Routine melanoma skin checks associated with lower all-cause mortality

Lower overall mortality, but not melanoma-specific mortality, was associated with melanoma diagnosed through routine skin checks, according to a study.

“Over the last decade, there has been renewed interest in melanoma screening, driven by the changing landscape of melanoma care,” Caroline G. Watts, PhD, of The Daffodil Centre, The University of Sydney, Cancer Council NSW in Sydney, Australia, and colleagues wrote. “In addition to cancer-specific mortality, the effect of cancer screening on all-cause mortality is also of interest, as reducing deaths from a particular cancer type should translate to an improvement in all-cause mortality unless investigation of positive screening results leads to deaths from other causes.”

Researchers conducted a prospective, population-based cohort study of 2,452 patients (median age at diagnosis, 65 years; age range, 16-98 years) diagnosed with melanoma between Oct. 23, 2006, and Oct. 22, 2007, in New South Wales, Australia.

Melanoma was detected during a routine skin check in 858 (35%) of patients, while 1,148 (47%) found melanoma in a self-check exam, 293 (12%) had their melanoma discovered when checking other skin lesions and 153 (6%) were discovered in another way, according to physician responses to a questionnaire.

Cause of Death Unit Record File and Registry of Births, Death and Marriages were used to identify dates and cause of death and to identify patients. Over the 11-year follow-up period there were 162 deaths from melanoma and 604 deaths from other causes among the patients included in the analysis.

Those whose melanoma was detected via a routing skin check was associated with 59% lower melanoma-specific mortality (subhazard ratio = 0.41%; 95% CI, 0.28-0.6) and 36% lower all-cause mortality (HR = 0.64; 95% CI, 0.54-0.76). These results remained statistically significant for melanoma-specific mortality when adjusted to sociodemographic and some clinicopathologic prognostic factors, however when adjusted to mitotic rate and ulcerations, the association was no longer statistically significant (subhazard ratio = 0.68; 95% CI, 0.44-1.03).

“We found that melanomas discovered in asymptomatic individuals through routine skin checks were thinner, less likely to have been noted to exhibit recent change and associated with lower all-cause mortality than thicker lesions discovered initially by patients,” the authors wrote. “The fact that routing skin-check melanoma detection was significantly associated with lower all-cause mortality but not melanoma-specific mortality in the fully adjusted analyses may reflect residual or unmeasured confounding from sociodemographic characteristics (such as education level), medical access and health-seeking behaviors (such as physical activity) that are independently associated with both routine skin check and overall mortality.”