Dear Editor,
An overall reduction in skin cancer diagnoses is being reported during the coronavirus pandemic. 1 The cause for this decline is yet unknown and is likely to be multifactorial. It may be due to longer processing times for non‐coronavirus concerns at general practitioners and hospitals. Maybe fewer people are consulting the healthcare system with skin cancer suspicion, either because something is stopping them or because they do not have skin cancer in focus.
This study investigated whether there has been a decrease in public awareness of skin cancer during the coronavirus pandemic in 2020 compared to 2019. Additionally, the study examined if there has been a development through the pandemic. Therefore, public interest was investigated in the early phase and the latter part of 2020.
Internet traffic can be a proxy for public awareness. 2 Worldwide people search for health‐related information online, which makes web search queries on Google Trends a valuable data source on health tendencies. 3
The public awareness of skin cancer was investigated using Google Trends. Google Trends provides information on how many hits different terms had in a given week on Google. The highest interest on a search query is quantified as 100 relative search volume (RSV), decreasing to 0 RSV representing no interest (www.support.google.com/trends). Worldwide public query data for the following terms “skin cancer,” “melanoma,” “basal cell carcinoma,” and “squamous cell carcinoma” between March 2019 and December 2020 were downloaded.
Data from the coronavirus pandemic from March 2020 to December 2020 were divided in an early and a late period of equal length, the early coronavirus pandemic being from March to July and the late being from August to December. The level of RSV for each web search query during the two parts of the pandemic in 2020 was compared to the level in the corresponding time period in 2019. Welch's t‐test performed in IBM SPSS statistics version 25 (IBM, USA) was used to investigate if the mean RSVs were significantly different. P‐values below 0.05 were considered significant.
The awareness of “skin cancer,” “melanoma,” “basal cell carcinoma,” and “squamous cell carcinoma” was significantly reduced (P < 0.001) during the first 5 months of the pandemic compared to 2019 with a mean difference in RSV between −9 and −17.
In the latter part of 2020, smaller reductions in public awareness were found with a mean difference in RSV between −3 and −12. For “skin cancer,” “melanoma,” and “basal cell carcinoma,” the reduction was statistically significant (P ≤ 0.002). For squamous cell carcinoma, the reduction was statistically insignificant (P = 0.092). Table 1 presents all results.
Table 1.
Reduction in relative search volume (RSV) for worldwide Google searches for skin cancer‐related web search queries during the coronavirus pandemic in 2020 compared to the same time period in 2019
| Web search query | Mean difference in RSV (P‐value) | |
|---|---|---|
| March–July 2020 compared to 2019 | August–December 2020 compared to 2019 | |
| Skin cancer | −15 (P < 0.001) | −7 (P < 0.001) |
| Melanoma | −16 (P < 0.001) | −12 (P < 0.001) |
| Basal cell carcinoma | −17 (P < 0.001) | −11 (P = 0.002) |
| Squamous cell carcinoma | −9 (P < 0.001) | −3 (P = 0.092) |
It is very unlikely that there has been a real decline in skin cancer incidence in 2020. 1 The declining number of patients diagnosed with skin cancer during the coronavirus pandemic is most likely due to missed diagnoses. As a positive prognosis is highly dependent on a diagnosis being made at an early stage of the disease, it is important to re‐establish timely skin cancer diagnosis. 4 , 5 To be able to do this, it is important to know the reasons for the delay. This study suggests decreased worldwide public awareness of skin cancer as part of the multifactorial cause. Awareness was particularly reduced in the first months of the pandemic and was still reduced in the latter part of 2020. Google Trends can be used to follow the interest in skin cancer during the continued coronavirus pandemic.
Ethical approval
No ethical approval from the Committee on Health Research Ethics was needed. The data used in this study were freely available information on trends.google.com and were completely anonymized.
Conflict of interest: None.
Funding source: None.
References
- 1. Earnshaw CH, Hunter HJA, McMullen E, et al. Reduction in skin cancer diagnosis, and overall cancer referrals, during the COVID‐19 pandemic. Br J Dermatol 2020; 183: 792–794. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Ling R, Lee J. Disease monitoring and health campaign evaluation using Google search activities for HIV and AIDS, stroke, colorectal cancer, and marijuana use in Canada: a retrospective observational study. JMIR Public Health Surveill 2016; 2: e156. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3. Heerfordt C, Heerfordt IM. Has there been an increased interest in smoking cessation during the first months of the COVID‐19 pandemic? A Google Trends study. Public Health 2020; 183: 6–7. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Pollack LA, Li J, Berkowitz Z, et al. Melanoma survival in the United States, 1992 to 2005. J Am Acad Dermatol 2011; 65: S78.e1–S78.e10. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Thompson AK, Kelley BF, Prokop LJ, et al. Risk factors for cutaneous squamous cell carcinoma recurrence, metastasis, and disease‐specific death. JAMA Dermatol 2016; 152: 419–428. [DOI] [PMC free article] [PubMed] [Google Scholar]