Comparison of the mean value of clinicopathological parameters of tumour between young and old patients
| Parameters | Mean±SD or number | P-value | ||
| Young patients (<50 years) | Old patients (≥50 years) | All patients | ||
| CRC (cases per year) | 54.91±9.07 | 89.09±10.94 | 144.00±18.61 | |
| Colon cancer (cases per year) | 17.00±6.93 | 34.45±6.98 | 51.45±13.05 | |
| Rectal cancer (cases per year) | 37.91±5.20 | 54.64±8.62 | 92.55±12.40 | |
| RSCRC (cases per year) | 8.73±4.10 | 16.82±4.67 | 25.55±7.15 | |
| LSCRC (cases per year) | 46.18±7.04 | 72.27±9.33 | 118.45±14.69 | |
| Age (years old)* | 38.82±7.46 | 62.01±8.65 | 53.17±13.94 | <0.001 |
| Tumour size (cm)† | 5.92±3.12 | 5.99±2.98 | 5.97±3.02 | 0.818 |
| Smallest tumour size (cm)† | 1.3 | 1.0 | 1.0 | |
| Largest tumour size (cm)† | 17.0 | 18.0 | 18 | |
| Total count of positive LNs† | 265 | 402 | 667 | |
| Total count of dissected LNs† | 1587 | 2726 | 4313 | |
| Positive LNs† | 1.84±3.37 | 1.39±2.34 | 1.54±2.73 | 0.107 |
| Dissected LNs† | 11.02±6.10 | 9.43±5.04 | 9.96±5.46 | 0.004 |
| LNR† | 0.18±0.29 | 0.18±0.30 | 0.18±0.29 | 0.964 |
All data were normally distributed and thus statistical tests were done using the independent and two-tailed student t-tests with equal variances were assumed (In Levene's test, the homogeneity assumption of the variance was met). The value with bold printed indicates the significant p-value.
*Assessed among 1584 patients.
†Assessed among 433 patients.
CRC, colorectal cancer; LNR, lymph node ratio; LNs, lymph nodes; LSCRC, left-sided colorectal cancer; RSCRC, right-sided colorectal cancer.