How tattoos could raise the risk of cancer, doctors reveal – as experts warn of the particular colour that may be more harmful

When doctors in Australia discovered a hard mass in the breast of a 36-year-old woman known to have genetic risk factors for cancer, they immediately performed a biopsy, fearing she had an aggressive tumour.

But tests quickly revealed it wasn’t cancer. It was a blob of tattoo ink – the patient was heavily tattooed and some of the ink had collected in a gland in the breast, mimicking the appearance of a tumour, the surgeons reported in a medical journal in 2022.

In a second, very similar case – this time involving a 50-year-old woman – described in the Journal of Medical Imaging and Radiation Oncology in June, a suspected cancerous lump turned out to be hardened tattoo ink.

Twenty years ago, just 16 per cent of adults in the UK had a tattoo. Today, it’s nearer 30 per cent as body art, once largely the preserve of sailors, bikers and rock stars, has become mainstream.

Now everyone, from England football legend David Beckham to Princess Eugenie, has embraced inked skin.

But while the vast majority of those with tattoos experience few – if any – significant side-effects, they are by no means risk-free. Well-documented adverse reactions range from photosensitivity (where tattooed skin becomes more sensitive to sunlight, causing itching, swelling and a stinging sensation) to allergic reactions – which result in similar symptoms and are most often triggered by certain metals used in red ink.

At least one in ten people who gets a tattoo experiences skin reactions that involve itching, pain, inflammation and swelling for at least three weeks after having it done, according to a study published by scientists at the University of Copenhagen, Denmark, last December in the journal Dermatology.

More recently, an investigation by the Food and Drug Administration (FDA) in the US found that a third of the 75 tattoo inks they tested contained potentially harmful bacteria that may lead to serious infections in some people.

More serious, albeit extremely rare, complications can include the life-threatening liver infections hepatitis B and hepatitis C, as well as HIV – almost always from contaminated needles. But now there is another emerging concern about tattoo ink’s possible links with certain types of cancer.

In May, a study published in The Lancet reported that adults who had even just a single tattoo were 21 per cent more likely to develop lymphoma – a type of blood cancer that affects more than 16,000 people a year in the UK.

The disease occurs when white blood cells, called lymphocytes, start to grow out of control. 

Normally, in a healthy body, lymphocytes – which are part of the immune system – help to fight off infections. But they can turn cancerous due to factors such as a weakened immune system, or long-term exposure to chemicals such as pesticides or insecticides.

They then multiply uncontrollably, damaging vital organs: around 5,000 people a year in the UK die from lymphoma.

When scientists at Lund University in Sweden compared tattoo rates in 1,300 patients diagnosed with various forms of lymphoma between 2007 and 2017 with healthy adults of the same age (20 to 60), those with body ink were more likely to have lymphoma.

Perhaps surprisingly, the risk didn’t seem to increase with more tattoos – just one or two carried the same cancer danger as multiples. The researchers said: ‘Tattoo ink often contains carcinogenic [cancer-causing] chemicals and we found it was associated with an increased risk of lymphoma – more research on this is urgently needed.’

In June 2023, the UK’s Health and Safety Executive announced that it was recommending the restriction of certain hazardous substances used in tattoo ink, which contains some 200 chemicals and additives. These included chemicals known to cause cancer, gene mutations, skin corrosion and serious eye damage.

It’s not clear how exactly tattoo ink might spark the cancer-growing process in lymphoma. And other studies have found no such connection with a heightened lymphoma risk.

But what research has shown is that the pigments used in ink can and do travel through the bloodstream to congregate in lymph nodes – the network of bean-shaped glands throughout the body that helps regulate the immune system’s response to foreign organisms.

Once there, they can clump together to form a semi-solid mass which – viewed on an MRI scan – can look uncannily like a cancerous growth.

‘When the body metabolises tattoo ink, it can sometimes end up collecting in lymph nodes in the neck, armpit and groin,’ says Dr Jonathan Kentley, a consultant dermatologist at Chelsea and Westminster Hospital in London and spokesman for the British Skin Foundation.

‘There have been cases where patients have had their lymph nodes surgically removed because it was thought they had cancer when they didn’t. Instead, it was tattoo pigment.’ The theory is that it congeals, then calcifies into a lump.

When some cancers – such as breast cancer – spread through the body, they usually move first to nearby lymph nodes, in the armpit in the case of breast cancer.

A report in the journal Cureus in 2022 highlighted the case of the 36-year-old tattooed woman from Hobart, Tasmania, who was undergoing regular breast cancer screening as she had a genetic mutation that put her at very high risk. It was on one such scan that doctors noticed a small, hard mass in one of her breasts.

‘It’s not that the pigment necessarily does any harm, but more that it can lead to confusion over whether it’s cancer or not, sometimes leading to patients having unnecessary procedures [such as biopsies],’ says Dr Kentley.

Separately, other studies have suggested certain types of skin cancer may be more likely to form in tattooed areas.

In 2020, researchers at Dartmouth-Hitchcock Medical Centre in New Hampshire in the US studied 156 patients with tattoos who developed basal cell carcinoma – a type of skin cancer that affects around 75,000 people a year in the UK.

It usually develops on areas most exposed to the sun, including the face. And although this type of skin cancer is rarely life-threatening, it can destroy surrounding facial tissue if not removed.

The study found that, in patients with tattoos, the cancer was 80 per cent more likely to form on inked skin than clear skin, reported the journal Epidemiology, suggesting tattoos raise the risk of cancerous growths forming.

Other research has also found that nearly 40 per cent of skin cancers that do form in tattoos develop on patches of red ink, possibly because exposure to the sun’s rays activates carcinogenic compounds found in this colour of ink.

Meanwhile, the use of dark-coloured inks can make it harder to detect malignant melanoma, the most dangerous type of skin cancer. Spotting dangerous moles at the earliest stage is crucial for improving the chances of survival.

Dr Kentley warns against getting a tattoo on areas of the body where there are any existing moles. ‘Most good tattoo artists will not tattoo over a pre-existing mole,’ he says. ‘If we do ever see cancerous moles within a tattoo, they’re usually ones that have appeared after it was done. But always do your research on the tattoo artist first.’

Britain’s 2,000 or so registered tattoo artists have to be licensed by a local authority – ‘make sure the one you choose is licensed and ask to see before and after pictures of other customers first,’ advises Dr Kentley.

‘Tattoos can be removed but most people underestimate the pain, the high cost and how long it takes. The lasers we use are expensive, it can take five to 12 sessions of treatment and the bill can run into thousands of pounds.’

The dangers of inking with your pet’s ashes

In recent years, there has been a growing demand for so-called ‘memorial tattoos’, where bereaved adults have the cremated ashes of their late relative or beloved pet mixed with the tattoo ink and used to decorate their body.

But is it safe? Although cremation (where temperatures exceed 1,000c) destroys all bacteria, the risk of infection from injecting ashes into the skin remains, says consultant dermatologist Dr Jonathan Kentley.

‘The ashes have to be incredibly sterile and need to be stored properly so contaminants don’t get in. They also need to be ground more finely than what comes out of the crematorium, or the body may react to it as a foreign material, causing a granuloma.’

This is a small, non-cancerous cluster of immune cells that forms a bump under the skin in response to infection or foreign objects. Although easily treated with steroid creams, a granuloma can become painful and inflamed.

In 2014, a 48-year-old woman in the US died from a flesh-eating bug, called streptococcal necrotising myositis, after becoming infected by a memorial tattoo on her back that contained the cremated ashes of her pet dog.