A new study has found that more people are now dying from non-melanoma skin cancer (NMSC) worldwide than from melanoma.
The study, conducted by researchers at Nice University Hospital in France, used patient data collected by the International Agency for Research on Cancer (part of the World Health Organization). It showed that while skin cancer caused 57,000 deaths globally in 2020, non-melanoma skin cancer was responsible for even more; Where 63,700 people lost their lives. The study upends conventional wisdom about the scale of the threat NMSC poses.
NMSC is considered less dangerous than other types of cancer; It is rarely fatal. It is often excluded from national cancer registry reports of overall cancer numbers. However, “rarely fatal” is not the same as “never fatal,” and if a large enough number of people develop this type of cancer, it can lead to a lot of deaths, a new report shows, According to what was reported by the “Science Alert” website from the prestigious scientific “The Conversation”.
Melanoma and NMSC share some features, as both are closely related to exposure to ultraviolet radiation either from the sun or from tanning beds. UV radiation is capable of producing cancer-causing mutations that lead to the formation of both skin cancer and NMSC.
The past several decades have seen significant increases in the incidence of both types of cancer; People’s holiday destinations and attitudes towards tanning have changed. Most of these cancers occur in white people; However, people with dark skin can also get skin cancer. Unfortunately, it often goes undiagnosed due to a lack of awareness among both patients and dermatologists.
However, there are some important differences between melanoma and NMSC.
While UV radiation is a risk factor for both, NMSC is more associated with chronic exposure to it all the time. As a result, tumors often arise on the face and head.
In contrast, occasional severe sunburn is closely linked to melanoma, especially on the torso.
There are two main types of NMSC:
– Basal cell carcinoma (BCC)
– Squamous cell carcinoma (SCC).
Both arise from a type of skin cell called keratinocyte.
Keratinocytes are the main type of cell that makes up the epidermis, the outer layer of skin. Mutations in keratinocytes, caused for example by exposure to ultraviolet radiation, can bypass the internal checks and balances that normally prevent cells from dividing uncontrollably, leading to tumor formation.
In contrast, melanomas are caused by cancer-promoting mutations in a different type of skin cell called melanocyte. There are about ten times fewer melanocytes than keratinocytes in the skin, but they play an important role in protecting our skin from damage by producing melanin.
Melanin is the pigment that determines our natural skin color and is produced in greater quantities after exposure to ultraviolet rays, causing tanning.
How do deaths occur?
Most cancer deaths result from secondary tumors that arise when cells of the original tumor break off and spread to distant sites in the body. Skin cancers are no exception.
However, metastasis is a very difficult process for cancer cells. It first needs to invade the surrounding tissue and then overcome the pressure of transport around the bloodstream before it can finally establish a colony in an environment completely different from the skin.
Melanoma cells are more effective at achieving all steps of metastasis than NMSCs; For example, melanoma cells share some characteristics with cells in the brain, and can therefore easily adapt to the brain as a new environment, forming secondary tumors there.
If it is the case that NMSC are much less likely to form dangerous secondary tumors, why do they cause more deaths than melanoma?
This is partly due to the numbers involved; While we have a good idea of how many people around the world develop melanoma each year, NMSC numbers are much less clear. But we know that the current official statistic of 1.2 million cases per year (compared to 325,000 cases of melanoma) is likely to be a gross underestimate. This is due to inconsistencies in how data on NMSC cases are collected and reported between different countries.
These data gaps mean that it is very difficult to get a complete picture of trends in the number of NMSC cases and how likely they are to cause death. Despite this gap, a particularly troubling part of this report is its conclusion that where you live in the world has a significant impact on how likely you are to survive an NMSC diagnosis. In this context, like all types of cancer, the earlier NMSC can be diagnosed and treated, the greater the chance of a positive outcome. It remains to be determined whether the tendency to view NMSC as relatively harmless has played any role in this trend, or whether it is entirely due to other factors such as easy access to diagnosis and treatment.
Optimistic outlook
Another, more optimistic reason for NMSC overtaking melanoma as a cause of cancer death may be the significant progress made in melanoma treatment over the past few years. After decades of increases in the annual number of deaths from skin cancer, the UK has finally turned a corner, and fewer people are now dying, although the number of cases continues to rise.
This trend is thanks to the availability of a host of new targeted treatments for melanoma that are saving lives every day. But prevention is always better than cure, and clearly more needs to be done to prevent these cancers from occurring in the first place. This can be achieved by ensuring that sun protection messages reach everyone at risk.
2023-10-17 14:17:11
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