Publication:

Comparing outcomes of open versus minimally invasive total mesorectal excision after total neoadjuvant therapy in rectal cancer: a national cancer database analysis

Background Total neoadjuvant therapy (TNT), in which systemic chemotherapy and pelvic radiation are delivered before surgery, improves pathological complete response, disease-free survival and treatment compliance in locally advanced rectal cancer. Large-scale data comparing open and minimally invasive surgery (MIS) approaches to total mesorectal excision (TME) specifically after TNT are lacking.

Methods The national cancer database was queried (2010–2020) for adults with clinical stage II–III rectal adenocarcinoma who received chemoradiotherapy and at least two chemotherapeutic agents before TME. Stage I or IV disease, primary resection without neoadjuvant therapy and MIS converted to open were excluded. Univariate analysis and multivariable logistic regression were performed. The primary outcome was inadequate lymph node retrieval (<12 nodes); the secondary outcome was 90-day postoperative mortality.

Results A total of 5,962 patients were included; 3,111 (52.2%) underwent MIS and 2,851 (47.8%) underwent open TME. Inadequate lymph node retrieval was less frequent with MIS (27.1%) than open surgery (33.2%) (OR 0.80; 95% CI 0.71–0.90; p<0.001). 90-day mortality was lower with MIS (0.8%) than open surgery (2.2%) (OR 2.46 for open; 95% CI 1.51–4.03; p<0.001).

Conclusions After TNT for rectal cancer, an MIS approach to TME was associated with a higher likelihood of adequate lymph node harvest and lower 90-day mortality than open surgery. These differences may reflect improved pelvic exposure, although selection bias toward more advanced tumors in the open cohort cannot be excluded. Prospective studies are warranted.