Expression of estrogen and progesterone receptors in carcinomas of the female breast in Tanzania

In Africa breast cancer has been reported to occur frequently in young females and to show an aggressive histological and clinical picture, suggesting that this malignancy might have a different biology from this disease in Western females. To investigate this, the present study assessed by immunohistochemistry the expression of estrogen receptors (ER) and progesterone receptors (PgR) in 60 fresh frozen breast cancer tissues from indigenous Tanzanian patients. This prospective study collected tissues from routine patients treated at the Muhimbili Medical Center, Dar es Salaam, Tanzania. These markers have not been previously investigated in indigenous sub-Saharan females with breast cancer. Patients in this study expressed lower frequencies of ER (33%) and PgR (18%) as compared to literature reports including those about African-Americans. Expression of these markers, however, correlated with the demographic, clinical and histological characteristics in a similar way as observed elsewhere. A compounding effect of younger patients' age, advanced disease or late stage at hospital presentation and race in this geographical region could be responsible for the poor expression of hormonal receptors in the majority of patients as observed in this study. A surprising finding was that the proportion of hormonal receptor positive tumors increased with disease duration. In view of the low frequency of expression of hormonal markers only 26.7% of the patients would be expected to benefit from hormonal therapy based on their expression of the hormone receptors. There is great need to undertake an inter-African study that would evaluate the hormonal status of more African women with breast cancer in different geographical regions of sub-Saharan Africa and document the true picture of their hormonal status. The outcome of these results could be important for treatment strategies for the second most common cancer among African women.