Related Experiment Videos
High Mammographic Density in Long-Term Night-Shift Workers: DDM-Spain/Var-DDM
Ana María Pedraza-Flechas1,2, Virginia Lope1,3, Carmen Sánchez-Contador4
1Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.
Summary
Long-term night-shift work (NSW) is linked to increased mammographic density (MD) in Spanish women. This association was primarily observed in postmenopausal women with over 15 years of exposure, suggesting MD may mediate the breast cancer risk from NSW.
Area of Science:
- Epidemiology
- Oncology
- Radiology
Background:
- Night-shift work (NSW) is a suspected risk factor for breast cancer.
- Mammographic density (MD) is a strong predictor of breast cancer risk.
- The relationship between NSW and MD has been underexplored.
Purpose of the Study:
- To investigate the association between night-shift work (NSW) and mammographic density (MD) in Spanish women.
- To determine if cumulative exposure to NSW influences MD.
- To explore potential mediating roles of MD in the NSW-breast cancer pathway.
Main Methods:
- A study involving 2,752 Spanish women aged 45-68 years, with 243 reporting NSW.
- Data collected via personal interviews on occupational history and confounders.
- Mammographic density (MD) assessed using a validated computer-assisted tool (DM-scan) by radiologists.
- Multivariable mixed linear regression models used to analyze the association between NSW and log-transformed MD.
Main Results:
- No overall association between ever working night shifts and mammographic density (MD).
- Women with over 15 years of night-shift work (NSW) showed a 25% higher MD compared to those with no NSW history.
- This association was significant in postmenopausal women and those working 5-7 night shifts per week.
Conclusions:
- Night-shift work (NSW) is associated with increased mammographic density (MD) only after more than 15 years of cumulative exposure.
- Mammographic density (MD) may be a key factor in the link between long-term night-shift work and breast cancer risk.
- Further research is needed to confirm these findings.