Risk factors for basal cell carcinoma in a southern Brazilian population: a case-control study

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.

A meta-analysis of sunburn and basal cell carcinoma risk

Basal cell carcinoma (BCC) is the most common cancer in the United States. Sunburn is a modifiable risk factor for BCC. The objective of this project was to synthesize research on BCC and sunburn to quantify the impact and severity of sunburn at different life stages on BCC risk in the general population. A systematic literature search of four electronic databases was conducted and data were extracted by two independent reviewers using standardized forms. Data from 38 studies were pooled using both dichotomous and dose-response meta-analytic methods. BCC risk increased with ever experiencing a sunburn in childhood (OR=1.43, 95% CI: 1.19, 1.72) and with ever experiencing a sunburn in life (OR= 1.40, 95% CI: 1.02, 1.45). Every five sunburns experienced per decade in childhood increased BCC risk by 1.86 (95% CI: 1.73, 2.00) times. Every five sunburns experienced per decade in adulthood increased BCC risk by 2.12 (95% CI: 1.75, 2.57) times and every five sunburns per decade of life increased BCC risk by 1.91 (95% CI: 1.42, 2.58) times. The data on sunburn exposure and BCC show that an increase in number of sunburns at any age increased the risk of BCC. This may inform future prevention efforts.

Daily Lifestyle and Cutaneous Malignancies

Daily lifestyle is a fundamental part of human life and its influence accumulates daily in the human body. We observe that a good daily lifestyle has a beneficial impact on our health; however, the actual effects of individual daily lifestyle factors on human skin diseases, especially skin cancers, have not been summarized. In this review, we focused on the influence of daily lifestyle on the development of skin cancer and described the detailed molecular mechanisms of the development or regulation of cutaneous malignancies. Several daily lifestyle factors, such as circadian rhythm disruption, smoking, alcohol, fatty acids, dietary fiber, obesity, and ultraviolet light, are known to be associated with the risk of cutaneous malignancies, malignant melanoma, squamous cell carcinoma, basal cell carcinoma, and Merkel cell carcinoma. Although the influence of some daily lifestyles on the risk of skin cancers is controversial, this review provides us a better understanding of the relationship between daily lifestyle factors and skin cancers.

Actinic keratoses: review of clinical, dermoscopic, and therapeutic aspects

Actinic keratoses are dysplastic proliferations of keratinocytes with potential for malignant transformation. Clinically, actinic keratoses present as macules, papules, or hyperkeratotic plaques with an erythematous background that occur on photoexposed areas. At initial stages, they may be better identified by palpation rather than by visual inspection. They may also be pigmented and show variable degrees of infiltration; when multiple they then constitute the so-called field cancerization. Their prevalence ranges from 11% to 60% in Caucasian individuals above 40 years. Ultraviolet radiation is the main factor involved in pathogenesis, but individual factors also play a role in the predisposing to lesions appearance. Diagnosis of lesions is based on clinical and dermoscopic examination, but in some situations histopathological analysis may be necessary. The risk of transformation into squamous cell carcinoma is the major concern regarding actinic keratoses. Therapeutic modalities for actinic keratoses include topical medications, and ablative and surgical methods; the best treatment option should always be individualized according to the patient.

Final diagnosis of 86 cases included in differential diagnosis of American tegumentary leishmaniasis in a Brazilian sample: a retrospective cross-sectional study

BACKGROUND

Cutaneous leishmaniasis is distributed worldwide, including Brazil. Its several clinical forms need to be distinguished from other dermatoses. Clinical similarities and lack of a gold standard diagnostic tool make leishmaniasis-like lesions a challenging diagnosis.

OBJECTIVES.

To report the final diagnosis of patients primarily suspected of having American tegumentary leishmaniasis (ATL).

METHODS.

A retrospective cross-sectional study was conducted on the basis of medical records of 437 patients with clinical suspicion of ATL, registered in electronic hospital system between 1980 and 2013. Demographic, clinical, and laboratory data were compiled.

RESULTS.

Analysis of 86 cases (19.7%) registered as ATL in one of the hypothesis revealed a different final diagnosis; 55 (63.9%) and 31 cases (36.1%) had skin and mucosal lesions, respectively. In 58 cases (67.4%), the requested PCR did not identify Leishmania sp. In 28 cases (32.5%), biopsies established the diagnosis and confirmed tumors, mycobacteriosis, and subcutaneous or systemic mycosis. Overall, 27% of the cases had inflammatory etiology, mainly nasal nonspecific inflammatory processes; 27% had infectious etiology, especially paracoccidioidomycosis and leprosy; 20% had neoplastic etiology, mainly basal and squamous cell carcinoma; 15% had miscellaneous etiology, including neuropathic ulcer, traumatic ulcers, idiopathic ulcer; 11% missed the follow-up.

STUDY LIMITATIONS

Some cases had no final diagnosis due to loss of follow-up.

CONCLUSION.

ATL can be confused with several differential diagnoses, especially inflammatory and infectious granulomatous diseases as well as non-melanoma skin cancers. Clinicians working in tropical areas should be aware of the main differential diagnosis of leishmaniasis-like lesions.

Multiple skin neoplasms in subjects under 40 years of age in Goiania, Brazil

OBJECTIVE

To describe the trend for malignant skin neoplasms in subjects under 40 years of age in a region with high ultraviolet radiation indices.

METHODS

A descriptive epidemiological study on melanoma and nonmelanoma skin cancers that was conducted in Goiania, Midwest Brazil, with 1,688 people under 40 years of age, between 1988 and 2009. Cases were obtained from Registro de Câncer de Base Populacional de Goiânia (Goiania’s Population-Based Cancer File). Frequency, trends, and incidence of cases with single and multiple lesions were analyzed; transplants and genetic skin diseases were found in cases with multiple lesions.

RESULTS

Over the period, 1,995 skin cancer cases were observed to found, of which 1,524 (90.3%) cases had single lesions and 164 (9.7%) had multiple lesions. Regarding single lesions, incidence on men was observed to have risen from 2.4 to 3.1/100,000 inhabitants; it differed significantly for women, shifting from 2.3 to 5.3/100,000 (Annual percentage change – [APC] 3.0%, p = 0.006). Regarding multiple lesions, incidence on men was observed to have risen from 0.30 to 0.98/100,000 inhabitants; for women, it rose from 0.43 to 1.16/100,000 (APC 8.6%, p = 0.003). Genetic skin diseases or transplants were found to have been correlated with 10.0% of cases with multiple lesions – an average of 5.1 lesions per patient. The average was 2.5 in cases without that correlation.

CONCLUSIONS

Skin cancer on women under 40 years of age has been observed to be increasing for both cases with single and multiple lesions. It is not unusual to find multiple tumors in young people – in most cases, they are not associated with genetic skin diseases or transplants. It is necessary to avoid excessive exposure to ultraviolet radiation from childhood.

[Descriptive study on basal cell eyelid carcinoma]

OBJECTIVE

To describe a series of cases of basal cell carcinomas of the eyelid.

METHODS

A descriptive and retrospective study was conducted by reviewing the medical outcome, histopathological history, and photographic images of 200 patients with basal cell eyelid carcinomas. All were treated in the Herzog Carl Theodor Eye Hospital in Munich, Germany, between 2000 and 2013.

RESULTS

In the present study, it was found that females are more affected than males. The mean age of presentation of the tumor occurred at the age of 70 years. In 50% of the cases the tumor was found on the lower lid, especially medially from the center of the lid. The lid margin was involved in 47% of all tumors. The mean diameter was 9.2mm. The recurrence rate after surgery with histologically clear resection margins was 5%. There was a significant relationship between tumor diameter and age. As tumors where located farther away from medial and closer to the lid margin, they became larger.

CONCLUSIONS

There is a predominance of women affected by this tumor. This may be related to the fact that the sample was taken from those attending an oculoplastic surgery clinic, where there are generally more women than men attending. The formation of basal cell carcinomas increases with age. The infrequent involvement of the upper lid could be explained by the protection of the the eyebrow. The frequent involvement of the lower lid may be due to the light reflection (total reflection) by the cornea on the lower lid margin. Also chemical and physical effects of the tears may be more harmful on the lower lid. Patients tend to ask for medical help when they are females, younger, when the tumor is closer to the medial canthus or when the tumor is away from the lid margin.

Indoor tanning and non-melanoma skin cancer: systematic review and meta-analysis

OBJECTIVE

To synthesise the literature on indoor tanning and non-melanoma skin cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed (1966 to present), Embase (1974 to present), and Web of Science (1898 to present).

STUDY SELECTION

All articles that reported an original effect statistic for indoor tanning and non-melanoma skin cancer were included. Articles that presented no data, such as review articles and editorials, were excluded, as were articles in languages other than English.

DATA EXTRACTION

Two investigators independently extracted data. Random effects meta-analysis was used to summarise the relative risk of ever use versus never use of indoor tanning. Dose-response effects and exposure to indoor tanning during early life were also examined. The population attributable risk fraction for the United States population was calculated.

RESULTS

12 studies with 9328 cases of non-melanoma skin cancer were included. Among people who reported ever using indoor tanning compared with those who never used indoor tanning, the summary relative risk for squamous cell carcinoma was 1.67 (95% confidence interval 1.29 to 2.17) and that for basal cell carcinoma was 1.29 (1.08 to 1.53). No significant heterogeneity existed between studies. The population attributable risk fraction for the United States was estimated to be 8.2% for squamous cell carcinoma and 3.7% for basal cell carcinoma. This corresponds to more than 170 000 cases of non-melanoma skin cancer each year attributable to indoor tanning. On the basis of data from three studies, use of indoor tanning before age 25 was more strongly associated with both squamous cell carcinoma (relative risk 2.02, 0.70 to 5.86) and basal cell carcinoma (1.40, 1.29 to 1.52).

CONCLUSIONS

Indoor tanning is associated with a significantly increased risk of both basal and squamous cell skin cancer. The risk is higher with use in early life (<25 years). This modifiable risk factor may account for hundreds of thousands of cases of non-melanoma skin cancer each year in the United States alone and many more worldwide. These findings contribute to the growing body of evidence on the harms of indoor tanning and support public health campaigns and regulation to reduce exposure to this carcinogen.