Skin Cancer 101: Symptoms, Causes, Types, Treatment & Prevention

Reports say that the incidences of skin cancer in Singapore is rising. In the last 50 years, the rate of non-melanoma skin cancer in people older than 65 had doubled. Alarmingly, the incidences also increased among the younger population aged 35 to 65. 

Formerly, people believed that the highest risk of skin cancer lies only in people with fair skin. Now, we understand that other factors, mainly our exposure to sunlight, come into play. Here’s what you need to know about skin cancer in Singapore. 

What is Skin Cancer?

Cancer happens when cells behave abnormally and multiply uncontrollably, resulting in a tumour that may spread to nearby tissues and distant organs. Skin cancer indicates that the tumour originated in the skin. 

Most cases of skin cancer start in areas exposed to sunlight. But there are also instances when cancer develops in unexposed skin. There are several types of skin cancer; each type presents different symptoms and requires different treatment. 

Types of Skin Cancer

The types of skin cancer depend on the location where it developed. Case in point, if the tumour originated in cells called basal cells, then the patient has basal cell carcinoma. Now, should the patient develop cancer in the cells that give our skin colour, then he or she most likely has melanoma. 

Here’s an overview of the different types of skin cancer:

Basal Cell Carcinoma

Basal cell carcinoma is the most common type of skin cancer, accounting for about 80% of all skin cancer cases. It starts in the round basal cells found in the epidermis, the outer layer of the skin. 

The most prominent risk factor in developing basal cell carcinoma is sun exposure, which is why most cases occur in the head and neck. However, please keep in mind that this type of skin cancer can also happen in skin that’s not usually exposed to the sun. 

Fortunately, basal cell carcinoma develops slowly and rarely spreads to other parts of the body. 

Squamous Cell Carcinoma

Among the types of skin cancer, squamous cell carcinoma is the second most common, accounting for about 20% of all skin cancer cases. 

The squamous cells where this type of cancer develop are also found in the epidermis, and like basal cell carcinoma, squamous cell carcinoma is highly associated with sun exposure. As such, the areas most commonly affected by squamous cell carcinoma are those exposed to the sun, like our lips or the outside of the mouth. Interestingly, it can also occur in hidden areas like the anus and vagina, burned skin, skin damaged by chemicals, or parts exposed to x-ray. 

Approximately 2 to 5% of squamous cell carcinomas spread to other body parts.

Melanoma

Underneath the epidermis is the inner layer of the skin called the dermis. Now, in the area where these two layers meet, you can find the melanocytes cells that produce melanin, the pigment that gives our skin its colour. 

Melanoma skin cancer starts in the melanocytes. Among all the skin cancer types, it is the most serious.

Merkel Cell Cancer

Finally, we have the Merkel cell cancer, also called the neuroendocrine carcinoma of the skin. You can find the Merkel cells just underneath the skin and in the hair follicles. For this reason, the most common sites of neuroendocrine carcinoma of the skin are the head and neck regions. 

Merkel cell cancer is a rare type of skin cancer, but according to reports, it is aggressive and tends to grow and spread quickly. 

Skin Cancer Symptoms

The symptoms of skin cancer highly depend on the type. To spot skin cancer early, consider the following: 

Symptoms of Basal Cell Carcinoma

The first thing to keep in mind in spotting basal cell carcinoma is that it usually happens in sun-exposed skin. People with fair skin are more likely to develop this type of skin cancer, but those with a darker complexion may also be affected. 

The symptoms of basal cell skin cancer include:

• A pearl-like bump or pinkish patch on the skin. Some people also describe it as flesh-coloured skin growth. 
• A lesion that bleeds or scabs, heals, and then returns. 

Note: Prompt basal cell skin cancer treatment is crucial. Left untreated, basal cell carcinoma may grow deep and affect the nerves and bones, potentially causing permanent damage. The good news is, basal cell skin cancer symptoms are easy to detect, so immediate intervention is likely. 

Symptoms of Squamous Cell Skin Cancer

People with fair skin are more likely to develop squamous cell carcinomas, especially in the sun-exposed body parts. Interestingly, when it occurs to people with a darker complexion, the affected areas are those not usually exposed to the sun. 

Squamous cell skin cancer symptoms include:

• A red, firm bump or nodule on the skin. In some cases, it looks like a scaly, crusted patch. 
• A sore that heals and then returns. 

Note: Like basal cell skin cancer, squamous cell carcinoma may also damage the nerves and bones if left untreated. Immediate skin cancer treatment is crucial. 

Symptoms of Melanoma

Melanoma skin cancer can develop anywhere in the body, regardless of whether the area is frequently exposed to the sun or not. But what’s unique about this skin cancer is its tendency to develop in an existing mole. 

The signs of melanoma skin cancer include:

• A “skin cancer mole,” which looks like a large brown spot with darker speckles. 
• Skin cancer may also develop in a mole that bleeds or changes appearance, size, or texture. 
• A small lesion that wasn’t previously there; often this lesion has an irregular border and may appear red, white, pink, or blue-black. 
• Sometimes the lesion also itches and burns. 
• In people with a darker complexion, the lesion may develop in the palms or soles of the feet. 

Note: Melanoma is the most serious skin cancer, so heading straight to the doctor once you suspect it is crucial. 

Symptoms of Merkel Cell Skin Cancer

As mentioned earlier, the rare Merkel cell skin cancer commonly starts in the head and neck regions. 

Merkel cell skin cancer signs include the appearance of a shiny nodule just beneath the skin or under the hair follicles. 

When to Seek Medical Help

It may be a little overwhelming to memorise all the signs of skin cancer, so to make it easier for you, remember to seek medical help if you notice the early signs of skin cancer; this typically includes a new, unexplainable or unexpected lesion on your skin, especially one that heals and then comes back. 

For the symptoms of melanoma skin cancer, refer to the ABCDE guide:

• Asymmetry: The other half of the lesion is not consistent with the other half. 
• Border: The lesion has ragged edges. 
• Colour: Pointing to uneven shades of white, red, tan, brown, black, or blue. 
• Diameter: The lesion has a significant size, more than 6 mm. 
• Evolution: The lesion is going through significant changes. 

Skin Cancer Causes and Risk Factors 

Now that you have a clearer picture of the symptoms of skin cancer, let’s talk about the causes and risk factors. 

According to experts, the primary cause of skin cancer is exposure to ultraviolet radiation from the sun. However, do note that the UV rays from tanning beds are just as dangerous. Besides being exposed to the harmful UV rays, the other risk factors include:

• A family history of skin cancer. 
• Fair skin complexion, including those with freckled skin, light eyes, and blond hair. 
• A job that involves consistent exposure to the harmful UV rays of the sun. 
• A history of bad sunburn or significant exposure to radiation. 
• The presence of multiple, large and irregular moles. 

Skin Cancer Stages and Diagnosis

Unlike other types of cancer that require multiple tests, a skin cancer diagnosis usually only needs two things: an examination of the skin cancer symptoms and skin biopsy. 

In examining the skin cancer signs, the doctor will pay close attention to the appearance of the lesion. In a skin biopsy, he or she will take a sample from the lesion and send it to the laboratory to check for cancer cells. 

Once confirmed, the next step is staging. 

Staging determines the extent of the skin cancer and, of course, the treatment. 

Staging For Basal Cell and Squamous Cell Carcinomas

Reports say that patients usually do not need staging for basal cell carcinoma since they rarely spread. Bigger squamous cell skin cancers might need staging, but since most cases do not metastasise, staging is also rarely done. 

Even so, below are the meanings behind non-melanoma cancer stages:

Stage 0: Also called Bowen’s disease or the pre-malignant or precancerous stage. This indicates that the cancer is still where it originally developed. Left untreated, it might progress into squamous cell carcinoma. 

Stage 1: This means that the cancer is 2 cm in diameter or less AND has one high-risk feature. High-risk features include:

• The tumour started in the lip or ear. 
• It has a thickness of more than 2mm. 
• It has penetrated the lower dermis. 
• It has penetrated the space around a nerve. 
• The cancer cells look very different from normal cells. 

Stage 2: It means that the tumor is more than 2cm in diameter AND has 2 or more high-risk features. 

Stage 3: It means that the tumour has grown into a bone in the face OR the tumour has affected a lymph node on the same side of the body.

Stage 4: This means that the tumour has infiltrated the spine or skull OR has spread to farther lymph nodes or other organs. 

Staging For Melanoma

Since the signs of melanoma skin cancer are quite different, the staging is a little different too: 

Stage 0: Also called melanoma in situ, this means that the cancer is still in the site where it developed. 

Stage 1: The tumour is 2 mm thick or less. It has not spread to lymph nodes or organs, but may or may not be ulcerated (with a breakdown of skin). 

Stage 2: The tumour is at least 1 mm in thickness and may grow to more than 4 mm. It hasn’t spread to the lymph nodes and other organs yet, and may or may not have ulceration. 

Stage 3: The tumour has spread to nearby lymph nodes but not to distant sites. The original cancer may no longer be visible, but if it is, it might be bigger than 4mm and present with ulceration. 

Stage 4: The cancer has spread to distant organs. 

Staging For Merkel Cell Cancer

Merkel cell carcinoma typically involves 4 stages, from 1 to 4. As the tumour grows and involves other structures like lymph nodes and organs, the higher the stage is. Case in point, stage 4 indicates that cancer has spread to distant sites. 

Skin Cancer Treatment

The treatment for skin cancer depends largely on the type and stage of cancer, and the patient’s tolerance to treatment and overall health. Skin cancer treatment in Singapore includes:

• Surgery to remove the tumour. In many cases, surgery is often the only treatment the patient needs, especially when the tumour is detected early. 
• Radiotherapy may be required if some cancer cells are still present after the surgery. This is also a common option if the site of cancer is difficult to operate on. 
• Cryotherapy may be the treatment of choice for small, superficial tumours. In this method, the doctor uses liquid nitrogen to freeze and destroy the tumour. 
• Topical chemotherapy, which uses creams to destroy the cancer cells. 
• Immunotherapy that uses creams to stimulate our immune system to kill cancer cells is also an option. 
• Photodynamic therapy is a new kind of skin cancer treatment. It uses light-sensitive medications and a special light to destroy cancer cells. 

Now, if cancer has already spread, the doctor may opt for a combination of surgery, chemotherapy and radiotherapy. 

Skin Cancer Prevention

The best way to protect yourself from skin cancer and its signs is to protect yourself from sun exposure. 

For instance, avoid going out during the hottest time of the day. If you really need to, don’t forget to wear sun protection like shades, a wide-brimmed hat, and long-sleeved shirts. Applying sunscreen with a Sun Protection Factor of 15 daily also helps. 

Are You Worried About Skin Cancer? 

If you’re worried about your risk, don’t hesitate to go for skin cancer screenings in Singapore. Likewise, you can also consult a doctor online to assess you for skin cancer symptoms, or request a physical visit by our house call doctors for a more convenient check-up. 

If you have been diagnosed with skin cancer and could use a personalised care plan for recovery, consider our cancer care services. A suitable trained caregiver or qualified nurse will be assigned to you and will provide the support you need in the comfort of your home. 

Sometimes, joining a support group and getting in touch with other skin cancer patients and survivors may help. The National Skin Centre, for instance, offers various support to people with long-term skin conditions. You can also check out the list of cancer support groups in Singapore.