Curcumin, the key bioactive phytochemical present in turmeric (Curcuma longa L.), is the most studied natural compound in cancer. Preclinical studies (in vitro and in vitro) and clinical trials have demonstrated curcumin's effectiveness as an anti-inflammatory agent. The existing evidence supports that curcumin inhibits the proliferation of many types of cancer cells and can play an important role in cancer therapy. This study analyses the existing evidence in the literature on finalized clinical trials (2010–2020) related to the effect of curcumin and turmeric-derived products that focused on different types of cancers, such as chronic myeloid leukemia, multiple myeloma, prostate, colorectal and pancreatic cancer as well as cancer therapy-related complications, including oral mucositis and radiation dermatitis. Original English language articles and clinical trials published between 2010 and 2020 were searched using mainstream scholarly databases, such as PubMed, ScienceDirect, Google Scholar, and ClinicalTrials.gov.…