ReviewMeta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factors
Introduction
This is the third and last part of a systematic meta-analysis on all published studies until September 30, 2002. All main risk factors for melanoma were investigated and results on naevi and sun exposure were published in previous papers 1, 2. In the present work, family history, actinic damage indicators and the remaining phenotypic factors were considered.
At this time, family history is considered one of the most important risk factors for cutaneous malignant melanoma and researches into potential melanoma susceptibility genes are ongoing [3]. Approximately 8ā12% of melanoma patients have a family history [4].
Cutaneous lesions, which may be considered indicators of acute and chronic exposure to UV radiations, were included as photodamage indicators. Actinic keratoses are also called solar keratoses because they indicate that sun damage has occurred. They are precursors of skin carcinomas, which means they can be the first morphological step in the development of skin cancer. It is estimated that up to 10% of active lesions will take the next step and progress to squamous cell carcinoma. In particular we analysed solar lentigo, actinic keratosis, solar elastosis and presence of skin carcinoma.
Several phenotypic characteristics were also analysed (hair colour, eye colour, skin colour, presence of freckles and photo-type), trying to investigate interrelationships and associations with the evaluation of adjustment for reciprocal effect.
Most of the evidence relevant to these factors comes from observational studies in humans, and most of these studies were case-control. Several methodological problems may bias the association between these risk factors and melanoma risk. A deep exploration of heterogeneity between study and possible sources of bias has been carried out searching for significant differences by study features, definitions adopted, characteristics of the populations and of the types of analyses.
Section snippets
Definition of outcome and exposures
The outcome of this systematic meta-analysis was histologically confirmed melanoma.
Selection of articles
Data searches were conducted on Medline (National Library of Medicine, Bethesda USA), using the PubMed interrogation interface, and EMBASE (Elsevier Science, Amsterdam, Holland) using OVID, as in the meta-analysis on naevi count [1]. The reference lists of the retrieved articles and preceding reviews 14, 15 on the topic were also checked. No language or time restrictions were applied.
Primary inclusion criteria, developed for the selection of all relevant articles, consider original independent
Discussion
In the two previous meta-analyses 1, 2, naevi counts and sun exposure experiences have been investigated with all heterogeneity factors. This meta-analysis considered the remaining important risk factors for melanoma. It was decided to avoid the evaluation of risk factors mentioned in certain publications where highly contradictory evidence of an effect was reported, such as sunscreen [56] and oral contraceptives 57, 58. These two risk factors were investigated in two recently published
Conflict of interest statement
The authors have no conflict of interest to disclose.
Acknowledgement
It is a pleasure to acknowledge that his work was conducted within the framework of support of Italian Ministry for University and Scientific and Technological Research (MURST) (āMinistero Istruzione Universit Ć” e Ricercaā), as part of the project āPNR per le Tecnologie in oncologia. Tema 2 1998: Sviluppo di metodologie innovative per la prevenzione (primaria e secondaria) delle neoplasieā, Grant No. 66002 received by the Laboratory of Clinical Epidemiology of āIstituto Dermopatico
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