Table 1

Distribution of breast tumors by joint ER and PR status in the studies of women 40 years or younger (premenopausal) and of women 55–64 years (postmenopausal), conducted in Los Angeles County, California

ER statusPremenopausalPostmenopausal
PR statusPR status
PositiveNegativePositiveNegative
Positive20951450159
Negative1914524127