Skin cancer may be more common among the elderly, but recent data shows that it is becoming more frequent in young adults, and even ranks among the ten most common cancers in Singapore. Get more insight into skin cancer, from our interview with Consultant in Dermatology and Dermatological Surgery, Dr Angeline Yong of Angeline Yong Dermatology.
Q: How common is skin cancer?
Skin cancer is the most common form of cancer in the world. In the United States (U.S.), more cases of skin cancer are reported each year than all the other types of cancer combined, and although less common in darker skin types than fairer skin types, it is still a very common form of cancer, with melanoma ranking as one of the top ten most frequent malignant diseases in Singapore. There has also been a rising trend in the incidence of this cancer in men and women over the last 40 years, with skin cancer ranking sixth overall in male cancers and seventh overall in female cancers in Singapore.
According to the Trends in Cancer Incidence in Singapore 2011 to 2015, there were 1,822 cases of skin cancer in Singaporean men and 1,404 in Singaporean women respectively compared to 2008 to 2012, where there were 1,524 cases of skin cancer in Singaporean mean, and 1,273 in Singaporean women.
Skin cancers are predominantly divided into melanoma and non-melanoma skin cancer (NMSC). In Singapore, NMSC is far more common than melanoma. Melanoma is the malignant tumour of melanocytes and behaves more aggressively than melanoma. NMSC, on the other hand, consists of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC), which can be further divided into more subtypes.
Q: Are more younger people developing skin cancer?
Although melanomas commonly occur in the 60’s and 70’s, there seems to be an increase of people under 60 and younger being diagnosed with this disease. In fact, it’s one of the most common cancers in young adults, affecting those in their 20’s and 30’s. Over 7,000 people in the U.S. are expected to die of melanoma in 2019, with melanoma accounting for less than 5% of all skin cancers. Despite this, it causes more than 75% of skin cancer deaths. The world’s highest incidence of melanoma is now in Australia and New Zealand (more than twice as high as in North America). This may be due to how close these countries are to the equator, their greatly reduced ozone layer, and their population of mostly fair-skinned people.
BCC and SCC cancers, collectively known as NMSC, are the most common forms of skin cancers. The predominant histological type is BCC (57.9%) followed by SCC (26.9%). Of the cancers with specific subsites, the majority of both BCC and SCC occur on the head and neck. Compared to melanomas, it’s estimated than more than one million cases of NMSC are diagnosed each year in the U.S. and their incidence is rising rapidly.
Anecdotally, there seems to be more young people (below 65) being diagnosed with skin cancer. It is unclear whether this increase is due to an actual elevation in incidence rates; or a result of increased disease awareness and more health-seeking behaviour among the younger population, as well as a willingness to seek medical advice sooner for an earlier diagnosis and/or treatment. While higher diagnosis in younger patients could be due in part to improved health-seeking behaviour and easy access to medical care, it may also be due to lifestyle factors and low awareness of sun-safe habits. In general, Singaporeans possess minimal awareness of sun protection. Younger Singaporeans also frequently lead a lifestyle of sun exposure without UV protection, and usually do not put sun protection as a priority.
Q: Is there a difference between skin cancer in older patients compared to younger patients?
We do see a difference in younger patients, particularly those in their 20’s or early 30’s. These younger individuals tend to present with more aggressive forms of cancer such as the morpheic, microglandular and infiltrative BCC subtypes. Most skin cancers are caused by cumulative sun damage over many years and it often takes decades for that damage to become cancerous.
SSC for example, may have gone through a precancerous stage, or be associated with other background field damage such as actinic keratoses (AKS) before developing into SCC. Likewise, indolent forms of BCC also tend to develop over many years. Hence, you see older patients in the 60’s age group presenting with a BCC that has been growing for five or six years, sometimes over a decade before seeking medical attention for it. In general, indolent forms of cancer need time to develop, so when you see a young patient with skin cancer, it is often one of the more aggressive forms that grow much more quickly.
Q: What are the risk factors for developing skin cancer?
The number one risk factor is long-term UV exposure, so significant risk factors include having an outdoor job and living in a sunny climate. If you’ve had five or more incidents of bad sunburn with blistered and peeling skin in your childhood and teens, it doubles your risk of developing cancer later in life. An abundance of more than 30 large and irregularly-shaped moles is also a risk factor.
Genetics also contribute to skin cancer development. If a close family member (parent or sibling) has had skin cancer, you are more likely at greater risk. There are likewise well-established genetic conditions that lead to increased skin cancer development at an earlier age. Another high-risk group are immunosuppressed individuals, such as transplant patients who are on long-term immunosuppressants.
Last but not least, having dark skin does not mean you’re immune from skin cancer. Everyone, regardless of skin colour can get this disease. Having said that, people with very fair skin, especially Caucasian redheads, need to take extra precaution against sun damage which is the number one risk factor.
Q: Is skin cancer deadly?
Aggressive skin cancers, such as melanoma and SCC, are certainly fatal. However, if diagnosed early, most forms are treatable. In fact, and when detected early, the 5-year survival rate for early melanoma (from the time of initial diagnosis) is around 92%. Nevertheless, this survival rate drops significantly if the melanoma is thicker or has spread to the lymph nodes. With distant metastasis, the survival rate drops to 23%.
Dr Yong from Angeline Yong Dermatology is an experienced and accomplished Singapore-based dermatologist accredited by the Ministry of Health. Prior to starting her own practice, Dr Angeline Yong was the founding consultant and lead of the hair transplant service of the National Skin Centre. She has in-depth experience and all-round expertise in dermatological surgery – from laser and follicular restoration, Mohs Micrographic Surgery, to other cold steel, scalpel techniques – and was the only dermatologist dual-accredited to perform both Mohs Micrographic Surgery and hair transplantation in the National Skin Centre.