Background and Objectives: To our knowledge, this is the first case–control study conducted in the Baltic countries that identified CM risk factors focusing on the investigated subjects’ phenotypic traits, severe sunburns, sunscreen and tanning bed use. Materials and Methods: This study analyses 180 subjects with CM (case group) and 182 randomly selected controls. All participants completed surveys about sun exposure habits and skin phototype (I–IV) according to the Fitzpatrick scale. Skin, eye, and hair colour, number of freckles, and melanocytic nevi greater than 2 mm in diameter (MN > 2 mm) on sites with maximal, intermittent, and minimal sun exposure were examined. Results: We determined five risk factors that significantly increased the odds ratio of CM (OR; 95% confidence interval): tanning bed use compared to non-use (6.46; 1.89–22.96), lack of sunscreen use compared to regular use (7.41; 2.88–19.09), and fair skin compared to medium and olive skin (2.06; 1.03–4.09). The probability of CM also increased with each instance of severe sunburn (2.57; 1.96–3.38) and with each additional MN > 2 mm in sun-exposed areas (1.05; 1.03–1.07). Conclusions: The results of this case–control study offer novel insights into modifiable risk factors for CM, highlighting potential targets for primary prevention strategies in the Baltic countries’ population, with dominant fair phenotypic traits of skin, eye, and hair colour.

Background/Objectives: Sun exposure and ultraviolet (UV) radiation significantly affect human health, especially concerning skin and eye conditions. Sun exposure is a risk factor for both cutaneous melanoma (CM) and cataract. To investigate the association between CM, cataract and the number of common melanocytic nevi (CMNs) in the Lithuanian population. Methods: A case–control study with 180 primary diagnosed CM subjects and 182 healthy controls was conducted. Participants underwent ophthalmic and dermatological examination, where a counting of the common melanocytic nevi (CMNs) on the face, outer surfaces of the upper arms, lower arms and hands was performed. A detailed ophthalmic slit lamp examination was conducted; additionally, lens status and cataract formation were evaluated according to the Lens Opacities Classification System III (LOCS III). Results: Subjects with an LOCS III grade of nuclear opalescence (NO) ≥3 had a 1.82 times higher risk of CM, and patients with a nuclear color (NC) grade ≥3 had a 2.02 times higher risk of CM. LOCS III evaluations of cortical (C) and of posterior subcapsular (P) cataract showed a 5.24 and 6.34 times increased risk of CM, respectively. The CMN number on the face increased CM risk by 1.25 times; on the outer surface of the upper and lower arms, correspondingly 1.05 and 1.04 times; and on outer surface of hands—1.29 times. Conclusions: All types of cataracts were found more often in patients with CM than in healthy subjects. The number of CMNs on the face and outer surfaces of arms and hands could be an indicator of higher risk for CM.

Background/Objectives: This is the first study in Eastern Europe to integrate skin and iris phenotypic characteristics with selected polymorphisms in genes related to skin aging, melanogenesis and skin pigmentation, and inflammatory regulation in relation to cutaneous melanoma (CM) risk. Methods: This case–control study included 180 patients with primary CM identified from the Hospital of the LSMU Kauno klinikos database and 181 controls without a personal history of skin cancer selected from a population-based study in Kaunas. All participants underwent dermatological and ophthalmological examinations and completed questionnaires assessing sun-exposure habits, including severe sunburn history, and Fitzpatrick skin phototype. The total-body number of common melanocytic nevi (CMN) >2 mm in diameter and the number of iris freckles were evaluated using standardized protocols. Five selected genetic polymorphisms, including TYR rs1126809, SLC45A2 rs26722, SLC45A2 rs16891982, IL6 rs1800795, and TNF-α rs1800629, were genotyped. Associations with CM were assessed using multivariable logistic regression. Results: We identified three phenotypical factors independently associated with increased odds of CM (OR; 95% CI): a total-body CMN count >15 (7.89; 4.29–14.53), ≥4 iris freckles (3.70; 2.04–6.74), and a history of severe sunburn (2.76; 1.50–5.07). Compared with Fitzpatrick skin phototype IV, phototypes II (0.35; 0.15–0.82) and III (0.28; 0.11–0.70) were associated with decreased CM odds. In the multivariable model the heterozygous SLC45A2 rs16891982 genotype was associated with increased CM odds (6.64; 1.48–29.83), while the IL6 rs1800795 Mono G genotype revealed an inverse association with CM (0.39; 0.16–0.97). Conclusions: A total-body CMN count >15, ≥4 iris freckles, and severe sunburn history revealed strong independent associations with increased CM risk. However, associations involving SLC45A2 rs16891982 and IL6 rs1800795 in this Lithuanian case–control study were model-dependent. These findings highlight the potential value of integrating selected genetic markers with phenotypic characteristics and sun-exposure history in the development of personalized CM risk prediction models; however, validation in larger populations is required.