Table 1.
Selected baseline characteristics* by category of social network size, in the Life After Cancer Epidemiology (LACE) cohort (N=2,264).
| Social network size | ||||
|---|---|---|---|---|
| Socially† isolated | Moderately integrated | Socially integrated | p-trend* | |
| N | 797 | 706 | 761 | |
| Person-years | 8,117 | 7,123 | 7,897 | |
| Family history of breast cancer (%) | 20.6 | 19.9 | 21.2 | 0.84 |
| Breast cancer-specific mortality (%) | 10.6 | 8.4 | 9.4 | 0.34 |
| Non breast cancer mortality (%) | 10.2 | 9.1 | 5.3 | <0.001 |
| Demographic variables | ||||
| Age (mean years) | 58.9 | 58.0 | 57.8 | 0.10 |
| Ethnicity (%) | ||||
| Caucasian | 79.1 | 78.6 | 82.4 | 0.12** |
| African-American | 4.1 | 5.7 | 5.1 | |
| Asian | 6.4 | 6.7 | 5.7 | |
| Hispanic/Latino | 7.0 | 6.4 | 3.7 | |
| Other | 3.4 | 2.6 | 3.2 | |
| Education ≥ college (%) | 33.4 | 35.2 | 36.9 | 0.36 |
| Severity of disease | ||||
| Stage | ||||
| 1 (%) | 47.4 | 45.8 | 46.3 | 0.97** |
| 2 (%) | 49.3 | 51.1 | 50.8 | |
| 3 (%) | 3.3 | 3.1 | 2.9 | |
| Nodal involvement (%) | 36.2 | 36.1 | 38.0 | 0.69 |
| Tumor size (cm) | 2.1 | 2.1 | 2.1 | 0.78 |
| ER positive tumor (%) | 81.6 | 83.1 | 80.2 | 0.36 |
| HER-2-neu receptor + (%) | 14.7 | 16.0 | 12.4 | 0.14 |
| Treatment | ||||
| Chemotherapy (%) | 54.6 | 55.2 | 61.9 | 0.002 |
| Radiation (%) | 63.7 | 63.7 | 61.5 | 0.57 |
| Tamoxifen (%) | 60.5 | 61.7 | 63.0 | 0.59 |
| Behavioral factors | ||||
| Body mass index (kg/m2) | 27.4 | 27.4 | 27.7 | 0.50 |
| Physical activity (METhr/wk) | 45.4 | 51.3 | 59.5 | <0.001 |
| Never smokers (%) | 47.5 | 50.9 | 60.0 | <0.001 |
| Alcohol (svg/wk) | 3.1 | 2.7 | 2.1 | 0.02 |
| Reproductive factors | ||||
| Age at menarche < 12 y (%) | 12.6 | 12.6 | 12.6 | 0.88 |
| Age at first birth > 30 y (%) | 24.3 | 24.7 | 24.2 | 0.29 |
| Parity (Any pregnancies ≥ 5 months (%)) | 76.6 | 83.9 | 91.8 | <0.001 |
| Postmenopausal (%) | 74.5 | 72.5 | 74.2 | 0.40 |
| Social variables | ||||
| High levels of support (%) | 46.2 | 49.3 | 55.6 | <0.001 |
| Living mother (%) | 32.8 | 38.3 | 43.9 | <0.001 |
| Other first-degree female relatives (mean) | 1.8 | 2.4 | 3.2 | <0.001 |
| Married (%) | 51.3 | 66.2 | 87.9 | <0.001 |
| Hours/wk socializing with friends | 1.8 | 2.7 | 3.5 | <0.001 |
| Religious, social, and cultural participation (%) | 41.9 | 83.9 | 99.4 | <0.001 |
| Volunteering (%) | 5.5 | 16.5 | 44.8 | <0.001 |
*
Except for age, all variables age-adjusted
**
p-value, Mantel-Haenszel chi square test
†
Means were imputed when data on a social network were missing. Ranges of values were 0–4 for socially isolated women, 4.1–<5.5 for moderately integrated women, and 5.5–8.0 for socially integrated women. This distribution reflects approximate tertiles.