Methods This is a retrospective, multicentre study of 91 patients with obstructive advanced colorectal cancer palliated with enteral stents between 2007 and 2011. Results K-ras wild-type tumours were diagnosed in 44 patients (48.4%); 82 (90.1%) received chemotherapy and 45 (49.4%) had additional biological therapy (34 bevacizumab, 11 cetuximab). Twenty-one (23.1%) experienced stent-related complications: 11 (52.4%) occurred in the K-ras mutant group (P = 0.9). K-ras wild-type patients were not less likely to develop adverse events than K-ras mutant patients (OR, 0.99; 95% CI: 0.4–2.7). Overall mean time to complication was 167.6 days (range 4–720 days), with no difference between the two groups (141 vs. 197 days; P = 0.5). Chemotherapy did not influence the risk of complications (OR, 0.56; 95% CI: 0.14–2.9), and there was no evidence that patients treated with chemotherapy and cetuximab were more likely to experience stent-related complications than patients treated with chemotherapy alone, or untreated (OR, 1.2; 95% CI: 0.2–5.9). Although perforation rates were higher with bevacizumab-based treatment (11.8% vs. 7%), this result was not statistically significant (P = 0.69). Conclusions K-ras mutation status, chemotherapy, and biological treatments should not influence colorectal stent-related complication rates.