Is there an association between multiple myeloma and prostate cancer?

In a series of 700 consecutive patients with prostate cancer, four patients were noted to have a history of multiple myeloma. An association between prostate cancer and multiple myeloma had not been previously described. An exploratory investigation of the biological basis of these two malignancies was undertaken to determine a possible mechanism for this association. A review of the genetic, molecular and chemical basis of prostate cancer and multiple myeloma development and progression is presented. A model suggesting the possible impact of immunosuppression from multiple myeloma and chemokines released by circulating myeloma cells including IGF-1, IL6, SDF1 and VEGF on the progression of prostate cancer to detectable stages is presented.