Estrogen and progesterone receptor status in breast cancer in Kuwait female population.

The levels cytosol estrogen (ERc) and progesterone (PRc) receptors were determined in 315 primary breast cancers of female Arab patients aged 23-80 years. Most of breast cancers (78%) occurred in women aged 21-50 years, and only 22% were in women aged 51-80 years. Breast cancers containing ERc and PRc concentrations in the range 5-50 fmol/mg of cytosol protein (mg c.p.) were found with similar frequency in women aged under or over 50 years (53% for ERc and 43% for PRc, respectively). On the other hand, breast cancers with ERc values of > 50 and > 100 fmol/mg c.p. were twice as frequent in women aged over 50 years as in women aged under 50 years. The frequency of breast cancers with PRc level of over 50 fmol/mg c.p. in women aged over 50 years was only half that in those aged under 50 years. In breast cancers of Kuwait Arab women the higher values of ERc (> 100 fmol/mg c.p.) and PRc (> 50 fmol/mg c.p.) were less frequent than in other populations reported in literature. The low frequency of breast cancer in postmenopausal Kuwait women is associated with low proportions of tumors with higher ERc and PRc contents. In contrast to this, data from literature indicate that in the North Western European and American populations the postmenopausal incidence rise of breast cancers is associated with increased proportions of tumors with higher ERc and PRc levels.