In this phase II, multicenter, self-controlled clinical trial, we will evaluate the safety and efficacy of OPERA® for treating anti-aromate inhibitors (AIs) induced arthralgia. The diagnosis of arthralgia will be based on the NCI-CTCAE v4.0 grade of ≥ 1 , A disorder characterized by a sensation of marked discomfort in a joint, mild pain (grade 1). Arthralgia will be assessed at the enrollment and every two months until the sixth month.

Aromatase Inhibitors (AIs) are recommended for the adjuvant treatment of hormone receptor positive breast cancers in the post-menopausal population. Compared with Tamoxifen, third generation aromatase inhibitors have been shown to significantly improve disease free survival (DFS), and include the steroidal inhibitor exemestane, and the nonsteroidal inhibitors, anastrozole and letrozole. Although the AIs are associated with fewer thromboembolic events and endometrial abnormalities than is tamoxifen, approximately 25% of postmenopausal women on AI report arthralgia, skeletal, and muscle pain. The multicentre double-blind placebo-controlled ma.17 trial by the National Cancer Institute of Canada Clinical Trials Group revealed marked increases in arthralgia (25% vs. 21%) and myalgia (15% vs. 12%) in patients on letrozole as compared with those on placebo. The Intergroup Exemestane Study shown a link between arthralgia and the ai exemestane (5.4% exemestane vs. 3.6% tamoxifen).The Arimidex, Tamoxifen Alone or in Combination (atac) trial, after 68 months' median follow-up, showed that the incidence of arthralgia was significantly higher in the anastrozole group than in the tamoxifen group [1100 of 3092 (35.6%) vs. 911 of 3094 (29.4%) patients]. Currently, evidences of drugs efficacy to reduce these side effects are sparse.OPERA® (GAMFARMA srl, Milan, Italy) is a new dietary supplement where α-Lipoic acid (240mg), BS (40mg), MSM (200mg) and Bromelain (20mg) are combined together in a single hard-gelatin capsule. The aim of this prospective study is to determine the efficacy and safety of OPERA® supplementation in a series of patients affected by arthralgia during AI treatment.

Inclusion Criteria:

• 18 years or older
• Karnofsky performance score≥70
• Indication for AI treatment in adjuvant setting for breast cancer
• Arthralgia with grade ≥0-1

Exclusion Criteria:

• Concomitant diseases, e.g. diabetes, renal insufficiency, alcohol abuse
• Concomitant rheumatological disease (Rheumatoid arthritis, Spondyloarthropathies, Psoriatic arthritis, etc.)
• Concomitant endocrinological disease (Acromegaly , Emocromatosis, etc)
• Any conditions that would complicate arthralgia assessment (e.g. Trauma, Glucocorticoid withdrawal, Hypertrophic osteoarthropathy, Osteoarthritis, Avascular necrosis, Gout, Systemic lupus erythematosus, Septic arthritis, etc.)