Skin cancer (non-melanoma): Symptoms and diagnosis
Skin cancer is one of the most common types of cancer. Non-melanoma skin cancer refers to a group of cancers that slowly develop in the upper layers of the skin.
The term non-melanoma distinguishes these more common types of skin cancer from the less common skin cancer. These are known as melanoma and can be more serious.
Non-melanoma skin cancer affects more men than women and is more common in the elderly.
The first sign of non-melanoma skin cancer is usually the appearance of a lump or discoloured patch on the skin. This continues to persist after a few weeks, and slowly progresses over months or sometimes years. This is the cancer or tumour.
In most cases, cancerous lumps are red and firm and sometimes turn into ulcers. Cancerous patches are usually flat and scaly.
Non-melanoma skin cancer often develops on areas of skin exposed to the sun. These could be the face, ears, hands, shoulders, upper chest and back.
When to get medical advice
See your GP if you have any skin abnormality. This could be a lump, ulcer, lesion or skin discolouration that hasn't healed after 4 weeks. While it's unlikely to be skin cancer, it's best to be sure.
Types of non-melanoma skin cancer
Non-melanoma skin cancers usually develop in the outermost layer of skin (epidermis). They are often named after the type of skin cell from which they develop.
The two most common types of non-melanoma skin cancer are:
- basal cell carcinoma (BCC)
- squamous cell carcinoma (SCC)
Basal cell carcinoma
Basal cell carcinoma (BCC) is also known as a rodent ulcer. BCC starts in the cells lining the bottom of the epidermis and accounts for about 75% of skin cancers
Basal cell carcinoma (BCC) usually appears as a small, shiny pink or pearly-white lump. It has a translucent or waxy appearance. It can also look like a red, scaly patch.
There's sometimes some brown or black pigment within the patch.
The lump gets bigger and may become crusty, bleed or develop into a painless ulcer.
Squamous cell carcinoma
Squamous cell carcinoma (SCC) starts in the cells lining the top of the epidermis and accounts for about 20% of skin cancers.
Squamous cell carcinoma (SCC) appears as a firm pink lump with a rough or crusted surface. There can be a lot of surface scale and sometimes even a spiky horn sticking up from the surface.
The lump is often tender to touch, bleeds and may develop into an ulcer.
Bowen's disease is a precancerous form of SCC. It is sometimes referred to as squamous cell carcinoma in situ. It develops slowly and is easily treated.
The main sign is a red, scaly patch on the skin that may itch. It affects elderly women and is often found on the lower leg. But it can appear on any area of the skin.
Bowen's disease is not classed as non-melanoma skin cancer. But it can sometimes develop into squamous cell carcinoma if left untreated.
Actinic keratoses, also known as solar keratoses, are dry, scaly patches of skin. These are caused by damage from years of sun exposure.
The patches can be pink, red or brown, and can vary in size from a few millimetres to a few centimetres across.
The affected skin can sometimes become very thick, and the patches can look like small horns or spikes.
Actinic keratosis isn't classed as non-melanoma skin cancer. But there's a small risk that the patches could develop into squamous cell carcinoma if untreated.
Overexposure to ultraviolet (UV) light is the main cause of non-melanoma skin cancer. UV light comes from the sun, as well as from artificial tanning sunbeds and sunlamps.
Sunlight contains three types of UV light:
- ultraviolet A (UVA)
- ultraviolet B (UVB)
- ultraviolet C (UVC)
UVC is filtered out by the Earth's atmosphere. UVA and UVB damage skin over time, making it more likely for skin cancers to develop. UVB is thought to be the main cause of non-melanoma skin cancer.
Factors that can increase your risk of developing non-melanoma skin cancer include having:
- a previous non-melanoma skin cancer
- a family history of skin cancer
- pale skin that burns easily
- a large number of moles or freckles
- medication that suppresses your immune system
- a co-existing medical condition that suppresses your immune system
Using sun lamps and tanning beds, increase your risk of developing skin cancer.
Repeated sunburn, either by the sun or artificial sources of light, will make your skin more vulnerable to non-melanoma skin cancer.
In most cases, non-melanoma skin cancer doesn't run in families. But research has shown that some families have a higher than average number of members who develop the condition.
For example, if you have a parent who's had squamous cell carcinoma, your risk of also getting it is 2 to 3 times higher than average.
Having a family history of melanoma also increases your risk of getting basal cell carcinoma.
Other risk factors
Certain factors increase your chances of developing all types of skin cancer.
- having pale skin that doesn't tan easily
- have blonde or red hair
- having blue eyes
- older age
- having a large number of moles
- having a large number of freckles
- having an area of skin that has been damaged by burning or radiotherapy treatment
- having a condition that suppresses your immune system, such as HIV
- having medicines that suppress your immune system (immunosuppressants), commonly used after organ transplants
- exposure to certain chemicals, such as creosote and arsenic
- having been previously diagnosed with skin cancer
The Irish Cancer Society website has more information about skin cancer.
Preventing non-melanoma skin cancer
Non-melanoma skin cancer isn't always preventable. But you can reduce your chances of developing it by avoiding overexposure to UV light.
You can protect yourself from sunburn by using high-factor sunscreen, dressing sensibly in the sun. Limit the amount of time you spend in the sun during the hottest part of the day.
Avoid using sunbeds and sunlamps.
Checking your skin for signs of skin cancer can help lead to an early diagnosis. This can increase your chances of successful treatment.
Your GP can examine your skin for signs of skin cancer. They may refer you to a skin specialist (dermatologist) or a specialist plastic surgeon if they're unsure or suspect skin cancer.
You'll have an urgent referral if you have squamous cell skin cancer.
Basal cell skin cancers usually don't need an urgent referral. Bu but you should still see a specialist within 18 weeks.
The specialist will examine your skin and may carry out a biopsy to confirm a diagnosis of skin cancer.
A biopsy is a procedure where some of the affected skin is removed so it can be studied under a microscope.
If your GP suspects skin cancer they may refer you to a skin specialist (dermatologist). The specialist should be able to confirm the diagnosis by carrying out a physical examination.
But they'll probably also perform a biopsy. This is a minor surgical procedure where a part or all of the tumour is removed and studied under a microscope.
This is usually carried out under a local anaesthetic. This means you'll be conscious but the affected area will be numbed, so you won't feel any pain.
A biopsy lets the dermatologist find out the type of skin cancer you have and if there's any chance of it spreading to other parts of your body.
Skin cancer can sometimes be diagnosed and treated at the same time. The tumour can be removed and tested. You may not need further treatment because the cancer is unlikely to spread.
It's usually several weeks before you receive the results of a biopsy.
If you have basal cell carcinoma, further tests aren't usually needed. This is because it's very unlikely that the cancer will spread.
But you may have a second basal cell carcinoma on a different area of skin. It makes sense to have all of your skin examined by the skin expert.
In rare cases of squamous cell carcinoma, further tests may be needed. This is to make sure the cancer hasn't spread to the lymph nodes or another part of your body.
These tests may include a physical examination of your lymph nodes. If cancer has spread, it may cause your glands to swell.
If the dermatologist thinks there's a significant risk of the cancer spreading, it may be necessary to perform a biopsy on a lymph node. This is called a fine needle aspiration (FNA).
During FNA, cells are removed using a needle and syringe so they can be examined.
Finding cancerous cells in a nearby lymph node would suggest the squamous cell carcinoma has started to spread to other parts of your body.
Staging skin cancer
Staging is used to describe how far a tumour has spread. The stage of your cancer will help determine your recommended treatment.
For non-melanoma skin cancer, this only applies to squamous cell carcinoma. There's no staging system for basal cell carcinoma.