# Curcumin Innovative Delivery Forms: Paving the Yellow Brick Road' of Antitumoral Phytotherapy
## 2 Biological Actions of Curcumin
### Medicinal Activity in Humans
#### 2.1.2 Antitumoral Action  
The first report on the anticancer activity of curcumin, in 1987 [62], rekindled the interest in this compound and brought it to the spotlight of the western society. Curcumin has been the subject of over 30 clinical trials in the context of cancer, some of them still ongoing. This clearly demonstrates its significant chemo-preventive and anticancer potential. * In colorectal cancer, curcumin was studied for both tumor prevention and chemotherapy. In cancer prevention, it was demonstrated to reduce by 40% the formation of aberrant crypt foci in smoking patients (intake of 4 g/day for one month) [63]. In a combination study, curcumin, and quercetin (1440 + 60 mg/day for six months) were shown to reduce the number and size of polyps in patients with familial adenomatous polyposis, a hereditary disorder characterized by the development of hundreds of colorectal adenomas which turn malign when left untreated [64]. In chemotherapy, 1 g/day curcumin for up to one month (prior to surgical removal of the tumor) was shown to improve the patient's body weight and to increase the apoptosis rates of the patient's tumor cells [65]. * In prostate cancer, a trial has demonstrated that curcumin/flavone association reduces the chances of developing cancer by lowering the levels of prostate-specific antigen (PSA). PSA levels are increased due to the presence of chronic inflammation in the prostate, which is one of the most significant causes of tumorigenesis [66]. Association of curcumin (5.4 g/day for seven days around chemotherapy) with docetaxel/prednisone (75 mg/m\({}^{2}\) + 24 mg, once every three weeks, for six cycles) demonstrated encouraging results, with a tumor objective response in 40% and a PSA response in 59% of the patients in a group having castration-resistant prostate cancer [67]. There is also preliminary evidence on the ability to reduce the formation of metastases. An association of polyphenols (pomegranate seed, green tea, broccoli, and turmeric), taken over six months, has lowered PSA by 63.8% (compared to placebo) in prostatectomy patients [68]. Note that, since these men have no prostate, PSA is produced only by neoplastic cells, thus being a good indicator of metastasis growth. Curcumin can confer radioprotective effect in patients with prostate cancer who undergo radiation therapy, reducing the severity of radiotherapy related urinary symptoms. Patients were given 3 g of curcuminoids per day (corresponding to ca. 2 g/day of curcumin) for one week before the onset of radiotherapy and until completion of radiotherapy [69; 70]. * In breast cancer, curcumin was used in co-therapy with both chemotherapeutic agents and radiation. A combination therapy with docetaxel and curcumin (in escalating doses of up to 6 g/day) was found to afford better therapeutic results than docetaxel used alone: histological improvements were observed in the fourteen patients under study, all having reduction or elimination of disseminated foci [71]. Curcumin was evaluated in two clinical trials regarding protective action against radiation-induced dermatitis during radiotherapy of breast cancer patients. Despite promising results on a pilot study, with slightly less severe dermatitis in the curcumin group, a second trial on 686 patients showed no significant changes in pain, symptoms, and quality of life of the patients taking curcumin (1.5 g daily) in regard to those taking placebo [72]. * Pancreatic cancer, in the advanced stage, is a condition with very poor prognosis. In a phase II study with twenty-one patients taking curcumin (8 g/day for up to 18 months), partial regression was observed during the treatment period; after treatment, patient responses varied, one of them having become stable and another having shown a strong tumor response [73]. Another trial evaluated the association of curcuminoids (8 g/day, corresponding to 6.14 g/day of curcumin) with a gemcitabine-based chemotherapeutic treatment.