PGR and breast cancer: However, the effect estimate for the association for ever seeing a fogger truck and breast cancer was slightly higher among case women with known ER/PR status (OR = 1.33; 95% CI: 1.11, 1.59) than among all women regardless of ER/PR status (OR = 1.16; 95% CI: 0.98, 1.37), although with overlapping confidence intervals.