Aromatase inhibitor-induced joint pain: Melatonin’s role

Current and future advances in practice: aromatase inhibitor-induced arthralgia

Aromatase inhibitors (AIs) have shown great success as adjuvant therapy for post-menopausal women with hormone receptor-positive breast cancers. AI-induced arthralgia (AIA) is a frequent AI toxicity contributing to non-adherence and discontinuation. This review aims to understand current knowledge of AIA. The mean incidence of AIA was 39.1% and the mean discontinuation of AI therapy due to AIA was 9.3%. Most of the AIAs were non-inflammatory. A shorter time since the last menstrual period and pre-existing joint pain were risk factors. Vitamin D3 supplementation may be a preventative measure and treatment with duloxetine, acupuncture and/or exercise is supported by large randomized controlled trials. There was consistent improvement in AIAs with switching to an alternate AI, and this could additionally allow continuation of cancer treatment with AI. Further research is needed to identify predictive biomarkers, better characterize AIA subcategories and study more reliable therapeutic options.

The JACS prospective cohort study of newly diagnosed women with breast cancer investigating joint and muscle pain, aches, and stiffness: pain and quality of life after primary surgery and before adjuvant treatment

BACKGROUND

Breast cancer affects one in eight UK women during their lifetime: many of these women now receive adjuvant chemotherapy and hormone therapy. Joint and muscle pains, aches, and stiffness are common but the natural history, aetiology and impact of these symptoms are unknown. A cohort study of newly diagnosed women with primary breast cancer was established to explore this. In this paper we present study methods and sample characteristics, describe participants' experience of musculoskeletal pain at baseline interview, and explore its impact on quality of life.

METHODS

Women with non-metastatic breast cancer were recruited following primary surgery into a multi-centre cohort study. They received questionnaires by post five times (baseline, 3, 6 , 9 and 12 months) to investigate prevalence, severity, location and correlates of musculoskeletal pain, and impact on quality-of-life. Pain was measured by the Nordic musculoskeletal questionnaire, the Brief Pain Inventory, and MSK-specific questions, and quality of life by the SF-36 and FACIT scales.

RESULTS

543 women (mean age 57 years, range 28-87, 64% postmenopausal) were recruited following surgery for primary breast cancer from breast cancer clinics in eight hospitals. Fifteen per cent of the eligible cohort was missed; 28% declined to participate. Joint or muscle aches, pains or stiffness were reported by 69% women with 28% specifically reporting joint pain/aches/stiffness. Quality of life, as measured by the FACT-B and adjusted for age, depression, surgery and analgesic use, is significantly worse in all domains in those with musculoskeletal problems than those without.

CONCLUSIONS

Our findings highlights the importance of a better understanding of these symptoms and their impact on the lives of women with primary breast cancer so that healthcare professionals are better equipped to support patients and to provide accurate information to inform treatment decisions. Further papers from this study will address these issues.

Aromatase and regulation of the estrogen-to-androgen ratio in synovial tissue inflammation: common pathway in both sexes

Sex hormones play an active role in inflammatory responses, with androgens being anti-inflammatory, whereas estrogens have both pro- and anti-inflammatory effects. In rheumatoid arthritis (RA) patients, low levels of androgens and high levels of estrone are found in the synovial fluid. Aromatase is the key enzyme for the conversion of androgens into estrogens. Proinflammatory cytokines stimulate aromatase activity so that the inflammatory milieu can induce conversion of androgens to estrogens. Moreover, testosterone inhibits aromatase activity. As local androgen levels are low in RA, this can contribute to high aromatase activity in the synovium. Importantly, aromatase-converted estrogens are converted into proproliferative and proinflammatory 16-hydroxylated estrogens. A hormone involved in aromatase activity is vitamin D, which downregulates aromatase in human RA macrophages. Collectively, evidence suggests a key role of aromatase in sex hormone balance during chronic inflammation and points to the importance of vitamin D as a possible new tool for aromatase modulation.