<prompt> What is the most common cause of osteoblastic bone metastasis in females?Ca breastCa cervixCa thyroidOsteosarcoma  <response>: The commonest cause of osteoblastic metastasis in women: Ca breastThe commonest in men is Ca prostateBone metastasis in Ca breast is of mixed type, i.e. both osteolytic osteoblasticBut is predominantly osteolytic.Bone Metastasis :The most common site for secondaries is BoneSkeletal metastasis may be osteolytic or osteoblasticMost of the metastasis are mixed type; predominantly osteolytic. 