Abstract: Objectives: To explore the association of colorectal cancer with environmental solar radiation and sun exposure
behavior, considering phenotypic variables (eye color, hair color and skin phenotype), dietary intake of vitamin
D and calcium, and socio-demographic factors.
Study design: Multicenter population-based frequency matched case-control study in Spain (MCC-Spain), with
2140 CRC cases and 3950 controls.
Methods: Data were obtained through personal interviews using a structured epidemiological questionnaire that
included socio-demographic data, residential history, environmental exposures, behavior, phenotypic and
dietary information. An environmental-lifetime sun exposure score was constructed combining residential history
and average daily solar radiation, direct and diffuse. Logistic regression was used to explore the association
between different variables. A structural equation model was used to verify the associations of the conceptual
Results: We found a lower risk of CRC in subjects frequently exposed to sunlight during the previous summer and
skin burning due to sun exposure. No association was observed in relation to the residential solar radiation
scores. Subjects with light eye or light hair colors had a lower risk of CRC that those with darker colors. Dietary
calcium and vitamin D were also protective factors, but not in the multivariate model. The structural equation
model analysis suggested that higher sun exposure was associated with a decreased risk of CRC, as well as dietary intake of calcium and vitamin D, and these factors are correlated among themselves and with environmental
solar radiation and skin phenotypes.
Conclusion: The results agree with previous observations that sun exposure, dietary vitamin D and calcium
intake, and serum 25(OH)D concentration reduce the risk of CRC and indicate that these factors may be relevant
for cancer prevention.
Otras publicaciones de la misma revista o congreso con autores/as de la Universidad de Cantabria