No evidence that wine helps chemo, despite the headlines

There's no evidence that drinking red wine can help chemotherapy

“A glass of red wine for women with breast cancer could boost the success rate of treatment” according to the papers – but the reality is a long way from what the headlines suggest.

The stories come from a scientific paper published in the journal Cancer Letters, looking at research on breast cancer cells grown in the lab.

The US-based researchers looked at a single chemical found in small amounts in red wine – resveratrol – and measured its effects on the potency of an experimental cancer drug, rapamycin (Sirolimus), that hasn’t yet been licensed to treat breast cancer.

On the basis of this evidence, suggesting that cancer patients should drink wine before their chemotherapy is wrong, misleading and clearly an over-interpretation of the data.

And the realities of the science behind the story highlight how careful we have to be when talking about lab research in the mainstream media.

What were the researchers doing?

The researchers, led by Dr Charis Eng of the Cleveland Clinic in Ohio were studying rapamycin, which was originally discovered in a fungus. It’s been proven effective in helping stop transplant rejections, and has been tested as a potential cancer drug with mixed results.

The team wanted to find out why rapamycin wasn’t as potent as initial studies suggested it ought to be, aiming to develop the drug as a more effective cancer treatment in the future. They’d discovered that a particular series of chemical reactions within cancer cells allowed them to ‘escape’ rapamycin’s effects.  To try and block these reactions, the scientists went searching for molecules that could make the drug more potent in lab tests.

Their hunt led them to resveratrol – a chemical found in several plants, notably peanuts and grapes.

Resveratrol and breast cancer – a chequered history

Despite breast cancer being more common amongst people who drink regularly, stories linking red wine to breast cancer treatment and prevention frequently crop up in the media. This is because  relatively large concentrations of resveratrol (far higher than those occurring in wine) can affect how cancer cells grow under experimental conditions.

In fact, researchers have now developed a pretty good understanding of how resveratrol affects cells, although they’re still some way from figuring out how it could be used to prevent the disease in real life. Building on this work, Dr Eng’s team thought it could be an ideal candidate as a ‘partner’ for rapamycin.

And as they suspected, they found that the combination was much more potent than either alone, publishing their findings in a scientific journal.

Breast cancer cells in the lab are not breast cancer

This is where things start to go slightly awry. Towards the end of their paper, the researchers speculate that the combination of rapamycin and resveratrol might have potential to treat breast cancer patients:

These results point to the possibility that the resveratrol–rapamycin combination may have therapeutic value in the treatment of breast cancer

…they write, before continuing:

Specifically, resveratrol-rich diets should be encouraged before and during rapamycin treatment . [our emphasis]

However, a human breast tumour is far more complex than the simple model they’d used to reach their conclusions. Tumours are complex, disorganised collections of different types of cell – immune cells, cancer cells, blood vessels, fibroblasts and stem cells to name but a few.

It’s a huge leap to say that resveratrol and rapamycin would affect a living, growing tumour in the same way as ‘pure’ cancer cells in a laboratory.

Resveratrol is not red wine

The researchers also make another assumption –  that foods containing resveratrol act in the same way as purified resveratrol when it comes to giving rapamycin a helping hand. Again, this may be true (or it may not), but at the moment it’s just a theory that needs testing.

And  – quite aside from anything else – red wine contains a significant amount of alcohol, which has quite a few effects on the human body, many of them harmful. For a start, a number of large studies have shown that it causes cancer. So it’s reasonable to say that testing the effects of alcohol on the effectiveness of the resveratrol/rapamycin combination would be a sensible idea before anyone is “encouraged” to do anything.

In the first piece of newswire coverage of the story that accompanied the paper, Dr Eng is quoted as saying:

If these observations hold true in the clinic setting, then enjoying a glass of red wine or eating a bowl of boiled peanuts – which has a higher resveratrol content than red wine – before rapamycin treatment for cancer might be a prudent approach.

Rapamycin is not chemotherapy

There’s a final cautionary note here. Some of the resulting media headlines confused ‘rapamycin treatment’ with ‘chemotherapy’ – even referring to it as a ‘common cancer treatment‘. As we’ve said above, rapamycin is not currently used to routinely treat breast cancer or any other form of the disease. A couple of related chemicals are: Temsirolimus has been licensed for kidney cancer patients, and Evsirolimus for treating a specific type of brain tumour.  These drugs work in a similar way to rapamycin.

So while this research suggests how the effectiveness of rapamycin (and possibly related drugs) might be improved in the future, it says nothing about what people currently being treated for breast cancer should or shouldn’t eat and drink.

It’s extremely unfortunate that a piece of careful laboratory research has resulted in headlines that may confuse breast cancer patients. Everyone involved in this story – the researchers, press officers, journalists and news editors – should reflect on how basic scientific research is communicated to the public, and how it can be improved.

Henry

Reference:

He X et al (2011). Resveratrol enhances the anti-tumor activity of the mTOR inhibitor rapamycin in multiple breast cancer cell lines mainly by suppressing rapamycin-induced AKT signaling. Cancer letters, 301 (2), 168-76 PMID: 21168265