Table 3.
Analysis of single-institution patients in subgroups of examined lymph nodes
| ≤9 LN lymph nodes | 10–16 lymph nodes | ≥17 lymph nodes | p value | |
|---|---|---|---|---|
| n | 301 | 301 | 300 | |
| Primary site | ||||
| Head | 72.9 % | 85.5 % | 82.8 % | <0.01 |
| Body/tail | 27.1 % | 14.5 % | 17.2 % | |
| Mean tumor size (±SD) | 38.2 (±28.5) | 34.6 (±18.7) | 33.6 (±19) | 0.456 |
| AJCC T stage | ||||
| Tis | 0 % | 0.3 % | 0 % | <0.001 |
| T1 | 12.6 % | 8.4 % | 7.1 % | |
| T2 | 40.0 % | 24.6 % | 15.2 % | |
| T3 | 43.9 % | 63.6 % | 74.4 % | |
| T4 | 3.5 % | 3.0 % | 3.3 % | |
| AJCC N stage | ||||
| N0 | 45.6 % | 39.6 % | 27.5 % | <0.01 |
| N1 | 54.4 % | 60.4 % | 72.5 % | |
| Regional nodes examined (±SD) | 5.74 (±2.3) | 13.3 (±2.2) | 23.2 (±4.6) | <0.01 |
| Regional nodes positive (±SD) | 1.1 (±1.4) | 1.8 (±2.2) | 3 (±3.1) | <0.01 |
| Mean lymph node ratio (±SD) | 0.22 (±0.37)a | 0.14 (±0.17)b | 0.13 (±0.14)c | pab, ac<0.01, pbc=0.897 |
| Lymph node ratio | ||||
| No positive nodes | 45.6 % | 39.6 % | 27.5 % | <0.01 |
| <0.2 | 15.6 % | 32.5 % | 45.9 % | |
| 0.2–0.3 | 7.8 % | 12.8 % | 14.0 % | |
| ≥0.3 | 30.9 % | 15.1 % | 12.7 % | |
pab is the p value for the difference between a and b. Similarly for pac and pbc