Table 3.
Univariate and multivariable analysis of patient and disease factors on overall survival in advanced esophageal cancer
|
Variable
|
Univariate
|
|
Multivariable1
|
|
|
Hazard ratio (95%CI)
|
P
value
|
Hazard ratio (95%CI)
|
P
value
|
|
| Chemotherapy | ||||
| Chemotherapy received vs not received | ||||
| If 0 < time ≤ 10 mo2 | - | < 0.001 | - | < 0.001 |
| If time > 10 mo | 0.95 (0.88-1.03) | 0.204 | 0.98 (0.86-1.11) | 0.699 |
| Age | 1.01 (1.01-1.01) | < 0.001 | 1.01 (1.00-1.01) | < 0.001 |
| Gender | ||||
| Female | 0.99 (0.96-1.02) | 0.420 | 0.90 (0.86-0.95) | < 0.001 |
| Male | 1 (reference) | 1 (reference) | ||
| Race (combined) | ||||
| Black | 1.09 (1.05-1.14) | < 0.001 | 1.02 (0.96-1.09) | 0.457 |
| Other | 0.86 (0.82-0.91) | < 0.001 | 0.87 (0.80-0.95) | 0.002 |
| White | 1 (reference) | 1 (reference) | ||
| Insurance type | ||||
| Medicaid | 1.28 (1.22-1.34) | < 0.001 | 1.21 (1.13-1.31) | < 0.001 |
| Medicare | 1.30 (1.26-1.33) | < 0.001 | 1.04 (0.99-1.10) | 0.119 |
| Other government | 1.15 (1.04-1.26) | 0.006 | 0.95 (0.82-1.10) | 0.493 |
| Not insured | 1.37 (1.29-1.45) | < 0.001 | 1.20 (1.09-1.31) | < 0.001 |
| Private | 1 (reference) | 1 (reference) | ||
| Income quartiles for place of residence | ||||
| $30000-$34999 | 0.94 (0.90-0.98) | 0.007 | Dropped out of the model | |
| $35000-$45999 | 0.93 (0.90-0.97) | < 0.001 | ||
| $46000+ | 0.87 (0.83-0.90) | < 0.001 | ||
| Less than $30000 | 1 (reference) | |||
| Treatment site | ||||
| Academic | 0.87 (0.85-0.89) | < 0.001 | 0.91 (0.87-0.94) | < 0.001 |
| Non-academic | 1 (reference) | 1 (reference) | ||
| Geographic location in United States | ||||
| Northeast | 0.92 (0.89-0.96) | < 0.001 | 0.96 (0.90-1.02) | 0.180 |
| Midwest | 1.02 (0.98-1.06) | 0.340 | 1.07 (1.01-1.14) | 0.032 |
| South | 1.03 (0.99-1.07) | 0.142 | 1.05 (0.99-1.11) | 0.138 |
| West | 1 (reference) | 1 (reference) | ||
| Residence area type | ||||
| Metro | 0.93 (0.86-1.01) | 0.086 | Dropped out of the model | |
| Urban | 0.95 (0.87-1.03) | 0.193 | ||
| Rural | 1 (Reference) | |||
| Number of comorbidities | ||||
| 1 | 1.20 (1.17-1.24) | < 0.001 | 1.09 (1.04-1.14) | < 0.001 |
| ≥ 2 | 1.45 (1.37-1.52) | < 0.001 | 1.16 (1.07-1.26) | < 0.001 |
| 0 | 1 (reference) | 1 (reference) | ||
| Year of diagnosis | ||||
| 2010-2014 | 0.99 (0.96-1.01) | 0.286 | Dropped out of the model | |
| 2004-2009 | 1 (Reference) | |||
| Grade | ||||
| 2 | 1.08 (1.00-1.18) | 0.065 | 1.06 (0.95-1.20) | 0.297 |
| 3 | 1.30 (1.20-1.41) | < 0.001 | 1.28 (1.14-1.44) | < 0.001 |
| 4 | 1.30 (1.15-1.48) | < 0.001 | 1.21 (1.02-1.45) | 0.032 |
| 1 | 1 (reference) | 1 (reference) | ||
| AJCC T stage | ||||
| pIS | 0.57 (0.30-1.09) | 0.090 | 1.11 (0.46-2.66) | 0.821 |
| T0 | 0.94 (0.69-1.26) | 0.665 | 0.86 (0.59-1.25) | 0.424 |
| T1 | 0.88 (0.84-0.93) | < 0.001 | 0.89 (0.84-0.95) | < 0.001 |
| T2 | 0.66 (0.62-0.69) | < 0.001 | 0.69 (0.65-0.74) | < 0.001 |
| T3 | 0.65 (0.63-0.68) | < 0.001 | 0.73 (0.70-0.76) | < 0.001 |
| T4 | 1 (reference) | 1 (reference) | ||
| AJCC N stage | ||||
| Positive | 0.94 (0.91-0.97) | < 0.001 | Dropped out of the model | |
| Negative | 1 (reference) |
1
12370 observations were used in the multivariable model.
2
As chemotherapy effect is not constant over time up to 10 mo, it was modeled with a time-dependent coefficient and the unadjusted hazard ratio for chemotherapy versus no chemotherapy is exp [-2.34 + 0.998 × log(time)] and adjusted hazard ratio is exp [-2.30 + 0.966 × log(time)].
AJCC: American Joint Committee on Cancer; CI: Confidence interval.