BACKGROUND:Aromatase inhibitors (AIs) are commonly used as adjunctive hormone treatment for early breast cancer patients. The major side effect of AIs is arthralgia, which affects adherence. Previous reviews suggested that acupuncture is effective in the management of cancer-related pain. The aim of this review is to evaluate the effects of acupuncture on arthralgia caused by AIs.

METHODS:This article examined randomized controlled trials (RCTs) measuring the effects of acupuncture on joint symptoms caused by AIs within 8 medical databases till May 2014. The quality of the articles was evaluated according to the Cochrane risk of bias (ROB) tool.

RESULTS:Four RCTs were identified in medical journals. Two studies were conducted with manual acupuncture and 2 studies were electroacupuncture. The range of sample size was between 32 and 67. One RCT showed significant improvement in the acupuncture group compared with the sham control group and another RCT showed a statistical difference between the electroacupuncture and waitlist group. The other 2 studies showed no statistical differences between control and acupuncture groups. Two studies conducted blood analysis to elucidate the mechanism of efficacy of acupuncture for arthralgia. The 2 positive studies had a lower ROB and 2 studies had a high ROB.

CONCLUSIONS:The systematic review suggests that acupuncture has potential benefits to improve arthralgia caused by AIs. However, further trials of adequate sample size, appropriate control group, and longer follow-up are necessary to investigate the efficacy of acupuncture in AI-induced arthralgia.

BACKGROUND:Aromatase inhibitor-induced musculoskeletal syndrome (AIMSS) leads to discontinuation of aromatase inhibitor therapy in a significant proportion of patients with breast cancer. Acupuncture is popular among cancer patients and has previously been shown to improve symptoms in a range of musculoskeletal complaints.

AIM:To determine the effectiveness and safety of acupuncture for the management of AIMSS in postmenopausal women with early-stage breast cancer.

METHODS:A literature search was carried out for randomised controlled trials (RCTs) on acupuncture for AIMSS in postmenopausal women with early-stage breast cancer. Characteristics of trials and outcomes were extracted from the retrieved articles, which were also assessed for risk of bias and quality of reporting.

RESULTS:Four RCTs were retrieved of sample size 32-67 (totalling 190 participants). Compliance with treatment was high and rates of adverse events were low. Of the three two-arm RCTs, two found no difference between acupuncture and sham acupuncture and one found that acupuncture was statistically superior to sham acupuncture. The fourth RCT, which incorporated three arms, found acupuncture and sham acupuncture to be statistically superior to usual care but there was no difference between true and sham acupuncture. Three trials that used non-penetrating sham as the control found no effect of acupuncture over sham, but the one trial that used superficial needle insertion found acupuncture to be superior.

CONCLUSIONS:Acupuncture is safe and results in improvement in AIMSS symptoms, but similar benefits are also elicited by non-penetrating sham acupuncture. Future research should seek to establish the durability of improvements.

White button mushrooms (Agaricus bisporous) are a potential breast cancer chemopreventive agent, as they suppress aromatase activity and estrogen biosynthesis. Therefore, we evaluated the activity of mushroom extracts in the estrogen receptor-positive/aromatase-positive MCF-7aro cell line in vitro and in vivo. Mushroom extract decreased testosterone-induced cell proliferation in MCF-7aro cells but had no effect on MCF-10A, a nontumorigenic cell line. Most potent mushroom chemicals are soluble in ethyl acetate. The major active compounds found in the ethyl acetate fraction are unsaturated fatty acids such as linoleic acid, linolenic acid, and conjugated linoleic acid. The interaction of linoleic acid and conjugated linoleic acid with aromatase mutants expressed in Chinese hamster ovary cells showed that these fatty acids inhibit aromatase with similar potency and that mutations at the active site regions affect its interaction with these two fatty acids. Whereas these results suggest that these two compounds bind to the active site of aromatase, the inhibition kinetic analysis indicates that they are noncompetitive inhibitors with respect to androstenedione. Because only conjugated linoleic acid was found to inhibit the testosterone-dependent proliferation of MCF-7aro cells, the physiologically relevant aromatase inhibitors in mushrooms are most likely conjugated linoleic acid and its derivatives. The in vivo action of mushroom chemicals was shown using nude mice injected with MCF-7aro cells. The studies showed that mushroom extract decreased both tumor cell proliferation and tumor weight with no effect on rate of apoptosis. Therefore, our studies illustrate the anticancer activity in vitro and in vivo of mushroom extract and its major fatty acid constituents.

Estrogen is a major factor in the development of breast cancer. In situ estrogen production by aromatase/estrogen synthetase in breast cancer plays a dominant role in tumor proliferation. Because natural compounds such as flavones and isoflavones have been shown to be inhibitors of aromatase, it is thought that vegetables that contain these phytochemicals can inhibit aromatase activity and suppress breast cancer cell proliferation. Heat-stable extracts were prepared from vegetables and screened for their ability to inhibit aromatase activity in a human placental microsome assay. The white button mushroom (species Agaricus bisporus) suppressed aromatase activity dose dependently. Enzyme kinetics demonstrated mixed inhibition, suggesting the presence of multiple inhibitors or more than one inhibitory mechanism. "In cell" aromatase activity and cell proliferation were measured using MCF-7aro, an aromatase-transfected breast cancer cell line. Phytochemicals in the mushroom aqueous extract inhibited aromatase activity and proliferation of MCF-7aro cells. These results suggest that diets high in mushrooms may modulate the aromatase activity and function in chemoprevention in postmenopausal women by reducing the in situ production of estrogen.