An appraisal of lymph node ratio in colon and rectal cancer: not one size fits all

Abstract

Application of a data-driven approach based on recursive partitioning generates differing lymph node ratios for colon, rectal and combined colorectal cohorts. In each cohort, LNR was similarly prognostic to standard nodal staging in respect to overall and disease-free survival. Overall survival was associated with a multiplicity of LNR values, whilst disease-free survival was associated with a single LNR only. The paper demonstrates the merits of utilising a data-driven approach to determining lymph node ratios from specific patient cohorts. Utilising such an approach enabled the generation of those LNRs that were most associated with particular survival trends in relation to overall and disease-free survival. These differed markedly for colon cancer, rectal cancer and combined cohorts. In general, the survival patterns associated with LNRs generated were similar to those observed with standard nodal staging.

Lymph node ratio is an independent prognostic factor for rectal cancer after neoadjuvant therapy: A meta‐analysis

“…So far, LNR cut‐off values vary in studies due to different statistical methodologies used to generate the ratio. Other than the robust mechanism for generating LNR reported by Medani et al, studies in our current meta‐analysis reported mainly median values or receiver operating characteristic (ROC)‐based values as the best cut‐off values (three studies used median LNRs as the cut‐off, another three adopted ROC curve analysis‐based LNR cut‐offs, one study used interquartile range, one study used a novel method with Maxstat, one study chose the best cut‐off based on other standards, and one study recommended 0.25 as the cut‐off value for the reason that 0.25 represents the number of metastatic LN of pN1 category based on 12 LNs harvested). Additionally, the remaining three studies generated the cut‐offs arbitrarily without declaring any data‐driven approaches.…”

The lymph node ratio does not provide additional prognostic information compared with the N1/N2 classification in Stage III colon cancer

“…Medani et al . have previously suggested that a data‐driven approach is needed to determine the cut‐off point for the LNR. By setting the specificity, the present study addressed this by using comparison with current nodal staging to guide determination of the cut‐off point.…”

“…Therefore, while the LNR is predictive of overall survival it does not offer a clinically significant advantage over the current N1/N2 classification. Medani et al [25] have previously suggested that a data-driven approach is needed to determine the cut-off Survival time (months) Figure 1 Kaplan-Meier curves demonstrating that the N1/N2 and LNR1/LNR2 classifications are both predictive of overall survival (P < 0.001 log-rank test). The numbers entering each time interval are given in the tables beneath the Kaplan-Meier curves.…”

Serosal surfaces, mucin pools, and deposits, Oh my: challenges in staging colorectal carcinoma

“…Several recent papers have suggested the usefulness of the lymph node ratio rather than the total number of involved lymph nodes. [47][48][49][50] This is not currently recommended but is an issue that may be considered for staging in the future.…”