Adjusted HRs and 95% CIs for incident breast cancer by region of residence at baseline (Southern vs Northern residence) and solar irradiance (low vs high solar exposure) stratified by breast cancer tumor characteristics: the WHIOS (n = 71,662)
| . | Cases . | Northern (>40°) vs Southern (≤37°) . | Langleys (gm-cal) per cm2 (300-325 vs 475-500) . | Watts (J/s) per m2 (0.4-0.5 vs 1.5-1.9) . | ||||
|---|---|---|---|---|---|---|---|---|
| ER status | ||||||||
| ER+ | 1,932 | 1.02 (0.92, 1.13) | 0.97 (0.86, 1.11) | 0.86 (0.73, 1.01) | ||||
| ER− | 346 | 0.97 (0.76, 1.25) | 0.90 (0.65, 1.25) | 1.00 (0.69, 1.46) | ||||
| PR status | ||||||||
| PR+ | 1,607 | 1.07 (0.95, 1.20) | 1.08 (0.94, 1.25) | 0.90 (0.75, 1.08) | ||||
| PR− | 634 | 0.90 (0.75, 1.08) | 0.71 (0.56, 0.90) | 0.79 (0.61, 1.04) | ||||
| ER/PR status | ||||||||
| ER+/PR+ | 1,572 | 1.07 (0.96, 1.21) | 1.09 (0.94, 1.26) | 0.90 (0.75, 1.08) | ||||
| ER+/PR− | 322 | 0.83 (0.64, 1.07) | 0.59 (0.42, 0.82) | 0.64 (0.45, 0.93) | ||||
| ER−/PR+ | 35 | 0.77 (0.36, 1.67) | 0.83 (0.30, 2.33) | 0.79 (0.25, 2.48) | ||||
| ER−/PR− | 305 | 1.00 (0.77, 1.30) | 0.90 (0.63, 1.27) | 1.01 (0.68, 1.52) | ||||
| Tumor size (cm) | ||||||||
| <0.5 | 186 | 1.04 (0.73, 1.47) | 0.96 (0.60, 1.53) | 1.49 (0.84, 2.66) | ||||
| 0.5-1 | 475 | 1.20 (0.97, 1.49) | 1.02 (0.79, 1.33) | 0.96 (0.69, 1.33) | ||||
| >1 to 2 | 982 | 0.90 (0.78, 1.05) | 0.88 (0.73, 1.05) | 0.75 (0.60, 0.93) | ||||
| >2 to 5 | 497 | 1.09 (0.89, 1.35) | 1.03 (0.79, 1.35) | 0.98 (0.70, 1.35) | ||||
| >5 | 86 | 0.49 (0.30, 0.79) | 0.45 (0.26, 0.80) | 0.49 (0.23, 1.03) | ||||
| Lymph node involvement | ||||||||
| No | 1,817 | 1.00 (0.89, 1.11) | 0.99 (0.87, 1.13) | 0.84 (0.71, 0.99) | ||||
| Yes | 610 | 0.92 (0.79, 1.06) | 0.82 (0.65, 1.04) | 0.80 (0.60, 1.06) | ||||
| Tumor grade | ||||||||
| Well-differentiated | 631 | 0.93 (0.77, 1.12) | 0.74 (0.59, 0.92) | 0.53 (0.40, 0.70) | ||||
| Moderately differentiated | 972 | 0.92 (0.79, 1.06) | 0.97 (0.81, 1.16) | 0.78 (0.62, 0.98) | ||||
| Poorly differentiated | 567 | 1.15 (0.95, 1.41) | 1.23 (0.95, 1.60) | 1.30 (0.94, 1.80) | ||||
| Anaplastic | 64 | 1.50 (0.84, 2.68) | 1.06 (0.51, 2.22) | 1.46 (0.67, 3.17) | ||||
| . | Cases . | Northern (>40°) vs Southern (≤37°) . | Langleys (gm-cal) per cm2 (300-325 vs 475-500) . | Watts (J/s) per m2 (0.4-0.5 vs 1.5-1.9) . | ||||
|---|---|---|---|---|---|---|---|---|
| ER status | ||||||||
| ER+ | 1,932 | 1.02 (0.92, 1.13) | 0.97 (0.86, 1.11) | 0.86 (0.73, 1.01) | ||||
| ER− | 346 | 0.97 (0.76, 1.25) | 0.90 (0.65, 1.25) | 1.00 (0.69, 1.46) | ||||
| PR status | ||||||||
| PR+ | 1,607 | 1.07 (0.95, 1.20) | 1.08 (0.94, 1.25) | 0.90 (0.75, 1.08) | ||||
| PR− | 634 | 0.90 (0.75, 1.08) | 0.71 (0.56, 0.90) | 0.79 (0.61, 1.04) | ||||
| ER/PR status | ||||||||
| ER+/PR+ | 1,572 | 1.07 (0.96, 1.21) | 1.09 (0.94, 1.26) | 0.90 (0.75, 1.08) | ||||
| ER+/PR− | 322 | 0.83 (0.64, 1.07) | 0.59 (0.42, 0.82) | 0.64 (0.45, 0.93) | ||||
| ER−/PR+ | 35 | 0.77 (0.36, 1.67) | 0.83 (0.30, 2.33) | 0.79 (0.25, 2.48) | ||||
| ER−/PR− | 305 | 1.00 (0.77, 1.30) | 0.90 (0.63, 1.27) | 1.01 (0.68, 1.52) | ||||
| Tumor size (cm) | ||||||||
| <0.5 | 186 | 1.04 (0.73, 1.47) | 0.96 (0.60, 1.53) | 1.49 (0.84, 2.66) | ||||
| 0.5-1 | 475 | 1.20 (0.97, 1.49) | 1.02 (0.79, 1.33) | 0.96 (0.69, 1.33) | ||||
| >1 to 2 | 982 | 0.90 (0.78, 1.05) | 0.88 (0.73, 1.05) | 0.75 (0.60, 0.93) | ||||
| >2 to 5 | 497 | 1.09 (0.89, 1.35) | 1.03 (0.79, 1.35) | 0.98 (0.70, 1.35) | ||||
| >5 | 86 | 0.49 (0.30, 0.79) | 0.45 (0.26, 0.80) | 0.49 (0.23, 1.03) | ||||
| Lymph node involvement | ||||||||
| No | 1,817 | 1.00 (0.89, 1.11) | 0.99 (0.87, 1.13) | 0.84 (0.71, 0.99) | ||||
| Yes | 610 | 0.92 (0.79, 1.06) | 0.82 (0.65, 1.04) | 0.80 (0.60, 1.06) | ||||
| Tumor grade | ||||||||
| Well-differentiated | 631 | 0.93 (0.77, 1.12) | 0.74 (0.59, 0.92) | 0.53 (0.40, 0.70) | ||||
| Moderately differentiated | 972 | 0.92 (0.79, 1.06) | 0.97 (0.81, 1.16) | 0.78 (0.62, 0.98) | ||||
| Poorly differentiated | 567 | 1.15 (0.95, 1.41) | 1.23 (0.95, 1.60) | 1.30 (0.94, 1.80) | ||||
| Anaplastic | 64 | 1.50 (0.84, 2.68) | 1.06 (0.51, 2.22) | 1.46 (0.67, 3.17) | ||||
NOTE: Adjusted for age, race/ethnicity, education, weight, family history of breast cancer, age at menarche, age at menopause, parity, age at first birth, hormone therapy duration of use, alcohol intake, and physical activity.