Prophylactic broad spectrum antibiotics as a new anti-myeloma therapy

Multiple myeloma is a common, yet incurable, haematological neoplasm. The reciprocal communication between malignant plasma cells, other cell types, and the extracellular matrix in the bone marrow micro-eco system is mediated by cell-cell and cell-matrix adhesion, as well as the production of different soluble factors, and is crucial for tumour growth and drug resistance. Inflammation and pro-inflammatory cytokines contribute to the clonal expansion of neoplastic plasmacytes. This extremely complex pathogenesis of multiple myeloma gives us the opportunity to promote numerous novel drugs and approaches based on the paradigm of targeted therapy. Immune dysfunction is a hallmark of multiple myeloma. Intrinsic and therapy-related immunosuppression leads to an increased risk of recurrent infection, the major cause of mortality. However, little data is available regarding the possible influence of infection on the biology and progression of multiple myeloma. Some authors have shown that pathogenic microorganisms can activate tool-like receptors on myeloma cells, as well as the robust production of pro-inflammatory cytokines; together these factors can contribute to myeloma growth, survival, and progression. Therefore, we proposed a simple, inexpensive, and new approach for anti-myeloma therapy that, to the best of our knowledge, is the first one concerning the prophylactic, long-term use of broad-spectrum antibiotics during the course of disease regardless of the chosen concomitant regimens. Prophylactic treatment with antibiotics should suppress the pro-inflammatory milieu produced during recurrent bacterial infections and prevent the activation of tool-like receptors on tumour cells, which are important factors responsible for tumour growth and survival in patients with multiple myeloma.