Table 3

Multivariable Cox proportional hazards regression models for overall survival stratified by histotype

VariableLevelHistology 1Histology 2
Multivariable hazard ratio (95% CI)*P valueMultivariable hazard ratio (95% CI)*P value
LN surgeryALND only1.0 reference1.0 reference
SLN biopsy only0.83 (0.62 to 1.12)0.2251.21 (0.82 to 1.79)0.330
SLN and ALND0.98 (0.78 to 1.22)0.8290.88 (0.69 to 1.12)0.298
AgePer 10 years1.74 (1.66 to 1.81)<0.0011.44 (1.37 to 1.51)<0.001
RaceWhite1.0 reference1.0 reference
Black1.52 (1.36 to 1.69)<0.0011.41 (1.29 to 1.54)<0.001
Other0.92 (0.77 to 1.10)0.3720.96 (0.80 to 1.16)0.677
Unknown1.14 (0.82 to 1.60)0.4330.84 (0.57 to 1.24)0.391
Charlson-Deyo score01.0 reference1.0 reference
11.26 (1.17 to 1.37)<0.0011.16 (1.07 to 1.26)<0.001
≥21.97 (1.75 to 2.21)<0.0011.40 (1.22 to 1.61)<0.001
Insurance statusPrivate insurance1.0 reference1.0 reference
Not insured1.54 (1.28 to 1.85)<0.0011.02 (0.81 to 1.29)0.851
Medicaid1.36 (1.15 to 1.61)<0.0011.09 (0.92 to 1.29)0.338
Medicare1.15 (1.05 to 1.26)0.0021.08 (0.99 to 1.19)0.087
Other government0.99 (0.69 to 1.44)0.9671.04 (0.71 to 1.53)0.833
Unknown0.95 (0.67 to 1.35)0.7741.47 (1.06 to 2.03)0.022
Income≥$63 3331.0 reference1.0 reference
$50 354–63 3321.08 (0.98 to 1.19)0.1081.03 (0.93 to 1.15)0.516
$40 227–50 3531.13 (1.01 to 1.25)0.0271.01 (0.90 to 1.13)0.909
< $40 2271.25 (1.11 to 1.42)<0.0011.01 (0.89 to 1.15)0.839
Unknown0.79 (0.34 to 1.87)0.1660.25 (0.08 to 0.79)0.017
Education (% no HSD)17.6% or more1.0 (0.88 to 1.14)0.9761.05 (0.91 to 1.20)0.531
10.9%–17.5%1.07 (0.96 to 1.20)0.2451.03 (0.91 to 1.16)0.654
6.3%–10.8%1.15 (1.04 to 1.27)0.0051.11 (1.00 to 1.24)0.049
Less than 6.3%1.0 reference1.0 reference
Unknown0.79 (0.34 to 1.87)0.5973.64 (1.10 to 12.03)0.034
Facility typeCommunity1.25 (1.05 to 1.48)0.0131.17 (0.95 to 1.44)0.144
Comprehensive community1.11 (1.03 to 1.20)0.0061.14 (1.06 to 1.24)<0.001
Academic1.0 reference1.0 reference
Integrated network1.13 (1.03 to 1.25)0.0131.0 (0.90 to 1.10)0.975
Unknown3.38 (2.48 to 4.62)<0.0011.18 (0.64 to 2.18)0.588
AJCC pathological N stagepN01.0 reference1.0 reference
pN11.74 (1.56 to 1.94)<0.0011.63 (1.49 to 1.80)<0.001
pN22.11 (1.84 to 2.43)<0.0011.62 (1.45 to 1.81)<0.001
AJCC pathological T stagepT11.27 (0.88 to 1.83)0.2100.97 (0.61 to 1.55)0.890
pT1A1.0 reference1.0 reference
pT1B1.70 (1.55 to 1.85)<0.0011.65 (1.49 to 1.83)<0.001
pT22.54 (2.26 to 2.85)<0.0012.06 (1.84 to 2.31)<0.001
pT3/3A/3B3.80 (3.39 to 4.27)<0.0012.79 (2.51 to 3.10)<0.001
GradeWell/moderately1.0 reference1.0 reference
Poorly/undifferentiated2.29 (2.12 to 2.48)<0.0012.15 (1.86 to 2.48)<0.001
Unknown1.24 (1.13 to 1.35)<0.0012.12 (1.82 to 2.48)<0.001
Lymph vascular invasionNot present1.0 reference1.0 reference
Present1.67 (1.54 to 1.81)<0.0011.55 (1.42 to 1.69)<0.001
Unknown1.11 (0.96 to 1.29)0.1471.14 (0.98 to 1.32)0.099
Adjuvant chemotherapyNo chemotherapy received1.0 reference1.0 reference
Chemotherapy received0.78 (0.70 to 0.86)<0.0010.77 (0.71 to 0.84)<0.001
Adjuvant hormone therapyNo hormone therapy received1.0 reference1.0 reference
Hormone therapy received1.05 (0.74 to 1.48)0.7840.97 (0.57 to 1.63)0.894
Unknown1.07 (0.86 to 1.33)0.5631.05 (0.83 to 1.32)0.709
Adjuvant radiation therapyNo radiation1.0 reference1.0 reference
Brachytherapy0.83 (0.76 to 0.91)<0.0010.74 (0.67 to 0.82)<0.001
External beam0.87 (0.79 to 0.95)0.0030.84 (0.77 to 0.92)<0.001
Other0.93 (0.57 to 1.52)0.7680.71 (0.43 to 1.16)0.171
  • *Hazard ratios estimate the risk of an event (death for any cause) in each group compared with that of the reference group. Hazard ratios lower than one represent a risk of events lower than the reference group, whereas hazard ratios higher than one represent a higher risk of events.

  • AJCC, American Joint Committee on Cancer; HSD, high-school diploma; LN, lymph node; LND, lymphadenectomy; SLN-B, sentinel lymph node biopsy.