Table 4.
Cox Regression Analysis of Risk of ≥Grade 2 RP
| Univariate Analysis | Multivariate Analysis | ||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| |||||||||
| Total Patients (n=136) |
Number of Patients with ≥Grade 2 RP (n=40) |
Percent of Patients with ≥ Grade 2 RP |
HR | 95% CI | p-value | AHR | 95% CI | p-value | |
|
| |||||||||
| Patient Characteristics | |||||||||
|
| |||||||||
| Male | 67 | 26 | 38.8% | 2.22 | 1.16-4.26 | 0.017 | 2.69 | 1.32-5.49 | 0.006 |
| Female | 69 | 14 | 20.3% | 1.0* | - | - | 1.0* | - | - |
|
| |||||||||
| ECOG PS | |||||||||
| 0 | 62 | 17 | 27.4% | 1.0* | - | - | 1.0* | - | - |
| 1 | 67 | 18 | 26.9% | 1.01 | 0.52-1.96 | 0.98 | 1.03 | 0.51-2.08 | 0.92 |
| 2 | 7 | 5 | 71.4% | 3.63 | 1.34-9.87 | 0.01 | 2.85 | 0.90-9.00 | 0.075 |
|
| |||||||||
| Treatment Characteristics | |||||||||
|
| |||||||||
| Surgery | 30 | 3 | 10.0% | 0.23 | 0.07-0.74 | 0.014 | 0.24 | 0.06-0.91 | 0.036 |
|
| |||||||||
| Concurrent Chemotherapy | 121 | 39 | 32.2% | 5.27 | 0.72-38.35 | 0.10 | 1.27 | 1.01-1.59 | 0.04 |
|
| |||||||||
| Consolidation Docetaxel | 16 | 8 | 50.0% | 2.11 | 0.97-4.58 | 0.06 | 4.42 | 1.79-10.92 | 0.001 |
|
| |||||||||
|
Bilateral Lung Dose
Volume Histogram |
|||||||||
|
| |||||||||
| V5<60% | 62 | 13 | 21.0% | 1.0* | - | - | 1.0* | - | - |
| V5≥60% | 74 | 27 | 36.4% | 1.90 | 0.98-3.69 | 0.057 | 1.16 | 0.44-3.10 | 0.76 |
|
| |||||||||
| V20<30% | 52 | 9 | 17.3% | 0.45 | 0.20-1.04 | 0.061 | 0.77 | 0.23-2.54 | 0.66 |
| V20≥30% and < 40 | 43 | 15 | 34.9% | 1.0* | - | - | 1.0* | - | - |
| V20≥40% | 41 | 16 | 39.0% | 1.15 | 0.57-2.33 | 0.70 | 1.08 | 0.50-2.34 | 0.84 |
|
| |||||||||
| MLD<18 Gy | 66 | 14 | 21.2% | 1.0* | - | - | 1.0* | - | - |
| MLD≥18 Gy | 70 | 26 | 37.1% | 1.95 | 1.02-3.74 | 0.044 | 1.19 | 0.42-3.32 | 0.75 |
|
| |||||||||
| SNP † | |||||||||
|
| |||||||||
| MTHFR (rs1801131)□ | |||||||||
| AA | 61 | 23 | 37.7% | 1.0* | - | - | 1.0* | - | - |
| AC | 60 | 12 | 20.0% | 0.47 | 0.24-0.95 | 0.36 | 0.30 | 0.14-0.67 | 00.003 |
| CC | 13 | 4 | 30.8% | 0.68 | 0.24-1.98 | 0.48 | 0.70 | 0.24-2.07 | 0.52 |
| AC/CC | 73 | 16 | 21.9% | 0.51 | 0.27-0.97 | 0.041 | 0.37 | 0.18-0.76 | 0.006 |
|
| |||||||||
| MTHFR (rs1801133)□ | |||||||||
| CC | 51 | 11 | 21.6% | 1.0* | - | - | 1.0* | - | - |
| CT | 59 | 19 | 32.2% | 1.56 | 0.74-3.28 | 0.24 | 1.24 | 0.57-2.73 | 0.59 |
| TT | 24 | 9 | 37.5% | 2.05 | 0.85-4.94 | 0.11 | 2.29 | 0.91-5.76 | 0.078 |
| CT/TT | 83 | 28 | 33.7% | 1.69 | 0.84-3.39 | 0.14 | 1.48 | 0.71-3.08 | 0.29 |
|
| |||||||||
| SOD2 (rs4880) | |||||||||
| TT | 32 | 11 | 10.5% | 1.0* | - | - | 1.0* | - | - |
| CT | 76 | 25 | 32.9% | 0.93 | 0.46-1.88 | 0.83 | 1.24 | 0.60-2.59 | 0.56 |
| CC | 28 | 4 | 14.3% | 0.40 | 0.13-1.24 | 0.12 | 0.57 | 0.17-1.85 | 0.35 |
| CT/CC | 104 | 29 | 27.9% | 0.78 | 0.39-1.57 | 0.49 | 0.84 | 0.52-2.21 | 0.85 |
*
Reference group for Cox regression
†
Each SNP was independently entered into a multivariate model that adjusted for gender, ECOG PS, use of surgery, use of concurrent chemotherapy, use of consolidation docetaxel, MLD, V5 and V20.
□
Data available on 134 patients
Abbreviations: AHR=adjusted hazard ratio; CI=confidence interval; HR=hazard ratio; MLD=mean lung dose; PS=performance status; RT=radiation therapy; V5=volume receiving greater than 5 Gy; V20=volume receiving greater than 20 Gy; RP=radiation pneumonitis.