Preoperative chemotherapy for colon cancer and short-term outcomes – a nationwide cohort study

Abstract Introduction High-risk colon cancer might benefit from preoperative chemotherapy (preCHT); however, data on its impact on short-term outcomes is limited. Method Patients with resected stage I-III colon cancer were identified from the Swedish Colorectal Cancer Registry from 2007 through 2017. Patients who received preCHT, regardless of intention, were compared with those undergoing upfront surgery. Primary outcomes included 30- and 90-day mortality and 30-day postoperative morbidity, defined as all medical and surgical complications classified as Clavien-Dindo grade 3 or higher (CD≥3). Result Among 24,910 eligible patients, 327 (1.3%) received preCHT. Postoperative mortality rates at 30- and 90-days days were comparable (1.5% vs. 1.6%, p = 1.00 and 2.8% vs. 2.6%, p = 0.86, respectively). However, overall postoperative morbidity (CD≥3) was higher in the preCHT group (33.9% vs 24.6%, p<0.001), despite similar rates of surgical complications, including anastomotic leakage (3.1% vs 3.5%, p = 0.37). The preCHT group was more likely to undergo multivisceral resections (50.8% vs. 12.1%, p<0.001), with a higher rate of R1 resections (6.4% vs 3.2%, p<0.001), reflecting more advanced disease (cT4: 57.2% vs. 8.8%; cN1-2: 52.3% vs. 25.1%) than in the upfront surgery group. Discussion PreCHT was safe in selected patients with high-risk, early-stage colon cancer, with no increase in postoperative mortality or major surgical complications. Despite greater morbidity and surgical extent and higher rate of R1 resections, preCHT appears to be a feasible treatment option in early-stage, locally advanced disease.