A comparison of lymph node yield in left colectomy specimens, with and without neoadjuvant therapy: an audit in a tertiary care centre

Introduction and objectives: The lymph node (LN) count and node positivity are important prognostic indicators in primary colorectal adenocarcinomas. The LN count shows significant variations with adjuvant therapy (AT). This study compares the LN status of AT-given (AT-G) and AT-not-given (AT-NG) left colectomy specimens.
Methodology: This retrospective study included all left colectomy specimens reported at the Department of Pathology, University of Peradeniya, for one year from October 2021. Clinicopathological data were extracted from the archives. The data were analyzed with demographic factors and neoadjuvant status.
Results: There were twenty-five (25) left colectomy specimens; 48% (n=12) were AT-G and 52% (n=13) were AT-NG. The male-to-female ratio was 2.3:1 (n=9:4) and 1:1 (n=5:5) in the AT-G and AT-NG groups, respectively. Patients’ age range was 42-83 years, and the majority were between 60-69 years in both groups. The AT-G group had >12 LNs in 46% (n=6) of cases and a mean LN count of 12. The AT-NG group had >12 LNs in 83% (n=10) of specimens, and a mean LN count of 19. LN positivity was 0% in 84% of the AT-G category and 53% in the AT-NG category.
Discussion and conclusion: The total cases were relatively similar in both groups, but more men received AT than women. The mean LN count and the LN positivity in the AT-G group were lower than that of the AT-NG group. The majority of the cases in the AT-G group were classified under the ypN0 category.