As many as 60% of breast cancer (BrCA) patients receiving radiation are known to develop fatigue with about 30% suffering persistent fatigue several months to years after treatment completion (12-23). The physical, psychological, and molecular mechanisms by which patients develop fatigue are poorly understood and most likely multi-factorial. One pathway that has received considerable attention is nuclear factor-kappa B (NF-kB)(24). The NF-kB pathway has emerged as having an important role not only in cancer treatment resistance but in the development of fatigue. NF-kB activation leads to over expression of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha, all factors related to inflammation and factors that have been found to be upregulated in patients receiving radiation as well as BrCA survivors with fatigue (25-29). A recently published study looking at TNF-alpha, fatigue and cachexia in cancer patients receiving docetaxol showed that NF-kB is upregulated in fatigued patients and that agents which inhibit TNF-alpha lead to better tolerance of chemotherapy dose escalation (30). Work by our group and others has shown that ionizing radiation increases NF-kB pathway activity in circulating immune cells (as well as within breast cancer cells) and that this effect is most pronounced in women previously treated with chemotherapy (31, 32). Our work has shown that the NF-kB pathway activity in circulating immune cells is also related to fatigue development in BrCA patients treated with radiation and that patients most at risk for persistent fatigue and NF-kB pathway activity are those who have received chemotherapy for their breast cancer (31).

Curcumin, a known inhibitor of NF-kB, has been shown to decrease NF-kB activation in human participants. In a recent study, 8 grams of curcumin by mouth daily for 8 weeks was well tolerated in patients with pancreatic cancer and other pre-malignant conditions with no associated toxicities (6, 8). Although there is concern over the body's absorption of curcumin, the bioavailability of curcumin in the study of pancreatic cancer patients was shown, with peak drug levels at 22 to 41ng/mL that remained relatively constant over the first 4 weeks of treatment with 8 grams of curcumin daily (8). Clinical trials with daily dosages of 1,125 to 2,500mg have also confirmed the safety of curcumin and also shown its ability to decrease inflammation in patients with rheumatoid arthritis and in post-operative patients (6, 33, 34). In vivo murine models of chronic fatigue syndrome have also shown that curcumin may also alleviate symptoms of fatigue (35). While these studies are promising, very little is known about the capacity of Meriva to inhibit NF-kB in women treated for BrCA. We hypothesize that oral Meriva, a known inhibitor of NF-kB, may be used to decrease levels of NF-kB activity in BrCA patients previously treated with chemotherapy who go on to receive radiotherapy (XRT), a carefully chosen group of patients at particular risk for high levels of NF-kB DNA binding (a direct measure of NF-kB pathway activity).

We have chosen to administer oral Meriva, 500mg BID, in our patient population based on the above data. Meriva-500 is a curcumin formulation that also contains phosphatidylcholine, derived from soy that has been shown to aid in absorption of curcumin (9), permitting a lower overall dose of curcumin. Of note, 1000 mg Meriva contains 200 mg curcuminoids (\>90% curcumin).

By decreasing activity of NF-kB and ultimately plasma IL-6, fatigue may improve in BrCA patients taking Meriva. Results from this study will contribute to the limited research available on the capacity of curcumin treatment, including Meriva, to inhibit NF-kB activation in vivo as well as symptoms of fatigue associated with excessive NF-kB pathway activity in BRCA patients.