Vitamin D threshold to prevent aromatase inhibitor-induced arthralgia: a prospective cohort study

Vitamin D threshold to prevent aromatase inhibitor-related bone loss: the B-ABLE prospective cohort study

Aromatase inhibitor (AI)-related bone loss is associated with increased fracture rates. Vitamin D might play a role in minimising this effect. We hypothesised that 25-hydroxy-vitamin D concentrations [25(OH)D] after 3 months supplementation might relate to bone loss after 1 year on AI therapy. We conducted a prospective cohort study from January 2006 to December 2011 of a consecutive sample of women initiating AI for early breast cancer who were ineligible for bisphosphonate therapy and stayed on treatment for 1 year (N = 232). Serum 25(OH)D was measured at baseline and 3 months, and lumbar spine (LS) bone mineral density at baseline and 1 year. Subjects were supplemented with daily calcium (1 g) and vitamin D(3) (800 IU) and additional oral 16,000 IU every 2 weeks if baseline 25(OH)D was <30 ng/ml. Linear regression models were fitted to adjust for potential confounders. After 1 year on AI therapy, 232 participants experienced a significant 1.68 % [95 % CI 1.15-2.20 %] bone loss at LS (0.017 g/cm(2) [0.012-0.024], P < 0.0001). Higher 25(OH)D at 3 months protected against LS bone loss (-0.5 % per 10 ng/ml [95 % CI -0.7 to -0.3 %], adjusted P = 0.0001), and those who reached levels ≥40 ng/ml had reduced bone loss by 1.70 % [95 % CI 0.4-3.0 %; adjusted P = 0.005] compared to those with low 25(OH)D levels (<30 ng/ml). We conclude that improved vitamin D status using supplementation is associated with attenuation of AI-associated bone loss. For this population, the current Institute of Medicine target recommendation of 20 ng/ml might be too low to ensure good bone health.

Effect of baseline serum vitamin D levels on aromatase inhibitors induced musculoskeletal symptoms: results from the IBIS-II, chemoprevention study using anastrozole

Severe deficiency of vitamin D in adults can cause musculoskeletal pain, stiffness, and joint discomfort. Musculoskeletal symptoms similar to those associated with vitamin D deficiency are frequently seen in breast cancer patients receiving adjuvant aromatase inhibitors (AIs). This is presumably due to oestrogen deficiency caused by AIs. However, no data are available on serum levels of vitamin D and their relation to developing musculoskeletal symptoms/arthralgia in women receiving an AI. IBIS-II is a multicentre randomized placebo controlled trial of the AI, anastrozole, in postmenopausal women aged 40-70 years, who are at increased risk of breast cancer. Serum vitamin D levels were measured for 416 participants. The samples were sent for assays in three batches: the first two batches (n = 250) included paired serum samples and the third batch (n = 166) included paired samples and samples from women who had arthralgia within the first year of follow-up. At entry, 56 (13%) women had adequate (≥ 30 ng/ml), 173 (41%) had inadequate (≥ 20-< 30 ng/mL), 167 (40%) were deficient (> 10-< 20 ng/mL), and 24 (6%) were severely deficient (< 10 ng/mL). At the time of analysis, 225 out of 834 (27%) women had reported arthralgia within the first year of follow-up. Baseline serum vitamin D levels did not significantly predict arthralgia within the first year of follow-up either in the overall group (OR 0.87 (95% CI: 0.67, 1.13; P = 0.30) or separately in the anastrozole (P = 0.60) or placebo groups (P = 0.38). Absolute serum levels of vitamin D increased significantly at one year in the anastrozole group (2.88 ng/ml, [1.71, 4.06; P < 0.0001]) but not in the placebo group (0.75 ng/ml [-0.35, 1.85; P = 0.18]). Only a small and a nonsignificant effect of baseline vitamin D levels were seen on the risk of musculoskeletal symptoms. This does not appear to be a major determinant of risk for these symptoms.

Individualization of treatment strategies

This section focuses on different aspects of the individualization of hormone treatment in breast cancer. This includes tumor-related biological factors such as expression of hormone receptors, HER-2, and Ki-67; host-related factors such as CYP2D6 or body mass index, and risk and/or development of specific toxicities and treatment adherence. The best predictor of response to hormonal interventions is the expression of hormone receptors, in particular, estrogen receptors. Treatment adherence and compliance are key factors and strategies aiming to identify and intervene when patients are at risk of abandoning treatment. Currently, routine assessment of CYP2D6 is not recommended to guide tamoxifen treatment. Likewise, there are no criteria regarding bone mass density, lipid profile, or arthralgias to recommend one class of agent versus another. Aromatase inhibitors should not be administered to patients who are pre- or perimenopausal.

Vitamin D and breast cancer: interpreting current evidence

Preclinical investigations and selected clinical observational studies support an association between higher vitamin D intake and 25-hydroxyvitamin D levels with lower breast cancer risk. However, the recently updated report from the Institute of Medicine concluded that, for cancer and vitamin D, the evidence was 'inconsistent and insufficient to inform nutritional requirements'. Against this background, reports examining vitamin D intake, 25-hydroxyvitamin D levels and breast cancer incidence and outcome were reviewed. Current evidence supports the pursuit of several research questions but not routine 25-hydroxyvitamin D monitoring and vitamin D supplementation to reduce breast cancer incidence or improve breast cancer outcome.

Adherence to oral endocrine treatments in women with breast cancer: can it be improved?

There is a perception that women on oral endocrine treatments for oestrogen receptor-positive breast cancer will be adherent to these medicines, as they are facing a serious life-threatening disease, and the oral endocrine treatments are effective, easy to use and generally well tolerated. This is not in fact the case, and this is the basis of the first half of this review. The second half is of whether the changes/interventions to 'improve' adherence do actually increase adherence to the oral endocrine medicines. The review shows that better outcomes are achieved with good adherence to endocrine treatments in breast cancer. The rates of adherence to endocrine treatments range between 15 and 50%, and are influenced by a large number of factors (e.g. adverse effects, lack of belief in treatment, psychological problems and poor patient-health care provider relationship). Interventions to minimise the adverse effects have been used in an attempt to improve the adherence to the endocrine treatment therapies, but it is not known whether these do actually improve adherence. Similar, it has been assumed that interventions by health professionals (doctors, nurses and pharmacists) will improve the adherence, but this has not been tested. In conclusion, in women with breast cancer, we know there is a problem with adherence. There are also many approaches and suggestions about how to improve adherence to the oral endocrine treatments, but none of these approaches/suggestions have been scientifically tested, and they need to be.

The effect of various vitamin D supplementation regimens in breast cancer patients

Vitamin D deficiency in the patients treated for breast cancer is associated with numerous adverse effects (bone loss, arthralgia, and falls). The first aim of this study was to assess vitamin D status, determined by 25-OH vitamin D levels, among women diagnosed with breast cancer according to demographic/clinical variables and bone mineral density (BMD). The second aim of this study was to evaluate the effect of daily low-dose and weekly high-dose vitamin D supplementation on 25-OH vitamin D levels. This retrospective study included 224 women diagnosed with stage 0-III breast cancer who received treatment at the James P. Wilmot Cancer Center at the University of Rochester Medical Center. Total 25-OH vitamin D levels (D(2) + D(3)) were determined at baseline for all participants. Vitamin D deficiency was defined as a 25-OH vitamin D level < 20 ng/ml, insufficiency as 20-31 ng/ml, and sufficiency as ≥32 ng/ml. BMD was assessed during the period between 3 months before and 6 months following the baseline vitamin D assessment. Based on the participants' baseline levels, they received either no supplementation, low-dose supplementation (1,000 IU/day), or high-dose supplementation (≥50,000 IU/week), and 25-OH vitamin D was reassessed in the following 8-16 weeks. Approximately 66.5% had deficient/insufficient vitamin D levels at baseline. Deficiency/insufficiency was more common among non-Caucasians, women with later-stage disease, and those who had previously received radiation therapy (P < 0.05). Breast cancer patients with deficient/insufficient 25-OH vitamin D levels had significantly lower lumbar BMD (P = 0.03). Compared to the no-supplementation group, weekly high-dose supplementation significantly increased 25-OH vitamin D levels, while daily low-dose supplementation did not significantly increase levels. Vitamin D deficiency and insufficiency were common among women with breast cancer and associated with reduced BMD in the spine. Clinicians should carefully consider vitamin D supplementation regimens when treating vitamin D deficiency/insufficiency in breast cancer patients.

Aromatase inhibitor-associated bone and musculoskeletal effects: new evidence defining etiology and strategies for management

Aromatase inhibitors are widely used as adjuvant therapy in postmenopausal women with hormone receptor-positive breast cancer. While the agents are associated with slightly improved survival outcomes when compared to tamoxifen alone, bone and musculoskeletal side effects are substantial and often lead to discontinuation of therapy. Ideally, the symptoms should be prevented or adequately treated. This review will focus on bone and musculoskeletal side effects of aromatase inhibitors, including osteoporosis, fractures, and arthralgias. Recent advances have been made in identifying potential mechanisms underlying these effects. Adequate management of symptoms may enhance patient adherence to therapy, thereby improving breast cancer-related outcomes.

Interventions to Alleviate Symptoms Related to Breast Cancer Treatments and Areas of Needed Research

Treatments for breast cancer produce a host of side effects, which can become debilitating. Some cancer treatment-related side effects occur in up to 90% of patients during treatment and can persist for months or years after treatment has ended. As the number of breast cancer survivors steadily increases, the need for cancer control intervention research to alleviate side effects also grows. This review provides a general overview of recent clinical research studies of selected topics in the areas of symptom management for breast cancer with a focus on cognitive difficulties, fatigue, cardiotoxicity, bone loss, insomnia, and cancer pain. We review both pharmacological and behavioral intervention clinical research studies, conducted with breast cancer patients and survivors. Additionally, clinical perspectives on symptom management and recommendations for areas of needed research are provided.