'Mammographic Density' meeting report
WHY STUDY MAMMOGRAPHIC DENSITY?
Report for BCNA
“Why Study Mammographic Density? A Plan for Future Research and Action” was the title of the satellite meeting held in conjunction with the “Familial Aspects of Cancer” meeting held at Mantra, Kingscliff, NSW in August 2010.
About 150 people attended this very interesting meeting which dealt with current knowledge of mammographic density (MD); discussion of methods of measuring MD; screening practices; biology, genetics and environmental determinants of MD and planning for future research into MD.
It is important to know how to measure dense areas of the breast; what type of screening tools perform more accurately; how the information can be related to clinical practice; whether the risks can be reduced; whether the density is related to environmental and/or hormonal influences; which genes play a role in determining density and which public health policies can benefit from such knowledge.
All these issues were discussed with the aim of identifying current knowledge and understanding of the causes of breast cancer so that better prevention and treatment strategies could be identified.
The white area in the mammographic image above is the ‘dense area’ referred to in ‘mammographic density’.
Information I learnt at this meeting included:
- Mammographic density is a strong and heritable risk factor for breast cancer.
- For women of the same age and body mass index, those with greater density are at a 2-6 times increased risk for developing breast cancer.
- Mammographic density appears to be determined at a young age.
- Late age at menarche (puberty) is associated with increased density.
- More aggressive cancers appear in dense areas, (partly because they are bigger when found).
- A large component in the variation of mammographic density is thought to be genetic.
- Increased rate of ‘interval cancers’ (i.e. those found between mammograms) is associated with dense breasts because the cancers are difficult to detect in the dense area and because of the increased risk from density.
- Mammographic density is modifiable.
- Not all young women have dense breasts.
- Digital mammography has greater contrast and performs better than film mammography in women under 50 yrs
- Ultrasounds (sonography) compliments mammography in dense breasts.
- Clouds play an interesting role in naming methods for estimating/measuring breast density e.g. Cumulus (and did I hear Nimbus somewhere?).
· Factors associated with increased density:
- Family history
- Later age at menarche
- Hormone replacement therapy
- Height
· Factors associated with decreased density:
- Age
- Parity (7% decrease for each birth)
- Postmenopause
- Weight
- Tamoxifen
There were talks about including mammographic density measures in risk prediction models; discussion about tailoring breast cancer screening programs according to mammographic density (e.g. more screening for those with increased density); identifying opportunities for further research to help understand the biological mechanisms of mammographic density
An update was given about the NBCF/BreastScreen Victoria Cohort Demonstration Project, which has fortunately been renamed ‘The Lifepool Project’ and which aims to recruit 100,000 Victorian women over 5 years to provide information for research.
The meeting was a great success and we can anticipate further meetings exploring this topic will follow. As one of the international speakers concluded, in keeping with the cloud theme:
“the forecast is cloudy, but clearing.”