Cancer of the Foot
- David Tollafield
- May 19
- 6 min read
Fighting Fear
Anyone hearing the words—cancer, tumour or growth can be forgiven for feeling scared. Rest assured, the foot is not such a common place for cancer. Even if a cancer has been diagnosed, fear not; most conditions can be addressed.
According to the Marsden Hospital (London), melanoma is the fifth most common skin cancer, but other forms of cancer exist. However, the foot is still a target, like other parts of the body.
The Mayo Clinic in the US suggests that only 1% of cancers affect bone. Information taken from the internet needs interpretation, and in reality, the foot is a low target for cancer.
Just words
Our body is made up predominantly of water and the building blocks called cells. Cells divide, repair and rebuild as we grow and age. If a cell is faulty, it causes a change in tissue. Tissue is called connecting or connective tissue, and it includes bone, muscle, nerves, and so on. Organs like the skin, kidneys, bowel and breast are also tissue. All tissue is made up of cells, so any cell that fails to form causes a change in function and appearance. Cancer is a change where the cells change and start to invade or produce abnormal chemicals.
Neoplasia means new tissue, but it may not be cancerous. In each case, the cells may form a swelling, and the Latin for swelling is tumor. The suffix -OMA means swelling.
So, let's forget about becoming too alarmed about tumours unless they are cancerous. Growth could mean a wart on the skin or a hard lump of fibrous tissue. As we age, skin bumps, lumps, and blemishes appear as part of the process of getting older.
Foot Cancer is Rare
Cancers are likely to affect the skin and nail beds, the arch of the foot, and deeper tissues such as fat, nerves, and small blood vessels, rather than bone or joints. My most memorable case was where I was sent a nasty foot with a mushy ulcer that the patient’s GP thought was a verruca. This turned out to be a melanoma. The patient lived 5 years before succumbing to medical complications. Dermatoscopes are now used with ever-increasing popularity and have reduced the need for biopsy.
A dermatoscope is a device for magnifying skin lesions to identify characteristics of abnormal change. It raises suspicions and increases the chances of earlier intervention. The literature tends to talk about other parts of the body rather than the foot being more common, and much of it gets tied in with the lower limb. Foot cancer can lead to early death, but I stress it is not common.
Of 367,667 new cancers reported (2015-17) by Cancer Research, under 1/2 died of the disease. While this appears alarming, this statistic does not tell us what type of cancer kills most and where that cancer exists.
If melanoma, a pigmented patch of skin (mole) that goes bad, needs urgent attention. At maximum strength, exposure to UV light from the sun needs as much protection on top of the foot as on the hands and arms. It is always important to check under the foot and between the toes.
Organs and Spread
Breast, ovarian and prostate cancers feature heavily in healthcare, with a renewed focus on bowel cancer for older patients and testicular cancers for men.
The spread of cancers, carried through the lymphatics and blood, is called metastasis. The original sites of cancer are called Primaries, and when it spreads to another location, these are called Secondaries. Often, the Secondaries raise suspicions in feet after a bone breaks in the metatarsal bones, and this is where a bone or joint cancer may come to be recognised.
Who is At Risk?
Abnormal swellings are more prevalent in middle-aged and older patients, although children can also be affected. Skin cancer not only affects fair-skinned or redheads. The pigmented type of tumour, melanoma, occurs in all races and affects all skin types and colours.
Everyone is potentially at risk. Sadly, bone cancer is more of a concern in younger people and is related to a cancer called sarcoma. Sarcomas affect connective tissue such as bone, fat, muscle, nerves and ligaments. Carcinomas affect organs, of which the skin is a primary organ, as it has so many functions.
While we see melanoma of the skin, we also see epitheliomas, of which squamous cell carcinoma is one such condition seen in the foot.
How come we miss some cancers?
‘A misdiagnosis of foot pain was made when this was actually related to the patient having lung cancer. The patient was seen by two physicians and an orthopaedic surgeon who had missed the diagnosis when providing treatment. The cancer, sadly, was detected too late.’ Afni Shah-Hamilton
Pressures on the health system and the process of undertaking tick-list approaches to clinical examination can prevent clinicians from thinking outside the box. Cost-cutting on diagnostic tests can also lead to missing cancers, which might otherwise be picked up. The argument for podiatrists undertaking more work on cancer has never been more critical, and the idea that this should rely on medical doctors alone in an area where the podiatrist is conversant with skin problems seems to miss the opportunity for better screening.
What are the Key Types of Tumours?
Some tumours, such as sarcoma, have a greater affinity for younger patients, although middle-aged adults typically present with this condition in their feet. Presentations can vary between patients. They might report pain instead of swelling. Testing for pain or swelling in the local lymph glands is important because the body filters and mops up infections and abnormal cell growths at these sites (armpit, groin, abdomen, chest, and neck).
Tips for assessing lumps and bumps
If any of the following features are present as a suspicious growth –
Lump size of more than 5cm
A sudden increase in size
A source of continual pain or discomfort
Change in colour
Bleeding without injury
It is important to monitor any changes that occur, especially colour changes, bleeding, and pain. The toenail is not an uncommon location for cancer in the foot. A hardened nail can change its appearance, and the loss of the nail structure can be replaced with strangely shaped skin.
A lady in her 70s wondered where her nail had gone, as it had an unusual appearance. I undertook a biopsy, removing a small piece of skin through the nail, and found this was a squamous cell carcinoma. This was not life-threatening, but she did have to lose a little bit of toe with her nail bed.
Pigments in the nail bed are more than likely due to an old blister that turned dark after injury—the pocket of blood changes colour from red to brown. Where there has been no known painful damage, then it could be the shoe causing the blood to be trapped under the nail after a walk, for instance. Always check that the pigment is not just a dye stain from the inside of your shoe. It should wipe off.
However, if the pigment is dark and spreads, bleeds, or is painless, and the nail itself changes or has a long, thin streak of dark pigment, this may be a type of cancer called sub-ungual melanoma.
Biopsy or taking a sample of the pigmented cell with normal skin is essential to classify its origin. I have biopsied many nails and nail beds; most are normal, but it is not easy to tell without a laboratory report. Today, the newer technique of diagnosing with a dermatoscope can reduce the need for some biopsies, and this is certainly recommended.
Thanks for reading ‘Cancer and the Foot’, written by David Tollafield and inspired by Podiatrist and foot cancer specialist, Afni Shah-Hamilton (2020).
You can connect to David on this site.
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