RESUMO
The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food and Drug Administration and European Union have incorporated changes in their guidelines to help consumers select products based on their sun protection factor and protection against ultraviolet radiation, whereas the Indian regulatory agency has not yet issued any special guidance on sunscreening agents, as they are classified under cosmetics. In this article, the authors discuss the pharmacological actions of sunscreening agents as well as the available formulations, their benefits, possible health hazards, safety, challenges, and proper application technique. New technologies and scope for the development of sunscreening agents are also discussed as well as the role of the physician in patient education about the use of these agents.
RESUMO
Lifestyle factors related to breast cancer risk were examined in a case-control study nested in a cohort in Karunagappally, Kerala, South India. We sought interviews with all the residents in Karunagappally with the population of 385,103 (191,149 males and 193,954 females) in the 1991 census and established a cohort of 359,619 (93% of the population in 1991) in 1990. For analysis 264 breast cancer cases with age > or = 20 years were selected from 438 breast cancer cases reported during the period 1990-2004 and for each case 3 non-cancer controls were randomly selected matched for age, religion and place of residence through the Cancer Registry, Karunagappally. Conditional logistic regression was used for the analysis. In the present study, in addition to a low number of pregnancies (P <0.001 and P for trend <0.001), more frequent intake of roots and tubers except tapioca (cassava) (OR for > or = 5 times =1.56, 95% CI=1.09, 3.09, P for trend <0.05), milk drinking (OR=1.78, 95% CI=1.17-2.69, P<0.01) and consumption of chicken meat (OR=1.84, 95% CI=1.09-3.09, P<0.05) were found to increase breast cancer risk. The present study further showed that consumption of tapioca which is a commonly used food item in South India, particularly in Kerala, reduced breast cancer risk (OR=0.55, 95% CI=0.37-0.83, P<0.01). Risk analysis was attempted among pre- and post-menopausal women separately and similar odds ratio were obtained. Consumption of tapioca (cassava) decreased risk of developing breast cancer among premenopausal women (P<0.001 and OR=0.35, 95% CI=0.18, 0.65) and a low number of pregnancies (P<0.01), consumption of roots & tubers (P<0.05), usage of chicken meat (P=0.05) increased the risk of breast cancer among post-menopausal women. Further studies seem warranted to confirm the possible protective effect of tapioca consumption. There is an increasing need of breast cancer prevention programs responsive to the cultural practices of the people and the study results should provide leads to cancer control programs especially in rural areas.