Role of lymph node yield and lymph node ratio in predicting outcomes in non-metastatic colorectal cancer

Abstract

BackgroundLymph node yield (LNY) of 12 or more in resection of colorectal cancer is recommended in current international guidelines. Although a low LNY (less than 12) is associated with poorer outcome in some studies, its prognostic value is unclear in patients with early‐stage colorectal or rectal cancer with a complete pathological response following neoadjuvant therapy. Lymph node ratio (LNR), which reflects the proportion of positive to total nodes obtained, may be more accurate in predicting outcome in stage III colorectal cancer. This study aimed to identify factors correlating with LNY and evaluate the prognostic role of LNY and LNR in colorectal cancer.MethodsAn observational study was performed on patients with colorectal cancer treated at three hospitals in Melbourne, Australia, from January 2010 to March 2016. Association of LNY and LNR with clinical variables was analysed using linear regression. Disease‐free (DFS) and overall (OS) survival were investigated with Cox regression and Kaplan–Meier survival analyses.ResultsSome 1585 resections were analysed. Median follow‐up was 27·1 (range 0·1–71) months. Median LNY was 16 (range 0–86), and was lower for rectal cancers, decreased with increasing age, and increased with increasing stage. High LNY (12 or more) was associated with better DFS in colorectal cancer. Subgroup analysis indicated that low LNY was associated with poorer DFS and OS in stage III colonic cancer, but had no effect on DFS and OS in rectal cancer (stages I–III). Higher LNR was predictive of poorer DFS and OS.ConclusionLow LNY (less than 12) was predictive of poor DFS in stage III colonic cancer, but was not a factor for stage I or II colonic disease or any rectal cancer. LNR was a predictive factor in DFS and OS in stage III colonic cancer, but influenced DFS only in rectal cancer.

Log odds of positive lymph nodes is prognostically equivalent to lymph node ratio in non-metastatic colon cancer

“…It has been proposed that the lymph node count can be used as a measure of the quality of surgery [23], however adequate lymph node harvesting cannot be achieved in approximately half of patients [24]. In the present study, 19.5% of all colon cancer resections were below the current benchmark of a minimum harvest of 12 lymph nodes; this is comparable to contemporary data from specialist centres [8,25], but more favourable than that from other population-based studies [26,27]. This variation in nodal harvesting can be due to patient factors (older age), operative factors (left sided/rectal operations) or the quality of the histopathological examination [28].…”

“…Traditionally, clinicians have relied solely on nodal disease involvement (including the total number of positive lymph nodes) when determining patient prognosis in CRC [8]. Biologically aggressive tumours however, can initially be placed in the same stage as less clinically aggressive tumours, irrespective of nodal disease.…”

Immunohistochemical‑based molecular subtyping of colorectal carcinoma using maspin and markers of epithelial‑mesenchymal transition

“…According to previous studies (14,18,19) LNR and pN stage proved to be independent prognostic indicators of OS for metastatic and non-metastatic CRCs, using the cutoff value of Table III. Molecular classification of colorectal cancer specimens, according to subcellular localization and percentage of positive cells for epithelial-mesenchymal transition-associated markers.…”

4K ultra HD technology reduces operative time and intraoperative blood loss in colorectal laparoscopic surgery

“…Recognizing the vascular structures, their divisions and their course within the mesocolic fat tissue is of fundamental importance in oncological surgery 12 . Lymph node visualization along the course of the vessels and the ability to remove them without encountering troublesome bleeding allow a more precise dissection 13 .…”