Table 3. Subgroup multivariate analysis stratified by overall stage.
| Endpoints | Variable | HR (95%CI) | Pa |
|---|---|---|---|
| Stage III | |||
| OS b | Treatment group, CCRT plus IC/AC vs. CCRT alone | 0.835 (0.488-1.430) | 0.511 |
| Age, ≥ 49y vs. < 49y | 2.074 (1.183-3.637) | 0.011 | |
| DFFS c | Treatment group, CCRT plus IC/AC vs. CCRT alone | 0.712 (0.338-1.499) | 0.372 |
| LRFFS d | Treatment group, CCRT plus IC/AC vs. CCRT alone | 0.821 (0.367-1.835) | 0.630 |
| Stage IV | |||
| OS b | Treatment group, CCRT plus IC/AC vs. CCRT alone | 1.234 (0.795-1.929) | 0.344 |
| Age, ≥ 49y vs. < 49y | 1.861 (1.157-2.992) | 0.010 | |
| DFFS c | Treatment group, CCRT plus IC/AC vs. CCRT alone | 0.761 (0.452-1.284) | 0.307 |
| LRFFS d | Treatment group, CCRT plus IC/AC vs. CCRT alone | 0.822 (0.388-1.743) | 0.609 |
OS = overall survival; DFFS = distant failure-free survival; LRFFS = locoregional failure-free survival; HR = hazard ratio; CI = confidence interval; CCRT = concurrent chemoradiotherapy; IC = induction chemotherapy; AC = adjuvant chemotherapy.
a Multivariate P-values were calculated using an adjusted Cox proportional-hazards model with backward elimination and the following parameters: age (≥ 49y vs. < 49y), gender (male vs. female), smoking (yes vs. no), drinking (yes vs. no), KPS (≥ 90 vs. ≤ 80), N category (N1 vs. N0), concurrent chemotherapy regimen (TP vs. PF) and treatment group (CCRT plus IC/AC vs. CCRT).
b Thirty-one in the CCRT and 24 patients in CCRT plus IC/AC with stage III (P = 0.292), and 38 in CCRT and 41 in CCRT plus IC/AC with stage IV (P = 0.695) were dead.
c Seventeen in the CCRT and 12 patients in CCRT plus IC/AC with stage III (P = 0.327), and 33 in CCRT and 25 in CCRT plus IC/AC with stage IV (P = 0.243) experienced distant metastasis.
d Thirteen in the CCRT and 11 patients in CCRT plus IC/AC with stage III (P = 0.669), and 16 in CCRT and 12 in CCRT plus IC/AC with stage IV (P = 0.428) developed locoregional recurrence.