Melanoma is the most deadly skin cancer originating from melanocytes, and the prognosis of patients with advanced-stage melanoma differs widely between countries (1, 2). The morbidity of melanoma is found to increase worldwide in the past decades (3, 4). Melanoma of skin is more common in Caucasian population and the highest incidence of which was observed in Australasia, followed by North America in 2020 (5). In addition, people who are in older age groups have higher incidence rates of melanoma (6). In parallel, mortality rates have also continued increasing in the oldest patient groups (5). China is predicted to have one of the fastest growing aging populations in the world (7) and will face a heavy burden of melanoma in the future.

Only a few studies explored the burden of melanoma in Chinese population. Wu et al. (8) analyzed data from early round of Global Burden of Disease (GBD) 2017 and found that there has been a substantial increase in the burden of melanoma over the last decade in China. Bai et al. (9) investigated the long-term trends in the incidence and mortality of malignant melanoma, showing that age-standardized incidence rate (ASIR) of melanoma has increased from 1990 to 2019. With rapid population aging and economic development in recent years coupled with significant differences among provinces in China, existing studies may not accurately describe the current burden of melanoma across all provinces and there’s a need to comprehensively and multi-dimensionally investigate the burden of melanoma across different provinces using the latest research data. What’s more, little is known about the drivers of observed changes of burden caused by melanoma in China which could reflect the impact of three explanatory components including population growth, population aging and change of age-specific rates on melanoma burden.

Herein, we presented an updated analysis of the melanoma burden in China from 1990 to 2021 based on the most recent GBD 2021 China subnational study, and analyzed the incidence, mortality, prevalence and disability-adjusted life-years (DALYs) of melanoma by age and sex at both national and subnational level to make better targeted melanoma control policies. We also explored the potential contributions of three components which may drive the changes of death and DALYs due to melanoma during 1990–2021, in order to address corresponding interventions.

Based on the most recent epidemiological data from the GBD 2021 China subnational study, we found that although there was a slight decrease in ASMR and ASR of DALYs, the ASIR and ASR of prevalence in both sexes have risen continuously in the past three decades. Among younger adults aged <60 years, melanoma was more common in men, whereas among older adults who were aged >60 years, it was more common in women. The ASIR was higher in the coastal regions in China in 2021 and the ASR of DALYs was generally higher in the western provinces. Total numbers of death and DALYs of melanoma increased over the study period, mainly driven by population aging in China.

Over the past 30 years, the ASIR of melanoma in China has shown an upward trend, which may be due to increased radiation exposure, and people’s heightened awareness of skin lesions and improved diagnosis (5). Exposure to ultraviolet (UV) radiation in sunlight is one of the environmental risk factors for melanoma. Global warming also may result in increases in air pollutants, acid deposition, ozone depletion and exposure to UV radiation, increasing risk of melanoma (18). Improved public awareness of suspicious pigmented lesions and early, accurate detection has led to more melanoma cases being detected and treated in time. The upward prevalence has been influenced to some extent by the demographic changes in China. Population aging and growth has been rapid over the past few decades in China that it has caused a steady increase in the prevalence of disease (19). The ASMR and ASR of DALYs for cutaneous malignant melanoma in China have declined slightly, which may be due to the accessibility and affordability of health care and advances in medical technology (12).

Men diagnosed with melanoma have higher ASIR and ASMR in 2021. Extrapolated rationale for higher ASIR in men might be the behavior difference between men and women (20). Men in China are less likely to use sun protection and therefore get more exposure to UV rays (21). An online survey showed that only 21% of Chinese participants applied sunscreen, while male participants were less likely to use solar protection (22). Additionally, men are less sensitive to suspicious lesions and are more likely to delay in symptomatic presentation leading to advanced stage of disease than women (23). There are some evidence showing that men have significantly longer delay in seeking medical attention than women whose median and quartiles of delay time were longer than women, especially in some kinds of melanoma (21, 24).

Regarding the sex-age-specific incidence of melanoma, our study is not exactly consistent with the findings of previous studies that were conducted in fair-skinned populations (21, 25). Previous studies observed higher rates of melanoma in women before mid-life in the United States, Canada, Australia, and New Zealand and found an excess in men following mid-life (21, 26) while we found melanoma is more common in men under 60 years of age and women over 60 years of age in China. The reason may be due to differences in population behavior as well as ethnic variations (27). In general, adolescent and young adult women in fair-skinned populations have greater tanning risky behavior and socially determined aesthetic needs to the use of sunbeds, which causes higher melanoma incidence rates in their age (28). In our study, the higher incidence rate in young adult men may be, in part, due to more time spent outdoors, insufficient preventive behaviors and less likely to early detection (29). The higher incident rates observed in older women may be related to hormone change and specific sites of melanoma in Asian populations: acral lentiginous melanoma, a rare subtype of melanoma, is common in Asian, and the progressive decrease in estrogen with age loses its ability to regulate the growth and differentiation of tumor tissue, leaving the cancerous lesions more exposed in Chinese older female (27, 30). However, due to the long history of conflicting published results, whether menopause is associated with melanoma risk still needs to be resolved (30).

Regarding the spatial patterns of melanoma burden in China, the ASIR varied across provinces with higher ASIR in the eastern and northeast China, especially in some coastal provinces. Research conducted in other countries, such as Canada, and the United States has consistently revealed a similar pattern that melanoma is more common in coastal regions compared to inland areas (31–33). For example, it was discovered that Canadian maritime provinces, such as Prince Edward Island with a crude incidence rate of 33.9/100,000, and Nova Scotia with a rate of 30.8/100,000, had higher incidence rates of cutaneous melanoma compared to the inland provinces of Alberta (15.5/100,000), and Saskatchewan (14.5/100,000) (32). Within the same state, California, the incidence of melanoma in coastal counties was also significantly higher than in inland counties with an incidence rate ratio of 1.23 (95% CI: 1.05–1.43) (33).

We also found that the ASR of DALYs was generally higher in the western China. Differences in incidence and DALYs rates of melanoma in different regions of China may be explained by the disparity in medical care and UV exposure. In China, coastal provinces like Zhejiang are more economically developed than other regions and people have better access to better medical care (6, 34). The residents of this region may experience high incidence owing to the earlier detection and advanced medical technology (35). Conversely, the western region has a relatively weak economic foundation and a not-so-advanced health care leading to generally high DALYs rates. In addition, UV radiation as a major environmental risk factor for melanoma may also play a role in geographic disparities. The UV radiation depends on many factors like latitude, altitude, climate, anthropogenic behavior and so on (26). Some coastal and plain areas in China may be exposed to more frequent UV radiation. Most western provinces such as Guizhou are mostly mountainous areas with high altitudes where residents may also suffer high and intermittent UV exposure. The difference in melanoma between mountain and coastal residents may lies in the site of melanoma, with the former occurring more frequently on the head or neck and the latter on the trunk and extremities (31). However, our study did not investigate the difference between anatomical district of melanoma. More detailed analyses of body part of melanoma and geographical location will be needed to better understand its epidemiology. Anthropogenic behavior such as causing damage to the stratospheric ozone layer and using artificial light sources may also cause more UV exposure (36). With steel industry development, Jilin and Hebei (northeast China) may cause serious damage to the atmosphere, weakening absorption of UV rays. Thus people in these region may suffer more UV radiation and cause higher ASR of DALYs (36).

Population aging and growth are the main drivers of the increase in the numbers of death and DALYs of melanoma. Although China’s population growth is slowing, it is aging very rapidly and has the largest older adults population (37, 38). These demographic changes will likely exacerbate the burden on family and public healthcare systems (39). Therefore, effective preventive strategies and measures should be in place to reduce the increasing numbers of death and DALYs from melanoma. The Chinese Government attaches great importance to the prevention and control of cancer. While it is undoubtedly important to emphasize the urgency of control for leading causes of cancer types such as lung, stomach and liver cancer in China (40), tailored prevention and control measures for melanoma should also be in the agenda and steps should be taken to increase the awareness of this malignancy in Chinese population and reduce the burden in the context of an accelerating aging society.

We believe targeted primary prevention and education efforts could reduce the melanoma burden throughout China and high-incidence coastal and western provinces will benefit more (41, 42). Due to the low overall mortality of skin cancer and the insufficient evidence from randomized controlled trials to demonstrate the benefit of skin cancer screening in the general population (43), fewer countries have considered skin cancer screening in their statutory examinations. However, education and awareness about sun protection and the early symptoms of skin cancer remain appealing for this common and visible cancer, especially for melanoma, which could be eminently treated if detected early (44). In addition, patients and their surroundings should take the major responsibility for the early detection of melanoma (45). However, the typical early features of melanoma need to be clarified and publicized so that they can be promoted to population and primary care providers. If such preventive strategies could be implemented in China with a greater focus on specific populations or regions, it would be expected to increase the detection of early-stage melanoma in these rapidly expanding populations and reduce the burden of melanoma in the future.

Strengths of this study include the use of the most recent epidemiological data to show the spatial and temporal trends at both national and subnational level. Although the morbidity of melanoma in Chinese is not as high as western population, the incidence trend is still rising over the past three decades, which indicates the need of strengthening control and prevention of an often-neglected malignancy in the Chinese population. The current study also showed for the first time, the main drivers of the changes in total deaths and DALYs of melanoma using decomposition analysis from 1990 to 2021, providing important evidence to both clinicians and public health practitioners.

There are several limitations to our study. Firstly, the general limitations of the GBD data could affect our study. The study relies on GBD data, which may have fewer sources specific to melanoma in China, potentially affecting the precision of the estimates. However, the GBD modeling tool - Cause of Death Ensemble model, with its powerful modeling capabilities, could effectively compensate for the inadequacy of the data source (11). Secondly, we were not able to analyze the burden of histopathological subtypes of melanoma (like superficial spreading melanoma, nodular melanoma and lentigo maligna melanoma), as disease subtypes are not included in the GBD cause for now. Thirdly, underlying risk factors of melanoma, such as sunburns and the number of melanocytic nevi were not explored in this study due to data availability.

From 1990 to 2021, China has experienced a substantial increase in the burden of melanoma. It is beneficial to develop more targeted strategies for older adults populations, especially for women, to reduce the melanoma burden throughout China, particularly some coastal and western provinces.