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Published on: December 9, 2022
Total visual blindness is protective against breast cancer
Erin E Flynn-Evans1, Richard G Stevens, Homayoun Tabandeh
1Division of Sleep Medicine, Brigham and Women's Hospital, 221 Longwood Avenue BLI 438, Boston, MA 02115, USA. eevans@rics.bwh.harvard.edu
Cancer Causes & Control : CCC
|August 4, 2009
Summary
Blind women with no light perception (NPL) have a significantly lower prevalence of breast cancer than those with light perception (LP). This suggests light perception influences breast cancer risk.
Area of Science:
- Ophthalmology
- Oncology
- Endocrinology
Background:
- Observational data suggests lower breast cancer risk in blind women.
- Mechanisms like melatonin and circadian synchronization are hypothesized to be involved.
- Light perception may play a role in these mechanisms.
Purpose of the Study:
- To investigate breast cancer prevalence in blind women based on light perception.
- To compare breast cancer risk between blind women with no light perception (NPL) and those with light perception (LP).
Main Methods:
- A cohort of 1,392 blind women in North America was surveyed.
- Breast cancer cases (n=66) were identified.
- Multivariate-logistic regression models controlled for known breast cancer risk factors.
Main Results:
- Women with NPL had a significantly lower prevalence of breast cancer than women with LP (OR, 0.43; 95% CI, 0.21-0.85).
- Associations remained consistent across subgroups (postmenopausal, non-shift workers, varying exclusion periods).
Conclusions:
- Blind women with no light perception appear to have a reduced risk of breast cancer compared to those with light perception.
- Further research is needed to understand the impact of light perception on circadian rhythm and melatonin production in the blind and its relation to breast cancer risk.
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