Suggested minimum numbers of lymph nodes to be assessed for a reliable identification of a negative nodal status
| Suggested cut off number | Ref | Number of patients | Proportion with positive LNs | Mean number of nodes (range) | Method | Source of data |
|---|---|---|---|---|---|---|
| C, consensus; CRC, colorectal carcinoma; LN, lymph node; MI, multiinstitutional; RB, register based; SI, single institutional (Cserni et al).51 | ||||||
| 6 | 45 | 193 | 39% | 11 (1–36) | Probability of finding at least 1 positive node, calculated on the basis of binomial distribution | RB |
| 7 | 46 | 356 | 41% | 9.8 (0–66) | Comparison of Kaplan-Meier survival curves for patients with a given number of nodes assessed and patients with more lymph nodes assessed | SI |
| 7 | 47 | 108 | Not relevant (100%) | 8.4 (not indicated) | Evaluation of the number of tissue blocks (slides) required for identification of the first nodal metastasis in node positive CRCs, and comparison with the mean number of nodes embedded in a single block (cassette) | SI |
| 7 | 48 | 123 | 60 (49%) | 12.4 (2–43) | Comparison of the stage established on the basis of the 7 largest nodes and that based on all nodes | SI |
| 8 | 29 | 851 | 32% | 7.7 (not indicated) | Correlation between the number of examined nodes and the stages assessed by logistic regression analysis | RB |
| 9 | 49 | 140 | Not relevant (0%) | Median, 12 (3–38) | Survival analysis of Dukes’s B carcinomas in correlation with the number of LNs recovered, comparison with Dukes’s C carcinomas | SI |
| 12 | 20 | Not relevant | Not relevant | Not relevant | Consensus | C |
| 13 | 31 | 103 | 49% | 18.5 (2–69) | Analysis of cumulative percentage of node positive cases as a function of the number of LNs examined | SI |
| 14 | 30 | 196 | 39% | 17 (0–78) | Search for the number of LNs to achieve a node positive rate consistent with the National Cancer Data Base report by using the binomial test | SI |
| 14 | 50 | 1664 | 68% | 10.9 (0 to >15) | Kaplan-Meier estimates of survival curves by quartiles of the distribution of the number of nodes examined | MI |
| 16 | 38 | 224 | 55% | 8.9 (0–34) | Analysis of cumulative percentage of node positive cases as a function of the number of nodes examined | SI |
| 17 | 39 | 750 | 23–70% | 9.8 (0–62) | Analysis of cumulative percentage of node positive cases as a function of the number of nodes examined | SI |