Several solid
tumors like
breast cancer tend to spread to the bone, where the microenvironment is especially receptive to the
tumor by special interactions between bone cells and
tumor cells. Bone
metastases often lead to skeletal-related events with significant morbidity and mortality. The
therapy of bone
metastases and
osteoporosis with
bisphosphonates (BPs) has been established many years ago as a standard treatment. In the adjuvant setting,
cancer treatment-induced bone loss is a frequent cause of morbidity, and prevention and treatment of this condition with BPs and the
monoclonal antibody denosumab are also well established. Besides postmenopausal patients, several studies including 2 larger studies by the Austrian Breast and
Colorectal Cancer Study Group (ABCSG) and the
Cancer and
Leukemia Group B (CALGB) have shown an increase in bone mineral density in premenopausal women. BPs as anticancer treatment are, however, still controversial because several studies yielded conflicting results, with beneficial effects only in subgroups of patients. The publication of the latest Oxford overview of prospective trials is being awaited; at the presentation of the results, a 34% relative reduction of bone
metastasis and
a 17% improvement in overall survival was demonstrated in the subgroup of postmenopausal patients. These results will likely lead to an incorporation of the use of BPs into routine adjuvant
breast cancer treatment.