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Commercial companies are not alone in trumpeting the advantages of new treatments while down-playing drawbacks. Professional hype and enthusiastic media coverage can likewise promote benefits while ignoring potential downsides. And these downsides may include not only harmful side-effects but also diagnostic difficulties, as shown by events surrounding the breast cancer drug trastuzumab, better known by the trade name Herceptin.

In early 2006, vociferous demands from coalitions of patients and professionals, fuelled by the pharmaceutical industry and the mass media, led the UK National Health Service to provide Herceptin for patients with early breast cancer. ‘Patient pester power’ triumphed – Herceptin was presented as a wonder drug.

But at that time Herceptin had only been licensed for the treatment of metastatic (widespread) breast cancer and had not been sufficiently tested for early breast cancer. Indeed, the manufacturers had only just applied for a licence for it to be used to treat early stages of the disease in a very small subset of women – those who tested positive for a protein known as HER2. And only one in five women has this genetic profile.

The difficulties and costs of accurately assessing whether a patient is HER2 positive, and the potential for being incorrectly diagnosed – and therefore treated – as a ‘false positive’, were seldom reported by an enthusiastic but uncritical press. Nor was it emphasized that at least four out of five patients with breast cancer are not HER2 positive. [9, 10, 11, 12]

It was not until later that year that the UK’s National Institute for Health and Clinical Excellence (NICE) – the organization charged with looking at evidence impartially and issuing advice – was able to recommend Herceptin as a treatment option for women with HER2 positive early breast cancer.

Even then, there was an important warning. Because of mounting evidence that Herceptin could have adverse effects on heart function, NICE recommended that doctors should assess heart function before prescribing the drug, and not offer it to women with various heart problems, ranging from angina to abnormal heart rhythms. NICE judged that caution was necessary because of short-term data about side-effects, some of them serious. Long-term outcomes, both beneficial and harmful, take time to emerge. [13]

On being sucked into a maelstrom

In 2006, a patient in the UK, who happened to be medically trained, found herself swept along by the Herceptin tide. She had been diagnosed with HER2 positive breast cancer the preceding year.

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Similar pressures for use of Herceptin were being applied in other countries too. In New Zealand, for example, patient advocacy groups, the press and the media, drug companies, and politicians all demanded that breast cancer patients should be prescribed Herceptin. New Zealand’s Pharmaceutical Management Agency (PHARMAC), which functions much as NICE does in the UK, similarly reviewed the evidence for use of Herceptin in early breast cancer.

In June 2007, based on its review, PHARMAC decided that it was appropriate for early breast cancer patients to receive nine weeks of  Herceptin, to be given at the same time as other anti-cancer drugs, rather than one after another. This nine-week course was one of three regimens then being tried around the world. PHARMAC also decided to contribute funds to an international study designed to determine the ideal length of Herceptin treatment.

However, in November 2008, the newly elected government ignored PHARMAC’s evidence-based decision and announced funding for a 12-month course of the drug. 14 Numerous uncertainties remain about Herceptin – for example, about when to prescribe the drug; how long to prescribe it for; whether long-term harms might outweigh the benefits for some women; and whether the drug delays or prevents the cancer returning. A further concern that has emerged is that Herceptin, when given in combination with other breast cancer drugs such as anthracylines and cyclophosphamide, may increase the risk of patients experiencing adverse heart effects from about four patients in a hundred to about 27 patients in a hundred. [15]