Hype Exceeds Evidence on Cancer Immunotherapy (Commentary)

Scanning electron micrograph of an oral squamous cancer cell (white) being attacked by two cytotoxic T cells (red), part of a natural immune response.

Scanning electron micrograph of an oral squamous cancer cell (white) being attacked by two cytotoxic T cells (red), part of a natural immune response. (National Institutes of Health)

People with cancer face many challenges, including the symptoms of the disease, the toxicity of the treatment, financial costs, and social expectations. Here’s a new threat: navigating their care in an ocean of hype.

Cancer drugs are all too often hailed as miracles, breakthroughs, game-changers, or even cures, even when they are no such thing. We recently reported in JAMA Oncology that these words were used 50 percent of the time to describe drugs not approved by the FDA, and 14 percent of the time to describe drugs that had only worked in mice. The leap from helping a mouse to saving a human is uncertain, long, and overwhelmingly unsuccessful.

Even when we do have drugs that work, hype may mislead us about how well they work and how many people they will benefit.

Consider immunotherapy. This new form of cancer therapy, which uses the body’s own immune system to fight cancer, has captivated the public imagination, is a topic of the nightly news, and has been featured in at least one Super Bowl ad.

When immunotherapy works, the result is terrific, even life-changing. Today, though, only a tiny minority of patients expected to die from cancer will benefit from immunotherapy. As is often the case, hype sadly exceeds evidence, creating misunderstandings between patients and their doctors.

Although immunotherapies have been used for a hundred years, such as the deliberate injection of bacteria into the body to stimulate the immune system, 2011 marked the approval of the first immunotherapy for cancer, a so-called checkpoint inhibitor named ipilimumab (Yervoy). This class of drugs unleashes the body’s immune system against cancer, and is the subject of much enthusiasm.

Using U.S. national cancer statistics and FDA approvals, we estimated the percent of cancer patients who might actually benefit from immunotherapy. The result was surprising, given the way these drugs are described.

To do this, we first calculated the percent of cancers for which immunotherapy has been approved as of February 2017. From that number we determined that two-thirds (68.8 percent) of Americans predicted to die of cancer will die of one that currently has no FDA-approved immunotherapy options. These include prostate cancer, colon cancer, and ovarian cancer, among others.

We next determined the percentage of cancer patients that could expect to see their tumor shrink from immunotherapy. Tumor shrinkage is widely considered to be a prerequisite to benefiting from these drugs. Only 26 percent of patients had this happen.

Finally, we combined those two calculations and asked, of all patients dying of cancer in America this year, how many might benefit from a checkpoint inhibitor drug? We assumed the best-case scenario: that every patient with one of these cancers could afford the drug and get access to it.

The answer was just 8 percent. We also ran the numbers another way by setting a lower bar for success, and credited these drugs for any patient whose cancer did not grow substantially during follow-up. Even with that adjustment, the estimate was less than 10 percent.

What do these results mean? When immunotherapy works, there is no argument — the results are terrific. Patients with otherwise life-threatening cancers live far longer than expected and some may even be cured. But at least today, few patients can expect to be among the lucky ones.

Some argue that these drugs will be approved for more cancers in the years to come, or that they may work better in combination with other drugs or one another. While we hope that comes true, it is not the reality today. And for several common cancers, like colon and breast cancer, we already know that these drugs work poorly — there is a reason why the first approvals were in cancers like melanoma — and we fear the percentage of people benefiting from cancer immunotherapy will not change greatly.

Who is to blame for the disconnect between reality and hype? All of us. Doctors, researchers, the pharmaceutical industry, reporters, patient advocates — all use sensational language to describe these drugs. To make matters worse, the United States is one of the only countries to permit direct-to-consumer advertising, resulting in an astonishing 80 drug ads airing every hour — some of which are misleading.

We owe it to people with cancer to do better. Navigating the waters of accurate information and reasonable hope is a big challenge for oncology. Deciding when and how to treat cancer is a sacred journey that patients and their doctors make together. Distorting the effectiveness of treatments in the public eye can tear the very fabric that unites patients and doctors. Misunderstanding ensues. Expectations become disappointments. A good death becomes a bad one.

The intrusive nature of hype — without context, without nuance, and without limit — can be a huge challenge faced by cancer patients in America. For that reason, it should come as no surprise that many cancer patients have an inflated understanding of their prognosis compared to what their doctors understand. Too many patients and their families are inevitably let down when they find themselves among the 90 percent who don’t benefit from immunotherapy.

We are not pessimists in our quest to improve survival and quality of life for cancer patients. Instead, we are optimists that we can all do better in communicating the reality of cancer care to patients, to the public, and even to physicians. That way, we may all make more honest choices if and when we must cope with cancer.

Nathan Gay, MD, is an oncology fellow at Oregon Health and Science University. Vinay Prasad, MD, is assistant professor in the Division of Hematology Oncology at Oregon Health and Science University and the author of “Ending Medical Reversal.” The views expressed in this article are the authors’ personal opinions and do not represent those of OHSU.

This story was originally published by STAT, an online publication of Boston Globe Media that covers health, medicine, and scientific discovery.

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