Abstract

A correlation between prevalence of breast cancer with blindness has not been attempted in India and only scanty information is available at the world scenario as well. We have done a pilot study by epidemiological survey of blind menopausal (high risk age group) women (n = 204) from Chennai to find the prevalence of the disease. In the present study,  menopausal visually challenged women have shown that the ratio at risk of developing  breast cancer in this group is very much lower ( 1:100 ) compared to sighted women in the similar age group, The  risk of developing breast cancer  is 1:78 (Cumulative Risk  35 - 64 age), among sighted women  in Chennai. Statistical analysis of the present data also provide enough evidence that blind women who are > 40 years of age had 13% greater risk of breast cancer compared with those in the study group < 40 years (RR = 1.125; 95% CI = 0.07 to 17.74).The susceptibility to develop the disease among partially blind women is almost twice than that of totally blind women (RR = 2.14; 95% CI = 0.14 to 33.68). Similarly menopausal stage of a woman has more risk of developing breast cancer than pre-menopausal stage (RR = 5.18; 95% CI = 0.33 to 80.75). Vision loss after menarche also indicates an increased risk (RR = 8.27; 95% CI = 0.54 to 127.6).The intervals for these  risks give a very wide range of possible values for the corresponding risk ratio due to small sample size and the rarity of breast cancer among blind women. The topographical location of India close to the equator and life style pattern of the people could be the major reasons for the very low prevalence of breast cancer in Chennai. None of the other high or low risk factors were found to be influencing blind women to develop breast cancer. The relationship between visible light and breast cancer can be studied by taking blind menopausal women as a model.

Key words: Blindness, breast cancer, epidemiology.