Analysis of global skin cancer epidemiology in 2022 and correlation with dermatologist density

Dear Editor,

Skin cancer represents a significant health burden, with rising incidence worldwide. ¹ We analysed melanoma and non‐melanoma skin cancer rates across 185 countries, examining the relationship with dermatologist density to understand healthcare system effectiveness. The International Agency for Research on Cancer (IARC) GLOBOCAN 2022 estimates provided data for melanoma (ICD‐10 code C43) and non‐melanoma skin cancer (NMSC, ICD‐10 code C44), with NMSC incidence excluding basal cell carcinoma while mortality includes it. ² CDC data contributed melanoma incidence by ethnicity in the United States. ³ Age‐standardized rates per 100,000 person‐years were calculated using the World standard population, accounting for varying population age structures. ⁴ Dermatologist density data was sourced from an unpublished L'Oreal survey covering 31 countries, with density calculated per 100,000 population. ⁵ This survey compiled information from official registries, publications and professional associations. ⁵

In 2022, there were 331,722 estimated melanoma cases (58,667 deaths) and 1.2 million NMSC cases (69,416 deaths) globally. The highest age‐standardized incidence rates (ASR) for melanoma were found in Oceania (29.78/100,000), North America (16.3) and Europe (10.43). Notably, mortality‐to‐incidence ratios were highest in Africa (0.35) and Asia (0.30), compared to North America and Oceania (both 0.02), suggesting potentially worse prognosis. NMSC, while generally less lethal, resulted in more estimated deaths globally than melanoma (69,416 vs. 58,667) due to its much higher incidence, highlighting the importance of including NMSC in skin cancer prevention strategies (Table 1).

TABLE 1.

Estimated incidence and mortality of melanoma and NMSC by continent (GLOBOCAN 2022).

	Melanoma				NMSC				Total
	Incidence		Mortality		Incidence		Mortality		Incidence		Mortality		Mortality‐to‐incidence ratio
	N	ASR	N	ASR	N	ASR	N	ASR	N	ASR	N	ASR
World	331,722	3.22	58,667	0.53	1,234,533	10.37	69,416	0.59	1,566,255	13.59	128,083	1.12	0.08
Africa	7477	0.9	2859	0.37	30,632	3.54	9269	1.18	38,109	4.44	12,128	1.55	0.35
Latin America and the Caribbean	20,291	2.41	5842	0.65	72,981	7.7	8090	0.79	93,272	10.11	13,932	1.44	0.14
Northern America	112,807	16.3	8737	1.06	607,867	62.24	5701	0.59	720,674	78.53	14,438	1.65	0.02
Europe	146,321	10.43	26,180	1.48	330,062	14.22	13,111	0.5	476,383	24.64	39,291	1.98	0.08
Oceania	19,823	29.78	1902	2.28	72,145	113.63	1218	1.3	91,968	143.41	3120	3.58	0.02
Asia	25,003	0.41	13,147	0.21	120,846	1.9	32,027	0.49	145,849	2.32	45,174	0.7	0.30

Abbreviation: ASR, age‐standardized rates per 100,000 person‐years using Segi world standard population.

Certain populations demonstrate increased susceptibility to skin cancers due to physiological conditions, genetic predispositions and lifestyle choices, which partly explain regional disparities. ⁶ Gender analysis revealed equal melanoma incidence between males and females until age 54, after which male incidence rates continuously increased relative to females, reaching a male‐to‐female incidence rate ratio of 2.14 by age 85. Ethnicity data from the United States showed that non‐Hispanic whites had an ASR of 30.2, which was 34 times higher than non‐Hispanic blacks, 25 times higher than non‐Hispanic Asian or Pacific Islanders and 6 times higher than Hispanic. These disparities suggest the need for targeted screening and prevention strategies, particularly in resource‐limited settings.

Dermatologist density varied from 1.05 to 6.08/100,000 between African and European countries. We examined whether high‐incidence countries had higher dermatologist density and whether this density was associated with mortality‐to‐incidence ratios. High incidence is not correlated with high density and countries like Australia, the United Kingdom and Canada achieved low mortality‐to‐incidence ratios despite low dermatologist densities (Figure 1). This suggests successful outcomes depend on factors beyond specialist availability, including public health initiatives, efficient referral systems and integrated pathways. ⁷ , ⁸ Some countries with higher dermatologist densities showed less favourable outcomes. Brazil exhibited high dermatologist density despite low melanoma incidence while maintaining high mortality rates.

FIGURE 1.

Mapping of dermatologist density with age‐standardized incidence and mortality‐to‐incidence ratios of melanoma.

The IARC estimates precision varies across regions for melanoma and NMSC. Countries with high‐quality registries generally provide accurate melanoma data, but NMSC is often underreported even in these nations. In many low‐ and middle‐income countries, estimates for both cancers rely on neighbouring countries' data or mortality‐to‐incidence ratios, affecting accuracy. ⁹ NMSC estimation faces additional challenges due to issues in histological confirmation, multiple NMSCs per patient and outpatient management, leading to significant global underestimation. ¹⁰ Regarding dermatologist density, the absence of official registries in many countries introduces a layer of uncertainty and dermatologists face competing demands from various skin conditions (such as tropical diseases in low‐ and middle‐income countries).

While specialist access is important, successful outcomes depend on healthcare systems that integrate multiple care levels, public health initiatives and efficient resource use, with solutions adapted to local contexts. Future efforts should focus on system‐wide strategies involving GPs, specialized nurses and AI‐powered apps for patient triage/education. Study limitations involve key unmeasured confounders like skin colour population proportion, income among others.

FUNDING INFORMATION

The study was sponsored by La Roche‐Posay Laboratoire Dermatologique.

CONFLICT OF INTEREST STATEMENT

Dr Kerob and Mr Salah are employees of La Roche‐Posay. Pr Ezzedine has served as a consultant for La Roche‐Posay, L'Oréal, Incyte, MSD, BMS, AbbVie, Pfizer and Pierre Fabre. Pr Passeron has served as a consultant for La Roche‐Posay, L'Oréal, SVR, Symrise, Isis Pharma, Bioderma, Beiersdorf, ISDIN, Pierre Fabre and Hyphen. Dr Khurana and Mr Balan are employees of FutureBridge and have served as consultants for La Roche‐Posay.

ETHICAL APPROVAL

Not applicable. This study analysed publicly available aggregated data without direct human subject involvement.

ETHICS STATEMENT

Not applicable.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are openly available in https://gco.iarc.fr/today/en.