Space-Time Clustering and Seasonality in Diagnosing Skin Cancers in Wallonia (South-East Belgium)

Abstract

Background: In Westernized populations, the number of diagnosed cases of primary cutaneous cancers, particularly malignant melanomas and basal cell carcinomas (BCC), has been previously shown to fluctuate during specific periods of the year. Objective and Method: The aim of the present 6-year study was to explore the seasonality if any in skin cancer detection in Wallonia (south-east Belgium). Results: For both malignant melanomas and BCC late spring/early summer and mid-autumn were the periods of highest diagnosis prevalence irrespective of gender. The amplitude of this bimodal evolution remained within the range of 2 standard deviations around the monthly means. Similar seasonal variations were also found in non-neoplastic controls consisting of laboratory samplings of onychomycoses and non-infectious onychodystrophies. Conclusion: There is reason to believe that this timing and rhythm is unrelated to any specific cancer chronomics. Rather, the present findings suggest unspecific seasonality in diagnosing skin disorders including malignancies. A variable patient awareness of changing aspects of the skin according to seasons probably represents the major influence of the described space-time clustering of skin cancer diagnosis.

Is melanoma survival influenced by month of diagnosis?

“…Moreover, a clinically based study conducted in Wallonia also found a higher number of cases diagnosed in late spring/early summer [32]. While we found no difference according to age and sex, previous reports suggested that seasonality was more pronounced among females [5,18,29,33] and people over 55 years of age [5,6,12].…”

Interest in Skin Cancer in Urban Populations: A Retrospective Analysis of Google Search Terms in Nine Large German Cities

“…The results of the current study are consistent with previous studies showing a higher number of searches during the summer (30,39). This could be due to the fact that diagnoses of NMSC and melanoma are more common in the late spring and early summer (49), which could influence an increase in search volume. In addition to these factors, search volume might be influenced by public health policies and media campaigns (50).…”

What Do Germans Want to Know About Skin Cancer? A Nationwide Google Search Analysis From 2013 to 2017

“…Moreover, Figure 2 demonstrates that the public interest increases in late spring, when people more frequently wear short-sleeved clothing due to rising temperatures and decreases in late summer when temperatures begin to decrease in Germany [ 36 ]. The seasonal variation may also be affected by diagnoses of NMSC and melanoma, which are reported to be significantly higher in late spring and early summer [ 37 , 38 ]. These seasonal differences in search volume were also reported by Bloom et al with regard to skin cancer and melanoma in the United States [ 17 ].…”