Curcumin and Piperine in Patients on Surveillance for Monoclonal Gammopathy, Smoldering Myeloma or Prostate Cancer

This study tests whether curcumin (the active ingredient in turmeric) and piperine (from black pepper) can slow the progression of early-stage blood cancers or prostate cancer that is being monitored rather than actively treated. **You may be eligible if...** - You are 18 or older and in reasonably good health (able to care for yourself) - You have been diagnosed with a pre-cancerous blood condition called MGUS or smoldering myeloma and are currently on watchful waiting - OR you have non-metastatic prostate cancer and have chosen active surveillance as your management approach **You may NOT be eligible if...** - Your cancer requires active treatment right now - You have significant liver, kidney, or heart problems - You are on blood thinners or certain other medications that may interact with curcumin - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.