Background
Methods
Patient population
Statistical analysis
Results
Cohort iC + CRT
Cohort iC + CRT | Cohort CRT | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
45–55 Gy | 55+ Gy | 45–55 Gy | 55+ Gy | |||||||
N | % | N | % | P | N | % | N | % | P | |
Facility | 0.39 | 0.0031 | ||||||||
Nonacademic | 335 | 56 | 71 | 52 | 672 | 63 | 163 | 72 | ||
Academic | 259 | 43 | 65 | 47 | 390 | 37 | 58 | 26 | ||
NA | 7 | 1 | 1 | 1 | 4 | 0 | 4 | 2 | ||
Age | 1 | 0.0081 | ||||||||
< 65 | 303 | 50 | 69 | 50 | 474 | 44 | 122 | 54 | ||
≥ 65 | 298 | 50 | 68 | 50 | 592 | 56 | 103 | 46 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Gender | 0.047 | 1 | ||||||||
Female | 297 | 49 | 81 | 59 | 514 | 48 | 109 | 48 | ||
Male | 304 | 51 | 56 | 41 | 552 | 52 | 116 | 52 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Race | 0.88 | 0.18 | ||||||||
White | 493 | 82 | 115 | 84 | 869 | 82 | 190 | 84 | ||
Black | 81 | 13 | 17 | 12 | 168 | 16 | 27 | 12 | ||
Other | 19 | 3 | 3 | 2 | 20 | 2 | 7 | 3 | ||
NA | 8 | 1 | 2 | 1 | 9 | 1 | 1 | 0 | ||
Insurance | 0.31 | 0.095 | ||||||||
None | 12 | 2 | 2 | 1 | 28 | 3 | 7 | 3 | ||
Nonprivate | 320 | 53 | 63 | 46 | 633 | 59 | 117 | 52 | ||
Private | 265 | 44 | 70 | 51 | 391 | 37 | 99 | 44 | ||
NA | 4 | 1 | 2 | 1 | 14 | 1 | 2 | 1 | ||
Income | 1 | 0.45 | ||||||||
Above median | 389 | 65 | 90 | 66 | 546 | 51 | 118 | 52 | ||
Below median | 207 | 34 | 47 | 34 | 503 | 47 | 97 | 43 | ||
NA | 5 | 1 | 0 | 0 | 17 | 2 | 10 | 4 | ||
Residential setting | 0.33 | 0.077 | ||||||||
Metro | 488 | 81 | 114 | 83 | 807 | 76 | 151 | 67 | ||
Urban | 77 | 13 | 16 | 12 | 189 | 18 | 53 | 24 | ||
Rural | 10 | 2 | 5 | 4 | 34 | 3 | 7 | 3 | ||
NA | 26 | 4 | 2 | 1 | 36 | 3 | 14 | 6 | ||
Charlson-Deyo Score | 1 | 0.25 | ||||||||
0–1 | 575 | 96 | 131 | 96 | 1006 | 94 | 217 | 96 | ||
≥ 2 | 26 | 4 | 6 | 4 | 60 | 6 | 8 | 4 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Year of diagnosis | 0.016 | < 0.001 | ||||||||
2004–2007 | 52 | 9 | 7 | 5 | 317 | 30 | 92 | 41 | ||
2008–2011 | 245 | 41 | 74 | 54 | 529 | 50 | 105 | 47 | ||
2012–2015 | 304 | 51 | 56 | 41 | 220 | 21 | 28 | 12 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Primary tumor site | 0.068 | 0.014 | ||||||||
Head | 411 | 68 | 94 | 69 | 764 | 72 | 140 | 62 | ||
Body | 171 | 28 | 43 | 31 | 271 | 25 | 74 | 33 | ||
Tail | 19 | 3 | 0 | 0 | 31 | 3 | 11 | 5 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Tumor size (cm) | 0.70 | 0.018 | ||||||||
< 3.8 | 265 | 44 | 65 | 47 | 486 | 46 | 82 | 36 | ||
≥ 3.8 | 283 | 47 | 64 | 47 | 448 | 42 | 111 | 49 | ||
NA | 53 | 9 | 8 | 6 | 132 | 12 | 32 | 14 | ||
Clinical N stage | 0.44 | 0.70 | ||||||||
0 | 367 | 61 | 89 | 65 | 692 | 65 | 143 | 64 | ||
1 | 234 | 39 | 48 | 35 | 374 | 35 | 82 | 36 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Chemotherapy | 0.20 | 0.74 | ||||||||
Single agent | 166 | 28 | 30 | 22 | 789 | 74 | 164 | 73 | ||
Multi agent | 435 | 72 | 107 | 78 | 277 | 26 | 61 | 27 | ||
NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Total radiation dose (Gy) | < 0.001 | < 0.001 | ||||||||
Median | 50.4 | 59.4 | 50.4 | 59.4 | ||||||
IQR | 50.4–52.5 | 56.0–59.4 | 50.4–52.0 | 57.5–60.0 | ||||||
Fraction | < 0.001 | < 0.001 | ||||||||
Median | 28 | 30 | 28 | 32 | ||||||
IQR | 27–28 | 28–33 | 26–28 | 30–33 |
Variable | Cox UVA | Cox MVA | ||||
---|---|---|---|---|---|---|
HR | 95% CI | P | HR | 95% CI | P | |
Facility | ||||||
Nonacademic | 1 | Ref | 1 | Ref | ||
Academic | 0.76 | 0.65–0.89 | < 0.001 | 0.79 | 0.67–0.93 | 0.0045 |
Age | ||||||
< 65 | 1 | Ref | ||||
≥ 65 | 1.04 | 0.89–1.21 | 0.64 | |||
Gender | ||||||
Female | 1 | Ref | 1 | Ref | ||
Male | 1.19 | 1.02–1.39 | 0.031 | 1.09 | 0.93–1.29 | 0.29 |
Race | ||||||
White | 1 | Ref | ||||
Black | 0.86 | 0.68–1.10 | 0.23 | |||
Other | 0.86 | 0.54–1.36 | 0.52 | |||
Insurance | ||||||
None | 1 | Ref | ||||
Nonprivate | 1.07 | 0.57–2.02 | 0.82 | |||
Private | 1.07 | 0.57–2.01 | 0.83 | |||
Income | ||||||
Above median | 1 | Ref | ||||
Below median | 1.05 | 0.90–1.24 | 0.52 | |||
Residential setting | ||||||
Metro | 1 | Ref | ||||
Urban | 1.00 | 0.79–1.26 | 0.98 | |||
Rural | 1.35 | 0.80–2.25 | 0.26 | |||
Charlson-Deyo Score | ||||||
0–1 | 1 | Ref | ||||
≥ 2 | 1.08 | 0.75–1.57 | 0.67 | |||
Year of diagnosis | ||||||
2004–2007 | 1 | Ref | 1 | Ref | ||
2008–2011 | 0.95 | 0.71–1.28 | 0.75 | |||
2012–2015 | 0.67 | 0.50–0.89 | 0.0068 | 0.71 | 0.53–0.95 | 0.021 |
Primary tumor site | ||||||
Head | 1 | Ref | ||||
Body | 0.87 | 0.73–1.04 | 0.12 | |||
Tail | 1.25 | 0.78–2.01 | 0.35 | |||
Tumor size (cm) | ||||||
< 3.8 | 1 | Ref | 1 | Ref | ||
≥ 3.8 | 1.20 | 1.02–1.41 | 0.027 | 1.16 | 0.98–1.37 | 0.082 |
Clinical N stage | ||||||
0 | 1 | Ref | ||||
1 | 1.15 | 0.98–1.34 | 0.091 | |||
Chemotherapy | ||||||
Single agent | 1 | Ref | 1 | Ref | ||
Multi agent | 0.69 | 0.58–0.82 | < 0.001 | 0.77 | 0.64–0.92 | 0.0041 |
Dose escalation | ||||||
< 55 Gy | 1 | Ref | 1 | Ref | ||
≥ 55 Gy | 0.80 | 0.65–0.97 | 0.027 | 0.77 | 0.63–0.95 | 0.013 |
Cohort iC + CRT | Cohort CRT | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
45–55 Gy | 55+ Gy | 45–55 Gy | 55+ Gy | |||||||
N | % | N | % | P | N | % | N | % | P | |
Facility1 | 0.26 | |||||||||
Nonacademic | 129 | 50 | 65 | 50 | 273 | 75 | 128 | 70 | ||
Academic | 129 | 50 | 64 | 50 | 93 | 25 | 55 | 30 | ||
Age | 0.91 | 0.59 | ||||||||
< 65 | 128 | 50 | 65 | 50 | 196 | 54 | 93 | 51 | ||
≥ 65 | 130 | 50 | 64 | 50 | 170 | 46 | 90 | 49 | ||
Charlson-Deyo Score | 0.65 | 0.48 | ||||||||
0–1 | 242 | 94 | 123 | 95 | 351 | 96 | 178 | 97 | ||
≥ 2 | 16 | 6 | 6 | 5 | 15 | 4 | 5 | 3 | ||
Income | 0.65 | |||||||||
Above median | 205 | 56 | 107 | 58 | ||||||
Below median | 161 | 44 | 76 | 42 | ||||||
Year of diagnosis | 0.71 | 0.85 | ||||||||
2004–2007 | 10 | 4 | 5 | 4 | 133 | 36 | 71 | 39 | ||
2008–2011 | 131 | 51 | 71 | 55 | 177 | 48 | 86 | 47 | ||
2012–2015 | 117 | 45 | 53 | 41 | 56 | 15 | 26 | 14 | ||
Tumor size (cm) | 0.67 | 0.78 | ||||||||
< 3.8 | 137 | 53 | 65 | 50 | 161 | 44 | 78 | 43 | ||
≥ 3.8 | 121 | 47 | 64 | 50 | 205 | 56 | 105 | 57 | ||
Clinical N stage | 0.58 | 0.51 | ||||||||
0 | 160 | 62 | 84 | 65 | 224 | 61 | 118 | 64 | ||
1 | 98 | 38 | 45 | 35 | 142 | 39 | 65 | 36 | ||
Chemotherapy | 0.59 | 0.54 | ||||||||
Single agent | 49 | 19 | 28 | 22 | 273 | 75 | 132 | 72 | ||
Multi agent | 209 | 81 | 101 | 78 | 93 | 25 | 51 | 28 |
Cohort CRT
Variable | Cox UVA | Cox MVA | ||||
---|---|---|---|---|---|---|
HR | 95% CI | P | HR | 95% CI | P | |
Facility | ||||||
Nonacademic | 1 | Ref | 1 | Ref | ||
Academic | 0.89 | 0.79–0.997 | 0.045 | 0.91 | 0.81–1.03 | 0.14 |
Age | ||||||
< 65 | 1 | Ref | 1 | Ref | ||
≥ 65 | 1.18 | 1.06–1.32 | 0.0038 | 1.18 | 1.05–1.32 | 0.0055 |
Gender | ||||||
Female | 1 | Ref | ||||
Male | 1.05 | 0.94–1.17 | 0.44 | |||
Race | ||||||
White | 1 | Ref | ||||
Black | 0.99 | 0.85–1.16 | 0.91 | |||
Other | 0.99 | 0.67–1.48 | 0.98 | |||
Insurance | ||||||
None | 1 | Ref | ||||
Nonprivate | 1.33 | 0.94–1.88 | 0.11 | |||
Private | 1.09 | 0.77–1.55 | 0.63 | |||
Income | ||||||
Above median | 1 | Ref | 1 | Ref | ||
Below median | 1.21 | 1.08–1.36 | < 0.001 | 1.21 | 1.08–1.36 | < 0.001 |
Residential setting | ||||||
Metro | 1 | Ref | ||||
Urban | 1.02 | 0.88–1.17 | 0.83 | |||
Rural | 1.14 | 0.83–1.56 | 0.43 | |||
Charlson-Deyo Score | ||||||
0–1 | 1 | Ref | ||||
≥ 2 | 1.01 | 0.78–1.30 | 0.94 | |||
Year of diagnosis | ||||||
2004–2007 | 1 | Ref | ||||
2008–2011 | 0.92 | 0.81–1.04 | 0.19 | |||
2012–2015 | 0.91 | 0.77–1.07 | 0.25 | |||
Primary tumor site | ||||||
Head | 1 | Ref | ||||
Body | 0.96 | 0.85–1.09 | 0.57 | |||
Tail | 1.04 | 0.76–1.43 | 0.80 | |||
Tumor size (cm) | ||||||
< 3.8 | 1 | Ref | ||||
≥ 3.8 | 1.08 | 0.96–1.21 | 0.22 | |||
Clinical N stage | ||||||
0 | 1 | Ref | ||||
1 | 1.09 | 0.97–1.22 | 0.17 | |||
Chemotherapy | ||||||
Single agent | 1 | Ref | 1 | Ref | ||
Multi agent | 0.79 | 0.70–0.90 | < 0.001 | 0.81 | 0.71–0.92 | 0.0016 |
Dose escalation | ||||||
< 55 Gy | 1 | Ref | ||||
≥ 55 Gy | 0.91 | 0.78–1.05 | 0.19 |
Total cohort
Variable | Cox UVA | Cox MVA | ||||
---|---|---|---|---|---|---|
HR | 95% CI | P | HR | 95% CI | P | |
Facility | ||||||
Nonacademic | 1 | Ref | 1 | Ref | ||
Academic | 0.80 | 0.73–0.88 | < 0.001 | 0.90 | 0.81–0.99 | 0.036 |
Age | ||||||
< 65 | 1 | Ref | 1 | Ref | ||
≥ 65 | 1.15 | 1.05–1.26 | 0.0027 | 1.18 | 1.07–1.30 | 0.0013 |
Gender | ||||||
Female | 1 | Ref | 1 | Ref | ||
Male | 1.11 | 1.01–1.22 | 0.024 | 1.08 | 0.98–1.19 | 0.13 |
Race | ||||||
White | 1 | Ref | ||||
Black | 0.96 | 0.85–1.10 | 0.58 | |||
Other | 0.89 | 0.66–1.20 | 0.43 | |||
Insurance | ||||||
None | 1 | Ref | ||||
Nonprivate | 1.20 | 0.88–1.62 | 0.25 | |||
Private | 1.02 | 0.75–1.38 | 0.91 | |||
Income | ||||||
Above median | 1 | Ref | 1 | Ref | ||
Below median | 1.22 | 1.11–1.34 | < 0.001 | 1.20 | 1.08–1.32 | < 0.001 |
Residential setting | ||||||
Metro | 1 | Ref | ||||
Urban | 1.07 | 0.95–1.21 | 0.27 | |||
Rural | 1.25 | 0.96–1.64 | 0.10 | |||
Charlson-Deyo Score | ||||||
0–1 | 1 | Ref | ||||
≥ 2 | 1.06 | 0.86–1.30 | 0.61 | |||
Year of diagnosis | ||||||
2004–2007 | 1 | Ref | 1 | Ref | ||
2008–2011 | 0.85 | 0.76–0.95 | 0.0045 | 0.92 | 0.81–1.05 | 0.20 |
2012–2015 | 0.62 | 0.55–0.71 | < 0.001 | 0.77 | 0.66–0.89 | < 0.001 |
Primary tumor site | ||||||
Head | 1 | Ref | ||||
Body | 0.92 | 0.83–1.01 | 0.088 | |||
Tail | 1.13 | 0.87–1.48 | 0.35 | |||
Tumor size (cm) | ||||||
< 3.8 | 1 | Ref | 1 | Ref | ||
≥ 3.8 | 1.11 | 1.01–1.22 | 0.035 | 1.15 | 1.04–1.27 | 0.0049 |
Clinical N stage | ||||||
0 | 1 | Ref | ||||
1 | 1.08 | 0.99–1.19 | 0.098 | |||
Chemotherapy | ||||||
Single agent | 1 | Ref | 1 | Ref | ||
Multi agent | 0.63 | 0.57–0.69 | < 0.001 | 0.78 | 0.69–0.87 | < 0.001 |
Induction chemotherapy | ||||||
No | 1 | Ref | 1 | Ref | ||
Yes | 0.58 | 0.53–0.64 | < 0.001 | 0.73 | 0.65–0.83 | < 0.001 |
Dose escalation | ||||||
< 55 Gy | 1 | Ref | 1 | Ref | ||
≥ 55 Gy | 0.86 | 0.76–0.97 | 0.012 | 0.87 | 0.76–0.99 | 0.029 |