How Presentation of Recurrence Risk Influences Decision-Making

[gdpawel]

Adjuvant Chemotherapy for Breast Cancer: How Presentation of Recurrence Risk Influences Decision-Making

Celia Chao, Jamie L. Studts, Troy Abell, Terence Hadley, Lynne Roetzer, Sean Dineen, Doug Lorenz, Ahmed YoussefAgha, Kelly M. McMasters

From the Division of Surgical Oncology and the Department of Medicine and Behavioral Oncology Program, James Graham Brown Cancer Center; the Departments of Psychological and Brain Sciences and the Biostatistics-Decision Science Program, University of Louisville; and the Division of Medical Oncology, Norton Healthcare, Louisville, KY; Abell Research Consulting, Ouray, CO.

Address reprint requests to Celia Chao, MD, Department of Surgery, University of Texas Medical Branch, 301 University Blvd, Route 0527, Galveston, TX 77555-0527; e-mail: cechao@utmb.edu or Jamie L. Studts, PhD, James Graham Brown Cancer Center, 529 S Jackson St, Louisville, KY 40202; e-mail: jamie.studts@louisville.edu.

Purpose: The purpose of this study was to examine the impact of four methods of communicating survival benefits on chemotherapy decisions. We hypothesized that the four methods of communicating mathematically equivalent risk information would lead to different chemotherapy decisions.

Methods: Each participant received two hypothetical scenarios regarding their mother (a postmenopausal woman with an invasive, lymph node-negative, hormone receptor-positive breast cancer) and was asked to decide whether they would encourage their mother to take chemotherapy in addition to surgery and tamoxifen.

In the part 1, participants received one of four methods of describing the chemotherapy survival benefit: (1) relative risk reduction, (2) absolute risk reduction, (3) absolute survival benefit, or (4) number needed to treat. In part 2, each participant received all four methods. Following each decision, participants were asked to rate their confidence and confusion regarding their decision.

Results: Participants included 203 preclinical medical students. In part 1, participants who received relative risk reduction information were significantly more likely to endorse chemotherapy.

In part 2, there were no treatment decision differences when participants received all four methods of communicating survival benefits of chemotherapy.

However, receiving all four methods led to significantly higher ratings of confusion. In deciding on endorsing chemotherapy, participants understood the information best when presented with data in the absolute survival benefit format.

Conclusion: These results support the hypothesis that the method used to present information about chemotherapy influences treatment decisions. Absolute survival benefit is the most easily understood method of conveying the information regarding benefit of treatment.

Supported by the Center for Advanced Surgical Technologies (CAST) of Norton Hospital, Louisville, Kentucky and the Links for Life Foundation, Louisville, Kentucky.

Journal of Clinical Oncology, Vol 21, Issue 23 (December), 2003: 4299-4305

[gdpawel]

A number of cancer advocates were glad to see this study. They have argued for years that it is all in the presentation. When no alternatives are presented, people will tend to seize what is available. As this study points out, when relative risk numbers that really do not relate to actual risk are given, it makes informed decision making even more difficult.

The method used to present information about chemotherapy influences treatment decisions. In deciding on endorsing chemotherapy, patients understand the information best when presented with data in the absolute survival benefit format, rather than those presented with data in the relative risk reduction information format. Absolute survival benefit is the most easily understood method of conveying the information regarding benefit of treatment.

Discussions between doctors and patients about the risks and benefits of chemotherapy need to be changed. Being told that chemotherapy reduces your risk by 30% of recurrence can be misleading and meaningless, unless you know your risk in the first place. If your risk of recurrence is 15%, you are only reducing it by 5%. And this doesn't even reflect the harm that could be done to those who don't need the treatment.

What is that harm? There are the toxicities that can end your life: leukemia and heart failure. There are toxicities that can ruin your life: loss of libido, loss of cognitive function, severe joint pain, and bone fractures. These harms are usually ignored or understated. One of the reasons is because they are understudied.

How will gene profiling for prognosis and prediction be used in the real world? Will women choose chemotherapy even though they have only a small chance of a recurrence? The bias towards chemotherapy and its overuse still permeates our society and will affect how this profile test is used. Many women will opt for chemotherapy even for a one or two percent benefit. Will women consider a low risk result low enough to forgo chemotherapy, or will they persue it anyway because of historic bias?

[lynne.risdon]

Interesting email. However, do oncologists really know the chance of reocurrence for small early stage HER2 cancers? It seems to me that oncologists are still more biased toward staging(tumor size and nodes status versus Grading and HER2 status.

[gdpawel]

I've always known about the pervasive way clinical trials focus on the relative risk (which powerfully exaggerates the benefits of drugs) and drug companies frame the question in terms of relative risks (systematically inflates their value), and absolute risk.

The number needed to treat (NNT), developed in 1988 to avoid the confusing distinction between "relative" and "absolute" reduction of risk, is perhaps one of the most important, least recognized, and most emblematic distortions you can find.

Some years back, the NCI issued a clinical alert to oncologists announcing the results of several clinical trials showing that women with node negative breast cancer benefited from chemotherapy. According to "number needed to treat" analysis, one hundred women would have to undergo chemotherapy for 10 to benefit.

Ninety women would risk toxicities but get none of the benefits. So what is the harm? The toxicities included not only those that can end your life like heart failure and leukemia, but some of those that can ruin you life like loss of cognitive function, loss of libido, severe arthritis and risk of bone fractures. These harms are usually ignored or understated. One of the reasons is because they are understudied.

So it began the "standard" practice to administer chemotherapy to women with node negative breast cancer that still exists today. Treat everyone to improve the survival chances of a small minority. How will the new gene profiling tests for prognosis be used in the real world today? Will women choose chemotherapy even though they have only a small chance of a recurrence? The bias towards chemotherapy and its overuse still permeates our society and will affect how these profile tests are used.

Many women will opt for chemotherapy even for a one or two percent benefit. Will women consider a low risk result low enought to forgo chemotherapy, or will they persue it anyway because of historic bias?

The clinical alert mentioned above was issued in 1987, a year before the NNT was developed to avoid the confusing distinction between "relative" and "absolute" reduction of risk.

A more honest use of NNT is not just an issue of forthrightness, it is also cost-effective.

According to a previous NYT article, physicians, like Dr. Eric P. Winer, who directs the breast oncology center at the Dana-Farber Cancer Institute in Boston, are taking their own best shot at figuring out who really benefits from chemotherapy. He asks how sensitive the tumor is to estrogen, how aggressive a pathologist believes it is, how big it is, how much has spread to the lymph nodes and whether its surface has a type of protein, HER2, that is associated with a better response to chemotherapy. After talking through the decision with his patients, he is comfortable omitting chemotherapy in some who would have had it not long ago.

A statistically small reduction in risk my be very important to some women, while for others chemotherapy is not worth it. Is it a tuff decision to take something potentially toxic when you have a 90 percent chance of being cured without it? Studies like this reaffirm the way many oncologists still practice. It should help understanding to base cancer therapies on the "specific" characteristics of their patients.