Jane McCredie: Customised cures

CANCER patients looking for alternative treatments can find a dizzying array of products and services online, from weird diets and nutritional supplements to coffee enemas and bizarre electrical contraptions.

These often seem to come with a side dose of conspiracy theories about mainstream medicine and its manoeuvring to deny people access to these miracle cures.

And you can pretty well guarantee there’ll be a raft of emotional testimonials from patients thriving despite having been given just weeks to live by conventional practitioners.

These days, the cancer patient looking for solutions online is also likely to come across the emerging field of “personalised cancer medicine” (PCM), which uses genetic testing to customise cancer treatments.

On offer are well established tests, such as those for the inherited breast cancer-related BRCA1 and BRCA2 mutations, and others with varying levels of evidence including those that look for non-inherited mutations in tissue taken from the tumour itself (known as somatic testing).

Identification of both inherited and acquired mutations undoubtedly offers the potential to create targeted treatments for individual patients, ones that might improve outcomes and reduce side effects. Legitimate research and treatment trials have been conducted or are underway.

The problem is that the evidence for different kinds of testing isn’t always in and the companies marketing tests don’t always make that clear.

This is a largely unregulated field that can include private companies and individual practitioners spouting a lot of scientific jargon that may or may not be soundly based in evidence.

It’s a difficult landscape for an individual cancer patient to navigate, particularly when they’re confronted with emotive claims like: “If you want the peace of mind that comes from knowing that you are doing everything possible to beat your cancer with the least amount of side effects and the shortest recovery time possible, let [us] prepare a [personalised plan] for you.”

So, if you don’t buy their product, you can lie awake knowing you really haven’t given it your best shot?

A group of researchers from Harvard examined websites marketing PCM and found many were overstating the benefits and downplaying the potential limitations of testing.

“… the vast majority of companies that market somatic tests online promote tests that do not have evidence of clinical utility”, they write in the Journal of the National Cancer Institute.

Six websites, for example, offered chemotherapy sensitivity testing despite the fact that the American Society of Clinical Oncology has found insufficient evidence to recommend such tests.

Of the websites offering somatic analysis, only 28% offered tests that were endorsed by guidelines, whereas 88% marketed one or more non-standard tests, the Harvard researchers found.

That didn’t stop some extravagant claims being made on behalf of the tests.

One company claimed its products and services were “poised to transform cancer patient management, increase treatment efficacy, and reduce healthcare costs”.

Another told doctors the “actual test result will indicate the prognosis for your patient”.

And a third claimed to be “introducing a way to help treat cancer without a single patient side effect”.

Regardless of the accuracy of such claims, what seems beyond dispute is that patients need help to cut through the hyperbole.

“Until genomic tests are more highly regulated, and perhaps even after regulatory changes are in place, oncology providers will need to guide patients as they navigate decisions about PCM”, these researchers write, suggesting that may require some clinicians to improve their own grasp of genomics.
 

Jane McCredie is a Sydney-based science and medicine writer.