The consultation is over and I stand to escort her out. Through the open door, I notice the waiting row of patients staring drearily at the television.

“But I am not done yet,” my patient says plaintively. “I still have questions.”

She’s already extended a 30-minute consult and I’m pushed for time. From her purse, she unfurls a long list. With its different colours, arrows and flags it looks like a complicated transit map.

“Should I have my intravenous vitamins on the day of chemo or after it?”

I don’t have a chance to answer before she continues: “Can you move my chemo appointment to fit in a colon cleanse? They are really busy, you know. Booked out weeks in advance.”

It almost comes across as boasting and I feel mildly irritated.

“And my friend is having magnet therapy,” she continues. “She is nearly cured though the traditional doctors gave up on her.”

I have to interrupt her: “Can we discuss this another time? I am afraid there are many patients waiting.”

She is unfazed. “I need to feel heard, you know. I want to know about juicing therapy. It sounds so next generation.”

I nudge the door shut with my foot, and sit down. “I have lost patients to all of those treatments,” I tell her quietly. “If you really want my opinion, I’d say avoid them all. Your chemotherapy is going well.”

“Of course you were going to say that,” she replies. My irritation mounts. I’m conscious that cancer patients sometimes say their oncologists don’t even care to engage on issues of alternative therapies. I hold my tongue.

“Tell me why these things appeal to you,” I suggest. “Because they are natural. They heal your body from the inside, and they guarantee results,” she replies, tiredly, as if talking to a misbehaving child.

Research shows that nearly 70% of cancer patients and a staggering 90% of patients enrolled in an early phase clinical trial use alternative therapies. We now know that many of these therapies are not only unhelpful but are downright dangerous. Herbs and supplements can interact with chemotherapy and reduce its efficacy, a real drawback when therapy is given with curative intent.

Canadian researchers found that of the 44 bottles of herbs they tested, a full third were outright substitutions – the plant advertised on the bottle was simply not there. Genetic fingerprinting reveals that many popular supplements are filled with powdered rice and weeds. The World Health Organisation calls this a threat to consumer safety.

Electron therapy, radio waves, magnetic energy and light boxes as a cure for cancer have been consistently refuted by influential cancer organisations, including the American Cancer Society and Cancer Council Australia.

Gerson therapy is promoted as “the natural treatment that activates the body’s extraordinary ability to heal itself”. The Cancer Research UK website explains that it requires an individual to consume nine (yes, nine) kilos of fruit and vegetables and use three or four coffee enemas every day. There is a discreet mention that “in certain situations Gerson therapy could be very harmful to health”.

Young Jessica Ainscough, who shunned conventional treatment for her sarcoma, and recently died, was a follower.

In 10 years of being an oncologist I have witnessed some devastating consequences when practitioners recommend “alternative” therapies.

The emaciated breast cancer patient who was told to present to emergency because there was nothing else her alternative provider could do to help her walk. Neither could we. She died of spinal cord compression after vigorous manipulation of her back.

The man whose finances and prostate cancer had both spiralled out of control by the time he forked out $50,000 dollars on vitamin infusions. He regretted forgoing the proven benefit of chemotherapy.

There was the man whose wife discovered the extent of his natural therapy debt only after he died and was forced to sell the house.

There were the children who quit studying to help pay for their father’s imported exotic herbs sourced from the wild.

These stories are not unique – every oncologist tells a tale of financial and psychological ruin, experienced by the family long after the patient dies.

Every oncologist tells a tale of financial and psychological ruin, experienced by the family after the patient dies.

Many people will counter that the experience of chemotherapy is no less daunting, destructive, and even fatal. I agree. The difference, I believe, is that there is openly available literature from reputable sources that will tell you this. We can dissect the nuances of informed consent and clear communication but the truth is that chemotherapy recipients are increasingly provided with information and education, not to mention monitoring of toxicity.

Abandonment by the oncologist at the end of life seems a common regret – but I dare say it pales in comparison to the blatant dereliction of duty by alternative practitioners when cancer patients fall really ill. If you don’t believe me, ask a GP or an emergency physician, the other professionals asked to salvage these patients.

What do an oncologist and an alternative therapist talk about when a patient like Ainscough dies? Do we defend our individual art, ponder medical ethics or credit individual autonomy above all else?

I asked this question of several doctors and the answer was unequivocal. “We don’t talk.” As in, we never talk.

Oncologists and alternative health practitioners move in different spheres though plenty of evidence suggests we end up looking after the same patients. When I discover (usually belatedly) that my patient endured the broken promise of an unproven cure, I feel dejected. The more expensive, extreme or exotic the treatment the messier seems the ending.

I have little expectation that someone who would sell false hope to a vulnerable patient would talk me through their reasons why. I once ran into a licensed doctor who oversaw $500 vitamin infusions for cancer patients. The moment when we discovered what the other did was awkward to say the least. My expression asked, “Why?” I saw him struggle with the answer before he said, “Because patients want it.” There was no common ground for a conversation and we slid away into the crowd.

Does the natural therapist, coffee enema prescriber or wave therapy expert ever discuss patient care with an oncologist? Not in my experience. There is never written correspondence or a phone call, not even when a patient is desperately ill and it might help to know if some unconventional treatment has led to reversible toxicity. On the other hand, I occasionally receive requests for tests that the alternative provided can’t sign for. The last one was: “I need a scan to show which natural therapy will best penetrate the tumour.”

I politely declined.

The community practitioners who are best at checking in with oncologists are physiotherapists, palliative care nurses and general practitioners. They seem to have no qualms about sharing doubt, seeking advice and negotiating compromise.

But the point of many alternative therapies seems to be in their secret powers of healing. I know it’s often said but I honestly don’t consider arrogance a good explanation for why oncologists and alternative practitioners don’t talk. I would, however, say that dismay and distrust feature heavily. As does the troubling realisation that a doctor can face reprimand for inadvertent error but an alternative practitioner can get away with intentional harm.

This is not a reason to excuse the former but to regulate the latter. Perhaps this would make it easier to follow the advice that doctors need to familiarise themselves with the various forms of complementary and alternative medicines. It is conceivable that some worthwhile measures are tainted by the same brush as a lot of fraudulent ones.

Health literacy moves at a very slow pace. The alternative health industry, worth many billions of dollars, marches briskly. It will always attract unguarded patients who will cling to the faintest promise of recovery without associated harm. Whenever money changes hands and the premise sounds too good to be true, the motto remains: Caveat Emptor.