| Variable | Hazard ratio (95% CI) | p Value |
| Age at recurrence (years) | 1.007 (0.984 to 1.031) | 0.531 |
| Gender (male vs female) | 1.519 (0.724 to 3.184) | 0.269 |
| Smoking index (pack-years) | 1.001 (0.991 to 1.010) | 0.971 |
| Location (right vs left lung) | 0.697 (0.419 to 1.159) | 0.697 |
| Tumour size (cm)* | 1.132 (1.010 to 1.267) | 0.033 |
| Histological type (squamous cell carcinoma vs others) | 0.840 (0.522 to 1.351) | 0.471 |
| Extent of pulmonary resection (sublobar resection vs lobectomy or bilobectomy or pneumonectomy) | 1.644 (0.813 to 3.326) | 0.167 |
| T status (T2 vs T1) | 1.220 (0.746 to 1.998) | 0.428 |
| Visceral pleural invasion (present vs absent) | 0.932 (0.524 to 1.657) | 0.811 |
| No of LNs dissected (>15 vs ⩽15) | 1.101 (0.644 to 1.884) | 0.725 |
| Disease free interval (months) (>18 vs ⩽18) | 0.921 (0.573 to 1.482) | 0.736 |
| Mediastinal recurrence (present vs absent) | 1.031 (0.969 to 1.097) | 0.335 |
| Treatment for initial recurrence | <0.001 | |
| None | 1 | |
| With surgery | 0.118 (0.035 to 0.400) | |
| C/T and/or R/T | 0.319 (0.134 to 0.763) |
*The hazard ratio associated with tumour size is that the increase in hazard is associated with a 1 cm increase in tumour size.
C/T, chemotherapy; LN, lymph node; R/T, radiotherapy.