Table 2.
Relative hazard of breast cancer outcomes by level of social integration in the ABCPP (N=9,267*).
| Socially integrated |
Moderately integrated |
Socially isolated | p-value** | |
|---|---|---|---|---|
| N, LACE, NHS, SBCSS | 2,319 | 2,832 | 1,144 | |
| Recurrence | 286 | 419 | 187 | |
| Age, lag time-adjusted HR† | 1.00 | 1.25 | 1.39 | 0.002 |
| 95% CI | (1.07, 1.46) | (1.15, 1.68) | ||
| Model II HR‡ | 1.00 | 1.25 | 1.43 | <0.001 |
| 95% CI | (1.07, 1.46) | (1.18, 1.73) | ||
| Model III HR§ | 1.00 | 1.23 | 1.35 | 0.005 |
| 95% CI | (1.06, 1.44) | (1.11, 1.64) | ||
| Breast cancer-specific mortality | 204 | 295 | 151 | |
| Age, lag time-adjusted HR | 1.00 | 1.20 | 1.52 | <0.001 |
| 95% CI | (1.01, 1.44) | (1.24, 1.88) | ||
| Model II HR | 1.00 | 1.21 | 1.64 | <0.001 |
| 95% CI | (1.01, 1.45) | (1.33, 2.03) | ||
| Model III HR§ | 1.00 | 1.16 | 1.43 | 0.002 |
| 95% CI | (0.97, 1.39) | (1.15, 1.77) | ||
| All-cause mortality | 332 | 496 | 259 | |
| Age, lag time-adjusted HR | 1.00 | 1.26 | 1.61 | <0.001 |
| 95% CI | (1.10, 1.45) | (1.37, 1.90) | ||
| Model II HR | 1.00 | 1.25 | 1.69 | <0.001 |
| 95% CI | (1.08, 1.43) | (1.43, 1.99) | ||
| Model III HR§ | 1.00 | 1.17 | 1.42 | <0.001 |
| 95% CI | (1.02, 1.35) | (1.16, 1.52) | ||
| N, WHEL¶ | 834 | 1,329 | 809 | |
| Recurrence | 158 | 234 | 164 | |
| Age, lag time-adjusted HR | 1.00 | 0.92 | 1.07 | 0.40 |
| 95% CI | (0.75, 1.12) | (0.86, 1.34) | ||
| Model II HR | 1.00 | 0.92 | 0.99 | 0.92 |
| 95% CI | (0.75, 1.13) | (0.79, 1.25) | ||
| Model III HR | 1.00 | 0.86 | 0.91 | 0.43 |
| 95% CI | (0.70, 1.05) | (0.72, 1.14) | ||
| Breast cancer-specific mortality | 102 | 136 | 102 | |
| Age, lag time-adjusted HR | 1.00 | 0.82 | 1.07 | 0.58 |
| 95% CI | (0.64, 1.06) | (0.81, 1.41) | ||
| Model II HR | 1.00 | 0.83 | 1.00 | 0.91 |
| 95% CI | (0.64, 1.08) | (0.75, 1.34) | ||
| Model III HR | 1.00 | 0.78 | 0.90 | 0.42 |
| 95% CI | (0.60, 1.01) | (0.67, 1.20) | ||
| All-cause mortality | 120 | 180 | 134 | |
| Age, lag time-adjusted HR | 1.00 | 0.94 | 1.28 | 0.04 |
| 95% CI | (0.75, 1.19) | (1.00, 1.63) | ||
| Model II HR | 1.00 | 0.93 | 1.16 | 0.23 |
| 95% CI | (0.73, 1.17) | (0.90, 1.51) | ||
| Model III HR | 1.00 | 0.86 | 1.04 | 0.93 |
| 95% CI | (0.68, 1.09) | (0.80, 1.35) | ||
| Non-breast cancer mortality, All | 146 | 245 | 140 | |
| Age, lag time-adjusted HR | 1.00 | 1.36 | 1.85 | <0.001 |
| 95% CI | (1.11, 1.67) | (1.46, 2.33) | ||
| Model II HR | 1.00 | 1.34 | 1.82 | <0.001 |
| 95% CI | (1.09, 1.65) | (1.44, 2.30) | ||
| Model III HR | 1.00 | 1.25 | 1.52 | <0.001 |
| 95% CI | (1.01, 1.54) | (1.20, 1.93) |
Analyses of recurrence include 9,237 women and do not include the 30 women with stage IV cancer.
p-value, standardized, continuous measure of social network size
Age- and lag time-adjusted model adjusted for age (continuous) and time between diagnosis and social network assessment (continuous).
Model II adjusted additionally for covariates including cohort (LACE, NHS (ref), WHEL, SBCSS), education (<HS, HS, some college, college degree or greater (ref)), race (White (ref), Black, Asian, Hispanic, other), stage (I (ref), II, III, IV), estrogen receptor status (no (ref), yes), Her2 neu status (no (ref), yes), parity (nulliparous, 1 pregnancy>20 weeks and age at first birth<20, 1 pregnancy>20 weeks and age at first birth≥20, 2+ and age at first birth<20, 2+ and age at first birth≥20), menopausal status (premenopausal, postmenopausal (ref)), comorbidity (no (ref), yes).
Model III adjusted additionally for possible mediating (lifestyle and treatment) variables including chemotherapy (no (ref), yes), radiation (no (ref), yes), surgery (no, lumpectomy, mastectomy (ref), other), hormonal therapy (none (ref), tamoxifen, aromatase inhibitors, or both), alcohol intake (none (ref), >0–<1.7, 1.7–<15, 15+ g/d), smoking (never (ref), past, current), physical activity (0–<10 (ref), 10–<20, 20+ METS/wk), and body mass index (<18.5, 18.5–25 (ref), 25–<30, 30+ kg/m2).
The association between social isolation and outcomes differed in WHEL for recurrence (Q=6.31, p=0.10), breast cancer-specific mortality (Q=7.69, p=0.05), and total mortality, (Q=6.17, p=0.10).