Risk factors for postoperative pneumonia in elderly patients with colorectal cancer: a sub-analysis of a large, multicenter, case-control study in Japan

Purpose Postoperative pneumonia affects the length of stay and mortality after surgery in elderly patients with colorectal cancer (CRC). We aimed to determine the risk factors of postoperative pneumonia in elderly patients with CRC, and to evaluate the impact of laparoscopic surgery on elderly patients with CRC. Methods We retrospectively investigated 1473 patients ≥ 80 years of age who underwent surgery for stage 0–III CRC between 2003 and 2007. Using a multivariate analysis, we determined the risk factors for pneumonia occurrence from each baseline characteristic. Results Among all included patients, 26 (1.8%) experienced postoperative pneumonia, and restrictive respiratory impairment, obstructive respiratory impairment, history of cerebrovascular events, and open surgery were determined as risk factors (odds ratio [95% confidence interval], 2.78 [1.22–6.20], 2.71 [1.22–6.30], 3.60 [1.37–8.55], and 3.57 [1.22–15.2], respectively). Furthermore, postoperative pneumonia was more frequently accompanied by increasing cumulative numbers of these risk factors (area under the receiver operating characteristic curve = 0.763). Conclusions Laparoscopic surgery may be safely performed in elderly CRC patients, even those with respiratory impairment and a history of cerebrovascular events.