Use of tamoxifen and aromatase inhibitors in a large population-based cohort of women with breast cancer. Br J Cancer. 2011;104:1558-1563. [PMID: 21522148 PMCID: PMC3101914 DOI: 10.1038/bjc.2011.140]

Artichoke polyphenols induce apoptosis and decrease the invasive potential of the human breast cancer cell line MDA-MB231

The human breast cancer cell line, estrogen receptor negative, MDA-MB231, was used to evaluate the antitumor effect of polyphenolic extracts from the edible part of artichokes (AEs). Treatment of cancer cells reduced cell viability and inhibited cell growth in a dose-dependent manner. Importantly, AEs did not have any effect on normal breast epithelial cell line, MCF10A. Chlorogenic acid (ChA), the most representative component of the polyphenolic fraction of artichoke, had no prominent effects on the cell death rate of MDA-MB231 cells. The addition of AEs to the cells, rather than ChA, triggered apoptosis via a mitochondrial and a death-receptor pathway, as shown by the activation of caspase-9 and caspase-8, respectively. Furthermore, an increase of the Bax:Bcl2 ratio and up-regulation of cyclin-dependent kinase inhibitor, p21(WAF1), crucial apoptotic players, were documented. According to our data on activation of caspase-9, a loss of mitochondrial transmembrane potential (Ψ(m)) was shown. Cell motility and invasion capabilities were remarkably inhibited by AEs-treatment in highly invasive MDA-MB231 cells. In addition, a significant decrease of proteolytic activity of metalloproteinase-2 protein (MMP-2), involved in degrading components of the extracellular matrix, was detected. Our findings indicate that AEs reduced cell viability, inhibited cell growth, triggered apoptotic mechanisms, and showed inhibitory properties against the invasive behavior of MDA-MB231 cancer cell line. Altogether, these data indicate the potential chemopreventive activity of artichoke polyphenolic extracts.

Managing the side effects of oral aromatase inhibitors

SUMMARY Aromatase inhibitors (AIs) are increasingly being used to treat postmenopausal estrogen receptor-positive breast cancer. In the short term they enhance or induce menopausal symptoms that compromise AI adherence, while in the long-term they adversely affect bone and probably also cardiovascular health, although this is mainly when compared to tamoxifen, which is cardioprotective. The distinct decrease in estrogen levels following AI administration is believed to be the main reason for the emergence of these side effects, although exact mechanisms remain to be elucidated. As such, management strategies to meet these AI-induced toxicities are still mainly symptomatic. In this review, current treatment options and promising new modalities under research will be discussed.

Adherence to adjuvant hormonal therapy among breast cancer survivors in clinical practice: a systematic review

Adjuvant hormonal therapy significantly improves long-term survival of breast cancer patients with hormone receptor-positive disease. Despite the proven clinical efficacy of tamoxifen and aromatase inhibitors, many breast cancer survivors either fail to take the correct dosage at the prescribed frequency (adherence) or discontinue therapy (persistence). This systematic review aims to: (1) determine the prevalence of adherence and persistence to adjuvant hormonal therapy among breast cancer survivors in clinical practice, and (2) identify correlates of adherence and persistence. We searched Medline, PubMed, PsycINFO, and CINAHL for studies that measured rates and/or correlates of adherence and/or persistence to adjuvant hormonal therapy. Studies were reviewed in a multi-step process: (1) the lead author screened titles and abstracts of all potentially eligible studies; (2) each coauthor reviewed a random 5 % sample of abstracts; and (3) two sets of coauthors each reviewed half of all "maybe" abstracts. Any disagreements were discussed until consensus was reached. Twenty-nine studies met inclusion criteria. Prevalence of adherence ranged from 41 to 72 % and discontinuation (i.e., nonpersistence) ranged from 31 to 73 %, measured at the end of 5 years of treatment. Extremes of age (older or younger), increasing out-of-pocket costs, follow-up care with a general practitioner (vs. oncologist), higher CYP2D6 activity, switching from one form of therapy to another, and treatment side effects were negatively associated with adherence and/or persistence. Taking more medications at baseline, referral to an oncologist, and earlier year at diagnosis were positively associated with adherence and/or persistence. Adherence and persistence to adjuvant hormonal therapy among breast cancer survivors is suboptimal. Many of the correlates of adherence and persistence studied to date are not modifiable. Our review reveals a critical need for further research on modifiable factors associated with adherence to adjuvant hormonal therapy, and the development of behavioral interventions to improve adherence in this population.

Adherence to long-term adjuvant hormonal therapy for breast cancer

Tamoxifen is an essential drug in treating hormone receptor-positive breast cancer and has been used successfully for the past three decades. More recently, aromatase inhibitors (AIs) have also shown great promise in reducing breast cancer recurrence. To receive the optimal benefits, patients need to take these drugs for a period of 5 years. Yet, despite the known positive patient outcomes associated with their use, adherence to both tamoxifen and AIs is substantially less than ideal. This article reviews the most recent literature reporting adherence rates for tamoxifen and AIs, as well as correlates of adherence. Factors that help to explain nonadherence are reviewed, including the side-effect profile, and approaches to intervention to enhance adherence are discussed.

Clinical profiles predict early nonadherence to adjuvant endocrine treatment in a prospective breast cancer cohort

Nonadherence to adjuvant endocrine breast cancer treatment adversely affects disease-free and overall survival. Clinical predictors of nonadherence may allow for specific interventions to reduce nonadherence and improve survival. The aim was to investigate whether clinical characteristics predict nonadherence. Clinical characteristics and information on adherence were obtained from 417 patients with breast cancer in a population-based prospective cohort from southern Sweden using patient charts, pathology reports, and questionnaires filled out at the 1- and 2-year follow-up visits. At the 1- and 2-year follow-up visits, 36 (8.6%) and 33 (9.7%) patients were nonadherent, respectively. Thirteen of the nonadherent patients declined treatment and were never prescribed endocrine treatment. A body mass index (BMI) < 25 kg/m(2), preoperative current smoking, and drinking alcohol less often than twice a month predicted nonadherence at the 1-year [relative risk (RR), 5.24; 95% confidence interval (CI), 2.75-9.97] and the 2-year visits (RR, 4.07; 95% CI, 2.11-7.84) in patients with at least two of these clinical characteristics. When low histologic grade (I) was added to the model, having at least two of these four clinical characteristics predicted nonadherence at the 1-year (RR, 4.94; 95% CI, 2.46-10.00) and the 2-year visits (RR, 4.74; 95% CI, 2.28-9.87), the two profiles had a sensitivity ranging from 60.6% to 72.7%, whereas the specificity ranged from 68.0% to 78.4%. Nonadherence at the 1-year visit was associated with an increased risk for early breast cancer events (HR, 2.97; 95% CI, 1.08-8.15), adjusted for age and tumor characteristics. In conclusion, two clinical profiles predicted early nonadherence and may allow for targeted interventions to increase adherence if validated in an independent cohort.

Estrogen, male dominance and esophageal adenocarcinoma: is there a link?

Esophageal adenocarcinoma is a cancer with poor prognosis, and its incidence has risen sharply over recent decades. Obesity is a major risk factor for developing this cancer and there is a clear male gender bias in the incidence that cannot be fully explained by known risk factors. It is possible that a difference in the expression of estrogen, or its signaling axes, may contribute to this gender bias. We undertook a comprehensive literature search and analyzed the available data regarding estrogen and estrogen receptor expression, and the possible sex-specific links with esophageal adenocarcinoma development. Potentially relevant associations between visceral vs subcutaneous fat deposition and estrogen expression, and the effect of crosstalk between estrogen and leptin signaling were identified. We also found limited studies suggesting a role for estrogen receptor β expression in esophageal adenocarcinoma development. The current literature supports speculation on an etiological role for estrogen in the male gender bias in esophageal adenocarcinoma, but further studies are required.