Impact of neoadjuvant immunotherapy on postoperative complications after surgery for rectal cancer

Despite the increasing use of immunotherapy in treating various cancer types, there is still limited understanding of its impact on surgical complications. We used a national database to examine the difference in surgical outcomes for rectal cancer patients who received standard neoadjuvant chemoradiation plus neoadjuvant immunotherapy and patients who received neoadjuvant chemoradiation only. This retrospective cohort study used the National Cancer Database (NCDB). We selected patients aged 18-90 with T1-3, N1-2, and M0 rectal cancer who underwent curative-intent surgery between 2010 and 2020. We performed a 1:1 propensity match to control for patient age, sex, Charlson-Deyo comorbidity index, surgical approach, and tumor site. Our primary outcome was difference in surgical outcomes (hospital length of stay, unplanned 30-day readmission, 30-day mortality) between the two groups. Secondary outcomes included days from diagnosis to surgery and pathologic outcomes. Our study included 26 229 patients, of which 126 received immunotherapy in addition to chemoradiation and 26 103 received only chemoradiation. In our matched population of 125 pairs of patients, patients who received immunotherapy and chemoradiation underwent surgery later compared to patients who only received chemoradiation (median 245 vs. 144 days, p