Melanoma thickness: the role of patients' characteristics, risk indicators and patterns of diagnosis

Factors associated with early vs. late diagnosis of cutaneous melanoma remain poorly understood.

To identify factors with a significant impact on melanoma thickness.

Patients with previous melanoma (n = 347, median age at diagnosis: 56.5 years, 44.7% female, 55.3% male) were recruited for this monocentre, non-randomized, observational study between April 2012 and March 2013. All patients were assessed by means of a structured interview and systematic clinical and dermoscopic full-body examination. Melanoma thickness in association with patients' characteristics, risk indicators and patterns of diagnosis was submitted to statistical analyses.

Univariate analyses revealed associations between a statistically significant lower Breslow thickness and participation in specialized dermoscopic screening programs, personal history of more than one previous melanoma, diagnostic examination with a dermatoscope, diagnostic examination by board certified dermatologist, high number of common and/or atypical nevi, younger age at time of diagnosis, higher level of education, or superficial spreading or lentigo maligna melanoma subtype (all P ≤ 0.01). In a multivariate regression analysis only three of these criteria: (i) participation in specialized screening programs (P < 0.0001); (ii) melanoma subtype (P < 0.0001); and (iii) diagnostic examination with a dermatoscope (P = 0.040) and one interaction term ('younger age' x 'female sex', P < 0.0001) showed an independent influence on a significantly lower melanoma thickness.

The screening of patients in specialized surveillance programs resulted in melanoma detection at significantly earlier stages. The use of dermoscopy, SSM or LMM histotype and younger age in connection with female sex were also characteristics that were independently associated with significantly thinner melanomas in multivariate analyses.