The measurement of constitutive and facultative skin pigmentation and estimation of sun exposure in Caucasians with basal cell carcinoma and cutaneous malignant melanoma

Occupational solar exposure and basal cell carcinoma. A review of the epidemiologic literature with meta-analysis focusing on particular methodological aspects

BACKGROUND

Numerous epidemiologic studies and a few systematic reviews have investigated the association between occupational solar exposure and basal cell carcinoma (BCC). However, previous reviews have several deficits with regard to included and excluded studies/risk estimates and the assessment of risk of selection bias (RoSB). Our aim was to review epidemiologic studies with a focus on these deficits and to use meta-(regression) analyses to summarize risk estimates.

METHODS

We systematically searched PubMed (including MEDLINE) and Embase for epidemiologic studies. Study evaluation considered four main aspects of risk of bias assessments, i.e. Selection of subjects (selection bias); Exposure variables; Outcome variables; Data analysis.

RESULTS

Of 56 identified references, 32 were used for meta-(regression) analyses. The overall pooled risk estimate for BCC comparing high/present vs. low/absent occupational solar exposure was 1.20 (95% CI 1.02-1.43); among studies without major deficits regarding data analysis, it was 1.10 (95% CI 0.91-1.33). Studies with low and high RoSB had pooled risk estimates of 0.83 (95% CI 0.73-0.93) and 1.95 (95% CI 1.42-2.67), respectively. The definitions of exposure and outcome variables were not correlated with study risk estimates. Studies with low RoSB in populations with the same latitude or lower than Germany had a pooled risk estimate of 1.01 (95% CI 0.88-1.15).

CONCLUSION

Due to the different associations between occupational solar exposure and BCC among studies with low and high RoSB, we reason that the current epidemiologic evidence base does not permit the conclusion that regular outdoor workers have an increased risk of BCC.

Organ transplant recipients express enhanced skin autofluorescence and pigmentation at skin cancer sites

BACKGROUND

Skin autofluorescence and pigmentation can estimate photodamage and sun exposure. These techniques may quantify differences in actinic damage between high-risk organ transplant recipients (OTRs) and immunocompetent patients.

METHODS

Age and gender-matched OTRs (n = 15) and immunocompetent controls (n = 15) with a new keratinocyte carcinoma (KC) were included. We measured skin autofluorescence (370 nm excitation, F370) and skin pigmentation at five standardized body sites; and determined black light-evaluated solar lentigines on the shoulders and photosensitivity to UVA and simulated solar radiation (SSR) as minimal erythema doses (MED).

RESULTS

F370 autofluorescence values were enhanced at KC site versus other body sites in OTRs (2208 vs. 1458-1898 AU, p < 0.05). Compared with non-OTRs, OTRs expressed higher F370 autofluorescence at KC site (2208 vs. 1385 arbitrary units AU, p = 0.01) and the shoulder (1898 vs. 1525, p = 0.05). Likewise, OTRs had increased skin pigmentation (25.0 vs. 20.8 pigment%, p = 0.05) and solar lentigines (3.5 vs. 3.0, p = 0.048) on the shoulders. MED tests showed increased UVA photosensitivity in OTRs (2.4 vs. 1.7 times higher than expected, p = 0.03), whereas SSR photosensitivity was similar.

CONCLUSION

Quantified F370 autofluorescence, skin pigmentation, and density of solar lentigines could serve to assess photodamage in OTR. Increased UVA photosensitivity may account for higher skin photodamage.

Skin autofluorescence reflects individual seasonal UV exposure, skin photodamage and skin cancer development in organ transplant recipients

IMPORTANCE

Ultraviolet radiation (UVR)-induced skin cancers varies among organ transplant recipients (OTRs). To improve individual risk assessment of skin cancer, objectively quantified skin photodamage is needed.

OBJECTIVES

We measured personal UVR-exposure dose in OTRs and assessed the relation between individual UVR exposure, skin cancer and objectively measured photodamage in terms of skin autofluorescence, pigmentation, and black light-evaluated solar lentigines.

MATERIALS AND METHODS

Danish OTRs with (n=15) and without a history of skin cancer (n=15) kept sun diaries from May to September and wore personal dosimeters recording time-stamped UVR doses in standard erythema doses (SED). Photodamage was quantified as skin autofluorescence with excitation at 370nm (F370) and 430nm (F430), skin pigmentation (pigment protection factor, PPF), and black light-evaluated solar lentigines.

RESULTS

OTRs with skin cancer received a higher UVR dose than OTRs without skin cancer (median 116 SED vs. 67 SED, p=0.07) and UVR exposure doses were correlated with increased PPF (p=0.052) and F370 on the shoulder (F370_shoulder) (p=0.04). We found that skin cancer was associated with F370_shoulder (OR 10.53, CI 3.3-31,938; p=0.018) and time since transplantation (OR 1.34, CI 0.95-1.91, p=0.097). A cut-off at 7.2 arbitrary units, 89% of OTRs with skin cancer had F370_shoulder values above 7.2 arbitrary units and F370_shoulder was additionally related to patient age (p=0.09) and black light-evaluated solar lentigines (p=0.04).

CONCLUSION

F370 autofluorescence indicates objectively measured photodamage and may be used for individual risk assessment of skin cancer development in OTRs.

Effects of intrinsic aging and photodamage on skin dyspigmentation: an explorative study

Photoaging is associated with increasing pigmentary heterogeneity and darkening of skin color. However, little is known about age-related changes in skin pigmentation on sun-protected areas. The aim of this explorative study was to measure skin color and dyspigmentation using image processing and to evaluate the reliability of these parameters. Twenty-four volunteers of three age-groups were included in this explorative study. Measurements were conducted at sun-exposed and sun-protected areas. Overall skin-color estimates were similar among age groups. The hyper- and hypopigmentation indices differed significantly by age groups and their correlations with age ranged between 0.61 and 0.74. Dorsal forearm skin differed from the other investigational areas (p<0.001). We observed an increase in dyspigmentation at all skin areas, including sun-protected skin areas, already in young adulthood. Associations between age and dyspigmentation estimates were higher compared to color parameters. All color and dyspigmentation estimates showed high reliability. Dyspigmentation parameters seem to be better biomarkers for UV damage than the overall color measurements.

A melanoma risk score in a Brazilian population

BACKGROUND

Important risk factors for cutaneous melanoma (CM) are recognized, but standardized scores for individual assessment must still be developed.

OBJECTIVES

The objective of this study was to develop a risk score of CM for a Brazilian sample.

METHODS

To verify the estimates of the main risk factors for melanoma, derived from a meta-analysis (Italian-based study), and externally validate them in a population in southern Brazil by means of a case-control study. A total of 117 individuals were evaluated. Different models were constructed combining the summary coefficients of different risk factors, derived from the meta-analysis, multiplied by the corresponding category of each variable for each participant according to a mathematical expression.

RESULTS

the variable that best predicted the risk of CM in the studied population was hair color (AUC: 0.71; 95% CI: 0.62-0.79). Other important factors were freckles, sunburn episodes, and skin and eye color. Consideration of other variables such as common nevi, elastosis, family history, and premalignant lesions did not improve the predictive ability of the models.

CONCLUSION

The discriminating capacity of the proposed model proved to be superior or comparable to that of previous risk models proposed for CM.

Site-dependent actinic skin damage as risk factor for melanoma in a central European population

Sun exposure is causal for melanoma but is subject to bias of recall so that it is difficult to dissect the role of particular patterns of sun exposure. In this hospital-based case-control study (n = 1991), we aimed to analyze pigmentation traits and signs of actinic damage at different anatomic locations as markers of melanoma risk in central European patients. Although all signs of actinic damage (freckling, wrinkling and solar lentigos) were significantly associated with melanoma risk in multivariate logistic regression models adjusting for age and sex, the strongest associations were observed for the dorsal parts of the body: adjusted odds ratios [OR] were 4.22 for wrinkling on the neck, 3.43 for solar lentigos and 3.37 for freckling on the back (all P < 0.001), respectively. These associations were independent of age, sex and pigmentation traits. Our results indicate that signs of actinic damage are predictors of melanoma risk, particularly on the back.

Visible changes of female facial skin surface topography in relation to age and attractiveness perception

OBJECTIVES

Evolutionary psychology suggests that a woman's age and physical appearance are important mate choice criteria. Given that changes in female facial skin surface topography are important, prominent visible signs of aging, male perceptual sensitivity for variation in this trait may also affect preference and attractiveness judgment.

METHODS

Two experiments were conducted to investigate perception (Experiment 1) and noticeability (Experiment 2) of skin surface topography manipulations in facial images of six British women, aged 45-65 years. In Experiment 1 skin surface topography cues were completely removed on the cheeks, the "crow's feet" area adjacent to the eye, under the eyes, above the upper lip, and on the forehead while, in Experiment 2, it was removed gradually (20% increments) on the forehead and around the eyes. In both experiments, stimuli were presented to American and German participants (total N = 300, aged 15-55 years) in omnibus pair-wise combinations (within-face). With each pair, respondents were asked to select that face which they considered as younger looking (Experiments 1 and 2) and more attractive (Experiment 1).

RESULTS

Faces with skin surface topography cues removed were judged significantly younger and more attractive than their original (unmodified) counterparts, with modifications on the forehead and around the eyes showing the highest differences. In these areas, participants were able to detect at least a 20% visual change in skin surface topography.

CONCLUSIONS

The results support the assertion that even small changes in skin surface topography affect the perceptions of a woman's facial age and attractiveness and may, thus, also influence men's mate preferences.

Meta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factors

A systematic meta-analysis of observational studies of melanoma and family history, actinic damage and phenotypic factors was conducted as part of a comprehensive meta-analysis of all major risk factors for melanoma. Following a systematic literature search, relative risks were extracted from 60 studies published before September 2002. Fixed and random effects models were used to obtain pooled estimates for family history (RR = 1.74, 1.41-2.14), skin type (I vs. IV: RR = 2.09, 1.67-2.58), high density of freckles (RR = 2.10, 1.80-2.45), skin colour (Fair vs. Dark: RR = 2.06, 1.68-2.52), eye colour (Blue vs. Dark: RR = 1.47, 1.28-1.69) and hair colour (Red vs. Dark: RR = 3.64, 2.56-5.37), pre-malignant and skin cancer lesions (RR = 4.28, 2.80-6.55) and actinic damage indicators (RR = 2.02, 1.24-3.29). Sub-group analysis and meta-regression were carried out to explore sources of between-study variation and bias. Sensitivity analyses investigated reliability of results and publication bias. Latitude and adjustment for phenotype were two study characteristics that significantly influenced the estimates.

Meta-analysis of risk factors for cutaneous melanoma: II. Sun exposure

A systematic revision of the literature was conducted in order to undertake a comprehensive meta-analysis of all published observational studies on melanoma. An extensive analysis of the inconsistencies and variability in the estimates was performed to provide some clues about its Epidemiology. Following a systematic literature search, relative risks (RRs) for sun exposure were extracted from 57 studies published before September 2002. Intermittent sun exposure and sunburn history were shown to play considerable roles as risk factors for melanoma, whereas a high occupational sun exposure seemed to be inversely associated to melanoma. The country of study and adjustment of the estimates adjuste for phenotype and photo-type were significantly associated with the variability of the intermittent sun exposure estimates (P = 0.024, 0.003 and 0.030, respectively). For chronic sun exposure, inclusion of controls with dermatological diseases and latitude resulted in significantly different data (P = 0.05 and 0.031, respectively). Latitude was also shown to be important (P = 0.031) for a history of sunburn; studies conducted at higher latitudes presented higher risks for a history of sunburns. Role of country, inclusion of controls with dermatological diseases and other study features seemed to suggest that "well conducted" studies supported the intermittent sun exposure hypothesis: a positive association for intermittent sun exposure and an inverse association with a high continuous pattern of sun exposure.