SABCS 2013: Morning Report-Back on Aromatase Inhibitors

Huff Post headshot. nov 2013By Karuna Jaggar, Executive Director

The change from brand-name to generic aromatase inhibitors and hormone therapy adherence for early stage breast cancer

A study reported on this morning at the San Antonio Breast Cancer Symposium (SABCS) showed that 45% of breast cancer patients report that high drug costs often result in some form of non-adherence, meaning that patients are not taking prescribed treatments. Women who don’t take their prescribed treatments have lower survival rates. Not surprisingly, wealthier women (over $100,000) are more likely to be able to afford, and therefore take their drugs, than poorer women (less than $40K/yr). When the presenter compared the price of a one-month supply of everolimus ($9,416) vs. a one-month supply of anastrozole ($110), there were gasps across the large conference hall. Patients must come before pharmaceutical industry profits. 

Researchers: Hershman DL, Tsui J, Meyer JW, Glied S, Wright JD, Neugut AI. Columbia University Medical Center, New York, NY; Mailman School of Public Health, New York, NY; OptumInsight.

Randomized trial of exercise vs. usual care on aromatase inhibitor-associated arthralgias in women with breast cancer: The hormones and physical exercise (HOPE) study

Another study from this morning’s general session explored exercise as a remedy for the very common side effects of aromatase inhibitors (AIs). The goal is that if exercise controls side effects, more women will take the treatments, and see improved outcomes. After one year of getting recommended levels of exercise, women taking aromatase inhibitors reported a 30% decrease in joint pain. (Recommended exercise = 2x weekly strength training and 2.5 hrs moderate intensity aerobic activity.) One limit of the study is that we don’t know if the benefits are due to aerobic exercise, resistance training, or the combined effect. A number of women chiming in with personal experience said that doing even light exercise like walking helps ease joint pain from taking AIs. How can we make sure all women, in all communities, are able to get the recommended levels of exercise? Social inequities lead to health disparities and we need to support findings on the benefits of exercise with systemic public health solutions.

Researchers: Irwin ML, Cartmel B, Gross C, Ercolano E, Fiellin M, Capozza S, Rothbard M, Zhou Y, Harrigan M, Sanft T, Schmitz K, Neogi T, Hershman D, Ligibel J. Yale University, New Haven, CT; University of Pennsylvania, Philadelphia, PA; Boston University, Boston, MA; Columbia University, New York, NY; Dana Farber Cancer Institute, Boston, MA.

Anastrozole for prevention of breast cancer in high-risk postmenopausal women (IBIS-II): An international, double-blind, randomized placebo-controlled trial

Researchers reported that taking the breast cancer drug anastrozole (sold as Arimidex) for five years reduced the chances of post-menopausal women at high risk of breast cancer developing the disease by 53% compared with women who took a placebo. This is the report from the IBIS 2 trial that included post-menopausal women who were at increased risk of breast cancer because of family history, DCIS or breast density. Median follow-up was five years. In the placebo arm of the trial, there was a 5.6% incidence of breast cancer (including DCIS) which was reduced by over 50% to 2.8% in the anastrozole arm of the trial.

Although this is a significant finding about anastrozole, the media headlines coming out about this research may overstate the actual significance (for example, the Chicago Tribune ran this story under the headline “Arimidex halves breast cancer risk, study finds”). For one thing, the actual numbers of women being followed are significant but still small. In addition, the absolute risk difference between placebo group and the anastrozole group was only a 2.8% difference, with no difference in mortality rates between the two groups. So we are really talking about risk reduction, not prevention. This is significant reduction in breast cancer risk, but we must be clear to women that it lowers risk by a few percentage points in what is already a low risk; for any one individual, it cannot be said it would prevent you from getting breast cancer.

Another point to note is that the researchers compared anastrozole only to a placebo group, not to a control group of women taking other aromatase inhibitors (AIs). This is concerning because the authors believe anastrozole should be the drug of choice. If this drug is going to be promoted as a replacement for other AIs, we want to know how anastrozole performs not just compared to a placebo but also as compared to the other two AIs that are currently the risk reduction drugs of choice. In other words, is this a better drug than what’s already in use, or just a newer (perhaps more expensive) drug?

Last, but certainly not least, the authors of this study seemed to downplay the drug’s side effects, focusing on the fact that women need to be educated about side effects as opposed to normal aches and pains of aging. This may make sense except for the fact that other studies (in fact, in the presentation immediately following this one) have shown that in the first year of use, up to 20-30% of women stop taking the drug because of the side effects, most commonly because of muscular and skeletal pain as well as depression, insomnia, fatigue, and cognitive issues.

The authors rightly acknowledge long term follow-up is needed. We would also like to see direct comparisions of anastrozole to other AIs so high-risk women know exactly what their choices are if they consider taking any AI.

Researchers: Prof Jack Cuzick PhD a , Ivana Sestak PhD a, Prof John F Forbes MD b, Prof Mitch Dowsett PhD c, Prof Jill Knox MSc a, Simon Cawthorn MD e, Prof Christobel Saunders MD f, Nicola Roche MD d, Prof Robert E Mansel MD g, Gunter von Minckwitz MD h i, Bernardo Bonanni MD j, Tiina Palva MD k, Prof Anthony Howell MD l, on behalf of the IBIS-II investigators*


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