Identification and counselling of women at increased risk for breast cancer

Clinically detected local breast cancers have a cure rate of 50 per cent whereas screening detected malignant lesions up to 80 per cent.  Most of these tumors are found with mammography, ultrasound and magnetic resonance imaging (MRI).  The smaller the cancer, the higher the survival chance.  Medical imaging contributed to a large extend to improved cure rates by detecting lesions earlier in their biological life. When a suspicious lesion is detected, confirmation of malignancy is mainly made by transdermal biopsies.  In case of proven malignancy, subsequent surgery is the standard.

Microcalfications are an important indicator of premalignant and early lesions.  ‘In situ' cancers transform into real invasive cancers in roughly 25 % of the cases.  These premalignancies and "in situ's"  have a cure rate of almost 98 per cent provided that they are treated with adequate surgery (negative margins).  Microcalcifications can be detected with mammography and diagnosis is mainly established with stereotactic large core biopsies.  A substantial number of biopsies for microcalcifications turn out to be negative and need no further surgery. 

Recent scientific evidence indicates that breast cancer might be preventable in the true sense; meaning primary prevention.  Risk could be lowered for example through hormonal and nutritional interventions.  Even imaged lesions that predict for increased risk are recently found to be reversible.  Why should we be content with a near to 100 per cent cure rate when this cure is only achievable through surgery, radiotherapy with or without systemic treatments? The power of cancer prevention lies in the knowledge that surgery or any other invasive treatment might even not be necessary because there is no disease to start with.  While early detection significantly reduces mortality, primary prevention should be able to lower incidence and mortality further more.  How can breast cancer be prevented by the tools we presently have?

It is well accepted now that breast cancer susceptibility induction takes place during breast development suggesting that between induction and clinical appearance one must have a large window of opportunity to prevent the disease.  Genetic and phenotypic risk biomarkers can be detected early in adulthood and before the onset of disease.  While most of these biomarkers still need characterization, some, like breast density, have been validated recently with odds ratio's amounting to 4 in most studies.  They could not only identify women at increased risk but risk might be reverted by appropriate lifestyle measures like chemoprevention and nutrition.  It is well shown that antiestrogens can lower breast cancer risk almost to one third.  This effect is best seen in women that had high dense mammograms at the start of treatment and experienced a density decrease afterwards.  In other words, when hormonal therapy or other means like nutrition succeeds to reduce density, there is a good chance that the risk for breast cancer diminishes accordingly as seems be the case in preliminary work. 

Dr. Jaak Ph Janssens
Editor: European Journal of Cancer Prevention
Limburg University Centre, Belgium 

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