Epidemiology and incidence
Primary breast sarcomas accounting 0.0006% - 1% of all breast malignancies and PBOS is far less common which accounts for about 4 - 12.5% of primary breast sarcomas (2,3).
There is a discrepancy among the reports in the literature as three large studies of major referral centers over the same span of 40 to 50 years reported different incidences (2,3,4). Two studies from Md Anderson (4) and Mayo clinic(3) reported one to two cases of primary breast osteosarcoma among all sarcomas that they encountered in the same time window (almost 40-50 years); Meanwhile, the third study from Armed Forces Institute of Pathology in Washington DC has reported a much higher incidence of 50 cases within the almost the same period of 40 years (2).
Although PBOS has been reported in a wide range of ages from 16 years old teens (5) to 96 years old patients(6), it usually affects menopaused women in their sixties to eighties (2,3,4).