Factors affecting the number of lymph nodes retrieved after colo-rectal cancer surgery: A prospective single-centre study

Background: The number of harvested lymph nodes (LNs) in colorectal cancer surgery relates to oncologic radicality and accuracy of staging. In addition, it affects the choice of adjuvant therapy, as well as prognosis. The American Joint Committee on Cancer defines at least 12 LNs harvested as adequate in colorectal cancer resections. Despite the importance of the topic, even in high-volume colorectal centres the rate of adequacy never reaches 100%. The aim of this study was to identify factors that affect the number of harvested LNs in oncologic colorectal surgery. Materials and methods: We prospectively collected all consecutive patients who underwent colorectal cancer resection from January 1st 2013 to December 31st 2017 at Emergency Surgery Unit St Orsola University Hospital of Bologna. Results: Six hundred and forty-three consecutive patients (382 elective, 261 emergency) met the study inclusion criteria. Emergency surgery and laparoscopic approach did not have a significant influence on the number of harvested LNs. The adequacy of lymphadenectomy was negatively affected by age >80 (OR 3.47, p < 0.001), ASA score ≥3 (OR 3.48, p < 0.001), Hartmann's or rectal resection (OR 3.6, p < 0.001) and R1–R2 resection margins (OR 3.9, p = 0.006), while it was positively affected by T-status ≥3 (OR 0.33 p < 0.001). Conclusion: Both the surgical technique and procedure regimen did not affect the number of lymphnodes retrieved. Age >80 and ASA score ≥3 and Hartmann's procedure or rectal resection showed to be risk factors related to inadequate lymphadenectomy in colorectal cancer surgery.