Table 3.
Hazard ratios for the association of functional limitations with survival stratified by age, body mass index (BMI), and tumor stage*
| Variable | All-cause survival |
Competing-cause survival |
Breast cancer survival |
||||||
| No. of patients/No. of deaths | Unadjusted HR (95% CI) | Adjusted† HR (95% CI) | No. of patients/No. of deaths | Unadjusted HR (95% CI) | Adjusted† HR (95% CI) | No. of patients/No. of deaths | Unadjusted HR (95% CI) | Adjusted† HR (95% CI) | |
| Age, y | |||||||||
| <50 | 543/39 | 1.55 (0.81 to 2.99) | 0.85 (0.31 to 2.35) | 543/6 | 1.65 (0.70 to 3.86) | 1.86 (0.30 to 11.5) | 543/33 | 1.38 (0.67 to 2.85) | 1.04 (0.55 to 1.95) |
| 50–65 | 1003/103 | 1.19 (0.80 to 1.77) | 1.19 (0.74 to 1.92) | 1002/32 | 2.66 (1.0 to 2.60) | 2.49 (1.06 to 5.88) | 1003/71 | 0.87 (0.53 to 1.42) | 0.99 (0.89 to 1.10) |
| 65–79 | 656/127 | 1.94 (1.34 to 2.79) | 1.55 (1.01 to 2.40) | 656/74 | 3.01 (1.74 to 5.18) | 2.65 (1.39 to 5.04) | 656/53 | 1.09 (0.63 to 1.86) | 0.86 (0.44 to 1.68) |
| BMI, kg/m2 | |||||||||
| <25 | 730/82 | 2.49 (1.59 to 3.90) | 1.99 (1.20 to 3.32) | 730/37 | 3.51 (1.83 to 6.73) | 2.53 (1.16 to 5.51) | 730/45 | 1.59 (0.87 to 2.90) | 1.72 (0.90 to 3.30) |
| 25–30 | 635/82 | 1.41 (0.91 to 2.19) | 0.98 (0.58 to 1.64) | 635/31 | 4.95 (2.21 to 11.06) | 3.40 (1.21 to 9.49) | 635/51 | 0.70 (0.38 to 1.28) | 0.57 (0.30 to 1.08) |
| >30 | 500/65 | 1.47 (0.88 to 2.45) | 1.29 (0.70 to 2.37) | 500/32 | 2.68 (1.24 to 5.81) | 2.69 (1.05 to 6.90) | 500/33 | 1.07 (0.54 to 2.12) | 0.72 (0.34 to 1.53) |
| Tumor stage‡ | |||||||||
| I | 1027/86 | 2.45 (1.60 to 3.76) | 2.02 (1.23 to 3.32) | 1027/49 | 5.00 (2.65 to 9.45) | 4.30 (2.06 to 8.98) | 1027/37 | 1.04 (0.54 to 2.03) | 1.06 (0.51 to 2.19) |
| IIa | 734/89 | 2.12 (1.39 to 3.23) | 1.41 (0.86 to 2.29) | 734/38 | 3.06 (1.57 to 5.99) | 1.57 (0.73 to 3.40) | 734/51 | 1.63 (0.94 to 2.83) | 1.25 (0.69 to 2.29) |
| IIb | 369/73 | 1.22 (0.77 to 1.95) | 1.00 (0.57 to 1.73) | 369/23 | 2.76 (1.19 to 6.38) | 2.15 (0.66 to 7.08) | 369/50 | 0.82 (0.45 to 1.49) | 0.66 (0.34 to 1.26) |
| III | 68/20 | 52 (0.19 to 1.44) | 0.74 (0.42 to 1.30) | 68/1 | § | § | 68/19 | 0.56 (0.20 to 1.55) | 0.75 (0.22 to 2.64) |
The study population consisted of women diagnosed with breast cancer from the Life After Cancer Epidemiology study in the United States, 1997–2008, who provided complete information on functional limitations. CI = confidence interval; HR = hazard ratio.
Statistical tests are based on delayed entry Cox proportional hazards models. Adjusted models included age, race and/or ethnicity, education, BMI, smoking, physical activity, and comorbidity using the cut points in Table 1. In models examining overall and breast cancer–specific survival, additional adjustments for tumor characteristics (stage, lymph node status, and estrogen receptor, progesterone receptor, and HER2 status) and treatment (chemotherapy and radiation therapy) were performed using the cut points in Table 1.
Tumor stage at diagnosis was classified according to the TNM system based on the criteria of the American Joint Committee on Cancer as stage 0, I, IIa, IIb, III or IV.
Insufficient number of deaths to compute hazard ratios in this subgroup.